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STANDARD ERECTION MANUAL

(Boiler Auxiliaries)

Prepared by

Power Sector – Technical Services (HQ) Noida

Corporate Quality Assurance Bharat Heavy Electricals Limited,

New Delhi

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CFBC Boiler Erection (250 MW)

AIR PREHEATER

FOR QUAD SECTOR AIR PREHEATERS NEYVELI (R300 & R 301)

THE COPYRIGHT OF ALL DOCUMENTS AND DRAWINGS ARE THE PROPERTY OF BHARAT HEAVY ELECTRICAL LIMITED. THIS SHALL NOT BE USED WITHOUT THEIR WRITTEN PERMISSION IN ANY FORM OR PART THEREOF FOR ANY OTHER PURPOSES THAT FOR WHICH THIS PUBLICATION IS SENT TO THE RECEIVER.

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CONTENTS

1. CONTRACT DETAILS.

2. REGENERATIVE AIR PREHEATER – BRIEF DESCRIPTION

3. ERECTION ASSISTANCE POLICY

4. GENERAL FIELD ERECTION PROCEDURE NOTE

5. IMPORTANT INSTRUCTING DO‟S & DONT‟S

6. LIST OF APPLICABLE PGMA‟S

7. LIST OF INSTALLATION DRAWINGS,

8. RECEIPTS & STORAGE OF APH COMPONENTS

9. SUGGESTED FIELD INSTALLATION PROCEDURE

10. GUIDE TRUNNION TAPER FIR CHECKING PROCEDURE

11. SEAL CLEARANCE CHARTS

12. LUBRICATION CHARTS

13. AIR PREHEATER FIRE

14. LIST OF ILLUSTRATIONS

15. LAY-UP PROCEDURE

16. SEALANTS, THREAD LUBRICANT AND COATING COMPOUNDS

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01. CONTRACT DETAILS

CUSTOMER NUMBER : R 300 & R 301

PROJECT : NLC – NEYVELI 2 X 250 MW

LOCATION : NEYVELI

AIR PREHEATER SIZE : 29 VIMQ 1850 (80O PA)

NOS. / BLR : TWO

AIR PREHEATER SL. NO : 0633, 0634, 0635 & 0636

TOTAL ELEMENT DEPTH : 1850

HOT END ELEMENT : 0.63 DU 700 CARBON STEEL

HOT END INT. ELEMENT : 1.21 NF6 300 CORTEN STEEL

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02. REGENERATIVE AIR PREHEATER – BRIEF DESCRIPTION

General

The Regenerative air Preheater shall be Quad- sector type in which the Primary air sector is flanked between the Secondary air sectors.

In this type of heat exchange the heating surfaces are alternatively heated up by the flue gas passing through and cooled by the air passing over it. The heat is absorbed by the heat transfer matrix from the flue gases and releases to the air, The design of the air heater is such that it can give trouble free service for extended periods of time, without plugging of flow areas between heating element sheets,

The regenerative heat exchanger will have a gas tight insulated casing and must be rested on necessary steel structures.

Description

Each regenerative heat exchanger shall consist of the following salient components/ assemblies.

1. Modular Rotor

2. Rotor Housing and Connecting Plates.

3. Heating Elements

4. Sealing System.

5. Support Bearing and Guide Bearing.

6. Lubricating Oil circulation system.

7. Drive Mechanism including Auxiliary Drive.

8. Access Doors

9. Observation Port and Light.

10. Cleaning and Washing Devices

11. Rotor Stoppage Alarm

12. Deluge System

13. Element handling Arrangement

14. Fire Sensing Device

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1. Modular Rotor

The rotor is made up of 24 numbers of full sector modules that are attached to the rotor post by pinned connections. The modules are loaded with elements and shipped to site for easier, speedy and quality erection.

2. Rotor Housing and Connecting Plates

The housing is octagonal in shape and consists of the following: Two main pedestals, two side pedestals, four axial seal plates, two primary air panels, four other panels. And connecting plated with integral support beams. Sandwiched between the top and bottom connecting plated are the panels which form an integral structure to take axial and radial loads and also form a gas tight enclosure for the of fluids.

3. Heating Elements

Each air heater is provided with multi0 layers of heating elements. The cold end elements are basketed for each removal and replacement from the sides. Hot end elements are removable from the top of the gas ducts.

4. Sealing System

Over many years of continuous operation, the sealing has provided to be effective with minimum maintenance requirements. The design takes advantage of normal thermal growth to keep sealing surfaces in proper alignment.

The rotor is divided into equal forming a separate air or gas passage through the rotor. Fixed leaf type metal seals are radially and axially attached to the rotor structure between each sector. Sector shaped unrestrained radial sealing plates provide the sealing surfaces that divide the rotor into air and gas passage.

Because the seals are applied to the shortest leakage path and the sealing surfaces are externally adjustable, the most effective and continuous leakage control is assured. A circumferential bypass seal is provided to prevent air and gas from bypassing the rotor through the small space between the rotor and housing.

The sealing surfaces are adjustable from outside by loosening the lock nuts. The circumferential bypass seals can be adjusted only from inside of the rotor. As these seals control only bypassing of flow through rotor and the leakage in that path is being controlled by axial seals, there is no need to adjust them from outside.

5. Support bearing and guide bearing

The support bearing is of spherical roller thrust bearing type and is located at the bottom connecting plate. The guide bearing is of spherical roller type and is located at the top connecting plate. The bearing housings are designed to at as oil reservoirs for provision of integral oil circulation system.

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6. Lubricating Oil Circulation System

Both the support and guide bearings are provided with independent oil circulation systems. The oil circulation system consists of oil pump, oil cooler pressure and temperature indicators and flow switches. The lubricating oil system proposed is a proven design. An identical unit is also connected as standby.

7. Drive Mechanism Including Emergency Drive

The drive system envisaged is of peripheral pin rack- pinion type. It consists of a three input speed reducer one electric motor for main drive, another electric motor as standby drive, fluid coupling / centrifugal clutch, hand cracking facility for manual rotation and a pinion for meshing with the pin rack of the rotor. Normally drive is through the main electric motor and in the event of electrical trip out, the standby electric motor comes into operation automatically.

8. Access Doors

Adequate numbers of access doors are provided, both at the inlet and outlet ducts and also in the housing panels for inspection and maintenance.

9. Observation Port and Light

Observation Port and vapour proof light are provided. These are suitably located at the air inlet side to have a complete view of the cold end elements while in operation.

10. Cleaning and Washing Devices

A) Cleaning Device

The heat exchanger is provided with a swiveling arm type power driven cleaning device at gas inlet side & gas outlet side, for on load cleaning of air heater elements. The cleaning device unit is located on the hot end & cold end centre section wall with nozzle transversing horizontally in an area across the radius of the rotor, a short distance away from the element packs.

B) Off- Load Water Washing Device

Two fixed multi- nozzle washing pipes are fitted on one above and one below the rotor. Terminal points of the pipes to which surface connection can be given are located adjacent to rotor housing.

11. Rotor Stoppage Alarm

Rotor stoppage alarm is provided to indicate the slowing down of the rotor. This consists mainly of control unit, vane operated limit switch and vanes which are mounted on the trunnion. If the vanes fail to pass under the limit switch within the set time interval, the timer in the control unit transfers its

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contact to give an alarm in the control panel, to warn the operator that the rotor is slowing down.

Control Requirement

An alarm or annunciation is to be provided in the control panel to indicate the rotor slowing down condition.

12. ‘De Luge’ System

Two fixed multi- nozzle fire fighting manifolds are fitted on one above and one below the rotor. Terminal points of the pipes to which surface connection can be given are located adjacent to the rotor housing. During an air heater fire, both fire fighting and water washing manifolds must be used.

13. Element Handling Arrangement

Heat exchanger is provided with a hand operated hoist and trolley for handling of hot end elements from inside of the air preheater to the air preheater operating floor.

14. Fire Sensing Device - Thermocouple Type

Shell type thermocouple elements mounted on the measuring probe are arranged (in radial direction in the air outlet and gas outlet ducts close to rotor face, such that there is a measuring point between each tangential walls of the rotor.

The increase in temperature, due to fire, causes a momentarily and recurring increase of the thermo – electric voltage and the signal released by thermo elements is given to customer DCS at UCB for suitable alarm / annunciation. In the event of an fire alarm, the deluge system valves and water wash system valves shall be opened manually. This is essential because in the event of a fire alarm, inspection of the Rotor/ , APH is a must before deluging the rotor with water.

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04. GENERAL FIELD ERECTION PROCEDURE NOTE

General arrangement drawing is very important. It should be displayed and used during all phases of erection.

Shipping lists carry dispatch components with required drawings. This should be used at the beginning for component identification and supply position.

Notes on drawings take precedence over information in the installation manual. If there is a conflict of information between drawings and erection manual, BHEL / Ranipet engineering department should be

Drawings carry instruction for erection, designated as “ER NOTES” or “NOTES TO ERECTOR”.

Temporary braces and / or blocks are painted yellow. All items painted yellow must be removed prior to operation of the air preheater.

Transport and handling damages of the components are to be rectified before installation / assembly.

Hydraulic pump & jacks and radial seal straight edge (aluminum channel) are to be handed over to customer after installation is completed.

Over lapping of radial and axial seals are to be trimmed by grinding only, not by gas cutting. Trimming of sealing tabs to be done by grinding/hacksaw cutting only.

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Check for match marks for all assy. Components and install accordingly to match marks.

Use low hydrogen electrodes E-7018 unless otherwise specified. Proper preheating of electrodes and other precautions to be taken.

05. IMPORTANT INSTRUCTION: DO’S & DONT’S

Plan in advance the sequence of installation. Refer pert diagram given in this manual.

Keep the necessary tools and tackles ready before start of installation.

Contact the air preheater engineering department, if any deviation or rectification is to be made.

Apply rust preventive oil protect components from rusting due to long storage and bad weather.

Store the rotor modules in semi- covered shed or covered with tarpaulin, element cover sheets can be removed before light up of boiler.

Maintain the required accuracy in installation which leads fro a satisfactory operation.

Tighten bolts to the required torgue wherever given.

Fill the bearings with specified oil or equivalent even during installation.

Rotate the air preheater in the correct direction of rotation.

Keep a record of readings in the FQA check sheets which shall be dispatched for the reference of air preheater engineering department.

Weld rotor housing panels, connecting plates (hot & cold) to housing panels, connecting plates (hot & cold) to air and gas ducts as per drawing.

IMPORTANT INSTRUCTIONS: DON’TS

Do not mix up items belonging to different air preheaters.

Do not use shop lugs for lifting other components / assemblies.

Do not support any components on cold end / hot end centre sections / connecting plates while lifting them.

Do not carryout the bearing assemblies in open, dusty atmosphere.

Do not spoil the seal leaf by standing on the, by any other external load or interference with foreign material or by wring direction of rotation.

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Do not allow any foreign particle, such as electrode bits, glass wool etc., Enter heat transfer elements during erection.

Do not carryout final welds before final alignments, checks, etc.

Do not spoil the seal straight edge during trial run.

Do not start air preheater without filling with specified lubricants during erection check up.

Do not operate air motor without filter and lubricator even during trial run.

Oil level of support and guide bearings are to be checked only after stopping of lub oil units.

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06. LIST OF APPLICABLE PG MA’S

PG MA DESCRIPTION

52 – 000 ITEMS PER CONTRACT

52 – 010 ROTOR ASSEMBLY

52 – 011 POST AND TRUNNION ASSEMBLY

52 – 012 PIN RACK ASSEMBLY

52 – 013 RADIAL SEAL ASSEMBLY

52 – 030 ROTOR HOUSING ASSEMBLY

52 – 041 HOT END CONNECTING PLATE ASSEMBLY

52 – 042 COLD END CONNECTING PLATE ASSEMBLY

52 – 054 AXIAL SEAL ASEMBLY

52 – 055 BY PASS SEAL ASSEMBLY

52 – 100 ROTOR DRIVE ASSEMBLY

52 – 210 ACCESS DOOR ASSEMBLY

52 – 211 AIR SEAL PIPING

52 – 212 OBSERVATION PORT AND LIGHT ASSEMBLY

52 – 217 ROTOR STOPPAGE ALARM

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PG MA DESCRIPTION

52 – 220 GENERAL DETAILS

52 – 261 GUIDE BEARING ASSEMBLY

52 - 262 SUPPORT BEARING ASSEMBLY

52 – 271 OIL PIPING ASSEMBLY (GUIDE BEARING)

52 – 272 OIL PIPING ASSEMBLY (SUPPORT BEARING)

52 – 274 OIL CIRCULATION UNIT

52 – 301 DELUGE AND WASH PIPE ASSEMBLY (GAS INLET)

52 – 302 DELUGE AND WASH PIPE ASSEMBLY (GAS OUTLET)

52 – 325 TWIN NOZZLE CLEANING DEVICE ARRGT (HE)

52 – 326 TWIN NOZZLE CLEANING DEVICE ARRGT (CE)

52 – 329 CLEANING EQUIPMENT DRIVE UNIT

52 – 360 FIRE SENSING DEVICE

52 – 988 COMMISSIONNING SPARES

52 – 610 STEAM COIL AIR PREHEATER

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08. RECEIPT AND STORAGE OF COMPONENTS

Particular attention is to be paid with regard to receipt and storage of Air preheater components. All components of the Air preheater have ample strength to withstand the operating conditions and are well protected against damage in normal transit. However, rough handling during transit or thoughtless unloading at site may result in distortion and damage which should be rectified before erection starts.

Care and good judgment must be exercised when transporting and lifting the components so as to avoid bending or twisting, as such distortions will seriously hinder erection and possibly affect the performance of the complete Air preheater.

The elements, bearings, oil circulation units, rotor drives, power driven cleaning devices and electrical equipment must be stored in a closed dry place immediately after unloading to protect them against corrosion. When the bearings or heating surfaces elements are not to be used for an extended period, they should be protected by using a non-drying water repellent rust preventive oil such as RP 102 of Indian Oil Corporation. They must also be protected after erection of the boiler house has not been completed. All remaining parts may be stored in the open, provided they are laid down to avoid any distortion. No rain water should be allowed to collect in any of the components. The pin-rack and machined surfaces of sector plates and, in general, all the machined surfaces should be protected.

Note: Also refer the storage manual issued by Power Sector.

Storage and Preservation of Heating element Baskets, ref, fig

Anti rust oils for use on heating surfaces:

- RP 102 OF INDIAN OIL CORPORATION

- KOTE 203 OR RUSTOP 173 OF HINDUSTAN PETROLEUM

- RUSTROL 152 OF BHARAT PETROLEUM

- RUSGARD P – 214 Plastipeel chemicals & plastic Ltd, Thane.

A pressure pump, garden type spray can of 5 to 10 litres capacity is suitable to apply anti-rust oils with good penetration.

Note: Overlooking of minor details of drawings will lead to major rework.

In the above oils the “Carrier” oil is volatile and will usually evaporate in several weeks under ambient conditions, leaving a protective coating. This coating is water soluble and for this reason the material thus coated must be stored indoors or under protective covering at outdoors.

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The elements need not be cleaned with water at the time of light – up, if the protective coating was applied before 3 months.

Method of Cleaning and Coating

It is preferred that element baskets be stored inside of space is available. However, outdoor storage can be achieved with proper protection. The crates or boxes as shipped shall be opened and the elements should be sprayed with the recommended oil. If rust scales are noticed, the baskets can be cleaned with a jet of compressed air (6 ata) (a nozzle can be attached to the hose to be effective) first and then oil is applied over the rust which will absorb the oil and deter further rusting.

Method of Storage

Baskets after coating with oil shall be supported on timbers high enough to be free from the defects of surface water. Timbers (100 mm x 100 mm) or other means should be placed on top of the basket piles. Protective covering should be applied over the piles and extending down the sides and securely fastened to prevent deterioration. It will be necessary to periodically check the covering for deterioration‟s and the baskets for rusting. If rusting is observed, the areas should be re-sprayed with rust inhibiting oil.

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09. SUGGESTED FIELD ERECTION PROCEDURE

1. Check the elevation of supporting steel and note for any difference. If steel work is out of level by more than 10 mm, rectification of structures is to be carried out. Record readings in CHECK SHEET.

2. Mark Centre line on supporting steel for Air preheater location as per General Arrangement Drawing. Record readings in CHECK SHEET.

3. If variation of steel work is upto or below 10 mm but more than 1 mm, add suitable thickness of single plate and weld it with the structure. Grind off the top surface of the plate to be within a variation of ± 1 mm. If it is more than 10 mm, correct the structure.

Note: The plate that is welded with structure should have breather holes.

4. Locate the expansion arrangements in position on support steel and level them with shims provided. The tolerance on elevation should be within ± 1 mm. The surface level should be within 0.1 mm/M. Record final readings in CHECK SHEETS. Sliding surface of the expansion arrangement is self lubricated and this side is to be kept upper side.

5. Erect Main pedestals on expansion arrangements and support them temporarily, after maintaining the vertically and elevation.

Note: Wherever check sheets are mentioned refer FQA check sheets.

6. Pre- assemble support bearing assembly temporarily in cold end centre section.

7. Erect cold end centre section along with support bearing assembly.

8. Level the cold end centre section flange as per CHECK SHEET. Record the readings in CHECK SHEET. Ensure the gap between the hanger plates and cold end centre section web as given in the drawing in all the four corners.

9. Weld the cold end centre section webs with hanger plates by means of cleat angles provided as specified in the drawing of cold end connecting plate assy. Weld is to be tested with L.P.I.

10. Trial assemble Hot end centre section on main pedestal. Check diagonal distance between the split line corners of the centre sections as per check sheet. Maintain tolerance as per the CHECK SHEET.

11. Ensure the centre of the bore of the centre sections by plumbing. Check the distance between cold end & hot end centre sections in both sides, if variation found more than tolerance given in drawing it is to be corrected. At this position drill and install a drift taper pin between hot end centre

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section and main pedestals. Remove the hot end centre section and keep it aside.

12. Erect the side pedestals on expansion arrangement at proper elevation.

13. Erect cold end primary centre section - I & II to the elevation of main centre section.

14. Assemble the remaining portion of cold end connecting plate to cold end centre section. All splits are provided with drift pins which must be driven before bolting to achieve good alignment. Install pipe braces. Install the other housing panels. Bolt and tack weld the panels together to hold them in position.

15. Ensure vertically and elevation of all pedestals and panels with in 2 mm. Slight shifting may be required to achieve final alignment and record the readings in CHECK SHEET.

16. Level the Support bearing housing approximately to 0.1 mm / M with the help of segmental shims. However the housing has to be relevelled at the time of positioning the rotor with respect to housing splits. Open the support bearing housing temporary cover. Clean the internals of the bearing, adapter plate etc. Cover the bearing housing with a single sheet of gasket & cloth to avoid falling of foreign material into the bearing housing which would cause serious damages to the bearing.

17. Remove the temporary cover of support bearing housing. Install rotor post and trunnion assembly on the support bearing in accordance with the post and trunnion assembly drawing. This assembly must be lifted and suspended by using the lifting lugs provided on the rotor post. When lowering the post assembly on to the support bearing, jacks must be used to prevent damage to the support bearing and trunnion. Jacks must be located on the centre section assembly in accordance with information provided in the “ROTOR JACKING ARRANGEMENT”- drawing.

18. Plumb the rotor assembly and brace it temporarily.

CAUTION: Do not unhook the rotor post assembly from the crane until the assembly has been lowered on to the support bearing and is plumbed and adequately braced.

19. Lift the hot end centre section assembly using lugs provided and place it on main pedestals with reference to the previous match marks and refix the drift & taper pins and flange bolts.

20. Install hot end primary centre section assembly – I & II.

21. Install hot end connecting plate assembly including pipe braces. All splits are provided with drift and taper pins which must be driven before bolting to achieve good alignment.

22. Use proper lifting devices for handling guide bearing assy.

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23. Clean the guide trunnion and guide bearing assembly.

24. Install Guide bearing housing assembly as per drawing with proper orientation.

25. Ensure the taper fir between the guide trunnion and adapter sleeve by applying oil pressure (300 kg/sq.cm) through trunnion oil hole. Detailed procedure for pressure testing is given in this manual.

26. Assemble Guide bearing assembly and torque the cap screws to the specified torque value.

NOTE:a) Tighten the screws cyclically to achieve the specified value.

b) Rotate the rotor post to four 90” positions and check the tightness of the cap screws at each location.

27. a) Recheck the levels of cold end connecting plate, housing assembly and hot end connecting plate and adjust if necessary.

b) Complete the welding of the connecting plates. Housing assemblies and connecting plate to housing assembly as per the drawing EXCEPT THE ROTOR DRIVE PANEL. Drive panel may be in lack welded condition till the drive unit assembly is mounted and aligned. After drive unit leveling and pinion alignment with pin rack, the panel can be welded as per drawing.

c) Extreme care should be taken to avoid weld distortions. Step back method of welding is to be followed. Use E – 7018 low hydrogen electrodes, small electrodes and low current.

28. Adjust the shims at the support bearing housing to achieve the correct elevation of rotor post between the splits.

NOTE: a) Keep the cold end split distance as 101 mm so that it will become 95 mm after loading / erection of modules.

b) Level the support bearing housing. Recommended levelness of the bearing is within 0.1 mm/M. Check with master level at four places 90” apart. Apply sealing compounds in all the mating surfaces as specified in the drawing. Record the readings in CHECK SHEET. Torque tighten the hold down colts as specified in the drawing.

c) Surfaces above the oil level in the bearing housing must be coated with tight oil to prevent rusting during the period preceding start up of Air preheater.

d) If necessary, to expedite erection, a good grade of non-detergent motor oil of not less than SAE 50 may be used as temporary oil during erection.

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29. Level Guide bearing housing assembly to achieve the required elevation of housing sleeve above guide bearing housing as shown in the drawing.

Note: Keep the Critical dimension 6 mm more than the drawing dimension so that it will become required dimension after loading of modules.

30. Fill the specified lubricant as per the lubricant chat enclosed in this manual.

31 Level the rotor post. Use a suitable fixture and master level to get vertically of rotor post.

32. Lock the support bearing housing as specified in the drawing.

33. Lock the guide bearing housing as specified in the drawing.

34. Securely anchor the heater housing expansion arrangement to prevent shifting.

35. Give temporary blocks at the bottom to support the hot end tracking spool and cut the temporary bracings.

36. Align the tracking spool concentric to the rotor post and install tracking rods and stationary spool assembly as per drawing.

37. Remove the portion of the tracking spool flange which is screwed to facilitate the assembly of pins to the module with rotor post.

38. Remove side pedestal panel (Gas side) and upper connecting plate centre duct section for access to install modules. Attach housing pedestal bracing as shown in the illustration. Centre portion of hot end ducting must be left off for access above the area where modules are to be installed.

39. Attach module lifting extensions to module stay plates and torque bolts as specified on module lifting arrangement drawing. For torque value refer table / drawing.

40. Attach module lifting beams to lifting stay plate extensions.

41. Install turning lug to top of rotor post header as shown in illustration.

42. Turn post assembly to align module mounting holes with access opening in spool. Turning is accomplished by using the turning lug assembly which pinned to the rotor post header.

43. Proceed to install first rotor module taking care to align with mounting holes in post assembly.

44. Install post module mounting pins using hydraulic rams if needed.

45. Be sure the upper rotor pin is fully engaged and the lower lug is fully resting on the lower ring prior to removing the module lifting arrangement.

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46. With first and second modules installed temporarily space ad install four bolts between first and second modules at periphery.

47. Install additional modules, as per the erection instructions of the rotor assembly drawing.

48. A additional modules are attached continuously, check and correct chord dimensions by adding or removing spacers are required.

49. Following installation of last module, proceed to install permanent spacers and bolts in all the modules. Full length axial spacers are to be provided for installation at this time.

50. Check the chord dimensions and record in CHECK SHEET.

51. Check and correct rotor level to be within 0.1 mm/M record in CHECK SHEET.

52. Weld the permanent lock to the guide bearing as specified in the drawing.

53. With permanent spacers ad bolts in place, proceed to install pin risk. At this point the rotor assembly must be grounded (earthed) at all time. Grounding of the rotor is necessary to prevent flow of current through the bearing causing damage by arcing between bearing surfaces while welding is done on the rotor.

54. Install al Access doors in hot and cold end connecting plates and ensure proper approach platforms for all manhole doors.

55. Clean all the pin-racks. Place pin rack tabs in the pin-rack as per drawing before installing. Locate the pin rack in the rotor shell as per the rotor assembly drawing / pin – rack assembly drawing.

56. Assembly the pin racks as per drawing with clamps and adjusters/ wedges. Check the joints with pin space gauge tack weld the assembly. Manually rotate the rotor and examine for circularity of the pin-rack. Make temporary wedges and supports locally from scrap materials.

57. All the pin rack joint welds have to be carried out with extreme care to avoid weld distortions. Use small electrodes, low currents and special clamps.

58. Recheck the radial and axial run outs and record the readings in CHECK SHEET.

The maximum radial run out variation of pins is 3 mm.

The maximum axial run out variation of rack is 3 mm.

Mark radial high points of pin and axial high point of pin0 rack by welding.

59. Install rotor drive assembly as per drawing.

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NOTE: Check the direction of rotation of pinion with respect to rotor direction of rotation before installation as per GAD.

60. Turn rotor and locate the radial high point of pin and axial high point of lower bar that is closest to the pinion.

61. Adjust the drive assembly to the clearances shown as per drawing. Check and correct the root gap and bottom gap of pinion. If required drive panel may be adjusted to achieve drive unit & pinion dimension. Record the readings in CHECK SHEET.

62. Check pinion teeth for line contact with pins of pin rack by applying blue shim and adjust as required for full contact.

63. After the alignment of drive unit assembly and pinion aligment, weld the drive panel with adjacent panels, hot end connecting plates and cold end connecting plates.

64. Check to fill the specified oil to the required level as per lubrication chart.

66. Install pinion cover as per drawing..

67. With rotor drive in place and operable, weld module pins to post rings as specified in the drawing. Assemble the removed portion of the static spool flange with screws.

68. Align rotor and maintain the axial run out within 3 mm and record the readings in CHECK SHEET.

69. Weld rotor angles as per module assembly drawing and radial seal drawing to get correct elevation of T –bars as per seal setting drawing.

70. Install T- bar as given in the radial seal assembly drawing.

71. Align T-bar as given below:

72. a) Establish radius from rotor post to outer face of the T-bar.

b) Attach stationary reference pointer to rotor housing.

c) Adjust pointer to the established radius plus thickness of the gauge blocks or feelers.

NOTE: Trim T-bars & T- bar tabs of necessary to achieve alignment.

CAUTION: Attach reference pointer such that measurements will be made at point of seal contact of T-bars. (Refer seal setting drawing

d) Turn rotor and adjust T-bar. Maximum allowable variation is 3 mm for radial and axial run outs.

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CAUTION: T-bar holding bolt should be tightened to the specified torque as given in the radial seal assembly drawing. Tightening the holding bolts beyond the specified torque is not advisable.

e) Check the T-bars & pin-pack bars radial with reference to pointer and record the readings in CHECK SHEET. Pin rack bars should not protrude beyond T-bars.

73. Remove the panel bracing from side pedestal and install the panel and weld. Install remaining connecting plate duct portions and weld as per drawing.

74. Adjust the bypass seal holding angle as given below:

a) Establish the radius of holding angle from T-bar radial high point. Refer seal installation and by-pass seal assembly drawing.

b) Set up a pointer with reference to T-bar radial high point and adjust to established radius less thickness of feelers or other type of gauge block.

c) Turn rotor and adjust angle to this radius by loosening the retaining bolts and welding angles in o out as necessary. Maximum allowable variation is 3 mm.

d) Weld the angle with connecting plate as per the connecting plate assembly drawing.

75. Adjust the sector plates as shown in the seal installation and setting drawing. The level of sector plate should be recorded in the CHECK SHEET.

CAUTION: Ensure proper tightness of shims in the adjuster box assemblies to avoid failure during operation. Refer the table for torque tightening of the adjuster bolts. Use spherical washer supplied.

b) Maintain 0.75 ± 0.25 mm gap between hot end sector plate to tracking spool.

76. Align cold end stationary spool and weld segmental plates as per cold end static seat assembly drawing.

77. Install and weld rotor post seals as per Radial seal drawing. If necessary trim excess material from the ends of the seal sections to provide butt joints.

78. Install axial seals as per axial seal assembly drawing.

79. Adjust axial seal plate for seal clearance as per seal setting chart. Record axial seal clearance in CHECK SHEET. Install axial seal tabs near T-bar and pinrack bar as per drawing. Trim if necessary.

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NOTE: Use the straight edge provided to assist in proper adjustment. Refer drawing “Axial seal straight edge ashy”.

CAUTION: Check the direction of rotation and fit the seals in the leading side of seal holding bar.

80. Adjust the axial seal plate to sector plate seal such that the seal will butt against the sector plate tight by turning the screws. Refer figure.

81. a) Install bypass seals ass shown in bypass seal assy, drawing.

b) Adjust seal clearances as shown in seal clearance chart and record in check sheet.

c) Provide three layers of bypass seals near sector plates.

82. Install Radial seals as given below:

a) Fix the aluminum finger tabs provided at inboard and outboard of diaphragm plate and check the sector plates closer to the rotor. This is the established sector plate.

b) Move this diaphragm plate under the established sector and adjust the finger tabs to the required seal clearance.

c) Set the channel type straight edge (Aluminum channel) at a convenient location.

CAUTION: Radial seal straight edge support brackets which are to be left as it is, must be so located as not to interfere with cleaning device lance movement. If necessary, support the straight edge at the centre to prevent sagging.

d) Move the finger tabs under the straight edge and set the straight edge t sit over the tabs. Firmly clamp the straight edge.

e) Set one radial seal assembly butting the seal leaves with the straight edge. Move the seal under the established sector plate and confirm the correctness of the straight edge setting.

f) Then proceed with the installation of the rest of the radial seals.

CAUTION: Before setting the seals, ensure the correct direction of rotor rotation.

Fit seals on the leading side of the diaphragm.

After the seals are set, the rotor must not be turned backward. Radial seals will be damaged of done so. It will be easier for rotating the rotor for setting the seals if the cold end radial seals are set first and then the hot end radial seals.

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83. Install out board radial seal tabs as per radial seal assy drawing. Size of the tabs can be trimmed off by grinding to obtain proper fitment. Records radial seal clearance in CHECK SHEET.

84. Install inboard and outboard static seal assembly as per the drawing.

CAUTION: Welding of static seals to be done with extreme care.

e) Set one radial seal assembly butting the seal leaves with the straight edge. Move the seal under the established sector plate and confirm the correctness of the straight edge setting.

f) Then proceed with the installation of the rest of the radial seals.

CAUTION: Before setting the seals, ensure the correct direction of rotor rotation.

Fit seals on the leading side of the diaphragm.

After the seals are set, the rotor must not be turned backward. Radial seals will be damaged if done so. It will be easier for rotating the rotor for setting the seals if the cold end radial seals are set first and then the hot end radial seals.

83. Install out boar radial seal tabs as per radial seal assy drawing. Size of the tabs can be trimmed off by grinding to obtain proper fitment. Record radial seal clearance in CHECK SHEET.

84. Install inboard and outboard static seal assembly as per the drawing.

CAUTION: Welding of static seals to be done with extreme care.

85. Install axial static seals as per the drawing.

86. Install thermostat as per drawing for support and guide bearing assemblies.

87. Install Dipstick assembly as given below for guide and support bearing.

a) Make out proper orientation of the piping.

b) Thoroughly clean all pipes and fitting before installation.

c) Seal all pipe and fitting connection as shown.

d) All horizontal run of pipes must be level.

e) Refer to guide bearing assembly drawing and support bearing assembly drawing for necessary instructions to establish oil level.

f) Acid clean all the pipe lines after welding.

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88. Install oil circulation system fro support and guide bearing assy. Refer to fig. for block diagram of oil circulation systems.

89. Erect water washing and deluge pipe as given below:

a) Refer to the general arrangement drawing for proper orientation relating to the rotor rotation.

b) Install water washing and deluge pipe assy, as per drawing.

c) Rotate the nozzle pipe assy, in the hangers to line up discharge opening of the jets parallel to the heating surface and set expansion tolerance before welding.

d) Check customer piping is carried out as suggested.

90. Refer to the General Arrangement drawing for location and orientation of the cleaning device.

a) Install cleaning device as per drawing at hot end and cold end.

b) Use Air tight sealing compound and / or gaskets when attaching and leveling cleaning device to duct transition.

CAUTION: The cleaning device must be leveled and the nozzle set to the dimension as given in the cleaning device drawing. The variation should not exceed 12.5 mm. When checked at four equidistance points through traverse area of the cleaning device nozzle.

c) Check the cleaning device nozzle traverse dimension relating to heating element.

d) Check customer steam piping is installed as suggested.

e) Cleaning device nozzle should be parked at inboard end during operation of the boiler.

91. Install Observation port and light assembly as per the drawing. Locate Port and light assembly in such a place in the air inlet duct to obtain full view of cold end elements.

Adjust light to illuminate the most of the cold end elements across the air duct.

NOTE: Accessibility to the port and light is very important.

92. Install Fire sensing device in accordance with the drawing.

93. Install Rotor stoppage alarm as per drawing.

94. Install Oil carry over detector assembly and ensure water supply to the assembly.

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95. After installation is completed in all respects remove basket protection sheets and clean the Air preheater internals check up and cold test run have to be made in accordance with the check sheets in the presence of BHEL Ranipet Representatives.

96. After conducting an air leak test on the casing of the Air preheater insulation is to be applied as per the recommendation.

97. Fix aluminum finger tabs (seat gauges) as per the seal gauge drawing in HE & CE radial seals and axial seals.

98. Provide temporary covers / roof for drive unit. LOP units, soot blowers and Guide bearing assemblies to protect from dust / water using scrap materials.

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10. GUIDE TRUNNION TAPER FIT CHECKING PROCEDURE

1. Lock rotor by welding 150 mm channels at four sides between rotor and shell.

2. Remove the adapter sleeve, housing sleeve and guide bearing assembly and clean them using clean cloth.

3. Remove the guide bearing housing and keep it aside.

4. Clean the taper surface of the guide trunnion. Ensure that the oil hole and the groove in the trunnion are free from any blockage, by pumping oil through the oil hole.

5. Lower the adapter sleeve and housing sleeve assembly carefully on the trunnion. Scribe a line on the adapter sleeve and trunnion top and punch mark on the line.

6. Install the cap plate and cap screws.

7. Tighten the cap screws in a cyclic order to the specified torque.

8. Loosen the cap screws and withdraw them by 6 mm.

9. Connect the hydraulic pump with pressure gauge and connect it to the oil hole in the trunnion top through suitable hoses and nipples. Check for any leakage.

10. Pump oil keeping an eye on the pressure gauge. Hold (200 kg/sq.cm for bearing nos. 23052 & 23060. 250 kg /sq.cm for bearing no. 23072 and 300 kg/sq.cm for bearing No. 23192) pressure and watch for any pressure drop. If there is no pressure drop pump again till the release of adapter sleeve. Note down carefully the pressure at which the adapter sleeve is getting released from the trunnion.

29

30

12. RECOMMENDED LUBRICATION CHART

CUSTOMER NOs: R300 & R301 PROJECT: NEYVELI: 1 & 2

AIR PREHEATERS: 2 Nos. / BOILER

SL EQUIPMENT

DESCRIPTION IOC HPC BP

QTY/ APH

Fre. of Change

01 Main & Standby Elec. Motor Brgs.

Servogem 3

Lithon 3 MP Grease 3 0.4 Kg 6 months

02 Fluid Coupling Servo prime 46

Turbinal 46 Bharatturbol 46

6.8 lts Yearly

03

Main drive reducer

a) Gear case

b) Bearing

Servomesh SP 220

Servogem 3

Parathan EP 220

Lithon 3

Amocam 220

Bharat MP 3

100 Lts

0.3 kg

Yearly

6 month

04 Support Bearing

Servocyl C- 680

Cyncol TC – 680

Bharat Engol J- 680

100 Lts Yearly

05 Guide Bearing Servocyl C – 680

Cyncol TC- 680

Bharat Engol J – 680

100 Lts Yearly

06 Lub Oil Pump & Motor bearings

Servogem 3

Lithon 3 MP Grease 3 0.5 kg 6 months

07 Cleaning Device

a) Motor bearings & worm gear reducer

b) Two stage worm gear box

c) Sleeve Bearing

Servogem 3

Servomesh SP 460

Servogem HT XX

Lithon 3

Gear oil ST 140

----

MP grease 3

Spirol 140 EP

----

1 KG

1 Lit

0.2 kg

6 months

6 months

6 months

Note: Check Oil Level After Stopping of Lub Oil Systems.

Caution: Over Filling of Oil in Guide Bearing Assembly May Cause Air Preheater Fire.

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13. AIR PREHEATER FIRES

Air preheater fires are rare. A fire may occur during cold start up on oil or start up following hot stand by because of poor combustion of the fuel. The improper combustion results in unburnt or partially burnt oil condensing and depositing on the Airpreaheater element surface. As the temperature entering the Air preheater increases, this deposit is baked to a hard varnish like material. These deposits can ignite as temperature increase to 315 – 370Oc range. This ignition usually starts in a small area of the deposit. During the early stages of deposit ignition, external effects are not very apparent. The deposit restricts the flow of gas or air so that very little of the heat generated is carried away from the area of its origin. Downstream generated is carried away from the area of its origin. Downstream mixing of the fluids further minimizes any external effect. Most of the heat generated is absorbed by the metal heat transfer element nearby. The actual temperature build up during this period is relatively slow, If the condition can be detected at that time, the amount of water required to reduce the temperatures quickly to below the ignition temperature, is much less.

If the ignited deposit remains undetected it will continue to generate heat until the metal heat transfer element reaches 730- 765Oc At this point, metal may ignite with temperature reaching 1650 Oc and higher in a matter of minutes. Metal fires are self- sustaining and would require more water than is normally available to drop the temperature to a reasonable level. It should be noted that Co2, halon and other extinguishing agents are ineffective under these circumstances.

14. LIST OF ILLUSTRATIONS

01 Exploded view of Modular Air preheater.

02 Support bearing assembly – Integral type

03 Modified method of tracking hot end sector plate

04 Radial seal installation.

05 Axial seal installation

06 Axial seal plate to sector plate seal adjustable design.

07 Block Diagram for oil circulation system – GB

08 Oil circulation system

09 Recommended swivel joint and cleaning device piping support.

10 Storage and preservation of heating element baskets.

11 Pinion assy with Worthington hub.

32

33

34

35

36

37

38

39

40

41

OIL CIRCULATION UNIT

42

43

44

STORAGE AND PRESERVATION OF HEATING ELEMENT BASKETS

45

46

15. LAY UP PROCEDURE FOR AIR PREHEATER

1. After completion of installation if there is going top be considerable delay in commissioning the boiler the following preservation procedures have to be adopted.

2. All parts exposed outside should be cleaned from dust, debris etc. the drive assembly, bearing assembly; lubricant system shall be covered suitable. (ii) Wherever applicable the correct lubricant should be filled up to the required level.

3. The heater should be rotated once in five days a few turns to avoid brinelling of bearings.

4. Apply rust preventive to heating elements and cover them completely.

5. In general all other rotating parts can be given a few minutes run once in two weeks.

6. External loads should not be kept on the heater and care shall be taken from falling objects on Air preheater which may affect seal settings.

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16.0 SEALANTS, THREAD LUBRICANT AND COATING COMPOUNDS

HIGH TEMPERATURE THREAD LUBRICANT

There are a number of bolts which require to be tightened to a specified torque, further they are subjected to high temperature during operation causing them to seize making it extremely difficult of their removal if needed. A special lubricant is applied to the bolt threads and contact surface of the bolt head to acquire proper torque during tightening and also to serve as a anti seize medium during temperature service. Typical example: Turnnion bolt, support bearing mounting bolt, sector plate and Axial seal adjustors, axial seal plate to sector plate seal adjustors. Name of Lubricant:

1. Molycote – Imported

2. Mahomoly anti seize thread lubricant.

THREAD COATING COMPOUND

A number of threaded fasteners which ma7 require removal at a later date, are exposed to the gases and ambient air. The exposure of the fasteners to such adverse environment may result in corrosion and possibly the fastener may be damaged permanently. Removal also may be very difficult. Such fasteners are coated with a special compound which protects them during service and enables easy removal of them.

Typical example: Rotor basket door, cover bolts, bearing housing cover bolts.

Name of compounds: 1. Felpro5A – imported

SEALING COMPOUND

There are certain joints made of rough surfaces (fabricated or cast) which are to be sealed by suitable agent to avoid leakage of air and dust. A sealing compound is provided for this purpose which has to be applied to covers in trunnions and drive pinion.

Name of compounds: 1. Armcote - imported

2. Molysulf dust tight joints sealant and thinner.

A suitable thinner is also provided to remove the excess compound.

GASKET COMPOUND

At the joints of machined surfaces normally gaskets are used. For large surfaces a bead of the gasket compound is applied and the surfaces are

48

tightened. The compound dries and forms a leak proof gasket type layers which is pliable for removal. This can be applied to even threaded joints.

Example: Baring housing cover, water shield cover, sealing tube, etc.

Compounds: 1. Felpro – 51169 – imported.

2. GS- 2

SEALING TAPE

To make threaded joints leak proof Teflon tape is provided. They can be wound on the male thread to a suitable thickness and screwed on to make a liquid tight connection.

Note: Locations for the applicable of the above mentioned items are clearly indicated in the drawings.

Attention: Some of the compounds have low shelf- life.

SEALING AND ANTI - SEIZE COMPOUNDS FOR AIR PREHEATER

SL ITEM APPLICATION Qty/Blr

BRAND SUGGESTED SUPPLIERS

01

Sealing compound for dust tight joints

Air sealing covers in trunnion and drive pinion covers

2kg

Molysulf – Armocote or equivalent

M/s ASV Industry 334, Champaklal lts Sion koliwada Road Mumbai – 400 022.

02 Thinner To remove excess compound

0.5 kg

Molysulf – thinner or equivalent

M/s Anabond (p) Ltd 3A, Adyar bridge Rd III floor, Adyar Chennai- 600 020

03 Gas tight compound

Drive pinion air seal cover

0.5 kg

Hold tight / Shalloc or equivalent

M/s Jai Ganesh

04 Gasket sealer

Bearing housing covers & water shield assembly covers

1.0 kg

Holdtight / Shalloc or equivalent

Chemicals, 5, First main road, Kasturiba nagar, Adyar- Chennai- 20

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Ranipet

RADIAL FAN (NDZV WITH SLEEVE BEARING)

DOUBLE SUCTION

ERECTION MANUAL

Preparation by Checked by Approved by

S.SELVAM J.MOORTHY M.DESIGAN

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DOUBLE SUCTION (NDZV) WITH SLEEVE BEARING

4.0 CONSTRUCTIONAL FEATURES

NDZV fans are single stage, double inlet centrifugal machines. The rotor is simply supported by sleeve bearings located on both side of the impeller.

The major sub-assemblies of the fan are as follows:

Impeller with shaft assembly.

Bearings and thermometers.

Suction chamber and spiral casing.

Flow regulating devices.

Shaft seals.

Couplings.

IMPELLER WITH SHAFT ASSEMBLY

The impeller is a completely welded structure and is made from high tensile steel with backward curved blades. The selection of the material and thickness for the impeller/ shaft are computed on the basis of the stress analysis / critical speed programme carried out for each impeller and shaft. The impeller consists of centre plate, blade cover plate and impeller ring. All weldments are inspected thoroughly by NDT methods. The back plate of the impeller and the shaft flange has a machined groove which ensures correct location of the wheel relative to the shaft during assembly. Impeller is bolted to the shaft flange and locked by means of locking plates. Conical cover plates are provided at the inlet (bolts to the center plate) to guide the inlet flow and to protect the fasteners from exposure to the medium handled by the fan. The impeller is strees relived upon completion of all welding operation and is dynamically balanced after final machining. Replaceable wear liners are provided in the impeller blades. The shaft is machined to a high degree of surface finish for location of impeller, bearings and coupling half etc. the completed shaft is dynamically balanced. The critical speed of the rotor is well above the operating speed.

BEARING AND THERMOMETERS

The fan rotor is supported in between a fixed bearing and a free bearing. The fixed bearing is arranged on the coupling side. The fans are provided with sleeve bearings and oil lubrication. Provision for mounting temperature gauges (Mercury in steel thermometers and RTDs) are available on the bearing housings for local and remote (UCB) indication of bearing

51

temperatures. Platinum resistance thermometers (RTD) are provided with alarm and trip connections and for remote indication (control room) of bearing temperatures.

SUCTION CHAMBER AND SPIRAL CASING

Suction chamber and spiral casing are fully welded structures and are fabricated from sheet steel with adequate stiffeners. These are split suitably to facilitate easy handling and maintenance of rotor, etc. the oblique cone which forms the entrance to the impeller helps in accelerating the floe. The lower part of fan casing rests on the supporting brackets on the foundation.

FLOW REGULATING DEVICES

Fan outlet flow is controlled by inlet guide vane assembly or by inlet damper or by variable speed (VFD/ Hydraulic coupling). (Refer Technical for applicable flow control device)

a) INLET GUIDE VANE ASSEMBLY

Inlet vanes control device regulates the fan output (flow). The inlet vane assembly is locates at the inlet of the suction chamber for regulating the flow through the fan for different system demand. It consists of single piece casing, vanes, bearings for vane shafts and actuating lever.

The bearing housings are supported on the sidewalls of the casing. Levers and links for connection to the actuating lever connect the vane shafts. The vanes are actuated by means of an actuator. A graduated dial plate indicates the vanes position in degrees.

The Direction of Opening of Inlet Guide Vane shall be in the Opposite direction of rotation of impeller viewing from suction side.

b) DAMPER CONTROL ASSEMBLY

The damper control assembly is located at the inlet of the suction chamber for regulating the flow through the fans for different system demand. It consists of single piece casing, vanes, bearings for vane shafts and actuating lever.

The bearing housings are supported on the side walls of the casing. Levers and links for connection to the actuating lever connect the damper shafts. The vanes are actuated by means of an actuator. A graduated dial plate indicates the vanes position in degrees.

The Direction of Opening of inlet damper flaps shall be in the same direction of rotation of impeller viewing from suction end.

SHAFT SEALS

Seals for the shafts are provided to reduce the leakage through the gaps when the shaft passes through the suction chambers. It consists of labyrinth section for axial sealing. The labyrinth seal is centrally located and mounted in

52

bearing pedestal / casing wall which helps in precisely controlling the labyrinth passage.

COUPLINGS

The fan and the drive motor is coupled by means of flexible couplings.

FAN DRIVE

The fan is driven by an electric motor. For detailed instructions, the respective instruction manual should be referred.

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5.0 IMPORTANT INSTRUCTIONS

Care should be exercised while lifting the rotor assembly. Balance the rotor assembly and use the right type of lifting tackles.

Machined surface. If the same is found to have burns, shall be deburred locally using a smooth file/emery sheet.

For installation of primary packers and Conbextra grouting refer relevant chapter.

Ensure that the bases of the Fan parts are tightened without strain. Refer Annexure, for details

A table of tightening torques is provided in this manual, These values may be used only when specific values are not indicated in the drawings. Refer annexure for tightening torque values.

Ensure that the alignment of the coupling is done within 0.05mm.

Ensure that all critical clearances of the rotor to stator are properly maintained.

Ensure proper calibration of all instruments before installing them.

Before starting the Fan, ensure absence of foreign materials like welding electrodes, bolts, nuts, debris etc, in the interior of the Fan casing / ducts.

Never run the Fan/Motor without proper functioning of interlocks / protection.

Note: For commissioning the fan, Refer O & M Manual.

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6.0 TRANSPORT, INSPECTION, STORAGE AND PRESERVATION

TRANSPORT

Fans are dispatched in dismantled condition with proper packing. Handle all Fan parts carefully during transport. Avoid damaging control device, spiral casing and rotor by careless installation or by chains of lifting devices. Pay particular attention to impeller bearing housing and bearings. They should not be dropped on the floor or should not be mishandled. During transport of the shaft, avoid damaging the shaft seats and journal surfaces.

INSPECTION

When packages are received at site, check all parts with the help of the packing list and drawing, If necessary. Hake the list of missing parts (in case of shortage) and initiate action for replacement, insurance claim etc. check any damage which may have occurred to the parts during transit. Take steps to repair the damages, if any, in consultation with the manufacturer. Check the mating dimension like bores and key ways of coupling, suitable for Fan and motor as per drawing. Note down the product numbers of match or reference numbers punched/ painted on the parts to ensure proper assembly.

STORAGE

Due attention given towards storage of Fan components shall pay rich dividends. Fan parts, comprising of many components, are expected to perform certain specific functions. They require due care and attention from the time that are received at the site. Proper awareness in this sphere has averted costly repairs and delay in commissioning of projects.

MINIMUM GENERAL STORAGE REQUIREMENTS

SL.No. Fan Component Storage Locations Frequency (D)

1. Spiral casing Outdoor (a) Monthly

2. Suction chamber Outdoor (a) Monthly

3. Fabricated impeller Weather protected (b) Monthly

4. Flow regulating devices

Weather protected (b) Monthly

5. Bearing pedestals Indoor (c) Monthly

6. Bearing Indoor (c) Monthly

7. Fan shaft @ Indoor (c) Monthly

8. Connecting couplings

Indoor (c) Monthly

55

Note:

a. Above ground, on blocks, exposed to weather.

b. Out doors, above ground, on blocks covered with Tarpaulins and vented fro air circulation

c. Clean and dry warehouse.

d. Inspect the components at the given frequency and re preserve it suitably.

@ Preserve fan shaft as per the instructions given

PROCEDURE FOR PRESERVATION OF MACHINED SURFACES OF FAN SHAFTS AT SITE

1. Inspect the machined surfaces of the fan shafts immediately on receipt at site.

2. Clean the machined surfaces, if required, by using kerosene or mineral turpentine Exposed rust to be removed by rust removing solution (Phosphoric acid 10%).

3. Re-preserve by applying the following:

a) One cost of TRP 1706 RUST PREVENTIVE FLUID.

b) After drying, apply one coat of TRP 1710 and

c) After drying apply one more coat of TRP 1710.

4. Tarpaulin and wooden pieces dis-assembled are not to be used at site.

5. The preserved surfaces shall be wrapped with HDPE (High Density Poly Ethylene) sheets

6. Keep the shafts in covered storage.

7. Inspect the machined surfaces every month and re preserve as mentioned above.

56

RECOMMENDED PRESERVATIVE COMPONENTS

APPLICATION BRAND NAME

Machined surfaces (Indoor storage)

TRP 1706, TRP 1710

HDPE (High Density Poly Ethylene) sheets.

Machined surfaces (Outdoor storage)

TRP

Weldments De-oxy Aluminates

PRESERVATION TILL ERECTION

Disassembled Fan parts are to be stored in their ex-works packing. Welded plate parts are to be protected against the influence of weather under the covers of tarpaulin and on square timber protected against splash water and rain. These parts should not be piled up. They must be stored piece by piece so that no deformations can occur. The areas where paint is suspected to be giving way to the atmospheric action must be repainted after cleaning with fine emery paper.

Parts packed in boxes are to be stored in covered sheds fro protection against mechanical, chemical damage and contamination. These parts are to be unpacked in sequence of their erection just before they are installed. Wherever possible, these parts should be transported to site as per erection sequence in – packed condition. The active an effective life of protective media has its own life, In such cases, the protected items may need periodic re-inspection and reapplication of the protective. To ensure perfect safety of the equipment the instruction given in this regard must be strictly followed.

PRESERVATION OF FAN UP TO COMMISSIONING

After erection of Fan at site, conservation must be ensured up to commissioning and during trial operation. All bright surfaces must be sprayed with anti-corrosive agents / rust preventives.

PRESERVATION OF FANS DURING LONG SHUT DOWN

No special preservation is required for a shut down period up to 2 weeks.

Since the maximum effective life, of rust preventive oil/ anti-corrosive agents, when applied, has its own life (3 months), re preservation has to be carried out after 3 months.

The following procedure shall be adopted for long shut down / stand still period.

Remove the preservation using suitable solvent.

57

Brush or paint or spray with anti corrosive coating / Rust preventive oil on all the machined and bright surfaces which are exposed. Replace the oil completely which is originally put Inside the bearing housings. The bearing housings and the regulating device arc to be fully covered with polythene sheets and tied to prevent rain water entering or dust accumulation.

Rotate the rotor of Fans by hand once in a week to new position 90o away from the original position. This is done to avoid permanent set of the rotor as well as pitting of shaft and elements of bearings.

Run the Fan once in every month for at least 2 hours after removing the polythene cover on bearing housing and regulating device. After each running repeat the above steps.

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7.0 PREPARATION FOR ERECTION

The following details shall be thoroughly studied with the individual contracts regarding size, range, application and scope of supply with reference to the product offered.

System layout

Fan assembly drawing

Fan installation plan

System &Equipment foundation plan

Scope of supply and works by BIIEL and Customer

Shipping list with connected erection drawings.

All the dispatchable units received at site shall be properly identified with respect to documents and drawings. Any short supply or damaged items shall be immediately intimated to the concerned agencies, for transport, inspection, storage and preservation refer the relevant chapter.

The exposed machined surfaces and threaded portions leave the factory with protective preservatives. During storage, these preservative coatings shall be re-established if necessary.

Plan for tools, tackles, ringing and handling facilities required for the installation of Fans, Special attention may be paid to the size, shape and weight of the components as well… as the space limitation while proceeding with the Installation.

After the concrete pedestal is cast and set, visually inspect the foundation for strength and soundless. Check for cracks, holes, exposed steel reinforcements. Especially pay attention to check for any left out wooden shuddering material. The fittings around the foundation should be firm. Do not cut off the exposed ends of reinforcement as long as they are well with in the stipulated height of concrete pedestal. This may offer a good bonding between the mounting plate and the concrete pedestal.

Concrete foundation pier checking should be done with respect to the axis of the plant as shown in the layout drawing. The disposition of the Fan foundation bolt holes and Fan motor foundation pocket holes should be checked. The elevation of foundation should be checked with reference to the datum. Chipping of concrete to be done to the correct elevation. For the permissible tolerances in the foundation the concern foundation plan drawing may be referred.

59

Mark the center lien of foundation with respect to plant centre line, Identify the areas where primary packers are to be positioned. Ensure provision of embedded angles in the foundation. These should be in compliance with the relevant drawings.

The chipped areas at the already identified locations should be in excess of the primary packer plate dimension by 100 mm all around.

Inspect the primary packer and base plates and ensure the following:

Flatness of primary packer.

Dimensional compliance of bolt holes.

Grouting of primary packer/ bearing pedestal should be done in accordance with the procedure given in the relevant Chapter.

Remove the preservative coatings from machined components just before commencing erection. For their removal only liquid solvents should be used. Mechanical process like scrapping, grinding etc should not be employed. If any burrs are present remove them locally by using oil stones or emery paper.

A thin layer of Molykote paste may be applied at mating surfaces viz. machined components, like coupling bore, shaft ends, machined base, base plates etc., before commencing erection.

Attention should be paid to presence of match marks for components that are split to facilitate erection/ maintenance. Such of those components should be duly matched during assembly.

All threaded fasteners pertaining to rotor components should be a quality of class 8.8 or better, unless specified in the drawing.

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8.0 GROUTING INSTRUCTION

OBJECT

This document specifies the technical requirement and procedure to be observed by erection engineers to achieve correct shimming and non shrink grouting of fans. To take care of any special requirements, procedure and layout of primary packers, your attention is drawn to the concerned drawings on this subject supplied to your project.

REFERENCE DOCUMENT

The following documents are essential along with this manual for the correct performance of the work described in this specification.

Fan general arrangement drawing.

Layout of primary packers and shimming.

Civil drawings provided by Civil Designs / Consultant.

GENERAL REQUIREMENT FOR EXECUTION

The operation of shimming and anchoring the fans are mechanical operation requiring greatest care. The working areas must, therefore, be kept cleaned and isolated from all other activities, in order to achieve the required alignment precision and the items can remain stable.

SEQUENCE

All operations and inspection described hereunder must be performed in the chronological order. On completion of works, necessary protocols must be drawn up.

LAY OUT OF FOUNDATION WITH POCKET HOLES AND PLAN

Refer the general arrangement drawing and plan. Mark the longitudinal and transverse axes of machine and the reference axis in foundation. Before any erection work, all the dimension of the foundation and all positions of pockets must be checked and compared with general arrangement drawing. Foundation plan and elevation tolerance should be as mentioned in general arrangement drawing.

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PREPARATION OF FOUNDATION

HAMMER DRESSING

All the locations where primary / packers are to be placed shall be hammer dressed to remove all loose concrete/mortar present in the foundation.

The purpose is to

Eliminate loose concrete grout present and o reach hard sound concrete to ensure adherence of the subsequent layer of concrete.

Reach the proper level of primary packer specification in the drawing.

Enable free flow of grout.

This dressing is to be done additionally 100 mm all around the area of primary packers and also ensure 25 to 75 mm gap between primary packer bottom and dressed concrete depending upon the grade of grout material.

FOUNDATION POCKET DESIGNS

For the foundation pocket design refer the relevant drawing.

PRIMARY PACKER

Primary packers (Sole plates) are steel plates with nuts welded to the sides to form a tripod. All primary packers are manufactured and supplied as raw plates. Ensure the flatness of the primary packers. It will have holes suitable for accommodating the foundation bolts. Three numbers of M16 nuts and three screws of M16X125 mm are supplied as loose dispatch able units. These three nuts are to be welded to the primary packet at alto at suitable location to form a tripod.

PLACEMENT OF PRIMARY PACKER ON FOUNDATION

Primary packers shall be located on the machine foot location on the foundation after hammer dressing is carried out. Refer arrangement of primary packer drawing supplied to your project.

PREPARATION OF SHIMS AT SITE

Stainless steel shims will be supplied by BHEL, Ranipet for fans, For prime movers, the suppliers will supply necessary shims. Maximum height of shims aggregate must be less than 5 mm. Sheet or roll of 350 mm width will be supplied in calculated length for each type of fan. Customer/consultant to refer the motor drawing/erection manual for the exact arrangement of grounding etc., for motor.

Where ever the shims are inserted, they will be prepared at site to have U slots as shown in the relevant drawing.

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Each shim is to be prepared based on actual requirement to ensure maximum contact. Maximum number of shall not be more than 7

THE FOOT OF THE EQUIPMENT

The height from centre line will be maintained at our works within 0 and – 3 mm tolerance with taper not exceeding 1 mm / mtr.

LAYING OF PRIMARY PACKERES IN THE HORIZINTAL PLANE

The primary packers shall be laid according to the drawing released for your project.

LEVELING OF PRIMARY PACKERS

Primary packers shall be leveled by adjusting the screws.

Adjust the elevation of top surface of primary packer in relation to the reference level (Fan axis level.

Adjust the elevation at all points of primary packer.

Check the elevation. This check can be carried out by a theodolitte/ water level. The maximum permissible level change is + 0 to -2mm. The taper shall not exceed 1 mm/mtr.

Lock the level adjusting screws by tack welding with nut.

Primary packer top surface shall be applied with rust preventive.

EMBEDMENT OF PRIMARY PACKER

The primary packers shall be embedded with NON SHRINK GROUNT strictly following the instruction of the grout supplier. The curing time shall be as per manufacturer‟s data. After curing check the level of primary packer and cut off the adjusting screws flush with grout.

Before taking up the grouting, the grout material should be sample tested to meet manufacturer’s specification.

Ensure that the foundation pocket is NOT filled with the grout (where ever as shown in the drawing) by putting a thermo Cole as shown in the drawing to avoid grouting of foundation bolts.

SHIMMING

The positioning of the fan components shall be adjusted to achieve the final alignment (elevation) tolerances specified as before. Shims are to be prepared at site as per the requirement. Shims are to be placed between the primary packer and the machine foot. Shims are to be placed after cleaning the top surface of the primary packer. The erection Engineers shall choose

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minimum number of shims. The shims must be slipped side ways between primary packer and machine foot with out altering or de-forming the embedded primary packer or machine foot. Tack weld the shims together and also with primary packer.

ASSEMBLY OF FAN CASING

The casing parts can be assembled together by means of connecting flanges, fir bolts and guide plates. The horizontal ad vertical dividing flanges should be connected with sealing ropes. All parts are identified by match marks for proper assembly. Ensure dimensional compliance of the spiral casing.

GROUTING OF PRIMARY PACKERS OF FAN CASING

Level and grout the primary packer with out any air pockets, by maintaining its elevation with respect to the fan center line, Refer chapter on Grounding Instructions.

ALIGNMENT IF SPIRAL CASING

Position the bottom half of the spiral casing and by suitable shimming, ensure (by water balance) the relative elevation at four corners of the spiral casing. Ensure vertically of the spiral casing. Ensure alignment of spiral casing with respect to fan centre lines.

INSTALLATION OF BERAING PEDESTAL

Position the bearing pedestal and align it with respect to foundation and spiral casing. Ensure elevation of pedestal with respect to fan center line.

Ensure horizontality shall not exceed 0.04mm-mtr on the machined surface of the pedestal by using leveling spindles along the perpendicular to the fan axis and grout It using NON SHRINK GROUT with out any air pockets. Refer chapter Instructions.

ASSEMBLY AND INSTALLATION OF ROTOR

The following points must be checked and verified during assembly of rotor at site.

Clean the shaft flange groove and the Impeller groove with liquid solvents like CTC. Scrapping is not permitted.

Check for any burns at the mating flange and if found, remove them using smooth file or emery paper.

Apply rust preventive like MOLYKOTE 321R or OKS 511 at the mating surface and also on the fixing bolts.

Position the impeller with the shaft flange. Ensure proper seating of the locating groove in the shaft flange with the impeller. The impeller can be assembled with the shaft flange at any position.

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Fasten with supplied bolts. These bolts must be of quality 8.8 or better. Tighten to the rated torque. The tightening of the bolts must be sequential.

Zero gap between the impeller and the shaft flange mating planes.

Provision of locking plates as shown in the drawing.

Tightness of impeller fixing bolts to the rated torque value.

Assembly of conical cover plates with reference to the match marks.

Provision of asbestos cord between shaft ring and conical cover plate.

Zero gap between impeller and conical cover plate mating face.

Tightness of fixing bolts of conical cover plate to the rated torque values.

The shaft at the bearing seating area, apply to lub oil and cover with clean cloth.

MOUNTING OF BEARINGS

Position the bottom half of the bearing housing on the bearing pedestals.

Ensure above 80% Blue matching between bearing housing and the bearing pedestals.

PRECAUTION

It is required that every possible care to be taken so that the bearings are assembled properly. It is utmost important that the instructions given in the annexure regarding the assembly of the bearings are strictly adhered to in the same sequence as indicated to avoid any future problems.

Make sure that the bearing bore and shaft diameters are in accordance with the drawings. For the bearing clearances, refer drawing / Fan Technical Data.

No bearing shall be accepted if it found pitted rusted or damaged.

Wipe the bearings with clean cloth. For assembly details refer annexure.

ROTOR ALIGNMENT

The following points are to be checked and confirmed during rotor alignment.

Dimensional compliance of the bearing as per the drawing.

Correct elevation of bearing pedestal and Horizontality of bearing housing to 0.04mm/ mtr.

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The shaft at fixed ed bearing should be leveled to within 0.04mm/mtr. To achieve this, the free end bearing housing may be raised or lowered as required.

Provide shims of thickness 2 to 3 mm between the bearing housing and bearing pedestal fro future maintenance purpose.

Record the bearing clearances after assembly.

For the bearing clearances, refer drawing/ Technical Data.

COMPLETION OF ERECTION

Coupling bores and shaft end dimensions should be recorded prior to assembly.

Coupling halves may be heated in oil bath to around 90 Deg C above ambient temperature for easy mounting. (But never exceed a temperature of 120 Deg C.) (Soaking time 2 hrs). Mount the coupling halves. Mount the top half of spiral casing ensuring provision of sealing cords as indicated in the drawing. Check and record the impeller clearances. Install the inlet damper assembly. Ensure its orientation. The flaps of damper shall open in the same direction of rotation of impeller viewing from suction side. Couple the two damper assemblies and then connect to actuator. Ensure identical operation of damper flaps.

Ensure that, duct loads are not supported on the fan casing. This can be ascertained by the position of flexible elements in the expansion joints. Install the motor (any hydraulic coupling if applicable as per the guide lines given by the manufacturer. Motor is to be aligned to 0.05mm with respect to fan in both radial and axial direction. Ensure correct coupling gap (and hot alignment of the hydraulic coupling if applicable). Refer supplier‟s catalogue.

If the connecting couplings are GEAR / BIBBY type, fill the connecting coupling with recommended grease. Refer lubrication chart. All the coupling bolts should be tightened to the rated torque. Mount labyrinth shaft seal at shaft end. A minimum radial clearance of 0.1 mm should be maintained between labyrinth elements and shaft surface. As a final step in completion of erection, dowel all the areas as specified in the drawing after satisfactory trial run of fan and after rechecking fan- motor alignment.

Necessary protocols are to be recorded as per the QPI.

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10.0 LUBRICATINO INSTRUCTIONS

The fan bearings are lubricated by means of Oil lubrication

OIL SPECIFICATION

The oil to be used shall be a turbine quality. The oil must not foam during operation. Foam removing agents containing silicon must not be utilized. The oil must have well anti- corrosion properties.

RECOMMENDED OIL

Refer Technical Data Sheet Chapter 2.0

LUBRICANT FILLING

Fill the recommended lube oil (through a fine mesh strainer only up to the required level. Do not mix lubricants of different grade and make.

LUBRICANR CHECK

At first commissioning and after a basic overhaul, the entire oil must be drained after an operating period of 100 hrs. All dirt should be eliminated from the bearing housing. Then fill in again the oil through the fine mesh strainer.

CARE OF LUBRICANR

Test the quality of the oil every month and if found unsatisfactory and or containing water / dirt the oil should be changed immediately.

FREQUENCY OF OIL CHANGE

First change of oil : After 100 hrs. of initial operation.

Subsequent changes : Refer Technical Data sheet (chapter 2.0)

Check for oil contamination between oil changes as above.

During each oil change, drain flushes and refill.

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Ranipet

RADIAL FAN (NDV WITH ANTI-FRICTION BEARING)

SINGLE SUCTION

ERECTION MANUAL

Preparation by Checked by Approved by

S.SELVAM J.MOORTHY M.DESIGAN

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4.0 CONSTRUCTIONAL FEATURES

NDV fans are single stage, single inlet centrifugal machines. The rotor is simply supported by anti-friction bearings located on both side of the impeller.

The major sub-assemblies of the fan are as follows.

Impeller with shaft assembly

Bearings and thermometers.

Suction chamber and spiral casing.

Flow regulating devices.

Shaft seals.

Couplings

Drives

IMPELLER WITH SHAFT ASSEMBLY

The impeller is a completely welded structure and is made from high tensile steel with backward curved blades. The selection of the material and thickness for the impeller/shaft are computed on the basis of the stress analysis/critical speed programme carried out for each impeller and shaft. The impeller consists of back plate, blade, and cover plate and impeller ring. All Weldments are inspected thoroughly by NDT methods. The back plate of the impeller and the shaft flange has a machined groove, which ensures correct location of the wheel relative to the shaft during assembly.

Impeller is bolted to the shaft flange and locked plates. Conical cover plates are provided at the inlet (bolted to the back plate to guide the inlet flow and to protect the fasteners from exposure to the medium handed by the fan. Fan, the impeller is stress relived upon completion of all welding operation and is dynamically balanced after final machining. The shaft is machined to a finish for location of impeller, bearings and coupling half.etc. The completed shaft is dynamically balanced. The critical speed of the rotor is well above the operating speed.

BEARING AND THERMOMETERS

The fan rotor is supported in between a fixed bearing and a free bearing. The fixed bearing is arranged on the coupling side. The Fans are provided with anti-friction bearings and oil lubrication. Provision for mounting temperature gauges (mercury in steel thermometers and RTDs) are available on the bearing housings for local and remote (UCB) indication of bearing

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temperatures. Platinum resistance thermometers (RTD) are provided with alarm and trip connections and for remote indication (control room) of bearing temperatures.

SUCTION CHAMBER AND SPIRAL CASING

Suction chamber and spiral bearing are fully welded structures and are fabricated from sheet steel with adequate stiffeners. These are split suitably to facilitate easy handling and maintenance of rotor, etc. the oblique cone which forms the entrance to the impeller helps in accelerating the flow. The lower part of fan casing rests on the supporting brackets on the foundation.

FLOW REGULATING DEVICES

Fan outlet flow is controlled by inlet guide vane assembly or by inlet damper or by variable speed hydraulic coupling or by VFD motor. (Refer as applicable)

a) INLET GUIDE VANE ASSEMBLY

Inlet vanes control device regulates the fan output (flow). The inlet vane assembly is located at the inlet the suction chamber for regulating the flow through the fan for different system demand. In consists of single piece casing, vanes, bearings for vane shafts and actuating lever. The bearing housings are supported on the sidewalls of the guide vane casing.

Levers and links for connection to the actuating lever connect the vane shafts. The vanes are actuated by means of an actuator. A graduated dial plate indicates the vanes position in degrees.

The Direction of Opening of Inlet Guide Vane shall be in the Opposite direction or rotation of impeller viewing from suction side.

b) DAMPER CONTROL ASSEMBLY

The damper control assembly is located at the inlet of the suction chamber for regulating the flow through the fan for different system demand. It consists of single piece casing, flaps, bearings for flap shafts and actuating lever. The bearing housings are supported on the side walls of the casing.

Levers and links for connection to the actuating lever connect the damper shafts. The flaps are actuated by means of an actuator. A graduated dial plate indicates the flaps position in degrees.

The Direction of Opening of inlet damper flaps shall be in the same direction of rotation of impeller viewing from suction end.

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SHAFT SEALS

Seals for the shafts are provided to reduce the leakage through the gaps when the shaft passes through the suction chambers. It consists of a labyrinth section fro axial sealing. The labyrinth seal is centrally located and mounted on both side bearing pedestal. Casing wall which helps in precisely controlling the labyrinth passage.

The fan and the drive motor is coupled by means of flexible couplings.

FAN DRIVE

The fan is driven by an electric motor. For detailed instructions, the respective instruction manual should be referred.

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5.0 IMPORTANT INSTRUCTIONS

Care should be exercised while lifting the rotor assembly. Balance the rotor assembly and use the right type of lifting tackles.

Machined surface. If the same is found to have burrs, shall be deburred locally using a smooth file/ emery sheet.

For Installation of primary packers and Conbextra grouting refer relevant chapter.

Ensure that the cases of the Fan parts are tightened without strain. Refer Annexure, for details.

A table of tightening torque is provided in this manual. These values may be used only when specific values are not indicated in the drawings. Refer Annexure for tightening torque values.

Ensure that the alignment of the coupling is done within 0.05mm.

Ensure that all critical clearances of the rotor to stator are properly maintained.

Ensure that all critical clearances of the rotor to stator are properly maintained.

Ensure proper calibration of all instruments before installing them.

Before starting the Fan, ensure absence of foreign materials like welding electrodes, bolts, nuts, debris etc, in interior of the Fan casing/ ducts.

Never run the Fan/Motor without proper functioning of interlocks/ protection.

For commissioning the fan, operation and maintenance manual.

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6.0 TRANSPORT, INSPECTION, STORAGE AND PRESERVATION

TRANSPORT

Fans are dispatched in dismantled condition with proper packing. Handle all Fan parts carefully during transport. Avoid damaging control device, spiral casing and rotor by careless installation or, by chains of lifting devices. Pal particular attention to impeller bearing housing and bearings. They should not be dropped on the floor or should not be mishandled. During transport of the shaft, avoid damaging the shaft seats and journal surfaces.

INSPECTION

When packages are received at site, check all parts with the help of the packing list and drawing. If necessary. Hake the list of missing parts (in case of shortage) and initiate action for replacement insurance claim etc. check any damages which may have occurred to the [parts during transit. Take steps to repair the damages, if any, in consultation with the manufacturer. Check the mating dimensions like bores and key ways pf coupling, suitable for Fan and motor as per drawing. Note down the product numbers or match marks or reference numbers punched/painted on the parts to ensure proper assembly.

STORAGE

Due attention given towards storage of Fan components shall pay rich dividends. Fan parts, comprising of many components, are expected to perform certain specific functions. They require due care and attention from the time they are received at the site. Proper awareness in this sphere has averted costly repairs and delay in commissioning of projects.

MINIMUM GENERAL STORAGE REQUIREMENTS

Sl. No. Fan Component Storage Locations Frequency (D)

1. Spiral casing Outdoor (a Monthly

2. Suction chamber Outdoor (a) Monthly

3. Fabricated impeller Weather protected (b) Monthly

4. Flow regulating devices

Weather protected (b) Monthly

5. Bearing pedestals Indoor (c) Monthly

6. Bearings Indoor (c) Monthly

7. Fan shaft @ Indoor (c) Monthly

8. Connecting couplings Indoor (c) Monthly

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Note:

a) Above ground, on blocks, exposed to weather.

b) Out doors, above grounds, on blocks covered with Tarpaulins and vented for air circulation.

c) Clean and dry warehouse.

d) Inspect the components at the given frequency and re preserve it suitably.

@ Preserve fan shaft as per the instructions given

PROCEDURE FOR PRESERVATION OF MACHINED SURFACES OF FAN SHAFTS AT SITE

1. Inspect the machined surfaces of the fan shafts immediately on receipt at site

2. Clean the machined surfaces, if required, by using kerosene or mineral turpentine. Exposed rust to be removed by rust removing solution (Phosphoric acid 10%)

3. Re-preserve by applying the following:

a) One coat at TRP 1706 rust preventive fluid.

b) After drying, apply one coat of TRP 1710 and

c) After drying, apply one more coat of TRP 1710.

4. Tarpaulin and wooden pieces dis-assembled are not to e used at site.

5. The preserved surfaces shall be wrapped with HDPE (High Density Poly Ethylene) sheets.

6. Keep the shafts in covered storage.

7. Inspect the machined surfaces every month and re preserve as mentioned above.

PROCEDURE FOR PRESERVATION OF ANTI-FRICTION BEARINGS

1. The store room must be free from dust.

2. Ideal ambient temperature should be 20 to 30 deg c.

3. Relative air humidity should nor exceed 60%. It may be necessary to install air dehumidifier in places where relative humidity is high.

4. If the bearing is found to be dry and dirty, it should be thoroughly washed and cleaned before re-packing,

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5. The bearing should be first kept in a vessel filled with kerosene fro about half an hour and then washed to take out the dirt.

6. It should then be cleaned in another vessel with filtered kerosene.

7. The final cleaning is to be done by using petrol of mineral turpentine oil.

8. It should be then allowed to dry completely. Pressuraised air for cleaning or drying purpose is not recommended. (RUST GARD P214)

9. The washed any dry bearing is to be dipped in anti-corrosive oil.

10. The excess oil should be allowed to escape and bearing should be repacked in a waterproof sealable plastic bag and put in to the carton again.

RECOMMENDED PRESERVATIVE COMPONENTS

Application Brand Name

Machined surfaces (Indoor storage)

TRP 1706, TRP 1710

Machined surfaces (Outdoor storage)

HDPE (High Density Poly Ethylene) sheets.

Weldments De-oxy Aluminates

PRESERVATION TILL ERECTION

Disassembled Fan parts are to be stored in their ex-works packing. Welded plat parts are to be protected against the influence of weather under the covers of tarpaulin and on square timber protected against splash water and rain, these parts should not be piled up. They must be stored piece by piece that no deformation can occur.

The areas where paint is suspected to be giving way to the atmospheric action must be repainted after cleaning with fine emery paper. Parts packed in boxes are to be stored in covered sheds for protection against mechanical, chemical damage and contamination. These parts are to be unpacked in the sequence of their erection just before they are installed.

Wherever possible, these parts should be transported to site as per erection sequence in packed condition. The active and effective life of protective media has its own life. In such cases, the protected items may need periodic re_inspection and reapplication of the protective. To ensure perfect safety of the equipment the instruction given in this regard must be strictly followed.

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PRESERVATION OF FAN UP TO COMMISSIONING

After erection of Fan at site, conservation must be ensured up to commissioning and during trial operation. All bright surfaces must be sprayed with anti-corrosive agents/rust preventives.

PRESERVATION OF FANS DURING LONG SHUT DOWN

No special preservation is required for a shut down period up to 2 weeks.

Since the maximum effective life, or rust preventive oil/ anti-corrosive agents, when applied, has its own life (3 months), re preservation has to be carried out after 3 months.

The following procedure shall be adopted for long shut down / stand still period.

Remove the preservative using suitable solvent.

Brush or point or spray with anti corrosive coating/ Rust preventive oil on all the machined and bright surfaces which are exposed.

Replace the oil completely which is originally put inside the bearing housings.

The bearing housings and the regulating device are to be fully covered with polythene sheets and tied to prevent rain water entering or dust accumulation.

Rotate the rotor of Fans by hand once in a week to new position 90o away from the original position. This is done to avoid permanents et of the rotor as well as putting of shaft and elements of bearings.

Run the Fan once in every month for at least 2 hours after removing the polythene cover on bearing housing and regulating device. After each running repeat the above steps.

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7.0 PREPARATION FOR ERECTION

The following details shall be thoroughly should with the individual contracts regarding size, range, application and scope of supply with reference to the product offered.

System layout.

Fan assembly drawing

Fan installation plan

System & Equipment foundation plan

Scope of supply and works by BHEL and Customer

Shipping list with connected erection drawings.

All the dispatchable units received at site shall be properly identified with respect to documents and drawings. Any short supply or damage items shall be immediately intimated to the concerned agencies. For transport, inspection, storage and preservation refer the relevant chapter.

The exposed machined surfaces and threaded portions leave the factory with protective preservatives. During site storage, these preservative coatings shall be re-established if necessary. Plan for tools, tackles, rigging and handling facilities required for the installation of Fans. Special attention may be paid to the size, shape and weight of the components as well… as the space limitation while proceeding with the Installation.

After the concrete pedestal is cast and set, visually inspect the foundation for strength and soundness. Check for cracks, holes, exposed steel reinforcements. Especially pay attention to check for any left out wooden shuddering materials. The fittings around the foundation should be firm. Do not cut off the exposed ends of reinforcement as long as they are well within the stipulated height of concrete pedestal. This may offer a good bonding between the mounting plate and the concrete pedestal.

Concrete foundation pier checking should be done with respect to the axis of the plant as shown in the layout drawing. The disposition of the Fan foundation bolt holes and fan motor foundation pocket holes should be checked. The elevation of foundation should be checked with reference to the datum. Chipping of concrete to be done to the correct elevation. For the permissible tolerances in the foundation the concern foundation plan drawing may be referred.

Mark the center line of foundation with respect to plant center line. Identify the areas where primary packers are to be positioned. Ensure provision of

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embedded angles in the foundation. These should be in compliance with the relevant drawings.

The chipped areas at the already identified locations should be in excess of the primary packer plate dimension by 100 mm all around. Inspect the primary packer and base plates and ensure the following.

Flatness o primary packer.

Dimensional compliance of bolt holes.

Grouting of primary packer/bearing pedestal should be done in accordance with the procedure given in the relevant Chapter.

Remove the preservative coatings from machined components just before commencing erection. For their removal only liquid solvents should be used. Mechanical process like scrapping, grinding etc should not be employed. If any burrs are present remove them locally by using oil stones or emery paper.

A thin layer of molykote paste may be applied at mating surfaces viz. machine components, like coupling bore, shaft ends, machined base, base plates etc., before commencing erection.

Attention should be paid to presence of match marks for components that are split to facilitate erection/maintenance. Such of those components should be duly matched during assembly.

All threaded fasteners pertaining to rotor should be a quality of class 8.8 or better, unless specified in the drawing.

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8.0 GROUTING INSTRUCTION

OBJECT

This document specifies the technical requirement and procedure to be observed by erection engineers to achieve correct shimming and non shrink grouting of fans. To take care of any special requirement, procedure and layout of primary packers, your attention is drawn to the concerned drawings on this subject supplied to your project.

REFERENCE DOCUMENT

The following documents are essential along with this manual for the correct performance of the work described in this specification.

Fan general arrangement drawing.

Layout of primary packers and shimming.

Civil drawings provided by Civil Designs / Consultant.

GENERAL REQUIREMENT FOR EXECUTION

The operation of shimming and anchoring the fans are mechanical operation requiring greatest care. The working areas must, therefore, be kept cleaned and isolated from all other activities, in order to achieve the required alignment precision and the items can remain stable.

SEQUENCE

All operations and inspection described hereunder must be performed in the chronological order. On completion of works, necessary protocols must be drawn up.

LAY OUT OF FOUNDATION WITH POCKET HOLES AND PLAN

Refer the general arrangement drawing and plan, Mark the longitudinal and transverse axes of machine and the reference axis in foundation. Before any erection work, all the dimension of the foundation and all positions of pockets must be checked and compared with general arrangement drawing. Foundation plan and elevation tolerances should be as mentioned in general arrangement drawing.

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PREPARATION OF FOUNDATION

HAMMER DRESSING

All the locations where primary packers are to be placed shall be hammer dressed to remove all loose concrete/ mortar present in the foundation.

The purpose is to

Eliminate loose concrete grout present and to reach hard sound concrete to ensure adherence of the subsequent layer of concrete.

Reach the proper level of primary packer specification in the drawing

Enable free flow of grout.

This dressing is to be done additionally 100 mm all around the area of primary packers and also ensure 25 to 75 mm gap between primary packer bottom and dressed concrete depending upon the grade of grout material.

FOUNDATION POCKET DESIGNS

For the foundation pocket design refer the relevant drawing.

PRIMARY PACKER

Primary packers (Sole plates) are steel plates with nuts welded to the sides to form a tripod. All primary packers are manufactured and supplied as raw plates. Ensure the flatness of the primary packers. It will have holes suitable for accommodating the foundation bolts.

Three numbers of M16 nuts and three screws of M16X125 mm are supplied as loose dispatch able units. These three nuts are to be welded to the primary packer at alto at suitable location to form a tripod.

PLACEMENT OF PRIMARY PACKER ON FOUNDATION

Primary packers shall be located on the machine foot location on the foundation after hammer dressing is carried out. Refer arrangement of primary packer drawing supplied to your project.

PREPARATION OF SHIMS AT SITE

Stainless steel shims will be supplied by BHEL, Ranipet for fans. For prime movers, the supplier will supply necessary shims. Maximum height shims aggregate must be less than 5 mm. Sheet or roll of 350 mm width will be supplied in calculated length for each type of fan.

Customer/consultant to refer the motor drawing/erection manual for the exact arrangement of grouting etc. for motor. Where ever the shims are inserted, they will be prepared at site to have U slots as shown in the relevant drawing.

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Each shim is to be prepared based on actual requirement to ensure maximum contact. Maximum number of shall not be more than 7

THE FOOT OF THE EQUIPMENT

The height from center lien will be maintained at our works within 0 and – 3 mm tolerance with taper not exceeding 1 mm/ mtr.

LAYING OF PRIMARY PACKERS IN THE HORIZINTAL PLANE

The primary packers shall be laid according to the drawing released for your project.

LEVELING OF PRIMARY PACKERS

Primary packers shall be leveled by adjusting the screws.

Adjust the elevation of top surface of primary packer in relation to the reference level (Fan axis level)

Adjust the elevation at all points of primary packer.

Check the elevation. This check can be carried out by a theodolitte water level. The maximum permissible level change is + 0 to – 2mm. the taper shall not exceed 1mm/mtr.

Lock the level adjusting screws by tack welding with nut.

Primary packer top surfaces shall be applied with rust preventive.

EMBEDMENT OF PRIMARY PACKER

The primary packers shall be embedded with NON SHRINK GROUT strictly following the instruction of the grout suppler. The curing time shall be as per manufacturer‟s data. After curing check the level or primary packer and cut off the adjusting screws flush with grout.

Before taking up the grouting, the grout material should be sample tested to meet manufacturer’s specification.

Ensure that the foundation pocket is NOT filled with the grout (where ever as shown in the drawing) by putting a thermocole as shown in the drawing to avoid grouting of foundation bolts.

SHIMMING

The positioning of the fan components shall be adjusted to achieve the final alignment (elevation) tolerances specified as before. Shims are to be prepared at site as per the requirement. Shims are to be placed between the primary packer and the machine foot. Shims are to be placed after cleaning

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the top surface of the primary packer. The erection Engineers shall choose minimum number of shims. The shims must be slipped side ways between primary packer and machine foot with out altering or de-forming the embedded primary packer or machine foot. With out altering or de-forming the embedded primary packer or machine foot. Tack weld the shims together and also with primary packer.

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9.0 ERECTION INSTRUCTIONS

ASSEMBLY OF FAN CASING

The casing parts can be assembled together by means of connecting flanges, fir bolts and guide plates. The horizontal and vertical dividing flanges should be connected with sealing ropes. All parts are identified by match marks for proper assembly, ensure dimensional compliance of the spiral casing.

GROUTING OF PROMARY PACKER OF FAN CASING

Level and grout the primary packer with out ant air pockets, by maintaining its elevation with respect to the fan center line, Refer chapter on Grouting Instructions.

ALIGNMENT OF SPIRAL CASING

Position the bottom half of the spiral casing and by suitable shimming, ensure (by water balance) the relative elevation of four corners of the spiral casing. Ensure vertically of the spiral casing. Ensure alignment of spiral casing. Ensure alignment of spiral casing with respect to fan centre lines.

INSTALLATION OF BEARING PEDESTAL

Position the bearing pedestal and align it with respect of foundation and spiral casing. Ensure elevation of pedestal with respect to fan center line.

Ensure horizontality shall not exceed 0.04 mm/mtr on the machined surface of the pedestal by using leveling spindles along the perpendicular to the fan axis and grout it using NON SHRINK GROUT with any air pockets. Refer chapter Grouting Instructions.

ASSEMBLY AND INSTALLATION OF ROTOR

The following pints must be checked and verified during assembly of rotor at site.

Clean the shaft flange grove and the Impeller groove with liquid solvents like CTC. Scrapping is not permitted.

Check fro any burrs at the mating flange and if found, remove them using smooth file or emery paper.

Apply rust preventive like MOLYKOTE 321R or OKS 511 at the mating surface and also on the fixing bolts.

Position the impeller with the shaft flange. Ensure proper seating of the locating groove in the shaft flange with the impeller.

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The impeller can be assembled with the shaft flange at any position.

Fasten with specified bolts. These bolts must be of quality 8.8 or better. Tighten to the rated torque. The tightening of the bolts must be sequential.

Zero gap between the impeller and the shaft flange mating planes.

Provision of locking plates as shown in the drawing.

Tightness of impeller fixing bolts to the rated torque value.

Assembly of conical cover plates with reference to the match marks.

Provision of asbestos cord between shaft ring and conical cover plate.

Zero gap between impeller and conical cover plate mating face.

Tightness of fixing bolts of conical cover plate to the rated torque values.

The shaft at the bearing seating area, apply lub oil and cover with clean cloth.

MOUNTING OF BEARINGS

Position the bottom half of the bearing housing on the bearing pedestal.

Ensure above 80% Blue matching between bearing housing and the bearing pedestal.

PRECAUTION

It is required that every possible care to be taken so that the bearings are assembled properly. It is utmost important that te instructions given in the annexure regarding the assembly of the bearings are strictly adhered to in the same sequence as indicated to avoid any future problems.

Make sure that the bearing bore and shaft diameters are in accordance with the drawings. For the bearing clearances, refer drawing / fan Technical Data.

No bearing shall be accepted if it found pitted rusted or damaged.

Wipe the bearings with clean cloth. For assembly details refer annexure.

ROTOR ALIGNMENT

The following points are to be checked and confirmed during rotor alignment.

Dimensional compliance of the bearing as per the drawing,

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Correct elevation of bearing pedestal and Horizontality of bearing housing to 0.04mm/ mtr.

The shaft at fixed end bearing should be leveled to within 0.04 mm/mtr. To achieve this, the free and bearing housing may be raised or lowered as required.

Provide shims of thickness 2 to 3 mm between the bearing housing and bearing pedestal for future maintenance purpose,

Record the bearing clearances after assembly.

For the bearing clearances, refer drawing/ Technical Data.

Coupling bores and shaft end dimensions should be recorded prior to assembly.

Coupling halves may be heated in oil bath to around 90 Deg C above ambient temperature for easy mounting. (But never exceed a temperature of 120 Deg C). (Soaking time 2 hrs). Mount the coupling halves. Mount the top half of spiral casing ensuring provision of sealing cords as indicated in the drawing. Check and record the impeller clearances. Install the inlet damper assembly. Ensure its orientation. The flaps pf damper shall open in the same direction of rotation of impeller viewing from suction side. Couple the two damper assemblies and then connect to actuator. Ensure identical operation of damper flaps.

Ensure that, duct loads are not supported on the fan casing. This can be ascertained by the position of flexible elements in the expansion joints. Install the motor (and hydraulic coupling if applicable) as per the guide lines given by the manufacture. Motor is to be aligned to 0.05 mm with respect to fan in both radial and axial direction. Ensure correct coupling gap (and hot alignment of the hydraulic coupling if applicable). Refer supplier‟s catalogue.

If the connecting couplings are GEAR/BIBBY type, fill the connecting coupling with recommended grease. Refer lubrication chart. All the coupling bolts should be tightened to the rated torque. Mount labyrinth shaft seal at shaft end, A minimum radial clearance of 0.1 mm should be maintained between labyrinth elements and shaft surface. As a final step in completion of erection, dowel all the areas as specified in the drawing after satisfactory trial run of fan and after rechecking fan – motor alignment.

Necessary protocols are to be recorded as per the QPI

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10.0 LUBRICATION INSTRUCTIONS

The fan bearings are lubricated by means of oil lubrication.

OIL SPECIFICATION

The oil be used shall be a turbine quality. The oil must not foam during operation. Foam removing agents containing silicon must not be utilize. The oil must have well anti- corrosion properties.

RECOMMENDED OIL

REFER TECHNICLA DATA SHEET CHAPTER 2.0

LUBRICANT FILLING

Fill the recommended lube oil (through a fine mesh strainer only) up to the required level. Do not mix lubricants of different grade and mark.

LUBRICANR CHECK

At first commissioning and after a basic overhaul, the entire oil must be drained after an operating period of 100 hrs. All dirt should be eliminated from the bearing housing. Then fill in gain the oil through the fine mesh strainer.

CARE OF LUBRICANT

Test the quality of the oil every month and if found unsatisfactory and or containing water/ dirt the oil should be changed immediately.

FREQUENCY OF OIL CHANGE

First change of oil : After 100hrs. of initial operation.

Subsequent changes : Refer Technical Data Sheet (Chapter 2.0)

Check for oil contamination between oil changes as above.

During each oil change, drain flushes and refill.

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ELECTROSTATIC PRECIPITATOR

INTRODUCTION

This manual is intended to guide the erection personnel in the proper installation of electrostatic precipitator.

The precipitator is meant for collection of fly ash particles entrained in the flue gas leaving the boiler. The performance of the precipitator depends, apart from other factors, on the proper erection of various functional parts in strict accordance with the instructions outlines in this manual. Field experience has established that deviations from stipulated tolerances on alignment of electrodes, mounting of rapping mechanisms etc, reflect on the performance, affecting adversative that due care has to be exercised at every stage of erection, from inspection of components, received at site to final checking up of the overall installation.

The erection engineer shall get acquainted with the details of functional parts and constructional features of the precipitator, before proceeding with the erection. For this purpose a brief description of the working principles and functional elements of precipitator is given in the manual. All references to the drawings are given by the title of the Drawings, which are listed in the respective sections.

It is also required to fill the log sheets separately issued by Field Quality Assurance group of BHEL. These log sheets are not included in this manual. This manual may be used as a reference and for guidance, it is expected that before commencement of erection all the contract erection drawings shall be gone – through for proper erection.

Every possible care has been taken to ensure the contents are accurate. It must be recognized that no amount of written instructions can replace intelligent thinking and reasoning on the part of the erectors, especially when coping with individual site conditions. However, we would welcome every feed back and suggested for improvement of the contents of the manual.

BHARAT HEAVY ELECTRICALS LTD BOILER AUXILIARIES PLANT RANIPET

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TABLE OF CONTENTS

List of Illustrations

Precautions

Important Instructions

Electrostatic Precipitator

1.0 Working principle of Electrostatic Precipitator.

2.0 Constructional features of Electrostatic Precipitator

2.1 General

2.2 Casing

2.3 Internals

2.3.i Gas districution screen

23.ii Emitting electrode system

2.3.iii Collecting system

2.3.iv Rapper of emitting electrode system

2.3.v Electric‟s

2.3.vi Interlocks

3.0 Salient features of Electrostatic Precipitators

4.0 Storage instruction for EP components

5.0 Handling instructions for EP components

6.0 Erection procedure for electrostatic precipitators.

6.1 Introduction

6.2 Layout

6.3 Supporting structure

6.4 Slide supports

6.5 Casing structures & casing shell & ridges

6.6 Hopper assembly

6.7 Galleries and stairways

6.8 Gas paths centre line

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6.9 Collecting electrode suspension

6.10.1 Insulator supporting panels

6.11 Emitting system frame work top

6.12 Emitting system suspension

6.13 Emitting system frame work middle & bottom

6.14 Gas distributor assembly

6.15 a Emitting electrodes, collecting electrodes an d shock bars (400 mm plate system)

6.15 b Emitting electrodes, collecting electrodes and shock bars (750 mm CE plate system)

6.16 Collecting rapping mechanism

6.17 Diagonal stays

6.18 Alignment of collecting and emitting systems

6.19 Rapping mechanisms for collecting and emitting electrodes

6.20 Drive arrangement for emitting electrode – rapping mechanism

6.21 a Drive arrangement for emitting electrode – rapping mechanism

6.22 Hopper defection plates

6.23 Electrostatic precipitator funnels

6.24 Roof panels, outer roof, rectifier handling arrangements, pent house etc.

6.25 Insulator housing

6.26 Inspection doors

6.27 Insulation

6.28 Transformer rectifier, heating elements, thermostats, auxiliary control panels, electronic controllers and interlocks.

6.29 Final checks

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LIST OF ILLUSTRATIONS

Fig.1 Internal bracing casing for electrostatic precipitator

Fig.2 Hopper

Fig.3 Gas distribution screen at inlet

Fig.4 Gas distribution screen at outlet

Fig.5 Emitting system frame work without vertical drive – 3 level arrangement.

Fig.6 Emitting system frame work with side drive – 2 level arrangement.

Fig.7 Emitting electrode mounting arrangement.

Fig.8 Collecting system suspension and rapping mechanism - 400 mm wide CE plate

Fig.9 Collecting system suspension and rapping mechanism

Fig.10 Electronic controller

Fig.11 Auxiliary control panel

Fig.12 Lt. main switch board

Fig.13 Lifting bean for collecting plate

Fig.14 Location of ESP with preference to boiler

Fig.15 Supporting structure – stage –i

Fig.16 Supporting structure – stage – ii

Fig.17 Supporting structure – stage – iii

Fig.18 Supporting structure, fixed support and slide supports assembly

Fig.19 Casing structure – stage i

Fig.20 Casing structure – stage ii

Fig .21 Casing structure – stage iii

Fig .22 Casing structure – stage iv

Fig.23 Casing structure with casing shell stage v

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Fig.24 Casing structure with casing shell stage vi

Fig.25 Casing structure with casing shell stage vii

Fig.26 Spacing rood beams with tolerances

Fig.27 Dimensional check on collecting suspension frames - 400 mm wide CE plate

Fig.28 Dimensional check on collecting suspension frames - 750 mm wide CE plate

Fig.29 Collecting electrode – supporting angles slots location with reference to rapping Mechanism- 400 mm wide CE plate

Fig.30 a. Typical assembly of collecting electrode suspension arrangement showing the gas Path center line – for odd number of collecting electrode supporting angles – 750 mm wide collecting.

Fig.31 Typical assembly of collecting electrode suspension arrangement showing the gas path centre line- for even number of collecting electrode supporting angles – 400 mm wide collecting.

Fig.31 a Typical assembly by collecting electrode suspension arrangement showing the gas path centre line – for even number of collecting electrode supporting angles – 750 mm wide collecting.

Fig.32 Typical arrangement of collecting suspension (typical for seven field esp) – 400 mm wide CE plate.

Fig.33 Typical arrgt. of collecting electrode suspension (typical for seven field sp) -750 mm wide CE plate

Fig.34 Arrangement of supporting angles with reference to emitting system suspension points – 400mm wide CE plate.

Fig.35 Arrangement of supporting angles with reference to emitting system suspension points – 750 mm wide CE plate.

Fig.36 Arrangement of insulator supporting panels (typical for three field arrangement)

Fig.37 Dimensional check on frame of emitting system (top) – 400 mm wide CE plate

Fig.38 Dimensional check on frame of emitting system (top) – 750 mm wide CE plate

Fig.39 Typical assembly of frame part top with collecting electrode suspension showing the gas path centre line for odd number of collecting electrode supporting angle.

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Fig.40 Assembly of frame part top with collecting electrode suspension showing gas path centre line- for even number of collecting electrode supporting angles.

Fig.41 Emitting system suspension.

Fig.42 Locking arrangement of emitting system suspension assembly.

Fig.43 Typical method of arresting emitting system frame part top.

Fig.44 Dimensional check on frame of emitting system (middle) – 750 mm wide CE plate.

Fig.45 Dimensional check on frame of emitting system (bottom) – 750 mm wide CE plate.

Fig.46 Dimensional check on frame of emitting system (bottom) – 750 mm wide CE plate.

Fig.47 Frame of emitting system – top and bottom measuring the diagonals.

Fig.48 Gas distributor assembly.

Fig.49 Locking arrangement of screen sheets.

Fig.50 Checking the straightness of collecting electrode with the fixture – 400 mm wide CE plate

Fig.51 Form tool – 400 wide CE plate

Fig.51A Form tool – 750 mm wide CE plate

Fig.52 Cut away of collecting electrode row – 400 mm. wide CE plate.

Fig.53 Complete row of collecting electrode with shock bar – 400 mm wide CE plate.

Fig.54 Method of stretching the emitting electrodes – top and bottom tiers of emitting system.

Fig.55 Checking the straightness of collecting electrode with the fixture – 750 mm wide CE plate.

Fig.56 Cut away of collecting electrode row- 750 mm.wide CE plate.

Fig.57 Electrostatic precipitator‟s Huck bolt driving cycle.

Fig.58 Method of erection of shock bars with CE plates – 750 mm wide CE plates.

Fig.59 Method of lifting the CE plates.

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Fig.60 Emitting and collecting electrode assembly.

Fig.61 Method of measuring the retention force of the emitting electrode.

Fig.62 Tolerances – EP internals – 400 mm wide CE plate.

Fig.63 Go-gauge for checking electrode alignment 400 mm wide CE plate.

Fig.64 Tolerance – EP intervals – 750 mm wide CE plate.

Fig.65 Go-gauge for checking electrode alignment – 750 mm wide CE plate.

Fig.66 Typical mounting of inner arm for collecting electrode rapping mechanism (anti – clockwise mounting)

Fig.67 Typical mounting of inner arm for collecting electrode rapping mechanism (anti-clockwise mounting)

Fig.68 Typical mounting of inner arm for emitting electrode rapping mechanism (clockwise mounting)

Fig.69 Typical mounting for inner arm for emitting electrode rapping mechanism (anti –clockwise mounting)

Fig.70 Emitting system rapping mechanism with vertical drive.

Fig.71 Collecting electrode drive arrangement showing provision for thermal expansion.

Fig.72 Emitting system drive arrangement with screw and shaft insulator – side drive.

Fig.73 SKF bearing assembly – side drive

Fig.74 Emitting system drive arrangement with shaft insulator vertical drive.

Fig.75 SKF bearing assembly – vertical plate

Fig.76 Arrangement of hopper deflection plate.

Fig.77 Deflection plate mounting – on side wall of ESP.

Fig.78 Deflection plate mounting – on middle wall OF ESP

Fig.80 Welding detail of inspection door on casing and hopper

Fig.81 Typical fixing detail of thermostats for hopper

Fig.82 Typical fixing detail of heating elements for hopper

Fig.83 Erection network.

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PRECAUTIONS

Extra care you take during erection will ensure trouble free operation.

Proper sequence of erection is the only way for fast erection

Ensure the proper storage handling stocking, preservation of components and electrodes at site.

Refer to engineering department fro any doubts / deviations in the drawing.

Ensure all erection welding is done by certified / qualified welder only.

Check all components for defects, damaged and dimensional deviations and log them before erection.

Tonnage and quality erection should go hand in hand.

Inspect all weld joints for defects and rectify them to avoid leakage of air and seepage of water.

Over looking of minor details will lead to major rework.

Never erect a damaged component and compromise on quality.

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IMPORTANT INSTRUCTIONS ELECTROSTATIC PRECIPITATORS – Dos

01 Ensure the correct dimensions of the components with the help of drawing before erecting them.

02 Ensure the proper orientation of the slide supports with reference to the fixed support to allow for expansion in the correct direction.

03 Inspect all the collecting electrode suspension frames, emitting frame part top, emitting frame part middle and emitting frame part bottom for important dimensions and dimensional deviations before lifting them to the position.

04 Straighten all the collecting electrodes before with the help of the straightening fixtures and also correct the profile of the electrode with the help of form tool.

05 Row of collecting electrodes and emitting electrodes should be erected alternately one after another.

06 Use stretching tools fro erecting the emitting electrodes.

07 Ensure that the collecting electrodes are suspended such that the shock bars tend to lean towards the rapping mechanisms, in the case of 400 mm collecting plates only.

08 Check for the correct rotation of rapping mechanism.

09 Ensure that the hamper of rapping mechanism hit at the centre of shock bar / shock beam.

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IMPORTANT INSTRUCTIONS ELECTROSTATIC PRECIPITATIONS – Don’ts

01 Do not erect defective / damage components.

02 Do not use ESP components as temporary supports for erection.

03 Do not interchange the direction / position of components, (e.g.: left to right, right to left)

04 Do not store / stock the components in wrong position (e.g. upside down)

05 Do not erect the slide supports in wrong direction.

06 Do not fail to mark the centre line of gas path in roof beams before erecting the Colleting suspension and emitting electrode frames.

07 Do not erect collecting electrodes without checking the straightness with the help of a fixture.

08 Do not erect emitting electrodes without using stretching tool.

09 Do not erect broken / cracked insulators.

10 Do not forget to remove the temporary supports before commissioning.

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1.0 WORKING PRICIPLE OF ELECTROSTATIC PRECIPITATOR

The Electrostatic precipitator essentially consist of two sets of electrodes called Colleting Electrodes „and‟ Emitting Electrodes‟ and (also called discharge electrodes). The collecting electrodes is made up of steel sheet pressed to a special profile and the emitting electrode is a thin wire draw in the to a helical form. A unidirectional high voltage is applied between these electrodes, connecting its negative polarity to the emitting electrodes and the positive polarity to collecting electrodes, which are also earthed. The dust laden flue gas from boiler passes between rows of collecting and discharge electrodes. The high voltage induces ionization of gas molecules adjacent to the negatively charges emitting electrodes. The positive charges of the ions created travel towards the discharge electrodes and the negative charges towards the collecting electrodes. On their way to the collecting electrodes, the negative charges get deposited on the dust particles. Thus the dust particles are electrically charges. In the presence of high electric field between the electrodes the charged dust particles experience a force which causes the particles to move towards the collecting and finally get deposited on them. Minor portions of the dust particle, which have acquired positive charges, get deposited on the emitting electrodes also. Periodically these are dislodged from the electrodes by a process called „rapping‟. The particles then fall into the hoppers at the bottom.

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2.0 CONSTRUCTIONAL FEATURES OF ELECTROSTATIC PRECIPITATOR

GENERAL

The Electrostatic Precipitator may be divided into two major groups, viz., electrical parts and mechanical parts. The various parts of precipitator are illustrated in the EP General Arrangement drawing fro a typical precipitator. The Assembly of precipitator is divided into sub- groups, which are numbered in the drawing. The electrical parts comprise of high voltage rectifier, main and auxiliary controls, switches, heaters and inter-locks. The mechanical parts constitute the EP proper, which consist of the casing and functional parts forming internals of the precipitator.

2.2 CASING (Figure - 1)

This is made up of wall panels, hoppers, roof panels and supporting members. The casing rests on sliding supports, which are fixed, to the supporting structures. These supports allow for thermal expansion of the casing. The roof beams supports the weights of internals and rectifiers, disconnecting switches, insulator housing etc., mounted on it. These weights are transferred through the columns of wall panels to the supporting structures.

The Hoppers (Figure- 2) are delivered to the site in pre fabricated panels of suitable size. The bottom portions of hoppers are equipped with electrical heating elements to facilitate free flow dust into the ash disposal system.

In order to prevent untreated gas form sneaking below the colleting electrode each hopper is provided with sets of deflection plates suspended in the hoppers.

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2.3 INTERNAL

For optimum performance of the precipitator, it is essential that flues gas entering the precipitator is evenly distributed over its entire cross –sectional area.

For this purpose, two sets of gas distribution plate with perforations are located at the inlet of the casing. One set of gas distribution baffles is proved at the outlet of ESP.

Final adjustment of the gas distribution prior to commissioning of the precipitator will be carried out by installation of deflection plates or throttling perforations with screen sheets by AQCS/EDC. The screen is provided in the outlet funnel of ESP to ensure proper distribution of the flue has in the last field.

2.3 ii Emitting Electrode System

The most essential part of the precipitator is the discharge (emitting) electrodes system (Figure 5& 6). The discharge electrode system consists of a rigid box like frame, which is suspended from four insulators from roof of the precipitator. The insulator are housed in double walled insulator housings. In order to keep the insulators the dew point of the gas, each insulator compartment is equipped with electrical heating element of rating approximately 1 KW. The operation of the heating elements is controlled by Thermostat.

The emitting electrodes (Figure – 7) are hard drawn/ annealed spiral stainless steel wires of diameter 2.7. These are delivered at site in the form of coils, having hooks at the ends. At site these coils are stretched out between top and bottom holders in each tier of the discharge electrode framework by stretching tool.

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2.3 iii Collecting Electrode System

The collecting plates are made if steel sheets and shaped in special profile by roll forming. These profile of the collecting plate lend mechanical rigidity to it and also limit re-entrainment of collected dust during rapping. The collecting plates of 400-mm width are provided with hooks at the top edges with which they are hung. (Refer Figure 8 & 9). In the case of 750 mm wide collecting plates, slots are provided at the top edges.

The collecting electrodes of 750-mm width are hung from the hooks of collecting suspension frames, which are supported, from the roof beams.

2.3 iv Rapper for discharge Electrodes

During electrostatic precipitation, a fraction of the dust will be collected on the discharge electrodes. This suppresses the corona, which is the source of ionization. It is therefore necessary to rap clean the discharge electrodes occasionally. This is done with a rapping system employing tumbling hampers, which re mounted on a horizontal shaft in a staged fashion. These hampers hit the specially designed shock beams to which the intermediate part of discharge frame is attached. In this manner the vibrations generated by the hammers are transmitted to the discharge electrodes.

For two level emitting system; Two levels of rapping mechanism are connected to a geared motor mounted on the roof panel through the shaft insulator and pin wheel arrangement. (Figure – 5)

Each collecting plate of 400- mm width is hung on eccentric hook to ensure that the shock receiving plate of the collecting electrode is constantly resting against its shock bar. In this manner, the highest possible energy is transferred to the collecting plate when the tumbling hammer hits the corresponding shock bar. The tumbling hammer are mounted on a horizontal shaft in staggered fashion, with one hammer for each shock bar. As the shaft rotates slowly, each of the hamper in turn over balances and tumbles, hitting its associated shock bar. The shock bar transmits the blow simultaneously to all of the collecting plates in one row because of their direct contact with the shock bar. The shaft is connected to generated motor mounted on the side of the casing.

The frequency of rapping is adjusted by controlling the operation of the geared motor by means of programmer, mounted in the auxiliary control panel.

2.3 v. Electrics (Figure 10, 11, 12)

The precipitator is powered by high voltage transformed rectifier mounted on the roof. The negative polarity of the rectifier transformer is

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connected to the emitting system through high voltage switch and bare conductor. The electronic controlled regulating the power output of the rectifier is located inside the control room. An auxiliary control panel containing programmer, relays, switched, etc., necessary for regulation of the operation of rapping motors and heaters is also supplied and located inside the control room.

2.3. vi. Interlocks

Electrostatic precipitator is a high-voltage equipment. Safety of the operating personnel and protection of the equipment are ensured by an interlocking system. These interlocks are provide on inspection doors of the casing hoppers and insulator housings.

The interlocking system is designed such that access inside the precipitator can be gained only after switching off the power supply to the precipitator and grounding the relevant fields.

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3.0 SALIENT FEATURES OF ELECTROSTATIC PRECIPITATORS

For treating of flue gases emanating from each boiler one/ two /four precipitator are supplied. Each precipitator is designed to have a series of independent electrical fields (or systems) in the direction of gas flow, The functional parts (internals) and electrical accessories are being supplied for all of the fields in the precipitators connected to boiler. In each field, there are number of gas ducts. A gas duct is formed by two consecutive rows of collecting electrodes with a row of emitting electrodes midway between the. There will be as many number of row of emitting electrodes as the gas duct. Each field has got its own power source and main control. However, a common auxiliary control panel regulated the operation of all rapping motors and thermostatically controlled electric heating elements in all the field in one gas pass. Thus there will be as many number of passes connected to each boiler. This and maintenance purpose.

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STORAGE INSTRUCTIOSNS FOR ELECTROSTATIC PRECIPITATOR COMPONENTS

Stack all components well above the ground level to protect against water, dust and soiling Minimum height above the ground level shall be 300 mm.

Never stack a component upside down.

Protect the machined components (machined portions) like suspension tube, link rods, diagonal stays, shafts, against rusting and damage during storage. Ensure that the threads portions are covered properly to avoid damage.

Roof beams, supporting columns and hopper ridges are to be stored in a horizontal plane by providing supports at sufficient intervals to avoid any bending and twisting.

Wall and roof panels are to be stored on a horizontal plane one over the other. While stacking sliding of one panel over the other should be prevented by providing suitable supports.

All suspension frames of collecting electrode, frame of emitting system (top, bottom, and middle) shock bars beams, attachment ions etc., received in the packed condition shall be stored in a horizontal plane. Not more than 3 packages are to be stacked one over the other. Damaged packing are to rectified before stacking.

High voltage transformer rectifiers, control cubicles. Auxiliary control panels, LT boards, Interlocks, High voltage insulators, disconnecting switches heating elements, thermostats slide supports, carbon bushes, drive motors are to be kept in a closed storage to avoid rusting due to moisture and to protect against pilferage.

Collecting electrodes, screen, insulator hosing vertical beams, rapping shafts, inner arms, outer arms are to be kept in a semi closed storage to protect against rust and damage.

Shock beams, vertical stays, stair beams, supporting beams, attachment irons, vertical beams are to be stacked in a horizontal plane with supports at proper interval.

Ensure that fall the components of the High voltage rectifier panels and Auxiliary Control Panels are perfectly closed to prevent damages to cables by rodents and termites.

Keep the insulators over soft material to avoid any damage, Do not stack any other material over the insulator and keep the insulator sufficiently away from other materials so as to avoid the damage / cracks due to failing of metallic parts.

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The high voltage transformer rectifiers are to be stored in a fire proof enclosure and should be well guarded from fire hazards.

On receipt of the electrical components / equipment verify carefully damages/ pilferage. List of damages/ pilferage shall be sent to BHEL Ranipet. Necessary action for replacement/ repair/ insurance claim shall be initiated within a month. After inspection, ensure a safe storage.

Emitting electrode boxes shall be kept in a closed storage and shall be opened only when erection is taken up.

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5.0 HANDLING INSTRUCTIONS FOR ELECTROSTATIC PRECIPITATOR COMPONENTS

Components Requiring Closed Storage

Components Requiring Semi- Closed Storage

Slide Supports

Support Insulators Collecting Electrodes

SKF bearings Suspension tubes

Emitting Electrodes

Asbestos packing rope Inner arms

All fasteners Outer arms

Rapping motors Shafts

Shaft insulators Plain bearings

Carbon bushes Sleeves

Disconnecting switches Link rods

Bushing insulators Couplings

High voltage transformer rectifiers

Clutches

Electronic controllers

Auxiliary Control Panels Diagonal stays

Interlocks Pin wheel

Heating elements Reducer

Thermostats Adopters

Earthling rods Insulator housing

Pulley block

Mineral wool

i. Do not use door handles and bolt holes for lifting the components.

(for example: Insulator housing, disconnecting switches, inspection doors etc.)

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ii. Use stiffening beams for lifting slender members like roof panels, wall panels and roof beams etc., to avoid distortion.

iii. Do not use metal ropes for lifting collecting electrodes use only manila ropes and lifting beams to avoid damage to the electrodes.

iv. If top methods is adopted. Lift collecting electrodes to the top of electrostatic precipitator in full packs by lifting beam (figure – 13)

Open the packs at the top and the collecting electrode may be taken up one by one.

v. Handle emitting electrodes such that the surface does not get any scratch or pitting.

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6.0 ERECTION PROCEDURE FOR ELECTROSTATIC PRECIPITATORS

6.1 Introduction

For proper and efficient performance of the electrostatic precipitator, it is essential that the voltage distance between the collecting electrodes and emitting electrodes is maintained. Unless the erection is carried out in a sequential order and corrections are done stage by stage, the inter- electrode gap cannot be maintained within the given tolerance.

Layout

Refer – ESP Foundation plan

General arrangement drawings

Figure 14

Log sheet nos. 1 and 2

I) Check the foundation of electrostatic precipitator columns.

II) Mark the central lien for the precipitators.

III) Check, verify and log the measurements between the central lien of the precipitators (the middle pedestals) to central line of the side column pedestal. Ensure that this is within the tolerance of plus or minus 10 mm.

IV) Measure and verify the distance between the central of last row of boiler column pedestal and the fixed support of electrostatic precipitator column pedestals. Ensure this is within the tolerance of plus or minus 10 mm.

V) Fixed supports row of electrostatic precipitator column pedestal as reference, measure and log the distance between the centers the subsequent column pedestals on both axes. Ensure that this is within the tolerance of * plus or minus 10 mm.

6.3 Supporting structures (7 x – x 81)

Refer: Drawing – Supporting structures for electrostatic precipitators

Figure 15, 16 & 18

Log sheet No.3

a) Ensure that straightness of the electrostatic precipitator columns,

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b) Erect the columns on the appropriate pedestals check the vertically by pluming. Vertically shall be within 1 mm per meter height to a max of 10 mm.

c) Provide, wherever necessary, suitable shims at the bottom of the base plate and ensure that top of columns are in same level.

d) Maximum level difference permitted is plus or minus 5 mm.

e) Provide adequate shoring.

f) Check all the site welds for their completeness.

g) Remove the shoring after the whole structure it erected.

6.4 Slide supports drawing.

Figure 18

- Log sheet 4

Clean the spherical bearing surface of the supports and apply zinc Epoxy primer before placing then on the columns.

Place the slide supports on the centre of column top plate. Locate the guide bearing as per drawing maintain the orientation of the support top plate on such a way that the guides are parallel to the line joining fixed support of the ESP and the particular column.

Keep the top plate horizontal with the help of sprit level. Lock the top plates temporarily with column top using angle on the corners. Do not remove the lug angles provided.

Log all the measurements.

6.5 Casing, Structures, Casing Shell and Ridges

(7X-X48) (7X-X49) (7X-X43)

Refer: Casing Assembly drawing of electrostatic Precipitator

I) Refer figure, pre-assembly on the ground, the corner columns and the adjacent columns with bottom wall and top wall (gables) with bracing of inlet / outlet frame assembly.

II) Check the dimensional as per drawing. The diagonal difference shall be within 10 mm.

III) Complete the welding as per drawing and mark the break line on the columns.

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IV) Fix two rods mutually perpendicular on the corner column and one rod on adjacent column for the purpose of plumbing. Tie a plumb on each rod 100 mm way from the surface of the column.

V) Lift and place the whole frame assembly by lifting beam (site T & P).

VI) Check the vertically on both axes of the columns within 1 mm as per meter height Limited to 10 mm on the total height and lock the frames by guy ropes.

VII) Weld the column base to the top plates of supports as shown in the drawing.

VIII) Erect the erection of other corner frames.

IX) Erect the columns in the middle row. Lock the columns by guy ropes. Weld the column base to the top plates of supports.

X) Erect longitudinal ridge one by one on the middle row of column.

XI) Check the dimension and level the ridges. Complete the welding.

XII) Pre-assemble the longitudinal rood beam (LRB) on the ground for checking the straightness, sweep, camber as per log sheet and other assembly to suit the site condition. Place the LRB on the middle row.

XIII) It is preferable to pre-assemble the LRB keeping the bottom flange upward. The deviation in the LRB section shall be adjusted on the top flange. The bottom flange shall be maintained level and aligned.

XIV) Align and level the bottom flange of the longitudinal roof beam. Complete the welding.

XV) Erect the remaining columns in the same way as discussed earlier.

XVI) Erect horizontal; and diagonal bracing‟s between the columns and weld suitably.

XVII) Erect longitudinal roof beam on other rows of internal columns.

XVIII) Erect all transverse ridges and rest of the longitudinal ridges between the columns.

Check and log the levels and dimensions. The diagonal difference of hopper openings shall be within 7 mm.

XIX) Erect and weld the bottom and top walls of inlet / outlet frames and complete the welding.

XX) Erect side wall panels. Brackets are provided to have a proper platform for welding.

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XXI) Check for straightness, sweep camber of transverse roof beams and correct as per log sheet.

Note: Plug all the small gaps in the sidewalls, top and bottom wall of casing by welding.

XXII) Lift the transverse roof beam 10 position. Adjust to ensure the level of bottom surface of the transverse roof beam with that of the longitudinal roof beam – The level difference shall be within 5 mm. Ensure that all transverse roof beam of a row are in line.

XXIII) Check other dimensions and complete the welding.

XXIV) Erect Gas Distributor Housing as per the drawing. Complete the weld. Ensure the correct opening and the diagonal difference shall not exceed 10 mm.

6.6 Hopper Assembly (7X-X44, 7X-X45) Refer assembly drawing.

Hopper lower and upper part

I) Pre-assembly the hopper on the found. Match the top dimensions of particular hopper with the corresponding hopper opening dimensions. Complete the welding of the hopper. Fix and the weld the inspection doors of the hoppers.

II) Life the hopper assembly with the position it keeping the orientation of the hopper door as per the General Arrangement drawing (Hopper approach drawing – if in scope).

III) Support the hopper assembly with the ridges.

IV) Level the hopper bottom flange by spirit level and weld ensuring the hopper bottom elevation as per the GA drawing.

V) Seal and weld the hopper assembly with the ridges.

6.7 Galleries and stairways (89-610)

Refer: Galleries and railings drawing of electrostatic precipitator.

Erect the brackets, stairways, platforms with railings of galleries, leaving proper provision for thermal expansion as shown in the drawing.

6.8 Gas Path Centre Line (GPCL)

Refer: Roof panels assembly drawing.

Insulator supporting panels drawing

Figure 26

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Log sheet No.8

I. Gas path Centre Line (GPCL) is a line which passes through the centre of the effective width of each pass. All internals are mounted only with reference to these lines.

II. Mark the GPCL of the pass on the top flange of the first and last transverse roof beams or the ends of longitudinal roof beam as the case may be.

III. Stretch twine between the markings and transfer the GPCL on all the other roof beam top flanges. Do not mark the GPCL on each roof beam by taking separate measurements.

IV. Punch all the GPCL markings on roof beams for reference.

V. Transfer the GPCL from the flange to the bottom flange of the roof beam.

6.9 Collecting Electrode Suspension

Refer: Collecting electrode suspension arrangement drawing

Figure: 27, 28, 29, 30, 30A, 32, 33, 34 & 35

Log sheet Nos. 9a, 9b, & 10

I) The collecting electrode suspension is one of the vital components that decide the effective voltage distance. Any deviation either in dimension of the frames or in the or in the disposition of frames with reference to the GPCL would affect the performance of the electrostatic precipitator seriously.

II) All collecting electrode suspension frames, need not be identical. They may be of two or three styles depending upon the width of electrostatic precipitator with varying numbers of supporting angles, say, six, seven or eight in each.

III) Carry out the following quality checks before lifting the frames.

a) Maesure the diagonal between the corner slots / hooks of the individual frames.

The difference shall not exceed 7 mm.

b) Maesure the cumulative pitches between the angles starting from one end tolerance is + 3mm.

c) Rectify minor discrepancies like bends in the supporting angles.

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IV) Note that the edge of supporting angle, which, is, stiffened with additional angle, always point towards the collecting rapping mechanism.

V) Note that the GPCL shall pass through the middle collecting electrode row is the total number of collecting electrode rows per pass is odd. If it is even the GPCL will pass between the central pair of collecting electrode rows as shown in figure 30 & 31.

VI) The frames are bolted to the cleat angles (attachments) and supported on the bottom flange of roof beams.

VII) Take a supporting angle near the GPCL as reference. Maintain cumulative pitches of the supporting angles on either side within ± 3 mm. ascertain the cumulative pitches by taking measurements at two locations one at entry and the other at exit of each field.

VIII) Ensure that all the first slots on the rapping mechanism side of the frames are I one line by stretching twine. Adjust the frames in the direction of gas flow, if necessary, to maintain the slot/ hook alignment within a tolerance of ± 3 mm.

IX) Mount the stiffening beam, which is running across the middle of the frames leaving 3-mm gap from the side wall. Weld the other end of the beam with the other sidewall.

X) Weld all the supporting angle of individual frames with the stiffening beam.

XI) Erect supports and the cross beams.

XII) Weld the clean angles with individual frames on both sides of the roof beam. Do not weld the clean angles with the roof beams.

XIII) Weld the lock plates (5mm thick square plates) on four corners of each frame leaving 2 mm gap on the inner side of the field.

XIV) Note that entire collecting suspension arrangement is resting on the bottom flanges of the transverse roof beam and not welded to them.

6.10 Insulator supporting panels (7X – X 46)

Refer: Insulator supporting panels drawing.

Figures 34, 35 & 36

Log sheet No.11

I) The insulator supporting panels are supplied as separate Dus for easy identification and alignment and alignment.

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II) The exact position of the insulator supporting panels with respect to the GPCL and collecting electrode suspension frames is essential as this only would determine the inter electrode spacing.

III) Note the centre line punching on both x and y axes with reference to 400 mm diameter hole.

IV) Align the supporting panel taking the distance from GPCL fix the panel temporarily by angles on the sides.

V) Check the dimension 310- mm (distance between the centre lien of 400 mm hole) by plumbing as shown in Figure 34 for 400 mm wide plate. Tolerance is ± 5 mm.

VI) Measure the diagonals between the centres of the suspension holes of each field (four corner holes). The difference shall not exceed 3 mm. Refer Figure 36.

VII) Weld the insulator supporting panels fully with roof beams.

VIII) The roof panels over the roof beams shall not be erected at this stage. Instead, use the wooden planks for walkways.

IX) Weld the stiffener frame to the panels, beams, & roof beam.

6.11 Emitting system Frame work Top (7X-X21)

Refer: Frame of emitting system drawing.

Figures 37, 38, 39, 40

Log sheet No.12

I) Carry out the following quality checks.

a) Check the alignment of emitting electrode holders.

Check for the cumulative pitch of the emitting electrode holder across the frames.

Tolerance is + 3 mm.

b) Measure the diagonals between the corner holder of the frame.

The difference shall not exceed 7 mm.

ii) Place the two supporting beams of one bus section of emitting framework on the ridges/ temporary supports maintaining the correct distance between them.

iii) Check for the marking of CL of bus section on the supporting beams if not already marked, mark the CL of bus section.

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iv) Measure the diagonals of the suspension centres. The difference shall not exceed 5 mm.

v) Position the central frame part top on the supporting beams. If the number of rectangular hollow section is even for the bus section (BS), the centre line of bus section (CLBS) will fall in between the middle pair of rectangular hollows. If odd, the CLBS will bisect the middle hollow section.

vi) Bolt the frame to supporting beams.

vii) Place the other frames on either side of the central frame on the supporting beams taking cumulative distances with reference to CLBS. Fix them by locating bolts.

viii) Measure the diagonals of the corner holders of the assembled frame part top. The difference shall not exceed 7mm.

ix) Stitch weld the frames with the supporting beams.

x) Introduce the lifting tools through the “inlet” of the insulator – supporting panel on the four corners.

xi) Lift the frame part top assembly and suspend it form the lifting tools.

xii) Maintain a vertical clearance of 175 mm between the top surface of the hollow section (frame part top) and top surface of the collecting electrode supporting angles.

xiii) Complete the lifting positioning of frame part top of all the other bus sections.

6.12 Emitting system suspension (7X – X 13)

Refer: Emitting system suspension assembly drawings – Figures 41, 42 & 43

Note: Ensure the welding of stiffeners frame released under PGMA 7X –x 46 Under PGMA 7x – X46 under the insulated supporting panels.

i. Place the support flange concentrically to the opening on the insulators support panels and weld.

ii. Use adequate asbestos rope packing as shown in figure 41 on the supporting flange and place the support insulator.

iii. Use adequate asbestos rope packing on the support insulator and mount the supporting bracket over the insulator. Use shellac for fixing the asbestos rope.

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iv. Introduce the suspension rod from inside and hold it by bolting on the top. Introduce the bottom of the suspension rod in between the lugs welded on the supporting beams.

v. Tack weld the lug plates on both sides of the suspension rod gusset plates, before tightening the suspension rod nut as shown in figure 42. This is to arrest the rotation of the suspension rod while tightening.

vi. Tighten the suspension nut just sufficient to transfer the load from lifting tool to suspension rod. Measure the vertical clearance between the top surface of the collecting electrode supporting angle and the emitting frame part top. When this gets reduced by 1 mm from 175 mm stop tightening.

vii. Arrest the movement of the frame part top assembly at four corners as shown in figure 43 while arresting do not upset the free suspension.

viii. Arrest the movement of the frame part top assembly at four corers as shown in figure 43 while arresting do not upset the free suspension.

ix. In case the support insulator is not available at site, proceed with further erection of internals with lifting tool in position.

6.3 Emitting System Frame Middle and Bottom (7x-X22, 7x – X32)

Refer: Frame of emitting system assembly drawing.

Figure 44, 45, 46 & 47

Log sheet No.12, 13 & 14

i) Straighten the vertical beams.

ii) Suspend the vertical beams from the supporting beam. Use only one bolt at top for fastening.

iii) Insert the end middle frame through the end vertical beams and support them temporarily on the casing structures.

iv) Bolt the frame part bottom with vertical beams. All bolting shall be hand tight only. Full tightening of bolts will result in misalignment.

v) Suspend four heavy plumbs from the corner holders of the emitting frame to the emitting frame bottom. Ensure that the top and corner holders are in one vertical line in free position. Arrest the bottom frame. Check the cube diagonals as shown in Figure 47. The difference shall not exceed 10 mm.

vi) Check the diagonals of the bottom frame. Check the cube diagonals as shown in figure 47. The difference shall not exceed 10 mm.

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vii) Check the vertical alignment of electrode holders on frame parts middle with those on the top and bottom frame plumping at-least on four corners of each frame.

ix) Introduce vertical stays. First weld the vertical stays extreme end. Stretch at twine between these stays and place the other stays in alignment with the twine and tack weld them in position.

x) Complete the welding on emitting system frame work. Do attempt to close the minor gaps between the matching faces by tightening the bolts. Introduce shims packing necessary between these faces and complete the welding.

6.14 GAS DISTRIBUTOR ASSEMBLY (7X – X08)

Refer: Gas distributor Assembly drawing.

Figure 48& 49

i. Hook the screen sheets of the primary screen in slots provided on the supporting plate of G.D. Housing.

ii. Mount the bracing – leaving gap for thermal expansion as shown in the drawing.

iii. Erect the secondary screen sheets.

iv. Check the vertically of the screen sheets with plumb. Lock the screen with locking arrangements at the to as shown in the figure 49 and arrest the secondary screen at the middle as shown in figure 48.

v. Ensure that a minimum gap of 100 mm between the bottom edge of screen sheets and front wall surface as shown in figure48.

vi. Erect the GD screen at the outlet end of ESP.

6.15 Emitting Electrodes, Collecting Electrodes and Shock Bars

(7X-X15, 7X-X20, 7X-X24) (For 400 mm collecting plate)

Refer: Shock bars drawing

Figure 50, 51, 52, 53, 54

Log sheet No.15 (a) (15 (b)

i. Erect collecting electrodes. Starting from the middle of the filed and proceed towards both ends.

ii. Set up the collecting electrodes inside the straightening fixture as shown in figure 50 & 51.

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iii. Place each collecting electrodes inside the straightening fixture. Check for straightness of electrode. Straightening if required by hammering with wooden mallet. Straightening of the collecting electrodes is a vital part of erection work. Damages observed (in any) on the G profile, rectify the same using rounded chisel and form tool (figure 51 or 51 A as the case may be)

iv. Install the collecting electrodes. A crew of eight to the persons will be adequate for the purpose. One person will be available at each frame part middle and one at frame part bottom; three persons are required or inserting very electrode on to the suspension at the top.

v. For safety purpose a rope will be tied at check iron end of the electrodes before it is guided in to the field.

vi. Straighten the shock bars.

vii. Mount the shock bars after installing each row collecting electrodes. Every shock bar is held in position by bolts in the shock irons of two collecting electrodes on at either end.

viii. Insert the sleeve over the bolt on either side of the shock iron with a gap of 1 mm TACK WELD THE BOLT AND UNIT.

ix. Ensure that the intermediate transverse guide of collecting electrodes shall engage in the slot of adjacent collecting electrode.

x. Check the complete row of electrode visually alignment. „G‟ profiles of adjacent electrodes shall be properly aligned. Correct minor misalignment / bends of any at this stage itself by flame heating / wooden mallet.

xi. After erecting the collecting take up to erection of emitting electrodes. Three persons are required to install the emitting electrodes,

CAUTION: The emitting electrode shall not be stretched nay longer then just required to hook up the bottom.

Do not guide or hold the emitting electrodes with hand Otherwise it will result in uneven stretching, over stretched electrodes shall be discarded.

Stretching shall be done under close supervision

A) TOP TIER ERECTION

The first person will sir on the frame pat top, the second on the frame pert middle and third at the frame part bottom.

The person on the top will hand all emitting electrodes on the holders. Then he will fix the emitting electrode bottom hook with a stretching tool attached to a manila rope at the bottom.

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The third man at the frame part bottom will FRADUALLY pull the rope down wards, thus allowing a free spin of the stretching tool.

The stretching tool is pulled just up to the holder level, on the frame part middle.

The second person on the middle frame will insert the bottom hook of the emitting electrode into the holder and release the stretching tool.

The first man draws up the stretching tool and repeats the process for the other electrodes.

B) MIDDLE AND BOTTOM TIER ERECTION

The emitting electrodes are hung from the holders on the frame part middle/ bottom. The first man sits on the frame part middle, the second on the frame part middle / bottom and the third on the scaffoldings inside the hopper or on the ground. The man standing inside the hopper does the stretching.

The emitting system framework load must now be transferred to the suspension rod from the lifting tools, of not already done, as explained in section 6.12.00

Measure and log the spring back of emitting electrode randomly in all the field.

6.15 (b) Emitting Electrodes, Collecting Electrodes and Shock Bars

(7X-X15, 7X-X20, 7X-X24) (For 750 mm collecting plate)

Refer: Collecting Electrode Suspension

Arrangement

Shock bars.

Figure: 51A, 55, 56, 57, 58 & …

Log sheet No.15 (b)

i. Follow the instructions as explained in (6.15 a) (i) (ii)

ii. Install the collecting electrodes on the rows nearer walls after straightening, rough dressing as explained the above clauses. A crew of tem persons will be adequate for positioning the collecting electrodes. Lifting plates will be done as explained in the (figure 59.)

iii. Mark up distance 320 mm and 955 mm on EP walls, from the centre lines of the last and first colleting plates respectively.

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iv. Install shock bar guides and arrange shock bars on plates.

v. Fix the guise plates with temporary supports.

vi. Locate shock pas beneath both end rows of CE plate, 955 mm from the centre lien of collecting plate. Use lien dory for the purpose.

vii. Install shock pas on all rows of collecting plates with temporary supports and tack weld the shock bar reverse and against angle iron support.

viii. Complete the erection of colleting plates on the inner rows.

ix. Align shock bars with collecting plates use hydraulic jack.

x. Fasten the shock bars with collecting plates using huck bolts by huck hydraulic unit. Use the tools provided for the purpose.

xi. Adjust the shaft to achieve the required height.

xii. Remove the temporary supports on shock bar guide.

xiii. Follow the instructions as explained in 6.15 a (ix) to (xi)

6.16 OLLECTING ELECTRODE RAPPING MECHANIS (7 X – X 25)

Refer: Rapping mechanism drawing for collecting electrodes.

i. Pull shock bars of the outermost collecting electrodes in a filed towards the non- rapping side until the collecting electrodes become vertical and hold them temporarily. Check the vertically with plumb.

ii. Stretch a piano wire joining the top edges of the end shock bars of these collecting electrode rows.

iii. Locate the rapping mechanism rackets, taking measurements from the end rows, with expansion provision.

iv. Position the brackets carrying the plain bearing centrally between two shock bars so that they do not arrest top of the movement of the tumbling hammers. The election of the brackets shall be maintained from centre line of shock bat at tolerance.

v. Ensure that height of the shaft centre from the centre line of the shock pas is 310 mm. Tolerance ± 5 mm.

vi. Shaft centre line and the face of the shock pas shall be in one vertical plane.

vii. Erect the ladder (walkway)

viii. Insert the shock bar guides on the non-rapping side through the U clamps of the shock bars and weld then with sleeves.

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ix. Attach link rods to shock bar guides.

x. Pull all the shock bars towards the non rapping side using the link rods till all the collecting electrodes are vertical. The piano wire will serve as a reference line to decide the position of all shock bars.

xi. Erect shock bar guides and link rods on the rapping side.

xii. Weld the arrestors at both ends of the shock bar guides. Do not weld the shock bar guides to the wall panels.

xiii. Complete the welding of link rods, fasteners on both sides.

6.17 DIAGONAL STAYS (7X-X32)

Refer: Frame drawing of emitting system.

Install the diagonal stays. Locate the sleeves in such a way that the nut remains in the middle of the threaded portion. Weld the sleeves on the vertical beams.

6.18 ALIGNMENET OF COLLECTING AND EMITTING SYSTEMS

Refer: Figures 60, 61, 62, 63, 64 & 65.

Log sheet No. 15 (a) (15b) & 16

i. Proper voltage distance between collecting electrodes and emitting electrodes in essential for efficient performance of the electrostatic precipitator. The alignment of collecting an emitting system and the proper clearance between them can be attained only if the correct erection sequence and procedures as laid down here are strictly adhered to.

ii. Remove all the arrestors of the emitting framework without disturbing the alignment.

iii. Refer figure 62 measure dimension F (175 ± 10). Loosen or tighten the suspension nuts in steps of a quarter revolution to attain the dimensions F & D on both front and rear side of each field.

iv. Maesure the distance between the colleting electrodes and emitting system framework top. Take three sets of electrodes two on either ends or one in the middle. Take the readings near both transverse roof beams. As such six sets of readings will be available at the top needs shifting, in one direction. If so, fix the lifting tools and tighten tool and nuts until the load of the emitting system is equally shared between the lifting tool and the suspension nut must be equally tight. Hammer the bottom plates of the suspension rod in a direction opposite to the intended shift on the emitting framework. Release all the lifting tools the entire load if emitting system will be transferred to the suspension rod, which regain the

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vertical position. Simultaneously the emitting system will get shifted in the required direction.

v. Maesure the inter electrode gaps at the middle level preferable taking the same three sets of Electrodes. Minor corrections can be manipulated by means of the upper pairs of diagonal stays. While tightening one diagonal stay take care to release the other to facilities free movement of the emitting system. Lock both the diagonal stays with lock nuts after the inter electrode gaps are brought within tolerance.

vi. Measure the inter electrode gap at the bottom level. For corrections the lower pairs of diagonal stays will be used.

vii. Use a site fabricated „T‟ shaped go gauge for a final check on inter electrode spacing. Refer Figure 63&65.

viii. Mount the deflection sheets on top of emitting frame.

6.19 APPING MECHANISM FOR COLLECTING AND EMITTING EELCTRODE:

Refer:

- Rapping mechanism drawing for collecting electrode.

- Complete shaft drawing for emitting rapping.

- Figure No. 66, 67, 68, 69 & 70.

i. Straighten the shaft and remove rust on the shaft surface.

ii. Mount lower halves of the plain bearings on the brackets.

Note: Mark identification numbers for the LOWER AND UPPER PARTS OF PLAIN BEARING. They are not interchangeable.

a) Collecting electrode rapping.

b) Plain bearings for the entry and exit fields are mounted on brackets, which are welded on inlet gable and outlet gable respectively. For other fields they re mounted brackets installed in between the fields.

c) Emitting Electrode rapping:

Plain bearings are mounted on brackets welded on vertical beams.

iii. Adjust the bearings to be in one line. Check the level of the bearings by water level. Introduce shims, if needed.

iv. Mount the shafts on plain bearings. Insert set rings on both sides of one of the bearings as per drawing maintain a gap of 2 mm between ser ring

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and the bearings. Maintain a distance of 310 mm between the centre line of shock bar / shock beam and the centre of the shaft.

v. Maintain the angular displacement and pitch of the adjacent holes of the mating shafts and align. Preheat the sleeve and the mating ends of the shafts to 250 C and weld them as per the drawing.

vi. Check the straightness of the shaft assembly. Assemble the upper part of the bearings. Locate and weld the stopper pieces on either side of the plain bearings. (applicable only for collecting electrode rapping.

Note: inner arm disposition: after rapping one row of electrodes the adjacent row shall not be rapped before the shaft complete a quarter revolution.

Collecting rapping:

Successive inner arms shall be fitted to the shaft keeping 210o or 150o angular displacement, as shown in figure 66 & 67.

Emitting rapping:

The successive inner arms shall be fitted to the shaft keeping 240o / 210o or 120o / 150o angular displacement, as shown in figure 68 & 69.

vii. Inner arm shall be tight fir with the shaft and then shall be no play after bolting them with the shaft.

Collecting electrode rapping: ensure that the hammer is located centrally so as to hit the shock pad effectively.

viii. Emitting electrode rapping: Ensure that the hammer hits the centre of shock beam within ± mm.

ix. Tack weld all the fasteners.

6.20 rive arrangement for collecting electrode rapping mechanism (7X – X26)

Refer:

Drive arrangement drawing for collecting electrode rapping mechanism.

Figure: 71

i. Mount the brackets of the drive arrangement flush with casing wall in alignment with the shaft axis.

ii. Assemble the shaft end with gland and graphite packing.

iii. Check for the free rotation of the shaft and assembly clutch.

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iv. Assemble the coupling to motor shaft and mount the motor provide shims for proper alignment.

v. Assemble the clutch and coupling.

NOTE: V‟ groove on the coupling shall be just visible. This will ensure 10-mm gap for thermal expansion between coupling end and clutch. Refer figure 7:

vi Mark the correct direction of rotation of the shaft and fix the indicator at a prominent place on the gear unit. Paint a caution “DON‟T REVERSE THE ROTATION” on the bracket.

CAUTION: Reverse rotation will cause serious damage to the shock bar, shock bar guide, link rods and shaft and disrupt the alignment of the electrodes.

6.21 Drive Arrangement for Emitting Electrode Rapping Mechanism (7X – X17)

(a) Horizontal type

Refer:

- Drive arrangement drawing for emitting electrode – rapping mechanism.

- Figure: 72 & 73

i. Fix the connection piece to the casing wall.

ii. Introduce the correct type of screw inside the connection piece with shaft insulator in position.

Note: There are two types of screws and right hand and the other left hand. The purpose of the screw is chosen, it will build dust around the sh insulation and damage it.

iii. Assemble the cover.

iv. Insert the drive shaft.

v. Assemble the carbon bush on to the shaft with packing on either side and bolt the gland.

vi. Mount shaft insulator between shaft and the drive shaft and connect the screw.

vii. Assemble the SKF bearing as shown in figure 73.

viii. Assemble the clutch to the drive shaft.

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ix. Assemble the coupling to the motor shaft and mount the motor. Provide shims for proper alignment.

x. Assemble the clutch and coupling.

Note: ‘V’ Groove on the coupling shall be just visible. This will ensure 10-mm gap for thermal expansion between coupling and clutch. Simultaneously maintain the distance of 120 mm between the drive shaft end to the inside face of the cover. This will provide on either side of the shaft insulator, a clearance of 10 mm which is essential to avoid any impact on insulator. Refer figure 72.

xi. Mark the correct direction of rotation of the shaft and fix the indicator at a prominent location on the gear unit.

b) Vertical Type

Refer:

Rapping mechanism for emitting electrodes.

- Drive arrangement for emitting rapping mechanism.

- Figure: 72 & 73

i) Fix the thrust bearing on the bracket.

ii) Commence the erection upwards from thrust bearing continue erection with bearing shafts, vertical shafts pin wheels etc.

iii) Adjust the shaft vertically with a wedge to maintain a height of 300 mm above the roof panel (between the centre line of bottom pin of shaft insulator and the roof panel. Complete the welding of sleeve with the shaft remove wedge.

iv) Mount the shaft insulator assembly and the drive arrangement over the vertical shaft and roof panel.

v) Fix the connection piece to the rood panel.

vi) Fix the drive shaft fitted insulator housing on top of connection piece in line with shaft insulator assembly.

vii) Use alignment jig for motor to make the motor shaft co-acial with the drive shaft.

viii) Fix the grip couplings with the drive shaft and motor shaft.

ix) Mark the correct direction of rotation of the shaft and fix the indicator on the gear unit.

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6.22 Hooper Deflection Plates (7x – x11)

Refer:

Hopper deflection plate assembly drawing.

Figure: 76, 77 & 78

Log sheet No: 17

i) Weld the hooks intended for suspending the hopper deflection plates at the appropriate location, on the transverse channel as per drawing. Suspend deflection plates from the hooks.

Note: Ensure that a minimum gap of 80 mm between the extreme deflection plates and hopper as shown in the figure.

ii) Swing the deflection plate towards the hopper wall and the support to the hopper wall maintaining a minimum clearance of 300 mm as shown in the figure.

iii) Deflection plate between the collecting electrodes and the casing wall shall be positioned maintaining a gap of 25 ± 10 mm at the non- rapping side and 5 to 10 mm on the rapping side as shown in the figure 77 & 78.

One vertical edge of the deflection plate shall be located at the centre of the collecting electrodes. The other vertical edge of the deflection plate will be stitch welded to the casing wall and the gap if any, between the wall and the deflection plate shall be patched up with 1.6 / 2.5 mm sheet. Note that the bottom edge of the deflection plate shall not foul with the shock bars.

6.23 Electrostatic Precipitator Funnels: (7X –X50)

Refer:

- Inlet and outlet funnels drawing of electrostatic precipitator.

- General arrangement drawing for ESP.

- ID System layout drawing & Log sheet.

i) Assemble the inlet funnel with splitters and outlet funnels. Pre-assembly on ground can be resorted to facilities permit. Mount and weld the assembly ascertain that the election of the centre line ducts and the funnel opening are same and as per drawing.

Any discrepancy shall be reported to EDC / AQCS and EDC / Boilers before proceeding with further erection.

ii) Ensure that the funnels match with the connecting ducts.

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iii) Inside welding shall be leak proof.

iv) Close the inlet and outlet ducts near the dampers in one of the passes if there are two passes per Boiler any there of the passes if there are four passes Boiler. This is to limit possible damages, if any emitting electrodes during low temperature operation the boiler at the time of commissioning.

6.24 Roof Panels, Outer Roof, Rectifier Handling Arrangements, Pent House (7X – X47, X42, X56, X55)

Refer:

Roof panel assembly drawing.

Outer roof

Rectifier handling arrangement.

Pent house.

Complete the erection of roof panels. Welding shall be leak proof.

If penthouse and rectifier handling systems are in the scope of supply, weld their columns on the roof beam top flange.

Roof panel insulation followed by outer rood erection shall be taken up bay wise. Place the insulation material on the first bay. Erect the outer rood panels on that bay. Next, take up the third bay, fifth bay, seventh bay and so on. Follow it up in the second bay, fourth bay, sixth bay and so on. This procedure allows for proper working space on the outer roof panels and also protects the insulation the insulation from rain.

Weld the middle legs of the outer roof on the roof panels. Note that all the other legs are simply resting on the roof panels and not welded.

If rectifier handling system/ pent house is in scope, provide suitable cutouts to accommodate their supporting columns to prevent water leakage.

6.25 Insulator Housing (7 X – X06)

Refer:

- Insulator housing assembly drawing.

- Figure 79

i) Erect the support on roof panel after insulating it on all four sides and seal weld the support bottom with roof panel.

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ii) Mount the insulator housing over the supports and seal weld with the support from inside.

Note: All the openings in the insulator housing of a pass of support insulator heaters shall face either towards or away from centre line of bus section for convenient cable routing. Maintain the correct height of the bushing box opening.

iii) Ensure proper closing of the insulator housing.

6.26 Inspection Doors (7X-X23)

Refer - Figure: 80

Identify inspection doors meant for hoppers and casing wall panels. Weld the collar of the inspection door with the plate and there shall be no protection inside the hopper / the casing. Ensure that the doors close freely. Bolt the earthing cables on to the door and the flange.

6.27 Insulation (7X – X67, 7X-X68)

i) Weld the fixing pins on the surfaces to be insulated.

ii) Insert and tack weld the type „B‟ retainers on the fixing pin, so as retain the insulation, just up to the height of the stiffener.

iii) Place the mineral wool matters and press them on to the pins.

iv) Sew the wire netting of the mattresses at the ends by sewing wires.

v) Position the type „A‟ retainer on the pins and tack weld them.

vi) Tie the binding wires across the fixing pins below the retainers.

vii) Fix the casing support to the retainers by using the self- tapping screws.

viii) Lay the outer casings over the casing supports by screwing self- tapping screws.

ix) Take care while lapping the outer casing that in rainwater enters into the insulation.

6.28 Transformer Rectifiers, Heating Elements, Thermostats Auxiliary Control Panels, Electronic Controllers And Interlocks.

(7X-X76, 7X-X90, 7X-X72)

Refer:

- Insulator housing assembly drawing.

- Interlocking system and interlocking arrangement drawing.

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- Figures: 81 & 82

- Layout of Electrostatic Precipitator Control Room.

i) Transformer Rectifiers:

a) Install the transformer rectifier, disconnecting switches and busing insulators.

Note: The terminal connection between the transformer bushing, disconnecting switch and support insulator shall be firm using the connecting screw. Do not over tighten the connecting screw to cause damage to the tube. All flange connections shall be provided with gaskets to avoid water ingress.

b) Install the auxiliary control panels and electronic controllers inside the electrostatic precipitator control room.

Note: Always keep the doors / windows of the control room locked to avoid dust entry and also pilferage components from the control panels.

ii) Heaters:

a) Mount the support insulator heaters inside the insulator housing on the appropriate angle pieces. Ensure that heaters sit properly and concentric to the support insulators.

b) Mount the shaft insulator heater inside the chamber.

c) Insert the hopper heaters into the heater chamber as in the figure 81.

6.29 Final Checks

i) Ensure that the wall roof and hopper walls do not have any holes. Conduct leak / rain test.

ii) Ensure that all temporary stays, supports, etc., used during erection are removed.

iii) Ensure that the nuts and bolts in the rapping mechanism as well as on the emitting frames are locked by tack welding.

iv) Ensure that no welding beads, projections or sharp edges are left in the vicinity where flashover will occur during operation. Check all critical dimension.

v) Ensure that the earthing handles are welded on to the emitting framework nearer to the inspection door. Ensure that all earthling cables are properly fitted at doors and connections.

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vi) Ensure all gearboxes are filled with oil.

vii) Remove all foreign materials like welding rods, cut bits, wooden planks etc., from inside the ESP.

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