Extraction of Plant Design VIVA VOCE (Updated 08-05-2008 5pm)

8/3/2019 Extraction of Plant Design VIVA VOCE (Updated 08-05-2008 5pm)

1/17

PUMP (SELECTION)


2/17

PUMP (PROCESS DESIGN)

mm 25 mm

m

m

Fluid fro 50

mNs/m

kg/m

kg/h

m/s 32.174 ft/s

Pipe type

Economic pipe diameter, d

Mass flow rate, m

Pipe length, l

Fluid type

Viscosity,

Density,

Pipe cross sectional area, A

Fluid from M-102

Gravitational acceleration, g 9.81

0.740

977.652

5489.516

P-102Pump in charge

Commercial steel pipe

50

7.64

1.9635E-03

Carbon steel or Stainless steel?

Estimated pipe internal diameter:

Stainless steel

Get the economic pipe

diameter from DN

table in Appendix

referring to the

estimated pipe internal

diameter.

Other types:

d = (4A/)A=V/u

V=(m/3600)/u = 2 m/s (typical)

Carbon steel:d, optimum = 293G

0.53-0.37

Stainless steel:

d, optimum = 260G0.52-0.37

(1) Select pipe type with respect to fluid type

(2) Select pipe material

(3) Estimate pipe internal diameter

(4) Choose economic pipe diameter

(5) Determine pipe length


3/17


(6) Determine fitting/valve

I O

0

0

1 1 1.6

00

0

0

0

1 0.5

1 1

fully open 0 open 0

open 0

open 0

fully open 0

open 0

Plug valve open 1 0.4

Total: 3.5

1.0

0.15

Globe valve,

bevel seat-

90 square elbow90 standard long elbow

Sudden expansion (tank inlet)

Gate valve

Tee-entry from leg

Tee-entry into leg

Union and coupling

Sharp reduction (tank outlet)

75

45 standard elbow 0.35 15

0.8

0.45

0.2 10

35

23

0.5

1.5

1.2

1.8

45 long radius elbow

90 standard radius elbow

0.04

1

6

8.5

0.4

60

90

2

800

50

7.5

25

016

4

18

450

200

40

300

0

0

0

50

0

0

Unit K, number

of velocity

heads

Number of

equivalent

pipe

diameters

0

Pressurelossinpipe

fittingsandvalves(fortu

rbulentflow,Re>4000)

K, number of velocity

heads per unit

Number of

equivalent pipe

diameters per

unit

0

0

0

0

0

0

Fitting/Valve

85

35

00

Ran e: 0.6 - 0.8

Range: 30 - 40

(7) Calculate number of equivalent pipe diameter


4/17

PUMP (PROCESS DESIGN)z1 1.00

z2 3.90P1 1.013 1.013E+05 N/m

P2 1.013 1.013E+05 N/m

Total Developed Head (TDH)m

N/m

m

mm/s

m

m/h

m/s

mm

m

N/m

m

m

m

m/h

%

Fluid velocity, u =

as head of liquid =

Difference in elevation, z =

Friction factor, f =

2.90

Pipe absolute roughness =

Pipe cross sectional area, A =

Total Developed Head (TDH) =

Pipe relative roughness, e =

Reynolds number, Re =

Dynamic head =

Pressure drop, Pf =Length including misc. losses, L =

2.900S

taticHead

Total static head =0.794

PIPING LAYOUT

Dyna

micHead

Difference in pressure, P = 00.000

Operating volumetric flow, vo =

Pump efficiency =

1.963E-03

5.615

52445

0.000920

0.046

bara

41.39

44.29

Operating point =

bara

(Use: Single- or double-suction pump)

Volumetric flow rate, v =0.001560

m

m

(Satisfactory: Flow is turbulent)

4125

0.007029

11.89

(OK)

Relative roughness, e = absolute roughness/d

Refer to data in Appendix

Re = ( u d) /

v = u A 3600s/1h

L = l + (total equivalent pipe diameters d0.001m/1mm)

Pf= 8f(L/d) ( u)/2

Pressure drop as head of liquid = Pf/ ( g)

TDV = total static head + dynamic head

A = /4 (d 0.001m/1mm)

Take 2 m/s, typical velocity for liquid.

f = 0.04Re-0.16

for turbulent flow in clean commercial

steel pipes. (Genereaux, 1937) Otherwise, refer to Fig.

5.7.

(Genereaux, 1937)

Single-suction centrifugal pumps handle up to 0.0032 m/s at

total heads up to 15 m; either single- or double-suction

pumps used for the flow rates to 0.063 m/s and total headsto 91 m; beyond these capacities and heads double-suction or

multista e um s are used. Cho e 2004Cho e 2004

Refer to

Manufacturers Pump

Curve

(8) Check Reynold number (laminar or turbulent?)(9) Calculate total developed head

(10) Determine pump suction type


5/17


Net Positive Suction Head (NPSH)

m 4.20 m (Total length from pump outlet)

m 8.45 m (Total length of outlet piping)

m

m/s

N/m

m (Satisfactory: No Cavitation)

Operating fluid velocity, uo = 0.794

Vapor pressure of liquid at the pump

suction, Pv =

Vertical distance to pump inlet, H = 0.50

Total length of inlet piping, LT = 5.19

Total length to pump inlet, Li = 3.44

NPSH =

N/m71300

52445

0.007029

1800

3.44

Reynolds number, Re =

Friction factor, f =

Pressure drop, Pf =

Re = ( uo d) /

L = l + (total equivalent pipe diameter for miscellaneous

friction loss due to tanker outlet constriction and the pipe

fittings in the inlet piping d0.001m/1mm)

As a general guide,

NPSH should be

above 3 m for pump

capacities up to 100

m/h, and 6 m above

this capacity.

Pf= 8f(LT/d) ( uo)/2

NPSH = P1/g + H - Pf/g - Pv/g

(11) Calculate NPSH

(12) Check: Cavitation possible?


6/17


Job no. Sheet no. By LWS 2/4/08P-102 1

Units

C mm

kg/m Flow Norm. Max. Units

mNs/m u2 Velocity 2.90 0.00 m/s

kg/s f2 Friction loss 0.12 0.00 kPa/m

kg/s L2 Line length 4.20 4.20 m

f2L2 Line loss 0.51 0.00 kPaOrifice - - kPa

mm 30% Control valve - - kPa

Flow Norm. Max. Units

u1 Velocity 2.90 0.00 m/s (a) Heat ex. - - kPa

f1 Friction loss 0.12 0.00 kPa/m (b) - - kPa

L1 Line length 3.44 3.44 m (c) - - kPa

f1L1 Line loss 0.42 0.00 kPa (6) Dynamic loss 0.51 0.00 kPa

u1/2 Entrance 4.11 0.00 kPa

(40 kPa) Strainer - - kPa z2 1.00 1.00 m

(1) Sub-total 4.53 0.00 kPa gz2 9.59 9.59 kPaEquip. press (max) 101.30 101.30 kPa

z1 0.00 0.00 m Contigency None None kPa

gz1 0.00 0.00 kPa (7) Sub-total 110.89 110.89 kPa

Equip. press 101.30 101.30 kPa (7) + (6) Discharge press. 111.40 110.89 kPa

(2) Sub-total 101.3 101.3 kPa (3) Suction press. 96.773 101.3 kPa

(2) - (1) (3) Suction press 96.773 101.3 kPa 14.63 9.59 kPa

(4) VAP. PRESS. 0.00 0.00 kPa (8)/ g 1.53 1.00 m(3) - (4) (5) NPSH 96.77 101.30 kPa

(5)/g 10.09 10.56 mValve/(6)

Control valve %

Dyn. loss

Checked

50

DISCHARGE CALCULATION

Line size

%

(8) Diff. press.

0

Static head

Pump and Line Calculation Sheet

Fluid

Temperature

Density

Fluid from M-102

24.84

977.652

Line size

Equipment

Normal flow

0

Static head

0.740

Design max. flow

20%

50

1.525

1.830

SUCTION CALCULATION

Viscosity


7/17

PUMP (MECHANICAL DESIGN)

Cho e 2004Determination of Upper Limits of Specific Speed

(1) Determine upperlimit of specific speed

From total head and suctionhead.


8/17

Selection of the Best Operating Speed of Centrifugal Pump

m/h

%

m/h

m

m

10000 1246

11000 137113000 1620

Max 24075 3000

*Remarks: 1 gpm = 0.2271 m/h and 1 ft = 0.3048 m.

r/min

Conversion:

1gpm 0.2271 m/h

1 ft 0.3048 m

1 in 25.4 mm

Suction specific speed selected, S = 9316

Type of pump selected Volute, Diffuser

Type of pump stage selected Single-suction pump

1371

Operating speed selected, N = 11000

Inse

rttrialN Required specific

speed, Ns

Safety Factor =

Max. pump capacity =

Pump capacity =

6.177

5.615

Operating speed, N

(r/min)

Pump stage type Single-suction pump

Suction specific

speed rating

Specific speed selected, Ns =

Upper limit of specific speed, NsSuction Head =

10

11010

3.44

44.29Total Developed Head, TDH =

Volute, Diffuser

Volute, DiffuserVolute, Diffuser

3000

Required suction specific

speed, S

Turbine

(Use: Single- or double-suction pump)

20389

Average

GoodExcellent

Excellent

Pump type listed by

specific speed

8469

9316

Ns = NQ0.5

/H0.75

(Perry, 1997)

Refer to the comment at cell G55 beside TDH.

Single-suction centrifugal pumps handle up to

0.0032 m/s at total heads up to 15 m; either

single- or double-suction pumps used for the

flow rates to 0.063 m/s and total heads to 91

m; beyond these capacities and heads double-

suction or multistage pumps are used.

Cho e 2004

S = NQ0.5/NPSH

0.75(Perry, 1997)

Obtain the value from Figure 6.10 with respective

system total head and suction head.

Based on Suction Specific-Speed Ratings. Refer to Appendix.

Based on Pump

Types Listed by

Specific Speed.

Refer toAppendix

Select the N with the best speed

rating. Refer to the table above.

The value of this factor of safety can vary from

a low of 5 percent of the required flow to a

high of 50 percent or more.

(Chopey, 2004)


(2) Select the best operating speed (by trials)

(4) Determine pump type

(3) Calculate specific speed, Ns


9/17


18 %Percent head rise from BEP to shut off =

Specific speed selected, Ns = 1371

7 vanes 27 with droopVanes

specification

Vanes number, Z 7

By assumption.

Lobanoff 1992

Obtain vanes specification from Figure 3.2

with respect to percent head rise and Ns.

(5) Determine vanes specification and number, Z (from graph)


10/17


in

mm

2.08

53

Impeller outer

diameter, D2

Head constant, Ku 1.03

Obtain Ku from Figure 3.3 with

respect to vanes number and Ns.

(Lobanoff, 1992)

D2 = 1840 Ku H0.5

whereby H in ft.

RPM

Lobanoff 1992(Lobanoff, 1992)

(6) Determine head constant (from graph)

(7) Calculate impeller outer diameter, D2


11/17


ft/s

in

mm

Impeller width, b27

0.24

0.125

Cm2 12.09

Capacity constant, Km2

Obtain Km2 from Figure 3.4 with respect to

vanes number and Ns.

b2 = GPM 0.321 (Lobanoff, 1992)

Cm2 (D2 - ZSu)

Estimated Su = in. (This will be confirmed during

vane development and the calculation repeated if

necessary.)

Cm2 = Km2 (2gH)0.5

with g = 32.174 ft/s2

(Lobanoff, 1992)

(Lobanoff, 1992)

Lobanoff 1992

Lobanoff 1992

(8) Determine capacity constant, Km2 (from graph)(9) Calculate Cm2

(10) Calculate impeller width, b2


12/17


in

mm

in

inmm

mm

0.5D1/D2

1.04

27Eye diameter, D1

0.3Shaft diameter

under impeller eye,

Ds 8

Eye area 0.78501

Obtain D1/D2 ratio from Figure 3.5

with respect to Ns.

Eye area = Area at impeller eye (D1/4) - shaft are (Ds/4)

Lobanoff 1992

(11) Determine eye diameter:impeller OD, D1/D2 (from graph)

(12) Calculate eye area


13/17

ft/s

m/s

ft/s

m/s

ft

m

Suction eye

velocity, Cm1

11.25

Peripheral

velocity, Ut

3.43

49.88

15.20

NPSHR12

3.66

Nss 8898

Ut = D1 (in) RPM (Lobanoff, 1992)

229

Cm1 = GPM 0.321 (Lobanoff, 1992)

Eye area (in)

Obtain NPSHR from

Figure 3.6 with

respect to Cm1 andUt values.

Nss = (RPM GPM0.5

)/NPSHR0.75

Lobanoff 1992

(Lobanoff, 1992)

(13) Calculate suctioneye velocity, Cm1 &peripheral velocity, Ut

(14) Determine NPSHR

(from graph)


14/17

(Lobanoff, 1992)


in

mm

in

mm

in

mm

0.23Volute area, A8

146

Casing type Single-volute

Volute velocity

constant, K30.40

Cutwater

Diameter, D3

2.20

56

Volute width, b30.42

11

Obtain K3 from Figure 3.8

with respect to Ns.

A8 = 0.04 GPM

K3 H0.5

Refer to Guidelines for

Volute Width in Appendix.

Refer to Guidelines for CutwaterDiameter in Appendix.

(15) Determine volute velocity constant, K3(16) Calculate volute area (As), volute width (b3) & cutwater

diameter (D3)


15/17


D2 = 53 mm

D1 = 27 mm


16/17

INTERLOCK

Interlock System Condition

Process interlock between V-101,

V-102 and V-103

V-101 or V-102 or V-103 failed closed or plugged.

M-101 overfilled.

P-101 malfunction.


V-113, V-114, V-115 and V-

116.

V-112 or V-113 or V-114 or V-115 or V-116 failed

closed or plugged.

M-102 or M-103 overfilled.P-102 or P-103 malfunction.

Pipelines clogged: no flow from M-102 to M-103.


V-124, V-125, V-201, V-202

and

V-203.

V-123 or V-124 or V-125 or V-201 or V-202 or V-

203 failed closed or plugged.

M-104 or M-201 overfilled.

P-104 or P-201 malfunction.

Pipelines clogged: no flow from M-104 to M-201.

Process interlock between valve

for buffer tank, V-210 and V-

211.

Buffer tank valve or V-210 or V-211 failed closed

or plugged.

M-202 overfilled.

P-202 malfunction.Pipelines clogged.


17/17

INTERLOCK (CONT)


V-221, V-222 and V-223.

V-220 or V-221 or V-222 or V-223 failed closed or

plugged.

M-203 overfilled.

P-203 malfunction.

Pipelines clogged.


V-301, V-302, V-303 and V-304.

V-224 or V-301 or V-302 or V-303 or V-304 failed

closed or plugged.M-301 or M-302 overfilled.

P-301 or P-302 malfunction.

Pipelines clogged.

Safety interlock between V-305,

V-306, V-307 and V-308

V-305 or V-306 or V-307 failed closed or plugged.

P-303 malfunction.

Pipelines clogged: no flow from M-303 to HE-301.

Documents

Extraction of Plant Design VIVA VOCE (Updated 08-05-2008 5pm)