Managing Risks of Syn Compressor Operation with high Seal Oil Consumption

Nitrogen+Syngas 2015 Speaker: Muhammad Hashim Co Speaker: Ahsan Sarfraz Fatima Fertilizer Pakistan

Contents

Fatima Group Overview

Introduction & Problem Background

Risks & Operational Challenges

Risk Mitigation Measures

Success Factors

Key Learnings

Fatima Group-Overview

Fertilizers Sugar Trading Textiles

Pakarab Fertilizers

Fatima Fertilizer

Fatima Sugar Mills

Reliance Commodities

Reliance Weaving

Fazal Cloth Mills

Fatima Energy

Energy

Fatima Group - A story of success since 1936

1936 1966 1989 1990 1996 2003 2005 2009 2010

Year Established

Fatima Sugar Mills Limited

Reliance Commodities (Pvt.) Ltd

Pakarab Fertilizers Limited

Fatima Energy Limited

Fazal Cloth Mills

Reliance Weaving Mills Limited

Fatima Fertilizer Company Limited

Pakistan Mining Company Limited

Fatima Trading Company Limited

2012

Reliance Sacks Ltd

Plant Design Capacities

5

FUTURE PROJECTS

Ammonia DBN Phase 1 completion in Dec 2015 - 1500-->1650 MTPD Phase 2 completion in 2017 - 1650-->1800 MTPD

Ammonia 2200 MTPD Urea Solution 2200 MTPD Urea Granulation 1200 MTPD UAN 4500 MTPD NA 1500 MTPD DEF 900 MTPD

Fatima Fertilizer Safety Statistics-2014

Introduction-Synthesis Compressor The purified synthesis gas after Front End of Ammonia passed through

Dryer and Coldbox containing the proper ratio of hydrogen to nitrogen for ammonia synthesis is compressed in a turbine driven centrifugal Synthesis Gas Compressor C-104 having three stages with extraction and condensing turbine.

Syn Compressor C-104 Manufacturer: Clark / Dresser Rand Syn Turbine CT-104 Manufacturer: Delaval Stroke CT-104 Speed: 10466 rpm CT-104 power output: 23907 KW

CT-104

CT

LIC-87

LIC-74

LIC-72

Oil Tank

Oil Breather

AUTO

MAN

MAN

P-122 A

P-122 C

P-122 B

PIC-309

P-122C was not in original design but was added later to increase

reliability

P-121 A

P-121 B

l

AUTO

145 lit/min

Problem Background: C-104 HPC Vibrations History

Year C-104 HPC problem Actions taken

Jan. 2010 High vibration during hot start up / near critical speed (Trip Limit - 100) Start up sequance was changed.

April 2010 HPC high radial vibration. Bearing pads were replaced with new due to scoring on NDE

May 2010 High vibration on HPC Non Drive End Bearing,

Thrust bearing pads replaced

March 2011 C-104 HPC high radial vibrations overhauling

May 2013 C-104 HPC high radial vibrations issue Modified oil seals installed as per OEM in TA-13

Operational Problems after Oil seals Replacement in May 2013:

Abnormally high seal oil consumption (One seal oil pump capacity 145 lit/min at 1450 rpm)

Continuous operation of both seal oil and lube oil pumps. No stand by pump availability. Old seals were sent to vendor shop for examination and inspection and no

inventory of old design seals at site due to revised design. OEM demanded over Five Months for Root Cause and design

modification; FFL was left out with no other option either Shut down the plant due to high potential fire risk till the time OEM resolves the

problem. Work out the way to sustain plant operations without compromising process

safety till the time OEM recommend solution.

Immediate Risks and Sustainability Challenges:

Explosivity from oil breathers at seal oil controller lower openings.

Exposure to Gas break through / fire due to single level transmitter in original

design.

Time lapse of seal oil bottles due to high seal oil consumption.

Seal oil level control and its dump was on manual mode and increased risk during load fluctuations.

Potential of Fire in case of seal oil pump failure as no stand by availability. Significant compromise on operational flexibility due to unavailability of stand

by pump

CT

LIC-87

LIC-74

LIC-72

Oil Tank

Oil Breather

AUTO

MAN

MAN

P-122 A

P-122 C

P-122 B

PIC-309

P-122C was not in original design but was added later to increase

reliability

P-121 A

P-121 B

l

AUTO

145 lit/min

Risk Mitigations for Safe Operation:

Engineering Controls:

1. Two additional Level Transmitters were configured to increase reliability.

2. Seal oil control philosophy revised to put seal oil level control on auto / cascade.

3. Stand by seal oil pump cut in logic; Normal operating levels and Tripping limits revised.

4. Additional seal oil pump was procured and installed as a stand by.

5. Minimum Opening lock on Seal oil controller was placed to avoid gas breakthrough from breathers.

HP

MP C

T LP

LIC-87

LIC-74

LIC-72

Oil Tank

MP Breather

AUTO

MAN

MAN

P-122 A

P-122 C

P-122 B

PIC-309

P-121 A

P-121 B

l

AUTO

180 lit/min

Three LTs with PdI installation

Seal oil dump on cascade mode

Low level trip logic revision

Third seal oil pump installation, cut in logic

revision

Minimum Lock to avoid gas breakthrough from

breathers

Risk Mitigations for Safe Operation:

1. Operational Controls: a)New SOP was developed and each operating staff was trained and

validated (Tag Drills) on new instruction / guidelines with clarity of authority & empowerment.

2 In case of one seal oil pump fails; a) In case of tripping of one seal oil pump; unload C-104 from 200 to a

discharge pressure of 120 kg/cm2 to minimize oil depletion in seal oil bottles to gain response time to normalize conditions as per available margin.

b)Keep Seal Oil Dump Valve PIC-309 on cascade mode all the time to avoid any very low or very high pressure conditions.

3. In case of two seal oil pump fails; a)Back end board man to immediately actuate I-016 (Trip C-104) manually. b)Depressurize compressor LP and MP casing by actuating I-006

(Methanator Trip) and opening C-104 Suction PV-035 to 100% c) Depressurize and isolate compressor HP immediately.

Risk Mitigations for Safe Operation:

PV-35 suction vent

PV-107 discharge vent

HV-01 and MOV-02 Closure

MOV-003 Closure

Success Factors

Multidisciplined TEAM formulation for PHA HAZOP technique to identify and evaluate Risks Taking Engineering Controls where high risk area identified. Operating Procedures development and approvals. Training and Validation of Operators. Tag Drills to ensure correct response from TEAM.

Condition Monitoring Regimes Delegating TEAM Authority and Empowerment.

Conclusion:

During TA-14 inspection of oil seals, heavy scoring especially in inner seal ring with abnormally high seal clearance observed.

In TA-14 Seals replaced with further modified design (reduced seal clearance). conditions are running fine with only one pump capable to fulfill the requirements.

Key Learnings:

1. Fall back strategy of all modifications / replacements. 2. Lack of system to review OEM provided solutions.

Nourishing soils Enriching lives

Thank you

Questions & Answers ?

Managing Risks of Syn Compressor Operation with high Seal Oil Consumption ContentsFatima Group-OverviewSlide Number 4Plant Design CapacitiesFUTURE PROJECTSFatima Fertilizer Safety Statistics-2014Introduction-Synthesis CompressorSlide Number 9Problem Background:C-104 HPC Vibrations HistoryOperational Problems after Oil seals Replacement in May 2013:Immediate Risks and Sustainability Challenges:Slide Number 13Risk Mitigations for Safe Operation:Slide Number 15Risk Mitigations for Safe Operation:Risk Mitigations for Safe Operation:Success FactorsConclusion:Key Learnings:Slide Number 21Slide Number 22