Vibration of Rotating Machinery in Hawiyah Gas Plant

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Vibration of Rotating Machinery in Hawiyah Gas
Plant

• King Fahd University of Petroleum and Minerals
• Mechanical Engineering Departments

Presented by Ahmed Al-Jaafari 993714 Advisor
Dr. Meyasser Al-Haddad October 19,2004
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Outline

• Plant Overview
• Hawiyah Gas Plant Processes
• Vibration Group
• Case Study
• Conclusion

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Hawiyah Gas Plant

• Overview

• One of the newest plant.
• The first completely non-associated gas plant
• Completed four months ahead of schedule and
  under budget
• Designed and built from scratch to meet the
  increased local demand for sales gas

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• Overview

• Feed gas of the plant
• Juaf 407 MMSCFD (sweet)
• Khuff 1305 MMSCFD (sour)

• Plant production
• 1530 MMSCFD sweet gas
• 50 MMSCFD sulfur
• Increased the Kingdom's gas supply by 30 .
• Increase capacity 2,400 MMSCFD

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HAWIYAH GAS PLANT PROCESSES
SULFUR RECOVERY
DEHYDRATION DEW POINT CONRTOL
INLET AREA
GAS TREAT
SALES COMPRESSORS
SCFD Standard Cubic Feet per Day
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Maintenance Division
Work Shop
Areas Maintenance Crew
Planers
Technical Support Unit
Quality Assurance Engineers
Preventive Maintenance
Vibration Group
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ADRE System (Automated Diagnosis for Rotating
Equipments)
Vibration Group Devices and Software
Data Manager2000 (DM 2000)
C.S.I. Machinery Analyzer (Computational System
Incorporated)
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Vibration Readings
MOTOR
COMPRESSOR
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CASE STUDY
Bearing Defect
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Bearing Frequencies
BSF

• Ball Pass Frequency of Outer race (BPFO)
• Ball pass frequency of the Inner race (BPFI)
• Fundamental Train Frequency (FTF)
• Ball Spain Frequency (BSF)

FTF
BPFI
BPFO
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Bearing Frequencies Calculations
1. Bearing Frequency Equations
RPM revolutions per minuteS speed,
revolutions per secondBd ball or roller
diameterNb number of balls or rollersPd
pitch diameter? contact angle
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Bearing Frequencies Calculations
2. Rule of Thumb
OR 0.4 x (speed) x N IR 0.6 x (speed ) x N
FTF 0.4 x (speed)
Where N is number of balls
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Bearing Frequencies Calculations
3. Bearing Frequency Calculator
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Bearing Frequencies Calculations
Example ( SKF 7311BECBJ)
Since S 1800 RPM Bd 0.9474 in
Pd 3.449 in ? 40 0
Nb 12 balls
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Zone A
Zone B
Zone C
Zone D
Failure Modes
Bearing defect frequency region
Bearing component natural freq. region
Spike energy
1X 2X 3X
Stage 1
500
2000
20-60 kHz
Stage 2
Stage 3
Random high freq. Vibration
Stage 4
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Example 1
Analysis
Findings

• Non- of the bearing frequency match.
• Highlighted readings are the max.

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Example 1
Findings
Zone A
Zone B
Zone C

• 2 BPFO 2 BPFI.
• Bearing natural components freq.
• Side band freq. around the bearing natural freq.

Natural freq. Side Band freq.
2BPFI
Recommendation The bearing is defective in the
third stage of failure and has to be replaced.
2 BPFO
Note harmonic means 1x(freq), 2x(freq), 3x(freq)
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Replacing the bearing
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Example 2
Analysis

• Inner race defect frequency (BPFI) 332.6 Hz
• Outer race defect frequency (BPFO) 207.41 Hz
• Cage defect frequency
• (FTF) 23.05 Hz
• Ball spin frequency
• (BSF) 122.45 Hz

Bearing Frequency Calculation

• Findings
• side-bands freq. around the highest amplitude.
• the highest amplitude (prime spike vib.)
• 6xBPFO

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Example 2
Findings

• None of the bearing freq. match.
• The harmonic freq of BPFI do not match.
• The harmonic freq. of BPFO match with the
  readings.

Recommendation
The bearing outer race is in the third stage of
failure and has to be replaced.
Note harmonic means 1x(freq), 2x(freq), 3x(freq)
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Conclusion

• I have been exposed to different types of
  rotating equipments.
• I have gained good experience in analyzing the
  vibration readings and recommend the proper
  action.
• I have given the opportunity to work in the
  Aramco Shadgham shop and dealing with different
  types of rotating machines during maintenance and
  overhauling.
• I have been allowed to make studies and
  suggestions which improve the performance and
  reliability of the vibration group.

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Thank You