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At a compressor's steam turbine, frequent vibrations are faced at Journal bearings. The vibrations go from normal 13microns to about 45 microns. Steam temp and pressure are normal We previously faced oil charring issue at the bearings and the problem was rectified by applying nitrogen in the seal. We suspect that the same problem has reappeared. Can anyone suggest how can we confirm if this is oil charring and how the issue can be resolved?
 
Answers
10/09/2020 A: Pradip kumar, Saudi Aramco, pkgpanki@gmail.com
We faced the same type of problem with 1X vibration and it was intermittent for 20-30 minutes only on the NDE of the steam turbine. It happened for a long time and was not confirmed by root cause analysis, but after one year it was clearly showing signs of rubbing. We decided to inspect the oil seal first and we found the problem - it was rubbing between the shaft and oil seal due to deposition of carbon between them. At high temperature the oil was carbonised and formed coke. Maybe you need to inspect the turbine oil seal.
18/04/2019 A: keith bowers, B and B Consulting, kebowers47@gmail.com
You should check the oil temperatures into and out of each bearing. Also test the oil for viscosities and particularly any Increase in lube oil viscosity. Monitor everything to see if vibration increase is accompanied with change in lube oil temp. Be sure and monitor the oxidation and other deterioration of the lube oil.
Are the vibration variations starting suddenly and ending the same, or, are the increases/decreases gradual over hours/days ?
That the vibrations come and go indicates shedding of deposits from the rotor as a possible factor.
28/10/2018 A: Chirag Pethani, Reliance industries ltd, pethpethanichirag3113@gmail.com
Can you provide some additional information? What is location of your gland steam condenser is it above or below turbine surface.??