Maximal temperature for high head pump 1

[NghiaPP]

I 'm interesting to know what is the maximal temperature a high head pump can work ?
The pumping fluid is gas oil at few bars on suction side. Discharge pressure is 50 to 100 bar. The question is raised when I want to recover as much as possible heat from the low pressure section of the plant. Cross heat recovery from low pressure section to high pressure section is not preferred due to requirement of pressure relief system, which involves both gas and liquid relief in case of tube rupture.
I would appreciate if anyone could share experiences around operation and reliability of high head pump operated at temperature from 200 to 250 deg.C

 

[sshep]

We have some multistage pumps operating at higher temps than what you are dealing with. It can be done, but generally I think we try to avoid pumping any fluid which is above it's autoignition temp. Pumps can leak, seals fail, etc. Unfortunately, sometimes it is simply impractical not to pump fluids under these conditions. When you must then design with safety in mind- deluge system, MOV's for isolation, good firewater coverage, mechanical seals instrumented for shutdown on pressure, etc. The safety trade-offs of pumping vs your other concerns may not make pumping any better than your other alternative.

If this change is being considered simply for energy recovery then you might consider using an intermediate heat transfer medium. For example use your 250C waste heat to generate a medium pressure (15 bar) steam which can be used for heating elsewhere. We also use plenty of double shell units using an intermediate fluid in cases where we don't wish to directly pair incompatible fluids- this may allow other options to mitigate some concerns of how to handle an exchanger leak since the low pressure piping will not be exposed to high pressure in event of a leak.

just a thought- sshep

 

[NghiaPP]

Thank very much for your advices. The safety is a good point. I’m trying different process layouts in a study of process optimization.
Based on only one response, I suppose the high operating pressure is not very common in refineries. Searching of pump vendor shows that there are limit on operating temperature, possible due to sealing system.