Cryogenic Heat Exchangers

[EmmanuelTop]

Hello to forum members,


I would like to get some advices regarding exchanger selection for turbo-expander cryogenic plants (LPG recovery).

The lowest temperature which I will have in those exchangers is about -50C. Operating pressure goes all the way up to 100bar, and in some exchangers the differential pressure (pressure difference between hot and cold side) is more than 75bar. Flowrates are also quite substantial, ranging from 150,000kg/h to 200,000kg/h. Duties up to 8MW.

In general, I know that alluminum brazed plate-fin exchangers, printed-circuit exchangers, and Packinox-type of exchangers are suitable for such process conditions. I was hoping to get feedback from forum members, particularly from those people who have hands-on experience in cryogenic plant design and operation.

Best regards,

 

[EmmanuelTop]

It appears there is an association of brazed alluminum plate-fin exchangers manufacturers, called ALPEMA. The website is:

http://www.alpema.org/

ALPEMA offers PFHE standards for free:

http://www.alpema.org/standards.exe

I'm still looking, however, to find out if there are forum members with hands-on experience in cryogenic turbo-expander plant heat transfer equipment.

Best regards,

 

[pmover]

Yes, it has been about 7-years since I last spec'd a plate fin exchanger for turbo-expander gas processing facility.

What are you particularly interested in?

-pmover

 

[EmmanuelTop]

I would like to hear expert's opinion about the most suitable heat exchanger for service(s) described above. One of them is Inlet Gas/Residue gas exchanger, the other one is Deethanizer reflux condenser. Duties are 5 and 8MW.

Also, what vendors would you recommend for this application?

 

[dcasto]

this is the defacto standard. They have bought up all the other companies that made plate-fin exxchangers

http://www.chart-ind.com/app_ec_heatexchangers.cfm

sounds like about 150 MMSCFD plant to me.

The reflux condensor, would be a shell and tube. Do you mean you have a demethanizer at -120F reflux condensor?

 

[EmmanuelTop]

Hi DCasto,

Actually I have an LPG recovery plant with absorber-deethanizer system (very similar scheme with OHR process developed by Ortloff Ltd.), with absorber overhead temperature -50C. One of my concerns is finding suitable heat exchanger capable to withstand high differential pressure between the hot and the cold side of exchanger - for example, the difference in stream pressures is higher than 75bar for Inlet/Residue gas exchanger.

Thanks for the link. If you have any more comments I would like to hear them as well. Yoo seem to be Operations guy, and these are the people whose opinion I respect the most. No offense to others, of course.

Best regards,
Emmanuel

 

[maddocks]

I'd probably go with a BAHX (brazed aluminum) but delivery can be a serious problem. You may need to consider a more traditional stainless shell and tube if your schedule is tight.