Bypass of Kickbacks

[liberoSimulation]

I don't know if this is the right place to post a question with respect to the kickback lines of the centrifugal compressors.
Does any one can share his experience in an application where bypass lines are provided for min flow recycles (Kickbacks) of a big centrifugal compressor for some purposes?
The case I'm evaluating that a big compressor with kickbacks protecting refrigeration compressor (Ethylene Compressor).

Any experience is highly appreciated

Cheers

 

[sms]

Not sure what the question is. Almost all centrifugals have kick back for surge control at least.

-The future's so bright I gotta wear shades!

 

[liberoSimulation]

Tank you sms
My question:
Is it possible to provide bypass of a kickback valve installed for a compresor?

Cheers

 

[sms]

I am still not really sure what your question is, but I have seen surge control valves with bypass lines around them so in the event that the valve fails the manual bypass can be opened providing the necessary flow to keep the compressor out of surge.

-The future's so bright I gotta wear shades!

 

[pmover]

your question is not fully understood, but the following website may be of interest:

http://www.dresser-rand.com/controls/sc0498.htm

i trust this helps . . .

there are other websites that may be helpful as well. use google and "centrifugal compressor surge control" for criteria.

good luck!
-pmover

 

[jsummerfield]

Perhaps the question pertains to block and bypass valves around a control valve as applied to the surge/minimum flow recycle valve for a major rotating machine. Generally no bypass exists around a compressor spillback or kickback valve. BTW, ethylene compressor recycle valves tend to be large expensive valves that include severe service noise treatment. I am working on just such a valve right now. We are likely going with something like a 12-stage CCI drag valve - no bypass.

John

 

[liberoSimulation]

To jsummerfield
There is no need for bypass for large expensive valve and in clean service.
Therefore, if you got a problem in the valve, you will be forced to de-inventory the refrigeration system so you can work on the valve.
This is the reason why a bypass is highly recommended to avoid above bad situation.

Do you agree?

Cheers

 

[pmover]

seems like a decision to be made by the client or operator; provided an adequate explanation from engr is provided. also, recommend conducting economic analysis of the situation. furthermore, there are trade-offs associated in operating a refrigeration centrifugal compressor in this mode of operation - very inefficient operation; basically increased fuel consumption coupled with reduction in refrigeration capacity (depends upon compressor and driver).
more thoughts to ponder . . .
first off, if problem with anti-surge valve exist, i recommend effort be focused on obtaining a valve suitable for the service and/or investigating the control system for the compressor. for normal operation, that anti-surge control valve should not be opening.
it seems that the centrifugal compressor anti-surge system (piping, valve, etc) should be installed between the compressor inlet/outlet valves. so de-inventoring the system will only be the compresor piping, drums, etc. which is not the entire refrigeration system.

hope this helps . . .
good luck!
-pmover