LIQUID SLUGS VOLUME ? 1

[SILVERSTONE]

Hi everybody,

I have to design a slug catcher device to protect a screw compressor.
These compressors being able to work even if gas is mist containing, I'm interested by the cheapest solution : using a 16" pipe as slug catcher. To design it i need to know the volume of slugs wich could occur.
Is there a way to estimate slugs volume for a given pipe network ?

 

[zdas04]

In spite of all evidence to the contrary, slug-catcher design is much more art than science and you've hit upon the crux of the difficulty.

There are many rules of thumb for predicting slug size, but none of them work for all situations. I always start this exercise by looking at the system and trying to come up with a credible event that could put liquid into the system (with a screw compressor, your line pressures are probably pretty low so don't forget accumulated condensation). Next look for a place to accumulate a slug (usually a sag in the line). The volume of the accumulator should give you a hint as to the size slug you can get. Then triple it because there probably is an accumulator spot that is bigger than the one you found. That is the starting point for the design of the slug-catcher volume.

Good luck, none of these things are ever perfect so you have to try to err on the side of too much reserve capacity.

David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

The harder I work, the luckier I seem

 

[SILVERSTONE]

Thank you zdas04 for your answer.
I 'll look at my pipe network with more care.

 

[JDJ60]

Silverstone:

The man that invented and commercialized the B31.8 finger style (pipe) slug catcher is Norm Eagleton. Norm designed this style slug catcher 30+ years ago. I had the opportunity to work with him at Eagleton Engineering in Houston. Norm sold the company a few years ago but is still around. I would suggest you call Eagleton Engineering and get Norm's telephone number.