Pressure drop in pipelines for compressible gases 2

[ormsby]

Does anyone have a good source (book, test, memo, etc.) or even a written formula that I can use to calculate the pressure drop from landfill gas in a pipeline to an end-user?

Many Thanks,

Ormsby

 

[zdas04]

There's a million references. The one I find most useful Crane Technical Paper 410. There have been comments in this forum that it is out of print, but it is recently back in print (both Imperial and Meteric versions) and available at

http://www.cranevalve.com/tech.htm

for $36 US.

The GPSA Engineering Data Book is also very good, but it is a lot more expensive.

What pressure is the landfill gas running at? Below about 5 psig you'll have a pretty hard time getting any of the equations out there to accurately reflect reality. The assumptions that went into the calcs just assume higher density than you get from way-low pressure gas. I don't have a good solution other than to take the calculated volume with a large grain of salt (and oversize your pipe a size or two).

David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

 

[Akhibi]

I have often used this equation for the compytation of pressure drops for compressible gasses.

?p = 1.6 x 10^8 x V^1.85 x L
-----------------------
d^5 x P

?p= pressure drop (bar)
V = free air flow (m3/s)
L = pipe length (m)
d = inside pipe diameter (mm)
P = initial pressure (bar)

Greg Akhibi
SPDC Nigeria