Compressed Air Sizing

[esfo71]

Hello,

I am currently sizing a Compressed Air Network (Compressor CFM, HP, and Line Sizing) for a plant which has air service stations and pumps that are run by air. There are 13 Oil Supply Pumps (80 CFM @ 75 PSI each), 20 Waste Oil Return Pumps (40 CFM @ 75 PSI), and 31 air service stations (38 CFM @ 100 PSI each used for impact guns, for example).

How would I size the CFM required for the Compressor taking into account different facors like: Simultaneous Factor, Variability Factor, and Usage Factor?Also, I really am having a hard time sizing the piping for each branch. Can somebody explain to me how to do it knowing the CFM at the compressor?

I am very new when it comes to compressed air and was wondering if there was an online example, tutorial, or reference I could base myself on. Thank you.

 

[quark]

The first step is to check whether the compressed air requirement mentioned is SCFM or ACFM (I believe it should be SCFM).

Second step is to check what is the average consumption and what is the maximum consumption based upon diversity factors. You are the best judge for this.

To some extent, you can select the compressor based on average load and the receiver on maximum load. I can't be of much help unless I know these two values.

Split the piping into two networks with 100 PSI and 75 PSI pressures.

Refer Spirax Sarco's Compressed Air data book for system design.

Refer Crane TP 410 for pipe sizing.

The following links will be useful to you.

http://www.pyebarker.com/TechTips/techtip3.htm

http://www.kostic.niu.edu/Design-Methods-Intro2_452/sld001.htm

 

[MechEngNCPE]

Check out and get in touch with your local Atlas Copco rep. They can provide great guidance for this design. Ingersoll Rand would be another option. Tip - you can oversize your piping for the pneumatic impact guns, etc. to provide a little more storage capacity if you are worried about not having a reciever.

 

[chicopee]

Most compressor manufactors/distributors have in-house handouts that will address your inquiry.

 

[esfo71]

I uploaded the proposed layout for the compressed air network. Any suggestion would be appreciated. Some sample calculations or methodolgies based on the drawing would also be appreciated to get me going. Thank you.

http://files.engineering.com/getfil...-0bb6839ad0af&file=Compressed_Air_Network.pdf

 

[KiwiMace]

For Pipe Sizing you should use the following, which is fairly easy to spreadsheet and use.
Weymouth Formula for High Pressure Compressible Gas Flow
Equation 3-12 Crane 410 Page 3-3

Not sure if you were planning to use a receiver. These are typically sized around 2.5 USGal per CFM. Benefits include: reduce condensate into piping, reduce pressure variation in network, reduce compressor starts or load/unload cycles, reduce compressor peak capacity, longer compressor life.

Piping: Main water trap and filter at receiver, tap from top of pipe, filter, water trap and oilers at each station, No galv pipe after filters. Don't run main drops in anything less than 1/2" pipe even if the hose size is 3/8".