EXAIR uses our blog platform to communicate everything from new product announcements to personal interests to safe and efficient use of compressed air. We have recently passed our 5 year anniversary of posting blogs (hard for us to believe) and I thought it appropriate to share a few of the entries which explain some more of the technical aspects of compressed air.
Here is a good blog explaining EXAIR’s 6 steps to optimization, a useful process for improving your compressed air efficiency:
One of the Above 6 steps is to provide secondary storage, a receiver tank, to eliminate pressure drops from high use intermittent applications. This blog entry addresses how to size a receiver tank properly:
Thanks for supporting our blog over the past 5 years, we appreciate it. If you need any support with your sustainability or safety initiatives, or with your compressed air applications please contact us.
Most facility’s compressed air systems have evolved over time. A spur added here a spur added there. Eventually pressure drop issues develop. Common practice is to increase the air pressure at the compressor. While it may address the symptom it does not address the problem and is very costly. For every 2 PSI increase in pressure requires 1% more energy.
A properly designed system will be a loop with spurs. This will ensure all air
drops will share the air equally. The header loop should be able to carry all the air the compressor is capable of producing. Best practices suggest the distribution header should be sized to allow an air velocity not to exceed 30 ft/second. The formula to calculate this is:
A = 144 * Q * Pa V *60 x (Pd +Pa)
Pipe Diameter = √ (A*4/3.14)
A = cross sectional area if the pipe bore in square inches or ∏ x diameter squared / 4
Q = Flow rate SCFM
Pa = Prevailing absolute pressure. Sea level is 14.7
Pd = compressor gauge pressure or psig.
V = Design pipe velocity ft/sec
Example: Size a header for 500 SCFM at 100 PSI at an elevation at sea level
A = 144 x 500 x 14.7 / 30 x 60 (100 + 14.7) = 5.13 square inches
Pipe diameter then is square root of (5.13 * 4) / 3.14 = 2.56″
So an 2.56″ internal diameter pipe would be the proper size header.
The same formula can be used to calculate the sizes of the drops. In this case you would use the demand flow rate for Q.