Blower Differential Pressure 1

[riverhound]

I am new to blowers and need a little help. If I have a inlet pressure of 12 psia on the inlet side of the blower and a differential pressure of 6 psi what does that tell me? I expect it means the outlet pressure is 6 psi and 6 psi is lost to the equipment? If I was using this blower for aeration would the available psi for a diffuser be the 6 psi minus the friction losses? Thanks for the help

 

[Ron]

How can you have a positive pressure on the inlet side?

Outlet pressure minus friction losses is correct for diffusers.(Then consider depth of water)

 

[riverhound]

Thanks for the reply. Some information I looked at said the inlet pressure was 12 psia, which I take as 12 lb/in^2 atmospheric for the elevation of the blower. Can you explain why the pressure should be negative on the inlet side then. Thanks again.

 

[bimr]

The notation psia means "atmospheric" pressure. Atmospheric pressure at sea level is 14.7 psia = 0 psig. "g" stands for gauge pressure.


psig is pressure relative to a reference point, typically ambient pressure (usually safe to assume 14.7 psia, unless your calculation is for a pressure relative to that in a liquid column, e.g. at seabed conditions).

12 psia would equal -2.7 psig.

Ask your supplier what the blower discharge pressure is.

 

[bimr]

Pressure measurement is a reference to nominal sea level atmospheric pressure of 14.7 PSIA. For example, a blower producing an outlet pressure of 17.7 PSIA at sea level is creating a differential of 3 PSI.

A differential pressure of 6 psi across the blower should be a discharge pressure gauge reading of 6 psig.

 

[riverhound]

Thanks for all your answers