Question on a Compressed Air Leak 1

[Kisic7]

Does anybody know how to calculate the CFM on a compressed air leak when the air is not blowing into the atmosphere but into a liquid like the pickling acid?

I am trying to replace a compressed air bubble-system agitator with an energy efficient eductor in a tank mixing application. However, I do not know how to estimate the amount of air that is currently being blown through the agitator. I know that the agitator is currently blowing compressed air from a 1/8” pipe, and the CA line pressure is 95 psig. I do not know the density or the temperature of the acid being mixed but I can easily get that information if I find some use for it. Is there an equation for CA leaks that deals with the situation of leaks underwater or other liquids?

Please help

 

[zekeman]

W=A*sqrt{2kg/(k-1)*(p1/v1)[(p2/p1)^2/k-(p2/p1)^(k+1)/k]} where p1 is air pressure and p2 is liquid pressure and A is the orificw area. If the liquid pressure is less than 53%of the air pressure you have "choked" flow where the airflow is determined by an adiabatic expansion of the air to 53% at the orifice where it reaches acoustic velocity and the flow equation is the above except that .53 is substituted for p2/p1. The additional terms in the flow equation are
k= ratio of Cp/Cv
g=gravitational constant





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[bobc]

try this site for simple solutions.

http://www.scottsemicon.com/Ref_Airflow.html

bobc

 

[Kisic7]

Thank you for your responses.

zekeman, that equation seems to be a standard air-leaks equation only with a correction factor for the discharge pressure in the liquid, pressure being dependant on the depth. Do you know if viscosity of the liquid plays any role in the cfm output?

bobc, I believe that the link you provided only explains how to handle gasses other than air being compressed. Would you happen to have any quick-lookup cheat sheets on compressed air being discharged into a liquid?



Kisic7

 

[arto]

Don't know if this is helpful, but:
ANSI/FCI 70-2 used to convert air/N2 leakage rates in valves as
"1 Bubble/minute = 0.15 ml/min"
so I guess a bubble = 0.15 ml