Vent Hole Size

[Juanito70]

I would like some help on how to calculate (or an equation to use) to figure out if a vent hole the size of 5 inches is large enough to prevent a vessel from pressurizing. The vessel is 2170ft^3 and the airflow being pumped into the vessel is 80lbs/min. The vessel in at 80 degrees F and at sea level. How do I go about calculating to find out if the vent size of 5 in is enough to prevent the vessel to over pressurize? Please also let me know if I need to provide more information.

 

[rb1957]

on a simplistic level, if the outlet is a larger area than the inlet then you wouldn't expect appreciable pressure change. Of course this assumes a whole bunch of things like ...
there is good communication between inlet and outlet (not like they're on opposite ends of a maze),
that the inlet pressure is close to the vessel pressure.

if you want an accurate answer then you need to do a pressure flow analysis (like decompression). You have a vessel at a stable pressure (maybe with balanced in and out flows), an inlet flow starting at t=0, and this'll determine how the vessel pressure changes as the outlet flow adjusts to the changed inlet flow. Or maybe you've got a closed vessel and at t=0 you add your inflow and open the outlet.

btw, "vent hole size of 5inches" ... vent diameter of 5" or vent area of 5sq.in ?

another day in paradise, or is paradise one day closer ?

 

[Sparweb]

The FAQ's here:

https://www.eng-tips.com/faq.cfm?pid=378

contain several examples.


STF