Looking for assistance with closed loop inert gas process system blower requirements. In an open system discharging to atmosphere the calculated system pressure drop (PD) would be "X". Now,
same system in a closed loop arrangement returning the process gas to the system inlet, we have an actual PD of approx. 2X with regen blower maxed out. The excessive PD in the closed loop introduces air leak issues into the system along with excessive energy consumption and most of all, unstable blower performance. I have found that with insufficient gas volume within the closed loop system, the blower will operate off of its design curve (beyond designed PD). When you add volume to the system by adding an inline vessel or tank you will lower the PD and get a performance from the blower as if it were in a standard open system. It is as if the blower is starved for air.

I need to show that we can eliminate the high PD problem by adding gas volume to the system and I need to know how to calculate how much volume would be required for a blower to perform as if or almost as if it were in an open system. Any ideas or experience sharing would be greatly appreciated. This is the second time dealing with the same trouble in a closed loop system.
Thanks
Mike