Vacuum pump start up sop

[sandipr]

Dear All,

I want to know the standard operating procedure for start up of any liquid ring vacuum pump. also is there any effect on pump performance if seal flow is more than the required flow.

 

[JohnGP]

Hi sandipr,
The vacuum pump manufacturer is always a good place to begin, for start up procedure. Also, different setups will require specific procedures. But basically, a liquid ring vacuum pump must not be run dry, so the service liquid source must be functional and pump filled at least half full, the suction and discharge valves to the pump opened, pump started, and service liquid flow checked to be at the recommended preset value.
There will be an ideal flow rate for the liquid - too much and the volume of vapour moved by the impeller(s) is reduced, thereby reducing efficiency and performance, and possibly overload the motor. Too little liquid flow and the pump won't be able to pull the design vacuum.
There's more to consider such as whether the service liquid is recycled, so maybe cooling water to a heat exchanger to setup or get going, but not if once through.
Just some of my thoughts anyway,
Cheers,
John