eekman56
Industrial
- Feb 6, 2007
- 7
Hello. I have a diesel operated 6" trash pump. I'm pumping from a undergound chamber which is 17' deep, 23' long and 8' wide. A 36" line dumps into the chamber @ 6' from the top. My pump suction is located at the opposite end. Vacuum gauge reading when operating is 15". On the discharge side, I have a constant reading of 35psi. The pump is operated via a float switch so the suction never runs dry, never creates a vortex. Whenever the pump turns off via the float switch, and goes to come back on, we are getting air trapped at the top of the volute and the unit won't prime for some time. The unit is equipped with a venturi type priming system which incorporates a float in the priming chamber. We put a small ball valve in the top of the volute and cracked the valve to allow for air release. We also ran a small tube from this back into the water source to ensure the priming system still works when it needs to. This seems to work most of the time, but isn't failsafe. Without it, we have torn engine couplings. We even tried an electric drive unit with the same results. I guess my question is am I dealing with entrained air and if so what are my options. Any guidence would be appreciated.