Pumping from a vacuum vessel
Pumping from a vacuum vessel
(OP)
For some years we have been manufacturing a system which uses a positive displacement screw pump to remove liquid from a vacuum chamber. To prevent cavitation we keep a metre of liquid above the pump suction port and keep the suction line twice the diameter of the port as close to the pump as possible before reducing to the port size.
I have wondered if a centrifugal pump would have less trouble with cavitation and let us run the vacuum vessel "dry". Or would I still need to keep a head over the pump suction.
Delivery pressure is 2 to 6 bar, vacuum tank pressure above the liquid is 1 to 5 millibar absolute.
Has anybody got experience with this, Don't tell me to ask the pump manufacturer, because we are already successfully using the screw pump outside the manufacturer's specs.
Thanks,
Jeff
I have wondered if a centrifugal pump would have less trouble with cavitation and let us run the vacuum vessel "dry". Or would I still need to keep a head over the pump suction.
Delivery pressure is 2 to 6 bar, vacuum tank pressure above the liquid is 1 to 5 millibar absolute.
Has anybody got experience with this, Don't tell me to ask the pump manufacturer, because we are already successfully using the screw pump outside the manufacturer's specs.
Thanks,
Jeff





RE: Pumping from a vacuum vessel
RE: Pumping from a vacuum vessel
ET
www.vacuum-guide.com
RE: Pumping from a vacuum vessel
International College
Naresuan University
Phitsanulok
Thailand
RE: Pumping from a vacuum vessel
The fluid is transformer oil sg about 0.8, and we are degassing and drying in the vacuum chamber, so we can't let any air in before or after the pump. The equipment is often on portable skids or trailer mounted, so we are limited in height. The reason we are using screw pumps is because the customer we build them for is an agent for these pumps and wants to maximise the amount of their product in the plant, but this might change if it becomes more "cost effective" to use a centrifugal pump. I hadn't thought about a side channel pump.
Thanks
Jeff
RE: Pumping from a vacuum vessel
talk to the experts for this application listed on
www.vacuum-guide.com/firmenlisten/produkte/vacuum_impregnation.htm
ET
RE: Pumping from a vacuum vessel