I’m new to the chemical industry and have some questions about centrifugal pumps; I’d like to ask the more experienced colleagues for their advice
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When installing centrifugal pumps, is it necessary to take into account the installation height in order to ensure an adequate net positive suction head? In our factory, most centrifugal pumps receive feed from a higher position; for example, there is a centrifugal oil displacement pump, and the oil storage tank is located about 3 meters above it. Is it still necessary to consider the net positive suction head in this type of feeding arrangement? Thank you very much
It is recommended to pick up a reference book on Principles of Chemical Engineering to find out.
The installation height of the pump must definitely take into account the required net positive suction head (NPSHr) specified on the pump’s nameplate. “In our factory, most centrifugal pumps take in fluid from a higher height; for example, there is a centrifugal oil discharge pump, and the oil storage tank is located about 3 meters above it. Does this type of feeding method still require consideration of NPSH? Does this refer to backflow or suction?
In your operating condition of positive-pressure transfer with backflow into the pump, there is no need to consider the net positive suction head; however, it is necessary to take the net positive suction head into account in a negative-pressure situation
Sure, progressive cavity pumps also have cavitation problems.
It doesn’t seem to be backflowing; it seems to be being drawn in
I heard them say it’s about removing the oil; it should be sucked out, not like it’s being poured back in
When installing a centrifugal pump, it is necessary to refer to the required net positive suction head indicated on the pump’s nameplate, as well as the height of the liquid level of the medium to be pumped, and carry out verification calculations. This is to prevent problems arising from an incorrect installation height that could result in the inability to pump the medium
Whether it is backflow or suction, it should be designed and installed in accordance with the pump’s nameplate; otherwise, problems such as vacuum formation are likely to occur. . .
In this case, the inlet pipe of the pump is located at a relatively high position; when considering the net positive suction head, the 3-meter height difference must be taken into account, as well as the volatility of the oil
The NPSH provided by this manufacturer is always expressed in terms of water; it varies depending on temperature and the type of medium. It isn’t necessarily true that one can ignore NPSH when the liquid level is high – the temperature and type of the medium must be taken into account.