Cavitation problem in self-priming pumps
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Brothers, when using a self-priming pump to draw low-boiling-point reagents such as acetyl chloride in summer, the pump stops working after drawing for a while – how can this be fixed?
Factors that affect the self-priming performance of self-priming pumps include viscosity, specific gravity, boiling point, etc. The self-priming height of a self-priming pump is determined based on tests using water; the higher the viscosity, the lower the self-priming height and the lower the load on the pump. Use is prohibited once this value exceeds the rated limit ； The higher the specific gravity, the lower the suction pump height; this changes in proportion to the specific gravity of the medium ； The impact of boiling point on pumps is primarily evident in solvents with low boiling points; under negative pressure, the boiling point of these solvents decreases. When the ambient temperature exceeds this reduced boiling point, the solvent vaporizes, and the self-priming pump is unable to draw in fluid. Therefore, when transporting solvents, it is necessary to consider not only flow rate and head parameters but also the pump’s self-priming capability. The pump must have sufficient self-priming height; thus, self-priming pumps with good self-priming properties should be selected. Options such as the SFBX stainless steel self-priming pump, the ZXPB stainless steel explosion-proof self-priming pump, and the VSP explosion-proof high-performance vacuum self-priming pump can be considered.
The device’s net positive suction head is insufficient; it definitely can’t draw in fluid
1. Try to reduce the temperature; 2. Decrease the self-priming height; 3. Use a positive-displacement pump
If this phenomenon occurs every summer, it is related to the net positive suction head. It must be solved by raising the liquid level and lowering the liquid temperature. If it was working well in the past but not anymore, then it is necessary to conduct a thorough inspection of the section from the self-priming pump to the connection pipe to check for any air leaks, for reference.
A good example! In addition to the suggestions made by the experts above, it is also necessary to check whether there is any resistance in the pump inlet pipeline
I’ve encountered situations where the light-oil pump does not deliver the required flow rate in summer; generally, this is due to nitrogen being used to pressurize the underground pipes, the pump body needing to be vented, and the pump and its head requiring cooling. There is no perfect solution to this issue, so one can only look for key points in the operation process – as the saying goes, it comes down to intuition. . . . . An experienced driver driving with a newcomer on the road