What is the reason for insufficient outlet pressure but flow rate in a centrifugal pump?
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One of our company’s alkali solution circulation pumps has a head of 28 meters, with atmospheric pressure at the inlet. From what the operators told us earlier, it is capable of reaching a pressure of 4 bar (is this doubtful? ), but after a few days of operation, the outlet pressure dropped to less than 1 bar. The outlet valve, whether fully open or fully closed, still resulted in a pressure of 1 bar; however, water flow could be heard coming from the outlet check valve. I would appreciate it if fellow sailors could help analyze why the pressure at the pump outlet suddenly stopped rising (Note: The inlet filter has been cleaned and checked to ensure it is not clogged; the pump is running very smoothly with no abnormal noises. ）
This post was last edited by geniuslf on 2009-12-10 09:33. Is it running idly? Unpack the pump head and check it. Centrifugal pumps rely on the outlet valve to regulate pressure, with pressure being inversely proportional to flow rate; opening the outlet valve fully can easily cause overload when handling caustic solution!
Is this pump a regular centrifugal pump? The outlet pressure is 4 kilograms, which means there is pressure being built up. The outlet valve is closed, and the pressure is only 1 kilogram; it’s necessary to check whether there is a problem with the pump.
Is there gas remaining in the pump that hasn’t been expelled? Open it to check for exhaust.
1. A small amount of intake air. 2. Impeller damage
Open it and check, as the alkaline solution you used may have caused corrosion to the impeller seal.
Check the outlet pressure gauge; it’s possible that there is some gas inside the pump as well
Thank you all for your guidance; I’ll try each one separately to figure out exactly where the problem lies.
9# jbxzb First, check the pressure gauge, as alkali solution is used to prevent crystallization from blocking the gauge. Check the current to see if it is at the rated value. Check the traffic. Calculate the output flow rate. Look at Yang Cheng, height. It should be possible to determine what the problem is then
Looking only at the appearance isn’t sufficient; there might be air in the pump chamber, seal leaks, impeller failures, or a loose impeller cover (this has happened in our company before, and fortunately the cover was found in the pump chambers of other pumps). It’s advisable to disassemble the pump and check it if possible! Personal opinion!