Regarding the issue of excessive vibration in the outlet pipeline of centrifugal pumps
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Centrifugal pump, with an inlet pipe of DN80; at a distance of 50 cm from the pump, there is a drain at the bottom of the inlet pipe, approximately DN25 in size. Due to current requirements, an additional hose will be added for the exhaust modification. Material is pumped from the inlet discharge line to an outlet tank via this centrifugal pump. Problem: Every time the centrifugal pump is started to drain the material, the pump emits abnormal noises and the outlet pipeline vibrates severely. I wonder if any experts have any good solutions. Thank you!
My understanding of this process is not very good; these are just guesses for reference only. If the material is removed from a centrifugal pump, the pressure at its inlet decreases, which leads to cavitation as a result of this reduced inlet pressure. The problem lies in the fact that normal operation can only be restored if the suction pressure at the inlet of the centrifugal pump remains at or above the specified parameters. For reference.
1) To prevent cavitation, the diameter of the pump inlet pipe must be larger than the diameter of the pump inlet； 2) The inlet pipe adopts a top-level structure, with a sewage discharge valve at the bottom ； 3) Add a section of straight pipe (length: 3DN) from the diameter change point of the inlet pipe to the pump inlet to avoid noise ； A straight pipe is also added at the pump outlet, followed by a diameter change ； 4) Install fixed brackets on the inlet and outlet pipes ； The reducer joint causes a sudden change in fluid flow velocity, leading to flow deviation and increased noise ； Therefore, it is recommended to make revisions according to three measures. We also need to take a close look at the piping design and operating conditions.
According to the standards, the diameter at the inlet of a centrifugal pump generally needs to be larger. It is recommended to use a diaphragm pump with a temporary pipe for pumping, which is better.
The question you raised is quite unusual. Do you mean adding a pipe at the bottom of the pump’s inlet tube to feed material into the outlet tank? What are you trying to do? What principle? To be honest, I’m completely confused! Just do exactly as mentioned on the 3rd floor!
Bro, your idea is a bit strange. Try it a few more times and just burn this pump away – it doesn’t deserve to suffer like this!
……My understanding is that material is drawn out through that 25-inch discharge port using a hose, and then sent to a tank with the help of this centrifugal pump. The noise and vibration are likely caused by the fact that the feed pipe is too small; the low flow rate leads to cavitation. Reducing the flow rate at the pump’s outlet might help.:lol
This post was last edited by July VV Flowing Fire on 2022-5-20 at 14:39. It’s likely that cavitation is caused by too high resistance at the pipeline inlet