There are 2 pumps with different power levels, and I’m encountering some problems during the switching process. I would be very grateful if everyone could help analyze this issue. Thank you very much
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As shown in the diagram, when shutting down the pump, one stops the left-side pump while starting the right-side one; two people are responsible for both starting and shutting it down. What’s confusing is that the pressure at the outlet of the right-side pump remains around 5 kilograms throughout the startup process. But after a while, the pressure suddenly drops to 1 kilogram, the pipes vibrate severely, and the current level is very low, far below the rated value. It is important to be aware of a few things: the pipe connections have different diameters, and the two pumps have different power levels. But it’s still a bit messy; the elements haven’t been connected yet. What causes this phenomenon, how can it be avoided, and what is its severity? Dear friends, please help analyze this. Thank you so much
The piping is too messy and not easy to see; it would be best to mark it with red lines. It’s better to connect the two units in parallel, as there are no check valves at the outlets
No check valve, and connected, thank you
The exhaust isn’t working well; it doesn’t seem to be exhausting anything
Next time, keep the inlet and outlet open for a while to vent the pipeline, then close the outlet and proceed with the operation again
The pump on the left is smaller, while the one on the right is larger; when pumps with different flow rates are switched on, they operate in parallel. You can take a look at the disadvantages of operating centrifugal pumps in parallel – the absence of check valves can cause the pumps to rotate in reverse and get damaged
To put it simply: turn right to open and left to close; it’s the vertical check valves that move, the horizontal valve in the middle remains fully open at all times, while the horizontal valve on the right remains fully closed； The purification tower is the water inlet, and the water inlet pipe has two elbows. Now, when the valve on the right is opened, the pressure is normal at first; but once it is opened to a certain extent, the pressure drops and the pipeline vibrates, right? Is there any crackling noise from the pump body? It should have nothing to do with the change in diameter in the middle; if it is caused by such a change, it will only result in higher local resistance, serving merely as a flow restrictor at the pump outlet. Moreover, if the diameter change is too significant, there will be considerable noise at the area where the diameter changes (due to high flow rates). It is likely that cavitation is occurring in the pump – the diameter of your outlet pipe is clearly larger than that of the pump’s outlet pipe, and opening the valve fully might cause the pump to experience excessive flow. In addition, there are many bends at the pump’s inlet. If the pump body emits a cracking noise, the likelihood of cavitation is higher; moreover, cavitation also causes a sudden drop in pressure and flow rate, as well as severe vibration in the pipeline and pump body. The inlet pressure of the inlet pipeline is unclear; this is the only conclusion that can be drawn
It can only be caused by cavitation. Reduced pressure, decreased current, and increased vibration in the pump and pipes are all signs of cavitation. It has nothing to do with the pipe diameter change. It should be related to the opening degree of the inlet and outlet valves, especially the slow opening of the inlet valve (check valve).
There is no check valve, and the inlet is fully open. What I can understand is that the liquid is sodium hypochlorite; gas passes through the tower, and the solution will contain some acetylene gas