Cavitation elimination in water ring vacuum pumps
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P3301 is a water ring vacuum pump used to evacuate reactor R3101. The current situation is as follows: when R3101 reaches extreme vacuum, it is necessary to shut down the vacuum pumping valve for R3101 promptly. At this time, the vacuum pump experiences significant cavitation vibrations and noise; therefore, someone needs to be present at the vacuum pump to address the cavitation issue immediately. In other words, two people are required to operate simultaneously at both R3101 and P3301 (since R3101 and P3301 are not on the same floor). Are there any ways to reduce the need for manual operation, that is, to allow operation by one person, while ensuring that no air enters R3101 once an extreme vacuum has been achieved?
Thank you for the answer! Could you be more detailed?
1. There is a problem with the diagram: the process flow at the water ring vacuum pump is not fully shown. One option involves continuous water supply and drainage, while the other includes a cooling unit and a liquid separation tank. It’s not clear which of these configurations is used 2. What is the vacuum level required for the reactor? 3. Vacuum pump cavitation occurs because water is in a boiling state at high vacuum levels; the boiling point of water is proportional to pressure, with lower pressure resulting in a lower boiling point. 4. Solution: 1 is to add a loop between the outlet pipe and the inlet pipe of the vacuum pump, and install a valve on this loop for operation ； 2 is to find a way to lower the temperature of the water in the vacuum pump, bringing it below its boiling point at that pressure.
Just make an automatic valve that interlocks with the vacuum pressure. Cavitation in water ring vacuum pumps is inevitable when you create a very high vacuum level.
Continuous water replenishment. We’re now trying to lower the water temperature. Installing the cavitation protection tube also requires two people to operate it
Reduce the intake air temperature to supercool it
It is also possible to consider adding an inverter; after vacuum extraction is completed, the output power of the motor can be reduced by adjusting the inverter, thereby decreasing the amount of air being pumped out
The simplest method: replace the pneumatic cut-off valve on the second floor, which can be operated from the control room.
Replace it with a pneumatic shut-off valve at R3101. The cavitation protection section can also be replaced with a solenoid valve. It can be controlled simply by integrating it into the operation box