What’s the problem with a water pump pulling water in the reverse direction?
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In the workshop, there is a negative-pressure distillation process using an intermittent tower, along with a water-jet vacuum system; water keeps being drawn back into the buffer tank. What could be the reason for this?
The nozzle is worn, resulting in insufficient flow rate. The nozzle centering is poor. The water pressure is not sufficient. Check all these aspects.
Nozzle wear has worsened, and the exit flow velocity is insufficient； The nozzle is eccentric, which may lead to welding failure ； The water pump has insufficient flow and pressure; the intake area may be partially blocked. Also, check whether the check valve is in good condition.
If the gas phase coming out of the distillation tower is not completely condensed, it may carry liquid into the vacuum buffer tank (part of the gas phase passes through the condenser before being further condensed).
Is the check valve damaged?
The material processed in my tower tends to crystallize, and there is also some vacuum leakage in the entire distillation tower. There is always some crystallized material in the check valve and the buffer tank. The vacuum pump was replaced once; it’s not new, but it works slightly better than before. I’m not sure if this is related to the check valve being clogged by the material.
No. However, the material used in tower distillation tends to be drawn into the pump and to crystallize; often, there is a lot of crystallized material in the check valves
Obviously, it’s a problem with the check valve……
Let me tell you, I often disassemble jet pumps. 1. Check the pump impeller to see if there is any blockage. 2. Disassemble the jet pump and inspect the orifice plate to determine if it is blocked or if the holes in the orifice plate have enlarged (due to dirty water or foreign objects). 3. Check whether the steam supply to the distillation tower is stable