Gear pumps often get stuck
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There are currently two vacuum distillation columns, A and B. Column A operates at an absolute pressure of 1000 Pa, while column B operates at 200 Pa. A high-vacuum gear pump is located at the bottom of column B to serve as a circulation pump. There is also a high-vacuum gear pump under Tower A that supplies fluid to the circulation pump. When Tower A becomes empty during shutdown, the gear pump located beneath it gets stuck; this happens every time it shuts down. I would appreciate it if someone with expertise could tell me what causes this How to solve it
No impurities, there is a filter in front
You can try increasing the precision of the filter; sometimes, insufficient filter precision can also cause things to get into the gear pump
We are in the oil processing industry, and by the time of distillation, it’s basically impossible for there to be any mechanical impurities. Tower A is for the light-phase separation; its temperature is around 190 degrees. A small amount of oil may undergo polymerization, coking, carbonization, etc., but based on the situation regarding pump removal, this is not the main cause.
Dry operation is possible; by design, Tower A only has an upper limit for liquid level, and it is not convenient to install a sight glass at the bottom of the tower. When the system is shut down, it is necessary to rely on visual observations to determine whether the bottom of the tower is empty, which can result in short periods of dry operation.
After the goaf is created, the pump runs idle, and it is prone to jamming without coolant.
Could you elaborate on how dry running affects whether a pump can function? Is there any solution? Please give your advice
1. I think it’s a question of whether the tooth gap size can be adjusted； 2. Choose a motor with a higher torque ； 3. Reduce the pressure difference at the entrances and exits.