Aug 29, 2020
The reasons for the idling of the centrifugal pump are: the inlet medium of the water pump is insufficient or the inlet pressure is not enough, or the water inlet pipe of the water pump is blocked, or the air in the water pump cavity is not exhausted.
When the centrifugal pump is idling, the impeller does not touch or seldom touches the medium, it cannot work effectively, and the liquid cannot be sent out normally. These are all useless work. Because there is no effective work, the load on the motor is very small, and the current generated is also very small. There will be no impact on the motor. The idling of the water pump is indeed fatal to the pump.
Idling water pumps are prone to cavitation, causing damage to the pump body and flow parts; idling water pumps with mechanical seals or packing seals will not be lubricated by liquid, resulting in dry grinding and rapid damage; idling water pump rotors The components and pump body will heat up, and there will be no liquid cooling. The narrow gaps (such as seal rings) are easily seized by the effect of heat expansion and contraction; the idling multi-stage centrifugal pump balance plate will not be lubricated by anyone, and the balance plate will quickly Burned to death, damaged.
For early warning and maintenance of the centrifugal pump idling, it is recommended to improve the design of the centrifugal pump to a higher level:
1. Treat each gap position of the centrifugal pump and expand it under allowable conditions to prevent seizure;
2. The shaft of the centrifugal pump is subjected to special process treatment, quenching and tempering, heat treatment, etc., to increase the hardness, and use low-flexibility materials to prevent large swings and seizures during idling;
3. Use mechanical seals and packing cavities that do not need to be lubricated by liquid media; 4. Use enclosed self-lubricating bearings that do not require oil.
Compared with other centrifugal pumps, the pump cavity of the horizontal self-priming centrifugal pump has an increased volume and has a place where water can be stored. Before the self-priming centrifugal pump works normally, the cavity must be filled with liquid. There is a period of self-priming before operation. During this period of time, air is continuously discharged to the outside of the pump. This period of time is partly idling.
Set up idling induction system. The water pump is monitored in real time through modern equipment. When the centrifugal pump is idling, it immediately alarms and automatically shuts down to protect the safety of the unit.