The harm and prevention of water pump idling

Idling in the operation of the centrifugal pump is not allowed, the majority of users for the idling of the centrifugal pump "talk", the reason for this is because the cause of idling phenomenon do not understand, and do not understand how to solve it. In fact, the centrifugal pump will not cause damage in a very short period of idling (within 1 minute).

The reasons for centrifugal pump idling are: the inlet medium of the pump is not sufficient or the inlet pressure is not enough, or the inlet pipe of the centrifugal pump is blocked, or the air in the centrifugal pump chamber is not drained.

When the centrifugal pump is idling, the impeller does not contact or rarely contacts the medium, can not work effectively, and the liquid can not be transported out normally, which are useless work. Because there is no effective work done, the load on the motor is very small, the current generated is also very small, and the impact on the motor will not be anything. Centrifugal pump idling effect on the pump is indeed fatal, idling pump is easy to cavitation, the pump body and flow parts caused damage; Idling centrifugal pump mechanical seal form or packing seal form idling, will not get liquid lubrication, resulting in dry grinding, thus rapid damage; Idling centrifugal pump rotor components, pump will heat, no liquid cooling, by the effect of thermal expansion and contraction of the narrow gap position (such as sealing ring) is easy to bite; The idling centrifugal pump balance plate does not have any lubrication, and the balance plate will soon be burned and damaged.

When warning and maintenance of centrifugal pump idling, it is recommended to improve the design of centrifugal pump:

First, the various clearance positions of the centrifugal pump are treated and expanded under permitted conditions to prevent biting;

Second, the shaft of the centrifugal pump for special processing, tempering, heat treatment, etc., to improve hardness, with low flexibility of the material, to prevent idling large swing and kill;

3, the use of seals and packing cavities that do not need to rely on liquid medium lubrication;

Four, the use of closed self-lubricating bearings without refueling.

Compared with other multistage pumps, the volume space of the centrifugal pump chamber is increased, and there is a position where water can be stored. Before the normal operation of the multistage pump, the cavity should be filled with liquid, and there is a period of self-priming time before operation, during which the air is constantly discharged to the pump, and this period of time belongs to partial idling.

Set up the idling sensing system. Through modern equipment for real-time monitoring of centrifugal pump, when the centrifugal pump idling immediately alarm and automatic stop, to protect the safety of the unit.