Causes And Treatment Of Impeller Damage Of Horizontal Multistage Pump

Causes and treatment of impeller damage of horizontal multistage pump

Impeller is the main part of horizontal multistage, mainly including open, semi open and closed. The impeller of horizontal multistage pump is damaged in the following conditions and treatment methods:

(1)Wear and treatment of impeller ring of horizontal multistage pump

After the horizontal multistage pump runs for a period of time, most of the impeller ring will wear. The slight wear degree can be expanded on the inner hole of impeller with mould on lathe, and then the worn part can be turned. In order to maintain the original clearance, the mouth ring or guide vane bushing is used. The displacement of the mould after trimming will cause the eccentric problem of the impeller ring. It is necessary to deal with the radial and axial runout of the rotor, measure and adjust the axial spacing between the pump shaft components, so that the spacing between the adjacent impellers, the total spacing between the first and last stage impellers and the spacing between the pads installed between the segments are the same. When the balance disc seat is close to the balance disc, the width of the control impeller outlet is within the width of the stator inlet.

(2)Cavitation damage and treatment of horizontal multistage pump impeller            Impeller cavitation, also known as impeller decay, refers to the flow of liquid in the pump and the pressure at the inlet of the impeller is lower than the liquid saturation pressure, part of the liquid evaporates, when the bubble reaches the high-pressure area, it suddenly condenses, making the surrounding liquid as a supplement appear the problem of hydraulic impact. Continuous local impact on the impeller surface results in many honeycomb like cavities on the metal surface and regular distribution. Treatment of impeller cavitation:

①During installation, the height of horizontal multistage pump shall not exceed the actual suction height of the pump, and the length between the water inlet of the pump and the suction pipe shall be shortened, and the valve and elbow shall be reduced.

②It must be set according to the rated parameters of the water pump to ensure the safety and reliability of the rubber pad of the water inlet pipeline and the joint, and pay attention to check the fastening of the joint bolts.

③It is forbidden to stop the pump in the process of pumping, and the appropriate depth of suction pipe shall be selected to avoid over depth.