News

Home > News

Selection Guide for Screw Pump

Selection Guide for Screw Pump

1、 Selection of rotational speed for screw pumps

The flow rate and speed of a screw pump are linearly related. Compared to a low speed screw pump, a high speed screw pump can increase the flow rate and head, but the power is significantly increased. High speed accelerates the wear between the rotor and stator, which will inevitably lead to premature failure of the screw pump. Moreover, the length of the fixed rotor of a high speed screw pump is very short, which is prone to wear and tear, thus shortening the service life of the screw pump.

By using a deceleration mechanism or a stepless speed regulation mechanism to reduce the speed and maintain it within a reasonable range of less than 300 revolutions per minute, the service life can be extended several times compared to high-speed screw pumps.

2、 Quality of screw pumps

There are many types of screw pumps, and relatively speaking, imported screw pumps are designed reasonably and made of high-quality materials. However, the prices are high, and some services are not up to standard. The prices of accessories are high, and the ordering cycle is long, which may affect the normal operation of production.

Most domestically produced products are imitations of imported products, with varying quality. When selecting domestically produced products, when considering their cost-effectiveness, low speed, long lead, excellent material of transmission components, and long rated life are selected.

3、 Ensure that debris does not enter the pump body

The solid debris mixed in wet sludge can cause damage to the rubber material stator of the screw pump, so it is important to ensure that debris does not enter the pump chamber. Many sewage plants have installed crushers in front of the pump, and some have installed grating devices or filters to block debris from entering the screw pump. The grating should be promptly cleaned to avoid blockage.

4、 Avoid material breakage

Screw pumps are never allowed to operate under the condition of material interruption. Once a material interruption occurs, the rubber stator will be burned out due to dry friction and instantaneous high temperature. Therefore, the intact crusher and unobstructed grille are necessary conditions for the normal operation of screw pumps. Therefore, some screw pumps are also equipped with material interruption shutdown devices on the pump body. When a material interruption occurs, due to the self suction function of the screw pump, a vacuum will be generated in the chamber, The vacuum device will stop the screw pump from running.

5、 Maintain a constant outlet pressure

Screw pump is a positive displacement rotary pump. When the outlet end is blocked, the pressure will gradually increase to exceed the predetermined pressure value. At this time, the motor load increases sharply. The load of transmission machinery related parts can also exceed the design value, and in severe cases, the motor may burn out and the transmission parts may break. In order to avoid damage to the screw pump, a return valve is usually installed at the outlet of the screw pump to stabilize the outlet pressure and maintain the normal operation of the pump.


Message