Sludge screw pumps are widely used in sewage treatment plants for transporting water, wet sludge, and flocculant solutions due to their variable conveying, strong self-priming ability, reversibility, and ability to transport liquids containing solid particles. The selection of screw pumps should follow the principles of economy, rationality, and reliability. If the design and selection are not carefully considered, it will bring trouble to future use, management, and maintenance. Therefore, choosing a screw pump that is reasonable and reliable according to actual production needs can ensure smooth production and reduce repair costs. Below, Yangtze River Pump Industry brings you some tips for selecting and using sludge screw pumps.

1、 Choose the speed of the screw pump:

The flow rate and speed of a sludge screw pump are linearly related. Compared to low-speed screw pumps, high-speed screw pumps can increase flow rate and head, but their power is significantly increased. High speed accelerates the wear between the rotor and stator, which inevitably leads to premature failure of the screw pump. Moreover, the length of the stator and rotor of high-speed screw pumps 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 continuously variable speed mechanism to reduce the speed and keep 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、 Consider the quality of screw pumps:

There are many types of screw pumps on the market now. Relatively speaking, imported screw pumps have reasonable designs and excellent materials, but their prices are relatively high, and some services are not up to par. 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, and the quality of the products varies greatly. When selecting domestically produced products, when considering their cost-effectiveness, low speed, long lead, excellent transmission component materials, and long rated life are chosen.

3、 Ensure that debris does not enter the pump body:

The solid debris mixed in wet sludge can cause damage to the rubber stator of the screw pump, so it is important to ensure that the debris does not enter the pump chamber. Many sewage treatment plants have installed crushers before the pump, and some have installed grid devices or filters to prevent debris from entering the screw pump. The grid should be cleaned up in a timely manner to avoid blockage.

4、 Avoid material breakage:

Screw pumps are never allowed to operate in the event of material breakage. Once this occurs, the rubber stator will instantly generate high temperatures due to dry friction and burn out. Therefore, the integrity of the crusher and the smoothness of the grille are necessary conditions for the normal operation of screw pumps. Therefore, some screw pumps also install a material breakage shutdown device on the pump body. When material breakage occurs, due to the self-priming function of the screw pump, a vacuum will be generated in the chamber, and the vacuum device will stop the screw pump from running.

5、 Maintain a constant outlet pressure:

Screw pump is a type of positive displacement rotary pump. When the outlet end is blocked, the pressure gradually increases to exceed the predetermined pressure value. At this point, the motor load increases sharply. The load on transmission machinery related components may also exceed the design value, and in severe cases, motor burnout and transmission component fracture may occur. In order to avoid damage to the screw pump, a bypass overflow valve is usually installed at the outlet of the screw pump to stabilize the outlet pressure and maintain the normal operation of the pump.

Performance parameters of G-type single screw pump: