Selection and Application of Screw Pumps

Screw pumps are widely used in wastewater treatment plants for transporting water, wet sludge, and flocculant solutions due to their characteristics such as variable flow delivery, strong self-priming capability, reversibility, and the ability to convey liquids containing solid particles. The selection of a screw pump should follow the principles of being economical, reasonable, and reliable. If not carefully considered during design and selection, it can cause difficulties in future use, management, and maintenance. Therefore, selecting a screw pump that meets actual production needs and is reasonably reliable can ensure smooth production and reduce repair costs.

1. Selection of Screw Pump Speed
The flow rate of a screw pump is linearly related to its speed. Compared to low-speed screw pumps, high-speed screw pumps can provide increased flow and head, but their power consumption is significantly higher. High-speed operation accelerates wear between the rotor and stator, leading to premature failure. Additionally, the rotor and stator in high-speed pumps are shorter and prone to wear, thereby shortening the pump's service life.
It is more reasonable to reduce the speed through a reduction mechanism or variable speed drive, keeping the speed below 300 rpm. Compared to high-speed screw pumps, this can extend the service life by several times.

2. Quality of Screw Pumps
There are many types of screw pumps. Generally, imported screw pumps have a reasonable design and high-quality materials but are more expensive, may have inadequate service, high spare part prices, and long lead times, which could affect normal production.
Most domestically produced pumps imitate imported products, and their quality varies. When selecting domestic products, considering their cost-effectiveness, it is advisable to choose low-speed pumps with long lead screws, high-quality drive components, and long-rated service life.