Screw spindle pumps

 

 

Screw spindle pumps, also known as twin-screw pumps, are self-priming rotary displacement pumps that are suitable for pumping water-thin to highly viscous liquids (0.5 – 1,000,000 cSt.) with or without solids. from each other and move the liquid in an axial direction. The screw spindle pumps provide a pulsation-free liquid flow and ensure low shear, which means that the structure of the liquid to be pumped is hardly affected. These pumps can also be used for pumping gaseous liquids and liquids with a temperature range between -10 and +130°C. The capacity is adjustable over a very wide range by varying the speed (150 to 3800 rpm) by means of a frequency control (5 to 130 Hz). Characteristic for these pumps are the low NPSH required (NPSHr tor 0.5 m) and the extremely low noise level.

The pumps can be supplied with different spindles, the difference being mainly in the pitch of the spindles. A large pitch usually results in a higher flow and lower pressure. A smaller pitch leads to less flow and a higher pressure. Depending on the liquid to be pumped and the operating conditions, the pumps can be supplied with various shaft seals. Special versions are also available for abrasive liquids with hardened spindles and a hardened pump housing.

In terms of dimensions, the pumps are very compact due to the direct coupling between the electric motor and the pump part. This prevents alignment and saves maintenance costs.