a. Rotor pump
The rotor pump, also known as the colloid pump, the cam pump, the three-blade pump, or the universal delivery pump, is a positive displacement pump. It achieves the purpose of conveying fluid by means of the periodic transformation of multiple fixed-volume conveying units in the working chamber.
b. Screw pump
The screw pump is a type of pump that works according to the principle of revolving meshing positive displacement. The main working parts are eccentric screw (rotor) and fixed bushing (stator). Due to the special geometry of the two components, separate sealed chambers are respectively formed, the medium is uniformly pushed to flow in the axial direction, the internal flow rate is low, the volume remains unchanged, and the pressure is stable, so no eddy current and agitation will be generated. In addition, the screw pump also has the following advantages:
1) Wide range of pressure and flow. The pressure is about 3.4-340 kgf/cm2, and the flow rate can reach 300-3000 cubic meters;
2) Wide range of types and viscosities of liquids to be transported;
3) Because the inertial force of the rotating parts in the pump is low, a high speed can be used;
4) Good suction performance and strong self-priming ability;
5) The flow is uniform and continuous, the vibration is small, the noise is low, and the service life is long;
6) Compared with other rotary pumps, it is less sensitive to incoming gas and dirt;
7) Solid structure, easy installation, and maintenance.
Comparison of rotary lobe pump and single screw pump
1) The rotor pump can run dry, which is especially important when the material is suddenly cut off or the operation is wrong, preventing the pump’s damage and ensuring safe operation.
2) The volume of the rotor pump is small, which is one-third of the installation area of the single screw pump, which reduces the scope and cost of civil construction.
3) The rotor pump can realize online maintenance without dismantling the pipeline, which is convenient and quick and reduces downtime.
4) The non-extrusion working principle of the rotor pump, the adjustable shell design, prolongs the service time, reduces the number of maintenance, and saves the cost of spare parts.