lobe pumps and screw pumps both have a certain amount of self-priming power, the specific differences are as follows.
Without regard to the composition of the medium, the screw pump has a self-priming performance of 3-6m, the actual performance is determined by the properties of the transported medium, if the viscosity and specific gravity of the transported medium is higher the suction power is reduced accordingly. Screw pumps also have a good self-priming capacity, but avoid idling the pump body, and not more than 30 seconds.
The self-priming power of the lobe pump is also very high, mainly due to its rubber covered rotor, which provides a strong self-priming power without pump filling, with a maximum suction range of 9 m. In addition, the lobe pump can also produce good self-priming power at speeds above 200 rpm.
In addition, apart from the difference in self-priming capacity, they also have certain differences in their internal structure and conveying direction.
The difference in internal structure . A lobe pump is a pump in which two rotors rotate in opposite directions in the pump cavity, changing the volume from the inlet to the delivery port from large to small, while a screw pump is a pump in which a spiral-shaped screw rotates in a rubber stator, causing the material to rotate from front to back in a spiral movement from the discharge port.
The difference in conveying direction. lobe pumps can be reversed in the direction of delivery and are completely symmetrical in structure, whereas screw pumps cannot be reversed and their seals are under pressure when delivered in reverse.
The difference in floor space. lobe pumps are compact, require a smaller footprint and do not require additional space when servicing lobe pumps, and the calibre can be adjusted to customer requirements. Single screw pumps vary in size according to the number of stages, but because the screw is very long, a large space is required for maintenance and there is only one pump flange calibre for each model.