Screw pump, also known as "spiral water pump", "Archimede screw pump". A pump that spirals the water body in the axial direction by the rotation of the spiral blade. It consists of a shaft, a spiral blade and an outer casing. When pumping water, the pump is tilted into the water so that the inclination of the pump main shaft is smaller than the inclination angle of the spiral blade, and the lower end of the spiral blade is in contact with water. When the prime mover drives the screw pump shaft to rotate by the shifting device, the water enters the blade and rises along the spiral flow path until it flows out. The utility model has the advantages of simple structure, easy manufacture, large flow, small head loss, high efficiency, convenient maintenance and maintenance, but low lift and low speed, and a shifting device is required. It is mostly used for irrigation, drainage, and lifting of sewage, sludge and other occasions.
Screw pumps are divided into:
Single Screw Pump - A single screw engages a rotating pump in the internal thread groove of the pump body.
Twin-screw pump - A pump that delivers liquid by intermeshing two screws.
Three-screw pump - a pump that delivers liquid by intermeshing with multiple screws.
Advantage:
1 low speed (generally 20r/min ~ 90r / min), mechanical wear is small, no cavitation will occur.
2 The flow path is wide and can transport water containing solid matter.
3 The pump body structure is half open, and the operation inside the pump can be observed.
4 The flow state on the suction side has little effect on the hydraulic performance, there is no special requirement for the suction pool, the foundation excavation depth is small, the construction of the hydraulic structure is simple, and the civil construction cost is small.
Disadvantages:
1 large size, large footprint.
2 Due to mechanical processing conditions, the pump shaft can not be too long, so the lift is low, generally not more than 10m.
3 The height of the water absorption surface and the water surface should not change too much, otherwise it will affect the work efficiency and increase energy consumption.
