Easy to manufacture, large flow, small head loss, high efficiency and easy maintenance, but low lift and low rotation speed require a speed change device. It is mainly used for irrigation, drainage and lifting sewage and sludge. China has been using it since 1970s.
There are many screw pump manufacturers, including Tianjin, Anhui, Zhejiang and Jiangsu. If you buy three screw pump, I suggest you buy the brand "Xu Shen Screw Pump". Our company has used it for 4 years and there has been no problem. It feels worthwhile.
Design parameters:
(1) Installation inclination (θ). Installation inclination refers to the angle between the screw pump shaft and the horizontal plane. It directly affects the efficiency and flow of the pump. According to relevant data, the efficiency will decrease by about 3% for every degree of increase in inclination angle. It is generally considered that the inclination angle is 30 ~ 40, which is more economical.
(2) customs clearance. Clearance refers to the clearance between the spiral blade and the shell. The smaller the gap, the smaller the water leakage loss and the higher the efficiency of the pump.
(3) rotational speed (n). The rotating speed of screw pump is slow, generally 20 ~ 80 r/min. The experimental data prove that when the external diameter of the screw pump is large, the rotating speed should be reduced.
(4) Lifting height (h). Screw pump only has lifting height, but no water pressure height. Its lifting height is generally 3 ~ 8 m.