Centrifugal pumps or sewage pumps cannot meet the operating requirements for high viscosity liquids. The result of using these two pumps is that the pump motor speed slows down, the motor heats up, and the liquid cannot be discharged for a long time, leading to motor burnout.

Single screw pump, also known as snake pump or Moyno pump. This pump is a high viscosity pump that has been widely used in the past. The rotor is a single head male screw made of metal material (circular in cross-section perpendicular to the axis), and the stator is a special double helix made of rubber material (with a track shaped hole in cross-section perpendicular to the axis). The sealing line formed by the rotor rolling in the stator gradually moves towards the outlet end, causing the liquid to move along the axis from the inlet to the outlet. The advantage of this pump is that it delivers smoothly, with minimal pulsation and no stirring effect on the material. It is also insensitive to solid particles. However, due to the high frictional resistance, its energy consumption is significantly higher than other forms of rotary pumps. Compared with gear pumps, under the same flow rate, pressure and other indicators, the power configuration is basically 3:1. In addition, due to factors such as the stator material, the stator wears out quickly and needs to be replaced frequently, and it cannot be used in high-temperature environments.