Since the stator and the rotor are in an interference fit, they cannot be idling or dry running; The contact surface of the stator and the rotor usually needs a layer of fluid film to maintain lubrication.
When the fluid with high viscosity and poor fluidity is input, we need to pay attention to whether it can flow into the pump fast enough. If it cannot, it will easily cause the dry grinding and volumetric efficiency of the pump to change. So we need to pay attention to the speed of the fluid being conveyed and its viscosity.
For fluids with lower water content, the transport distance is shorter and higher pressure is required.
In order to ensure the life of the progressive cavity pump, we usually control the speed to a low level so that a large flow will not be generated. If you need to increase the flow, usually add a variable frequency drive (VFD) or stepless speed reducer. Speed and flow are often proportional. But the maximum flow rate of the progressive cavity pump in our factory can reach: 300m³/h;
The slip rate of low-viscosity fluid between the stator and the rotor is very high, which is likely to cause the efficiency of the pump to decrease.
The possible high starting torque may require the driver (motor) to be larger than otherwise required. Operating horsepower may be only half of the required starting horsepower.
Because the stator is rubber, large temperature fluctuation will lead to slight expansion, which means that the efficiency, flow rate and pressure will be different.