Rotary pump is essentially a category of volumetric pump. Under certain operating frequency conditions, the output flow of the rotary pump should be constant. From the working principle of the rotary pump, the output flow of the rotary pump depends only on The volume of its working chamber and its operating frequency, and (theoretically) independent of the discharge pressure, and has nothing to do with the physical and chemical properties such as temperature, viscosity, etc. of the medium being transported. When the rotational frequency of the rotor pump per minute is constant, the flow of the rotor pump is also constant.

 However, in the actual working environment, the flow rate of the rotor pump cannot reach the desired ideal state because it is affected not only by the machining accuracy but also by the temperature, viscosity, and discharge pressure of the medium to be transported.

The ideal working condition of the rotor pump is that the fit clearance between the impeller and its associated cavity, end cover and another impeller is zero. The efficiency in this state should be 100%, but in the actual processing and production, it is necessary to consider Due to material expansion, occlusal, frictional factors, and material properties, we generally need to control the clearance around the running rotor in the design, otherwise the rotor will be killed during the operation, so that the entire equipment can not work properly. We can't achieve the ideal 0-bit. We generally control the operating clearance between 0.08mm-0.30mm according to the specific structure and conditions. In this gap range, we can ensure the smooth and safe operation of the entire equipment, and we can also meet The need for hot cleaning processes such as CIP.

Due to the existence of gaps between the rotor pump operating parts, the viscosity, temperature, and discharge pressure of the rotor pump during the actual operation can have a relatively large influence on the flow of the final rotor pump.

The greater the viscosity of the medium, the smaller the flow loss of the rotor pump, but the greater the discharge pressure of the rotor pump, so we generally reduce the operating frequency of the rotor pump to reduce the rotor pump when the medium with high viscosity is delivered. The output pressure reduces the energy loss of the rotor pump during delivery. Ensure the safe operation of the rotor pump. Due to the relatively high viscosity of the medium being transported, the choice of low-speed high-torque power is more suitable for use under this operating condition.

When the medium with relatively low viscosity is conveyed, due to the existence of the fit clearance in the process of the rotor pump, it will generate a certain internal backflow under the working condition, and the loss of a part of the flow will have a certain proportional loss with the theoretical flow rate. The greater the discharge pressure, the greater the loss of flow, and the flow at a pressure point will be zero.

Therefore, when selecting a rotary pump, it is necessary not only to comprehensively consider the material properties such as viscosity, temperature, and discharge pressure of the transmission medium, but also to select an appropriate rotor pump rotation speed, power, and speed reducer according to different media properties, so that the selected rotor can be selected. The pump can meet the needs of the actual process flow.