1、 What is the working principle of a rotary pump?

Answer: Two rotors installed on two shafts are driven to rotate in opposite directions by synchronous gears. A small sealed cavity is formed between the rotor and the pump casing. When the rotor rotates, the air at the inlet end is discharged to form a vacuum, and the material is sucked in. The material filled in the cavity is continuously pushed from the inlet end to the outlet end by the rotating rotor, thereby achieving continuous operation of the pump.

2、 Briefly describe the performance characteristics of rotary pumps

Answer: 1. No need to manually pump, it has strong self suction force with a maximum suction range of 8.5m; Transport flow range 1-2000m ³/h

2. The maximum viscosity of the medium that can be transported is 100000 cp, and the slurry with a maximum solid content of 60%.

3. Can be reversed, suitable for loading and unloading scenarios, as well as sewage treatment fields that require backwashing of filter membranes.

4. Non blocking design ensures the passage of large-diameter materials, with a maximum passing diameter of 80mm.

5. The ternary flow precision casting mold and five axis linkage process empower and pump, making it efficient, energy-saving, and low-noise.

6. The double support structure makes the pump run more stably, and the output pressure can reach up to 1.8Mpa.

7. Smooth conveying, minimal pulsation, low shear force, capable of conveying mixed media of air, solid, and liquid, as well as media sensitive to cutting

8. The back cover is designed with a pull-out feature, which allows for maintenance without the need to disassemble the pump body and pipelines

9. A low speed of 10-650r/min, wear-resistant rubber lining, equipped with axial and radial wear-resistant plates, allows the pump to operate for longer periods of time and has a low failure rate.

10. For different working conditions, special devices such as safety valves and insulation cooling can be configured to meet the requirements of different working conditions.

11. Configure a reducer to adjust the motor speed and achieve the purpose of regulating the flow rate.

12. The application range of cam rotor pumps is extremely wide, with strong applicability. Different materials and rotors can be used according to different working conditions.

3、 What industries are rotary pumps mainly used in?

Answer: Rotary pumps are widely used in environmental protection, pharmaceutical industry, subway and high-speed rail, papermaking industry, petroleum industry, mining and heavy industry, tank bottom cleaning, agriculture, daily chemical industry, food industry, coating industry, municipal sewage treatment, livestock discharge and transportation, kitchen waste treatment and other fields.

4、 What should be noted before testing the rotary pump?

Answer: Before testing the rotary pump, the following items must be checked one by one: 1. Check the lubricating oil level. 2. Check whether the flange and connection device are well sealed and leak free. 3. For quick connect flanges, check if the fastening device is secure. 4. Check the steering of the drive motor.

5、 What are the reasons for the lack of flow in rotary pumps?

Answer: 1) If the inlet pressure is low, check the inlet pipeline to ensure that the pressure meets the specified requirements, otherwise cavitation may occur; 2) Entrance pipeline blockage; 3) The rotor is severely worn and there is leakage; 4) Safety valve issue. Check if the safety valve is not tightly sealed; 5) Low rotational speed; 6) The viscosity is too low, and the working range of the pump needs to be checked. If necessary, a new model should be selected.

6、 How long can a rotary pump run dry?

Answer: When a rotary pump is used for self-priming, the dry operation of the pump is a very important assessment indicator. In the initial stage of pump operation, there is no medium in the pipeline. It is necessary to evacuate the pipeline from the pump inlet to the medium liquid level to create negative pressure. This requires our pump to have a certain dry running ability or take certain measures to avoid dry running of the pump. Normally, the dry running time of a rotary pump can reach 0-30 minutes.

7、 What factors can cause abnormal heating during the operation of a rotary pump?

Answer: 1. Heat accompanied by noise is usually caused by damage to the bearing ball isolation frame. 2. The bearing sleeve in the bearing box is loose, and the front and rear covers are loose, causing heat due to friction. 3. The bearing hole is too large, causing the outer ring of the bearing to loosen. 4. There are foreign objects inside the pump body. 5. The large vibration of the rotor causes wear on the sealing ring. 6. Pump evacuation or excessive pump load. 7. The rotor is unbalanced. 8. Too much or too little lubricating oil and unqualified oil quality.

8、 Briefly describe the factors that affect the speed of rotary pumps

Answer: The factors that affect the speed of the rotary pump include:

1. Viscosity affects the rotational speed of rotary pumps

The operating speed of the pump needs to be appropriately selected according to the viscosity of the medium. The higher the viscosity of the material, the lower the corresponding pump speed. The appropriate rotational speed will enable the pump to achieve better performance and longer service life. Excessive rotational speed can cause cavitation, vibration, and noise during pump operation.

2. The solid content affects the speed of the rotary pump

The operating speed of the pump needs to be appropriately selected according to the solid content of the medium. The higher the solid content of the material, the lower the corresponding pump speed should be. Appropriate rotational speed will enable the pump to achieve better performance and longer service life. Excessive rotational speed can lead to abnormal wear of pump components, high failure rate, and high maintenance or replacement costs.

9、 What is the maximum pressure of a rotary pump?

Answer: The maximum pressure of a rotary pump is generally related to the machining accuracy of the pump. The higher the accuracy, the greater the output pressure. It is also related to the material strength and hardness. A higher hardness results in less wear and longer maintenance of high-pressure output. In general, the maximum pressure value of rubber rotors is greater than that of copper rotors and stainless steel rotors. Therefore, when selecting, different choices can be made based on the properties of the medium and the requirements of the workstation.

10、 Precautions for stopping the rotary pump

Answer: 1. Stop the pump and close the inlet and outlet valves to clean up the discharge of easily condensable materials. 2. After the pump has been out of use for a long time, the coupling should be manually rotated before use. There may be resistance to the hand feel, but it can rotate freely and evenly. And pay attention to identifying whether there are friction sounds and foreign objects inside the pump. 3. When reinstalling the pump and reduction motor, the coaxiality between the pump shaft and the motor shaft should be checked, and the position of the outer circle of the coupling should not exceed 0.1mm, otherwise it will cause pump vibration and affect the life of the main shaft.