How should screw rotor pumps be protected during operation?

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In screw rotor pumps, the rotor is made of elastic material, which serves as the main component in these pumps; this approach overcomes the limitation of traditional metal-cam rotor pumps regarding their poor adaptability to various types of media. Such pumps can be widely used for transporting media that contain particles, fibers, or a mixture of gas and liquid in challenging operating conditions. However, malfunctions may still occur during use and need to be addressed. Let me explain how to protect screw rotor pumps during operation: 1. While the pump is running, it is important to monitor the motor’s power output and the pump’s operational status; if any abnormalities are detected, the pump should be stopped to determine the cause. The mechanical seal should show no leakage or heating. Mechanical seals are used for stepless speed control; after the machine is started, the speed is adjusted gradually based on the digital display. It is strictly prohibited to turn the speed control knob while the machine is stopped, as this may damage the stepless speed changer. Regularly check the temperature of the pump and motor; when the pump is in water-cooled mode, the bearing temperature rise is 40°C. When the pump is in hot water retention mode, the bearing housing temperature may be 30°C higher than the pump body temperature. Valves on the imported pipelines cannot be used to regulate flow, in order to avoid cavitation that could cause vibration in the pump. It is strictly prohibited to close both the inlet and outlet valves completely while the pump is in operation. 2. Shutdown for maintenance: After turning off the power supply, the suction valve and discharge valve should be closed. When transporting highly viscous, particulate-containing, or corrosive fluids, the fluid inside the pump should be completely drained after shutdown for cleaning, in order to prevent deposits and damage to the pump. When transporting foods, medicines, and other such substances, the medium inside the pump should be completely drained after shutdown for cleaning, so that no residual medium remains and bacteria do not have a chance to grow. When the ambient temperature is lower than the freezing point of the medium, the medium inside the pump should be drained after shutdown to prevent the pump from cracking due to freezing. When a pump is not in use for an extended period, the medium inside it should be drained, and a small amount of lubricant should be added; then the pump shaft should be rotated by hand or with a tool. Rubber rotors must not be exposed to direct sunlight or temperatures as low as -20°C to prevent damage; pay attention to their functionality, and do not use aged rotors. After the pump has been out of use for an extended period of time, before turning it on, the coupling should be rotated by hand. If there is resistance felt, but it can still be rotated freely with even effort, this indicates that the equipment is in good condition. Finally, be sure to check for any friction noises or foreign objects inside the pump. When the pump and reduction motor are reinstalled in place, it is necessary to check the coaxiality of the pump shaft and the motor shaft. The deviation of the outer surface of the coupling in the up, down, left, and right directions should not exceed 0.1 mm; otherwise, it will cause vibration in the pump and affect the lifespan of the main shaft.