Multistage Pump Working Principle

Multistage Pump Working Principle

Multistage pump is a kind of centrifugal pump. It mainly depends on the rotation of the impeller to obtain the centrifugal force and thus the material. When the gas density reaches the working range of the mechanical vacuum pump and is drawn out, a high vacuum is gradually obtained. Is now widely used in petroleum, chemical, machinery, mining, light industry, medicine and food and many other industrial sectors.

Structure

1. Impeller The core part of a multi-stage pump, which has a high speed and high output force, and the blades on the impeller play a major role. The impeller must pass the static balance test before assembly. The inner and outer surfaces of the impeller need to be smooth to reduce the frictional loss of water flow.

2. The water inlet section, water outlet section and middle section are also called pump casings, which are the main body of the multi-stage pump. It plays a supporting and fixing role and is connected with the bracket on which the bearing is installed.

3. The pump shaft is connected to the motor by a coupling and transmits the torque of the motor to the impeller, so it is the main component for transmitting mechanical energy.

4. Bearing is a component that is supported on the pump shaft to support the pump shaft. There are two types of rolling bearings and sliding bearings. Rolling bearings use butter as a lubricant. It should be appropriate. Generally, the volume is 2/3 to 3/4. Too much volume will generate heat, too little and there will be noise and heat! The plain bearing uses transparent oil as a lubricant, and oil is added to the oil level line. Too much oil will seep and drift along the pump shaft, too few bearings will overheat and burn out and cause an accident! During the operation of the pump, the temperature of the bearing is highest at 85 degrees and generally runs at about 60 degrees. If it is high, find the reason (whether there are impurities, whether the oil is black, and whether it has water) and deal with it in time!

5. Sealing ring, also known as leakage reducing ring. The gap between the impeller inlet and the pump casing is too large, which causes the water in the high-pressure area of the pump to flow to the low-pressure area through this gap, affecting the water output of the pump and reducing the efficiency! Too small clearance will cause friction between the impeller and the pump casing and cause wear. In order to increase the backflow resistance and reduce the internal leakage, and delay the service life of the impeller and the pump casing, a seal ring is installed at the inner edge of the pump casing and the external assistance of the impeller, and the sealed gap is preferably kept between 0.25 and 1.10mm.

6. Stuffing box is mainly composed of packing, water-sealing ring, packing tube, packing gland and water-sealing pipe. The function of the stuffing box is mainly to close the gap between the pump casing and the pump shaft, and to prevent the water in the pump from flowing to the outside and the outside air from entering the pump. Always keep the vacuum inside the pump! When the pump shaft and the filler produce friction to generate heat, it is necessary to rely on the water seal tube to hold the water into the water seal ring to cool the filler! Keep the pump running normally. Therefore, pay special attention to the stuffing box inspection during the running inspection of the pump! The packing needs to be replaced after about 600 hours of operation.