Multi-stage pump knowledge analysis

At present, there are many kinds of centrifugal pumps sold in the market, which can be divided into a variety of centrifugal pumps according to the use environment and flow and head parameters, such as: multi-stage centrifugal pump, double suction centrifugal pump, pipeline centrifugal pump, ISG Various types of centrifugal pumps, such as single-stage single-suction pipe centrifugal pumps, and multi-stage centrifugal pumps are one of the most common types of centrifugal pumps.
A multi-stage pump is a simple series of many single-stage pumps that are combined. His output water pressure can be very large. It is a kind of centrifugal pump, and it also relies 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, it is extracted, thereby gradually obtaining a high vacuum. The multi-stage pump relies on the change of the pump chamber volume to achieve suction, compression and exhaust, so it is a centrifugal pump that can change volume.
The basic structure of the multistage pump is composed of six parts: impeller, pump body, pump shaft, bearing, sealing ring and stuffing box.

1. Impeller is the core part of the multi-stage pump. It has a high speed and a large force. 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 are required to be smooth to reduce the frictional loss of water flow.
2, Pump body is also called the pump casing, it is the main body of the multi-stage pump. It acts as a support and is attached to the bracket on which the bearing is mounted.
3. The function of the pump shaft is to connect the coupling to the motor to transmit the torque of the motor to the impeller, so it is the main component that transmits mechanical energy.
4. Bearing is a member that supports the pump shaft on the pump shaft, and has two kinds of rolling bearings and sliding bearings. Rolling bearings use butter as a lubricant to refuel properly. Generally 2/3~3/4 of the volume will heat too much, too little and there will be noise and heat! The sliding bearing uses transparent oil as the lubricant, refueling to the oil level line. Too much oil will ooze along the pump shaft and float, too few bearings will overheat and burn out, causing accidents! During the operation of the pump, the temperature of the bearing is up to 85 degrees, which is generally about 60 degrees. If it is high, it is necessary to find the cause. (Is there any impurities, whether the oil is black or not, whether it is in the water) and deal with it in time!

5, Seal ring is also known as the leak reduction ring. The gap between the impeller inlet and the pump casing is too large, so that the water in the high pressure zone of the pump flows to the low pressure zone through the gap, which affects the water output of the pump and reduces the efficiency. If the clearance is too small, the friction between the impeller and the pump casing may cause friction. 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 sealing ring is arranged at the joint of the inner edge of the pump casing and the external aid of the impeller, and the gap of the sealing is preferably maintained between 0.25 and 1.10 mm.
6. Stuffing box is mainly composed of packing, water sealing ring, packing tube, packing gland and water sealing tube. The function of the stuffing box is mainly to close the gap between the pump casing and the pump shaft, so that the water flow in the pump does not flow to the outside and the outside air does not enter the pump. Always keep the vacuum inside the pump! When the pump shaft and the packing friction generate heat, the water should be sealed by the water seal pipe to the water seal ring to cool the packing! Keep the water pump running normally. Therefore, in the inspection of the running of the pump, the inspection of the stuffing box is particularly important! The packing should be replaced after about 600 hours of operation.