Working principle of multi-stage pump transmission
Multi-stage pump is a kind of centrifugal pump, and it also relies on the rotation of the impeller to obtain centrifugal force and thus material. When the gas density reaches the working range of the mechanical vacuum pump, it is pumped out, thereby gradually obtaining a high vacuum. An appropriate amount of water is used as the working fluid in the multi-stage pump body. When the impeller rotates in a clockwise direction, the water is thrown around by the impeller.
Due to the centrifugal force, the water forms a closed ring of approximately equal thickness determined by the shape of the pump cavity. The inner surface of the lower part of the water ring is just tangent to the hub of the impeller, and the upper inner surface of the water ring just touches the top of the blade (in fact, the blade has a certain insertion depth in the water ring).
At this time, a crescent-shaped space is formed between the impeller hub and the water ring, and this space is divided by the impeller into several small cavities equal to the number of blades. If the lower part of the impeller is 0° as the starting point, the volume of the small cavity becomes larger when the impeller rotates 180° before the rotation, and it communicates with the suction port on the end surface, and the gas is sucked in. When the suction ends, the small cavity It is isolated from the suction port; when the impeller continues to rotate, the small cavity changes from large to small, so that the gas is compressed; when the small cavity communicates with the exhaust port, the gas is discharged out of the pump.
In summary, 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 with variable volume.
Multi-stage pumps can be used in many industrial sectors such as petroleum, chemical, machinery, mining, light industry, medicine and food. In many processes of industrial production, such as vacuum filtration, vacuum water diversion, vacuum feeding, vacuum evaporation, vacuum concentration, vacuum rehydration and vacuum degassing, multi-stage pumps are widely used. It can pump out flammable and explosive gas, and also can pump out dusty and water-containing gas. Therefore, the application of water ring pumps is increasing.
