Vacuum pump unit is a unit composed of different types of pumps in series. The pumping speed is relatively large and can be integrated into the application environment as soon as possible. There are many series modes of the unit, which are mainly named according to the changes of the previous pump, and its principle is naturally related to the selection of different pumps. To know the principle of vacuum pump unit, we must first know the principle of different pumps.

1. Principle of water ring vacuum pump

The impeller of the water ring vacuum pump blade is eccentrically installed in the cylindrical pump shell. Sufficient water is injected into the pump. When the impeller rotates, the water is thrown onto the pump shell to produce a water ring, and the inner surface of the water ring is tangent to the impeller hub. Because the pump casing and impeller are not the same center, the air inlet space between the right half hub and the water ring gradually expands, resulting in vacuum, so that the gas enters the air inlet space in the pump through the air inlet pipe. Then the gas enters the left half, because the volume between the hub rings is gradually compressed and the pressure increases, so the gas is discharged outside the pump through the exhaust space and exhaust pipe.

Vacuum pump unit

2. Principle of rotary vane vacuum pump

Rotary vane vacuum pump (referred to as rotary vane pump) is a kind of mechanical vacuum pump with oil seal. Its working pressure range is 101325 ~ 1.33 times; 10-2 (PA) is a low vacuum pump. It can be used as a single application, or as the front pump of other high vacuum pumps or vacuum pump units. It has been widely used in production and scientific research departments such as metallurgy, machinery, military industry, electronics, chemical industry, light industry, petroleum and medicine.

3. Principle of Roots vacuum pump

The principle of roots pump in vacuum pump unit is similar to that of Roots blower. Because of the continuous rotation of the rotor, the pumped gas is drawn from the air inlet into the space V0 between the rotor and the pump housing, and then discharged through the air outlet. Because V0 space is completely closed after suction, the gas in the pump chamber cannot be compressed and expanded. As everyone knows, when the top of the rotor overturns the edge of the exhaust port and V0 space is connected with the exhaust side, some gas is rushed back to space V0 due to the high gas pressure on the exhaust side, which suddenly increases the gas pressure. As the rotor continues to rotate, the gas is discharged from the pump.

Water ring vacuum pump, rotary vane vacuum pump and roots vacuum pump are all selected as booster pumps of vacuum pump unit. After understanding their respective principles, we need to have a general knowledge of the operation principle of the unit and be able to assist customers in better application.