The Classifications of Vacuum Pumps in Different Ways

A vacuum pump is a device that uses mechanical, physical, chemical, and physicochemical methods to pump a vessel to obtain and maintain a vacuum. It is one of the most common pieces of equipment in laboratories. Today, HWACH will discuss the different types of vacuum pumps.

Classification according to the working principle

According to the working principle of vacuum pumps, vacuum pumps can be basically divided into two types, namely gas transfer pumps and gas trapping pumps.

A gas transfer pump is a kind of vacuum pump that can make the gas continuously inhaled and discharged to achieve the purpose of pumping. A gas trapping pump is a kind of vacuum pump that makes gas molecules be adsorbed or condensed on the inner surface of the pump, so as to reduce gas molecules.

Classification according to the structure of the vacuum pump

According to the structure of the vacuum pump, it can be divided into a reciprocating vacuum pump, rotary vacuum pump, and jet vacuum pump.

Classification according to the working environment of the vacuum pump chamber

According to the working environment of the vacuum pump chamber, it can be divided into an oil-free vacuum pump and an oil-sealed vacuum pump.

Classification according to the way of working vacuum pump

According to the way of working of vacuum pumps, it can be divided into the rotary vane vacuum pump and diaphragm vacuum pump. And the common ones in our laboratory are circulating water vacuum pumps, diaphragm vacuum pumps, and rotary vane vacuum pumps. Their working principle is also different.

Working principle of circulating water vacuum pump: The pump body is equipped with an appropriate amount of water as the working fluid. When the impeller rotates, the water is thrown around by the impeller, and due to the centrifugal force, the water forms a closed circle of nearly equal thickness. At this time this circular vacuum pressure becomes small, the impeller continues to rotate and will be sucked in gas from the interface, and at this time the entrance is closed. The inhaled gas is compressed in also in the impeller rotation, and when the operation is connected with the outlet, the gas will be discharged out of the pump due to the high pressure of the compressed gas in the pump body, so as to achieve the function of pumping and vacuuming.

Working principle of rotary vane vacuum pump: two rotary vanes separate the crescent-shaped space enclosed by the rotor, pump chamber, and two end caps into three parts A, B, and C. When the rotor rotates, the volume of space A connected with the suction port is gradually increasing and is in the process of suction. The volume of space C, which is connected to the exhaust port, is gradually decreasing and is in the process of exhausting. The volume of the central space B is also gradually decreasing and is in the process of compression. As the volume of space A is gradually increasing (i.e., expansion), the gas pressure decreases, and the pressure of the external gas at the entrance of the pump is greater than the pressure in space A, so the gas is sucked in. When space A is isolated from the suction port, that is, it turns to the position of space B, the gas starts to be compressed, and the volume gradually decreases, as the gas is compressed pressure increases, and the gas is pressed into space C, and finally C is connected to the exhaust port. When the compressed gas exceeds the exhaust pressure, the exhaust valve is pushed open by the compressed gas, and the gas is discharged into the atmosphere through the oil layer in the tank. By the continuous operation of the pump, the purpose of continuous pumping is achieved.

The working principle of diaphragm vacuum pump: the circumferential motion of the motor makes the diaphragm inside the pump do reciprocate motion through the mechanical device, thus compressing and stretching the air inside the pump cavity to form a vacuum, and generating pressure difference with the external atmospheric pressure at the pumping port, under the action of pressure difference. Diaphragm vacuum pumps are oil-free vacuum pumps, rotary vane vacuum pumps are mostly oil pumps but there are also oil-free rotary vane pumps.

HAWACH diaphragm vacuum pump is widely used in vacuum filtration, rotary evaporator, freezing, drying, vacuum concentration, molecular distillation, and other research experiments, the series product design is delicate, low noise, smooth operation, the highest vacuum value of up to 700Kpa, strong pump force, corrosion-resistant cavity, safe and reliable, etc. There are different models available: SLVPGM033A, SLVPGM050A, SLVPGM050B, and SLVPGM100A. Its diaphragm pumps are suitable for 220vac/50HZ(110V/60HZ)

Advantages of HAWACH diaphragm vacuum pumps

  1. Low noise level, small vibration, compact design, also very suitable for laboratory use
  2. Lower operating costs due to good quality, shorter maintenance time, and longer maintenance intervals
  3. Diaphragm pump, pumping speed up to 60L/min
  4. No hydrocarbons: dry & oil-free diaphragm pumps