There are more and more types of vacuum pumps with the development of vacuum applications. The vacuum pumping system is often required to be composed of several kinds of vacuum pumps in order to satisfy requirements of production and scientific research.
What is a Vacuum Pump?
As a common device in laboratory, a vacuum pump is used to create or maintain the required vacuum level. It refers to a device or equipment that uses mechanical, physical, chemical or physical-chemical methods to evacuate the pumped container to obtain a vacuum. A vacuum pump is a device that uses various methods to improve, generate, and maintain a vacuum in a sealed space. It can be used in pharmaceutical and chemical industries, vacuum coating, vacuum drying, surface treatment, vacuum smelting, brick, ceramic manufacturing, food packaging, milking, beverage industry and other fields.
What are the Types of Vacuum Pump?
In terms of the working principle and the structure feature, vacuum pumps can be classified into the positive displacement pump and the momentum transfer pump.
1. Positive Displacement Pump
It mainly use volume change of the cavity to realize suction and exhaust so that the pressure can be increased and decreased. The gas is compressed before discharging from the cavity. It can be further divided into the reciprocating vacuum pump and the rotary vacuum pump.
(1) Reciprocating Vacuum Pump: The gas can be inhaled, compressed and exhausted by utilizing the piston in the cavity to do reciprocating motion, which is known as the piston vacuum pump as well.
(2) Rotary Vacuum Pump: The gas can be inhaled, compressed and exhausted by utilizing the rotary motion of the rotor part in the cavity. It can be roughly divided into four types, including the oil sealed vacuum pump, liquid ring vacuum pump, dry vacuum pump and roots vacuum pump. They have different working principles and structure features.
2. Momentum Transfer Pump
Relying on the high speed rotating blade and the high speed jet, the momentum transfer pump can transfer the momentum to the gas or gas molecule, which can transfer the gas continuously from the inlet to the outlet. This kind of pump can be classified into the following types.
(1) Molecular Vacuum Pump: It makes use of the high speed rotating rotor to transfer the momentum to the gas molecule so that it can obtain directional velocity. The gas can be compressed and driven to the exhaust port, and then it is exhausted by the front stage. This kind of pump can be specifically divided into the traction molecular pump, turbo molecular pump and compound molecular pump.
There is another method of classifications a s well. In terms of the working principle, vacuum pumps can be basically classified into the gas transfer pump and trapping pump. The former mainly includes the liquid ring vacuum pump (water circulating vacuum pump), reciprocating vacuum pump, rotary vane vacuum pump, dry vacuum pump, roots vacuum pump and molecular vacuum pump. The latter primarily refers to the adsorption pump and low-temperature pump.
All of these vacuum pumps play an important role in various industries.