Acquisition of vacuum

The equipment that can discharge gas from a closed container or reduce the number of gas molecules in the container is usually called vacuum acquisition equipment or vacuum pump. Vacuum pump refers to a device or equipment that uses mechanical, physical, chemical or physical chemical methods to extract air from the evacuated container and obtain vacuum. Generally speaking, the vacuum pump is a device that improves, generates and maintains vacuum in a closed space by various methods.

In the vacuum acquisition technology, there are two main technical methods:

(1) the gas is directly discharged from the closed container by some mechanical movement;

(2) Adsorption or condensation of gas molecules on the surface of low temperature by physical and chemical methods.

Introduction to vacuum pump

After the beginning of the 20th century, vacuum technology continues to develop, more and more types of vacuum equipment, the application field also gradually expanded, widely used in plastic machinery, pesticide chemical industry, dye chemical industry, brick and tile machinery, low temperature equipment, papermaking machinery, pharmaceutical chemical industry, food machinery, industrial electric furnace, electronic industry, vacuum equipment, petrochemical industry, metallurgy, mining and foundation treatment and other fields. According to the working principle of the vacuum pump, it can be divided into two basic types: gas transmission pump and gas trapping pump. The gas transmission pump is mainly through the continuous inhalation and exclusion of gas to achieve the purpose of air extraction, gas trapping pump by making gas molecules adsorbed or condensed on the inner surface of the pump, thus reducing the number of gas molecules in the container to achieve the purpose of air extraction. The main vacuum pump classification and principle, scope of application and the basic introduction of related vacuum pumps are as follows:

Rotary vane vacuum pump

The utility model relates to an oil-sealed mechanical vacuum pump (positive displacement pump), which is one of the most basic vacuum acquisition equipment in vacuum technology. It is mainly composed of pump body, rotor, rotary disc, end cover and spring. A rotor is eccentrically installed in the cavity of the rotary vane pump, and the outer circle of the rotor is tangent to the surface of the pump cavity (there is a small gap between the two). The rotor groove is equipped with two rotary vane with spring. When rotating, the top of the rotary vane is in contact with the inner wall of the pump cavity by centrifugal force and the tension of the spring, and the rotor rotates to drive the rotary vane to slide along the inner wall of the pump cavity. The suction port of the vacuum pump is installed with a coarse filter of metal wire mesh, which can prevent the solid foreign dust particles from inhaling the pump cavity. The oil separator is equipped with an exhaust transition device for efficient oil and gas separation. When the pump is stopped, the suction valve built into the suction port isolates the pump from the pumped system to prevent oil from returning to the pumped system. The pump is cooled by air. Vane vacuum pumps All pumps are driven by a direct motor through an elastic coupling.

Features:

The working pressure range is 101325~1.33×10-2Pa, which belongs to the low vacuum pump;

Can be used alone, can also be used as other high vacuum pump or ultra high vacuum pump before the pump; Simple structure, reliable work;

The dry gas in the sealed container can be removed, and a certain amount of condensable gas can be removed if there is a gas suppression device attached. However, it is not suitable for the extraction of gas containing too much oxygen, corrosive to metal, chemical reaction to pump oil and containing particulate dust;

There are two kinds of single-stage rotary vane vacuum pump and two-stage vacuum pump. Because the oil is used as a sealing material, it will cause the backflow of oil vapor and cause oil pollution to the vacuum system.