Vacuum Units Classification
Perfect vacuum system is composed of vacuum pump or vacuum unit and a series of auxiliary components such as pipelines, measuring devices, valves, electrical control systems. Here is a brief introduction to the common classification of vacuum units and their application fields.
Vacuum units are generally named according to the type of main pump, and then can be classified according to product characteristics, such as oil-bearing vacuum units and oil-free vacuum units; more commonly, according to the scope of vacuum application, they can be divided into low vacuum units, medium vacuum pump units, high vacuum units and ultra-high vacuum units.
low vacuum unit has high working pressure and large exhaust capacity. It is mostly used for vacuum transportation, vacuum impregnation, vacuum filtration, vacuum degassing of vacuum dryer, etc. Main pumps commonly used in low vacuum units, reciprocating pumps, water ring pumps, oil seal mechanical pumps, screw vacuum pumps, wet Roots pumps, jet pumps, molecular sieve adsorption pumps and other direct-discharge air vacuum pumps can be competent, but according to the cleanliness, humidity and other conditions of the pumped gas, it is necessary to configure and remove them. Duster, gas-water oil-water separator, drying trap and other facilities.
Medium vacuum unit is suitable for various vacuum systems requiring large pumping speed and obtaining medium vacuum, such as coating machine, vacuum smelting, vacuum heat treatment, medicine, chemical industry, electrical welding and other industries. In the past, the combination of Roots Vacuum Pump + Oil Seal Mechanical Pump, Roots Vacuum + Water Ring Vacuum Pump and Double Roots Vacuum Pump was the most common. With the rise of oil-free vacuum pumps such as screw vacuum pumps, oil-free vacuum units such as Roots vacuum pumps and screw vacuum pumps are gradually increasing, and their adaptability is wider.
high vacuum unit operates in the state of molecular flow. Its working pressure range is 10 ^-2-10 ^-6 Pa. It has small displacement and high pumping speed. Generally, the main pump is assumed by diffusion pump, molecular pump, titanium sublimation pump and cryogenic condensation pump. Because they can not work directly in the atmosphere, they must be equipped with front-stage pump and pre-pumping pump. In order to prevent pressure fluctuation, maintenance pumps and gas storage tanks are also needed.
The working pressure range of ultra-high vacuum unit is 10-6-10-10 Pa. The limit vacuum of the main pump should be above 10-7-10-8 Pa and the corresponding pumping speed should be guaranteed in the working pressure range, such as sputtering ion pump, turbo-molecular pump, etc. Moreover, the material of the system should be baked at high temperature of 200-450 C and low leakage rate should be guaranteed. Outgassing rate and so on.