Vacuum system is actually a similar name of vacuum unit. Vacuum unit is a set of closed-loop vacuum equipment composed of several vacuum pumps. It does not necessarily have some equipment such as radiator, condenser and so on. And can call vacuum system commonly affirmation is vacuum pump manufacturer all sorts of spare parts are complete. There are many kinds of vacuum application equipment, but no matter what kind of vacuum application equipment, there is a set of extraction system to remove the gas in the evacuated container, so as to obtain the required vacuum conditions in the vacuum container. For example, a container for vacuum treatment is connected with a vacuum pump by pipes and valves. When the vacuum pump vacuumizes the container, there must be a vacuum measuring device on the container, which constitutes a simple vacuum pumping system.
According to the specific situation, the advantages of all the above design types must be the ideal choice, but it is not possible. Therefore, it requires users to first understand that there are so many different design types in dry vacuum pump design, and then understand the impact of various types of pump design according to their own process characteristics. Such a choice can greatly reduce its use cost and obtain a stable vacuum system with a long life.
1. Composition and classification of vacuum units
The vacuum unit is generally composed of the following components: various vacuum pumps; vacuum measuring devices; vacuum valves; vacuum pipes and some other components, such as puffers, vacuum joints, gas tanks, bellows, dust collectors and vacuum relays.
According to the working pressure of the unit, there are coarse vacuum unit (> 1330pa), low vacuum unit (1330 ~ 0.13pa), high vacuum unit (0.13 ~ 1.3 × 10-6 PA), ultra-high vacuum unit (1.3 × 10-6 ~ 1.3 × 10-11 PA) and very high vacuum unit (< 1.2 × 10-11 pa).
2. High vacuum unit
(1) The main pumps are diffusion pump, molecular pump, sputtering ion pump, titanium pump, low temperature pump, etc.
(2) Select the pre pumping pump and gas storage pipe (shockproof, shorten the working cycle, prevent instantaneous large amount of air release in the vacuum chamber, and stabilize the outlet pressure of the diffusion pump)
3. Ultra high vacuum unit
The limit vacuum degree of the main pump shall be high, the air leakage rate shall be low, and it shall be resistant to baking at 200 ~ 450 ℃.
(1) Diffusion pump unit: reduce backflow and control pollution.
(2) Molecular pump unit: the hydrogen compression ratio is small, and the residual gas is mainly hydrogen.
(3) Sputter ion pump unit: usually used in combination with titanium pump.
(4) Low temperature pump unit: no pollution.
4. Low vacuum unit
The main characteristics of low vacuum unit are high working pressure and large exhaust volume, but the pumping speed is lower than that of high vacuum unit. It is mainly used in dry vacuum pump conveying, vacuum impregnation, vacuum filter, vacuum degassing, vacuum drying and other devices with large volume of crude pumping and outgassing of vacuum chamber and high working pressure. The main pumps of low vacuum units are commonly used reciprocating vacuum pump, oil seal vacuum pump, water steam jet pump, water ring vacuum pump, oil steam jet pump, molecular sieve adsorption pump and roots vacuum pump, etc. In order to use the low vacuum unit, it is also necessary to configure the elements such as dust remover, drying filter, etc. according to the process requirements such as the cleanliness and humidity of the extracted gas.