Add： No. 265 Juxiang Road, Jiaojiang District, Taizhou City, Zhejiang Province
Everyone knows that the perfect vacuum system is composed of vacuum pump or vacuum unit and a series of auxiliary components such as various pipelines, measuring devices, valves and electrical control systems. Therefore, the vacuum unit is generally based on the type of main pump. Naming, and then can be classified according to product characteristics, such as oil-containing vacuum units and oil-free vacuum units; more commonly, according to the scope of vacuum application, can be divided into low-vacuum units, medium vacuum pump units, high-vacuum units and ultra-high vacuum unit. Roots vacuum units are often used in vacuum systems such as chemical, food sublimation, and high-altitude simulation tests. These vacuum units are roughly of the following types. Let's take a look.
In general, the ultimate vacuum of a single-stage water ring pump is not high, but the pre-vacuum required by the Roots pump produced in China is higher now. Therefore, the single-stage water ring pump is not used as the fore pump of the Roots pump. A two-stage water ring pump that can increase the ultimate vacuum is used as a foreline pump. A two-stage water ring pump can also be used to increase the ultimate vacuum of the unit.
1. The ultimate vacuum of the Roots pump is low, especially when it is combined with the water ring pump, the scope of use is limited, the ultimate vacuum of the whole unit may be lower, but if two Roots pumps are connected in series Combined with the water ring pump, the ultimate vacuum of the unit can be greatly improved.
2, Roots pump - water ring pump - atmospheric pump unit: Even with a two-stage water ring pump, the ultimate vacuum is only within a certain range, which is limited by the saturated vapor pressure of water. The theoretical ultimate pressure of a water ring pump is the saturated vapor pressure of water. If the influence of factors such as gas reflux is considered, the limit pressure of the water ring pump is actually higher than the saturated steam pressure at the water temperature. In order to increase the ultimate vacuum of the foreline pump, the water ring pump can also be used in combination with the atmospheric pump.
3, Roots pump - water ring pump parallel mechanical vacuum pump: This unit is mainly used for vacuuming systems that need to deal with a large amount of water vapor, and the ultimate vacuum degree is high, for example, in vacuum drying.
In a vacuum system that requires a large amount of water vapor, it is appropriate to use a water ring pump, but because of its low ultimate vacuum, the ultimate vacuum of the entire unit is low. Although in a vacuum system requiring a high degree of vacuum, a mechanical vacuum pump having a higher ultimate vacuum is required as a foreline pump. However, due to the large power consumption of the water ring pump, the efficiency is very low, and the noise is high. In a vacuum drying system that requires a long time, the water ring pump is uneconomical as a Roots pump fore pump.
The vacuum unit is suitable for various vacuum systems that require large pumping speed and medium vacuum, such as coating machine, vacuum smelting, vacuum heat treatment, pharmaceutical and chemical engineering, electrical welding and other industries. In the past, the vacuum unit was mostly composed of a combination of Roots vacuum pump + oil seal mechanical pump, Roots vacuum + water ring vacuum pump and double Roots vacuum pump. With the rise of oil-free vacuum pumps such as screw vacuum pumps, oil-free vacuum units such as Roots vacuum pumps + screw vacuum pumps have gradually increased and become more adaptable.
The high vacuum unit works in the molecular flow state, the working pressure range is 10-2~10-6Pa, the displacement is small, and the pumping speed is large. Under normal circumstances, the main pump is composed of a diffusion pump, a molecular pump, a titanium sublimation pump and a low temperature condensing pump. To undertake, because they can not work directly in the atmosphere, it is necessary to configure the foreline pump, pre-pump, etc. In special cases, in order to prevent air pressure fluctuations, it is necessary to configure the maintenance pump and the gas storage tank.
The working pressure range of the ultra-high vacuum unit is 10-6~10-10Pa, and the ultimate vacuum of the main pump is required to be above 10-7~10-8Pa and the corresponding pumping speed is guaranteed within the working pressure range, such as sputter ion pump, Turbo molecular pump, etc., and the material composition of the system can withstand high temperature baking at 200 ~ 450 ° C and ensure low air leakage rate and gas output rate.
The above is the explanation of the company's classification of the Roots vacuum unit. I hope that it will be helpful to everyone. If you have any questions, please feel free to contact us.