Generally, roots vacuum pump unit must have
four elements in the design: ① the size of the container to be pumped; ② the
required working pressure; ③ the time required to reach the working pressure; ④
the nature and characteristics of the extracted gas. The selection of front
stage pump of vacuum pump unit is closely related to the above four elements.
According to different uses, the common front stage pumps of Roots
vacuum pump include rotary vane vacuum pump, slide valve vacuum pump, liquid
ring vacuum pump (including water ring vacuum pump) and gas circulating cooling
roots pump. The selection of the front stage pump should first consider the
characteristics of the gas to be pumped and the working pressure that can be
reached.
It is usually selected according to the following principles:
1. If the extracted gas has no particularity, is neither corrosive nor toxic,
nor is it a gas with low steam pressure, such as clean air, the rotary vane
vacuum pump should be considered as the first stage pump of the unit. Because
the rotary vane vacuum pump has large compression ratio and wide working
pressure range, the working pressure range of double-stage rotary vane vacuum
pump is from atmosphere to 1 × 10-2 PA, and that of single-stage rotary vane
vacuum pump is from atmosphere to 1 PA. Even if the single-stage rotary vane
vacuum pump is used as the front stage pump of the first stage roots unit, its
limit pressure can reach 1 × 10-1 PA. Due to the wide working pressure range of
the unit, this kind of configuration has good economy and is widely used.
Water Ring Vacuum Pump
Dry
Scroll Vacuum Pump
industrial vacuum pumps,vacuum furnaces
没有评论:
发表评论