Roots vacuum pump

Roots pump have ZJ series and ZJP series. As the input pressure is between 6.5-65 Pa. It is a kind of roots vacuum pump in which a couple of lobed rotors turn like 8-shape in high speed synchronously. Two rotors rotate and produce aspiration and exhaust which principle is just like a roots blower. As it works in a lower pressure, the free flow distance of gas molecule is longer and the resistance of gas passing a small gap is much large. Thus, a bigger compression ratio can be gained so that it can also be used as a blower pump. But it can not discharge the gas to atmosphere directly and requires to be used with a fore vacuum pump in series connection.
The Roots pumps are widely used in vacuum moulding, vacuum smelting, vacuum gas pumping, vacuum coating industry, vacuum distilling and vacuum drying of chemical and pharmaceutical industry etc. The pump is insensitive to a little dust.