Introduction to LGZJ screw Roots unit:

　　The LGZJ screw and Roots vacuum unit utilizes ZJ or ZJP type Roots vacuum pumps as booster pumps.When the vacuum level of a single screw pump cannot be achieved,additional Roots pumps can be used to meet the required vacuum level.The complete set,with our ZJLG screw vacuum pump as the backing pump,is mounted on a skid-mounted base,featuring a compact structure and easy operation.In addition to the main pump,backing pump,or intermediate pump,the unit also includes connecting pipes,stainless steel bellows,electric contact pressure gauges,and an electrical control box.If a condenser is added,we will provide a complete set of accessories according to your requirements for use.

　　The Roots pump used in the LGZJ screw Roots unit is either a standard ZJ type or a ZJP type Roots pump.Since the ZJ or ZJP type Roots pump can only be started and operated after the vacuum system has been pumped down to the allowable starting pressure of the Roots pump by the preceding pump,an electric contact pressure gauge is generally installed at the inlet of the unit to control the start and stop of the Roots pump.That is,after the preceding screw pump is started,the system begins to be pre-pumped.When the system pressure(i.e.,the pressure at the inlet of the Roots pump)reaches the set pressure allowing the Roots pump to start(i.e.,the pressure value indicated by the green needle of the electric contact pressure gauge),the Roots pump can be started and operated.If,due to special circumstances,the pressure at the inlet of the Roots pump exceeds the value indicated by the green needle on the electric contact pressure gauge when all pumps in the unit are operating normally,the Roots pump will immediately stop automatically.This achieves automatic overload protection for the Roots pump,thereby preventing the unit from experiencing overload and overheating that could lead to malfunction.

　　The LGZJ screw-type roots unit is paired with either a ZJLG screw pump+ZJ roots pump or a ZJLG screw pump+ZJP roots pump(with bypass valve).Depending on customer requirements,suitable models can be matched,such as a screw pump paired with a primary roots pump,or a primary screw pump paired with a secondary or tertiary roots pump.If the pressure is too high,our company does not recommend using a screw pump as the preceding pump.If the equipment is too tall or the skid-mounted unit is too large,we recommend using an air-cooled roots pump.For the preceding pumps,depending on different processes,molecular pumps or other higher vacuum degree preceding pumps can be matched.Welcome to inquire,and we will provide you with a more suitable solution.