By connecting Roots Mechanical Vacuum booster directly to the suction side of Dry type Vacuum pump in suction pressure range of 20~1×10-2torr, the process can be stable and the discharge capacity range from 600~3600m3/hr, and the operating cost is cheaper than operating the dry type vacuum pump only. Also, as it is oil free and water free type, no waste water problem is expected. As the discharge capacity for Dry type vacuum Pump is limited to 2~13m3/min, combination with Roots type mechanical Vacuum booster for larger capacities is advisable.
A system package suitable for process which include high condensing vapor and need high olume 1500~18000m3/hr and high vacuum20~1x10-3Torr. This system is consisted as 3 stage by onnecting Mechanical boosters directly to suction side of Dry type Vacuum Pump. These systems are also oil free and water free type, no waste water problem is expected and operation cost is lower to its capacity.