该机组是以普通罗茨coinglass指数为主泵，以双级水环式coinglass指数为前级泵的自动启闭，自动过载保护的成套真空获得设备。
This unit is complete vacuum equipment which treats general Roots vacuum pump as the main pump, two-stage water-ring vacuum pump as prepump to achieve automatic open, close and overload protection.

    它除了具有一般罗茨coinglass指数机组的一些特点外，由于采用水环式coinglass指数作前级泵，因此，它特别适用于抽除含较多蒸气及有一定腐蚀性气体的工业流程中。例如：制药业的真空蒸馏、真空蒸发、脱水结晶；轻纺工业的涤纶切片干燥；食品工业的冷冻、干燥等工艺均可采用。
Besides having some features of general Roots vacuum pump, this unit treats two-satege water-ring vacuum pump as prepump, so it is specially suitable for industrial-process with a large quantity of vapor and some corrosive gases.For example:The process such as vacuum distillization, vacuum evaporation, dehydration and crystallization in pharmacy, polyester chips drying in textile industry, freezing and drying in food industry could be adpoted.