Use:
The vacuum system is suitable for high vacuum distilling, vacuum vaporizing and vacuum dehydrating-crystal of chemical and medicine industry, vacuum drying and vacuum soaking of electric utility and light textile industry, freeze-dryer of food industry etc.
Structure and Features:
Roots pump is used as main chief pumps, double-stage liquid ring vacuum pump is as backing pump. They are connected in series. The roots pump and liquid pump can be started and closed automatically by vacuum relay or electric tactility pressure gauge. Possess overload selfprotective function. It has many virtues as follow compared with the ordinary Roots pump and liquid ring vacuum pumps:
●The system can pump ordinary gas, which possesses particles of dust, vapour, because water ring vacuum pump is as backing pump. It can be used in bad environment.
●If multilevel roots pumps are connected in series, the ultimate pressure of approximate is increased 1pa.
●In a quite wide pressure range (50Pa to 4000Pa) a stable, fairly high pumping speed can be gained
●Low power compare with multilevel
These can be combined as follow according as different useful request:
●A roots pump systems with double stage liquid ring vacuum pump
●Two roots pump systems with double stage liquid ring vacuum pump
●Three roots pump systems with double stage liquid ring vacuum pump

A roots pump systems with double stage liquid ring vacuum pump main performance-parameter table

System model	Pump model		Ultimate pressure(Pa)		Pumping speed	Inlet Diam	Outlet Diam	Motor power
	chief	backing	water	oil ring	L/s	mm	mm	Kw
JZJ(P)2S(Y)70-2	ZJ(P)70	2S(Y)K2	300	80	70	80	50	1.5	5.5
JZJ(P)2S(Y)70-1	ZJ(P)70	2S(Y)K3	300	80	70	80	50	1.5	7.5
JZJ(P)2S(Y)150-3	ZJ(P)150	2S(Y)K3	300	80	150	100	50	3	7.5
JZJ(P)2S(Y)150-1	ZJ(P)150	2S(Y)K6	300	80	150	100	50	3	11
JZJ(P)2S(Y)300-3	ZJ(P)300	2S(Y)K6	300	80	300	150	50	4	11
JZJ(P)2S(Y)300-1	ZJ(P)300	2S(Y)K12	300	80	300	150	80	4	22
JZJ(P)2S(Y)600-3	ZJ(P)600	2S(Y)K12	300	80	600	200	80	7.5	22
JZJ(P)2S(Y)600-1	ZJ(P)600	2S(Y)K25	300	80	600	200	100	7.5	55
JZJ(P)2S(Y)1200-3	ZJ(P)1200	2S(Y)K25	300	80	1200	200	100	11	55

A roots pump systems with double stage liquid ring vacuum pump main performance-parameter table

System model	Pump model				Ultimate pressure(Pa)		Pumping speed	Inlet Diam	Outlet Diam	Motor power
	chief	middle	middle	backing	water	oil ring	L/s	mm	mm	Kw
JZJ(P)2S(Y)300-222	ZJ(P)300	ZJ(P)150	ZJ(P)70	2S(Y)K2	1	0.5	300	150	50	4	3	1.5	5.5
JZJ(P)2S(Y)300-221	ZJ(P)300	ZJ(P)150	ZJ(P)70	2S(Y)K3	1	0.5	300	150	50	4	3	1.5	7.5
JZJ(P)2S(Y)300-221T	ZJ(P)300	ZJ(P)150	ZJ(P)70	2S(Y)K6	1	0.5	300	150	50	4	3	1.5	11
JZJ(P)2S(Y)600-223	ZJ(P)600	ZJ(P)300	ZJ(P)150	2S(Y)K3	1	0.5	600	200	50	7.5	4	3	7.5
JZJ(P)2S(Y)600-221	ZJ(P)600	ZJ(P)300	ZJ(P)150	2S(Y)K6	1	0.5	600	200	50	7.5	4	3	11
JZJ(P)2S(Y)1200-421	ZJ(P)1200	ZJ(P)300	ZJ(P)150	2S(Y)K6	1	0.5	1200	250	50	7.5	4	3	11
JZJ(P)2S(Y)1200-223	ZJ(P)1200	ZJ(P)600	ZJ(P)300	2S(Y)K6	1	0.5	1200	250	50	11	7.5	4	11
JZJ(P)2S(Y)1200-221	ZJ(P)1200	ZJ(P)600	ZJ(P)300	2S(Y)K12	1	0.5	1200	250	80	11	7.5	4	22

Notice:In main performance-parameter table the chief pump can choose series ZJ roots pump or series ZJP roots pump. When choose series ZJP roots pump. the letter ZJ in the system model change letter ZP. The signification of letter S is water ring vacuum pump; the signification of letter Y is oil ring vacuum pump.