LSJ water jet roots vacuum pump unit

1.LSJ water jet roots vacuum pump unit of application scope and feature

LSJ water jet roots vacuum pump unit, has feature of large capacity and high vacuum degree can also be used separately, water jet pump is used in coarse vacuum. In high vacuum, then in series on the Roots pump, the ultimate pressure can up to 150 pa, the ultimate pressure of water jet pump restricted by water temperature, which only reach a certain pressure, after adding the roots pump can achieve higher vacuum degree, and the capacity is larger than the general mechanical vacuum pump, suitable for light industry, food, medicine, oils, pesticides and other industries.

LSJ water jet roots vacuum pump unit

2.LSJ water jet roots vacuum pump unit of working principle

The working principle of water jet roots vacuum pump unit is to use the energy transfer of the fluid to produce vacuum. The working principle of Roots vacuum pump unit is to use a pair of rotor rotation at the same speed to produce compression and vacuum.

3.LSJ water jet roots vacuum pump unit of model description

L S J-160-150

L: Roots Pump

S:Water jet

J:Vacuum system

160:Water jet pump capacity 160m3/h

150:Roots Pump capacity 150L/S

4.LSJ water jet roots vacuum pump unit material:

1, Water jet pump nozzle is ceramic, the rest are propylene, or cast iron lining modified polyethylene (PE), cast iron.

2, Water tank, air chamber, centrifugal pump are polypropylene or carbon steel.

3, Pipe fittings and valves are reinforced polypropylene or carbon steel.

4, Roots pump is cast iron

5.LSJ water jet roots vacuum pump unit of technical parameters

When the working water temperature is 25°C, the atmospheric pressure is 101.323 kPa

Model Water jet roots vacuum pump Roots pump WeightKg Dimension







Centrifugal pump model Power


Model Capacity


Ultimate pressure


r/min Power


LSJ-50-70 3066 50 FZ50-28 4 ZJ-70 70 150 1450 1.5 750 1.7X1.5X1.5
LSJ-120-70 3066 120 FZ80-30 5.5 ZJ-70 70 150 2900 1.5 980 1.8X1.5X1.5
LSJ-160-150 3066 160 FZ80-32 7.5 ZJ-150 150 150 2900 3 1050 2.2X1.5X1.8
LSJ-230-150 3066 230 FZ100-20 11 ZJ-150 150 150 2900 3 1120 2.6X1.6X1.7
LSJ-320-150 3066 320 FZ100-20 15 ZJ-150 150 150 2900 3 1150 2.6X1.6X1.7
LSJ-400-300 3066 400 ISW150-250 18.5 ZJ-300 300 150 1450 4 1450 3.2X1.8X1.8
LSJ-700-300 3066 700 ISW150-315A 22 ZJ-300 300 150 1450 4 1600 3.5X2.2X1.8

Note: ZJ-300, ZJ-600 Roots units do not have air chamber

6.LSJ water jet roots vacuum pump unit of Precautions for the use

1.The equipment should be placed indoors as far as possible. If placed outdoors, the shading and rainproof tube shed should be built to avoid sun and rain and shorten the service life of the equipment.

2.The unit should be placed on the concrete floor, the vacuum pump unit suction inlet and the suction container connection pipeline should be as short as possible, the pipe diameter can not be less than the suction inlet specifications, otherwise affect the pumping volume.

3.When the unit is working, due to the operation of the centrifugal pump and the suction of the pumped high temperature medium, the working water temperature rises, and the working vacuum is reduced. Cold water should be constantly injected for exchange, or the cooling coil should be installed in the water tank.

Special attention: if you need to stop using for a long time, or in the winter to prevent freezing crack, you must put all the remaining water in the cooling water jacket of the Roots pump!

6.1 Installation site

1.Roots vacuum pump unit should be installed in a bright, dustless building.

2.The installation ambient temperature of Roots vacuum pump is 5 ~ 40℃.

3.Full spacemust be left around Roots vacuum pump to facilitate daily inspection, maintenance, disassembly and assembly.

6.2. Foundation engineering

1.Roots vacuum pump unit and the front pump are installed on the same frame to form a unit and then installed on the concrete foundation. Large pumps of vacuum pump unit must be installed separately to pour the concrete foundation.

2.Determine the compression area and depth of the concrete foundation according to the weight of Roots pump and the pressure resistance of the foundation.

3.In order to bury the foundation bolts in the concrete, sufficient holes must be set aside according to the position of the hole in the foundation when the concrete foundation is poured.

4.Make the base surface level.

6.3. Installation

Roots vacuum pump must be installed on the horizontal base surface, if the base surface is not smooth, it will affect the normal operation of the pump.

1.Make the wooden frame according to the position of the hole of the foot, fix the foundation bolt on the wooden frame, put it into the reserved hole, pour concrete into the reserved hole, put it for a few days, and remove the wooden frame after the concrete is hardened.

2.Put the Roots vacuum pump on the foundation, calibrate the level with a level gauge, pad the uneven part of the vacuum pump unit with metal gaskets, tighten the foundation bolts, and fill the cracks on the bottom surface with cement.

6.4. Pipe laying

Note: During the work, if welding slag and other foreign matter enter the pump, it will cause serious damage or destruction to the Roots pump and the front pump. Therefore, it is necessary to strictly clean the pipeline before installation.In the process of work is strictly prohibited to breathe in the gas with particles and dust, so it must be equipped with the corresponding filter device.

1.There is no welding slag, impurities and other foreign bodies in the inlet and outlet gas pipeline, and it has sufficient ventilation capacity.

2.A section of elastic pipe shall be installed in the connecting pipe from the outlet of Roots vacuum pump to the inlet of the front pump to reduce the impact of the vibration of the front pump on the Roots vacuum pump.

3.In order to shorten the pre-pumping time, in the general system, the inlet of the front pump is connected with the Roots vacuum pump exhaust port, and the bypass pre-pumping pipeline and valve need to be installed.

4.In order to prevent the oil return or water return when the front pump stops (when the front pump uses the water ring vacuum pump), the water ring Roots vacuum pump unit should install a vent valve or check valve on the intake pipe of the front pump.

5.The pipe connection flange shall be sealed with O-type rubber sealing ring and coated with vacuum Cocker grease. The whole vacuum system must be sealed without leakage.

6.The inlet and outlet of cooling water of the pump should be connected to the pipeline, and the valve should be installed on the inlet pipe to regulate the amount of water.

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