1、 The purpose of Roots water ring vacuum unit:

The JZJ2B (S) series Roots liquid ring vacuum unit is composed of a ZJ type Roots pump as the main pumping unit and a 2BV (2SK) type liquid ring vacuum pump or Roots liquid ring vacuum unit as the front stage pump. It can not only be used to remove general gases, but also to extract gases containing moisture and a small amount of dust. Compared with general mechanical vacuum pumps, it has the advantages of not being afraid of oil pollution, water vapor, and dust; Compared with general liquid ring vacuum pumps, it has the advantages of high ultimate vacuum degree and high pumping speed under higher vacuum degree conditions. It is an ideal vacuum pumping equipment for drying, dehydration, and vacuum degassing in industries such as textiles, food, chemicals, and pharmaceuticals.

2、 Characteristics of Roots water ring vacuum unit

1. The JZJ2B series Roots liquid ring vacuum unit adopts an efficient and energy-saving 2BV type liquid ring vacuum pump as the front stage pump. Therefore, the JZJ2B series Roots liquid ring vacuum unit has the advantages of high efficiency, compact structure, no leakage (2BV series is designed according to mechanical seal standards, different from 2SK series packing seals), corrosion resistance (2BV series uses aluminum bronze impellers), and high protection level compared to the JZJ2S series Roots liquid ring vacuum unit.
2. The working fluid of the front stage pump of the Roots water ring vacuum unit is mostly water, and organic solvents (such as methanol, ethanol, xylene, acetone, etc.) or other liquids can also be used. Using the front stage pump as a closed-loop system greatly reduces environmental pollution and greatly improves the recovery of organic solvents. The ultimate vacuum degree is determined by the saturated vapor pressure of the working fluid.

3、 Selection precautions for Roots water ring vacuum unit

1、 Understand the composition of the extracted gas, whether it contains condensable vapor, whether there are particles or dust, and whether it is corrosive. When choosing a vacuum pump, it is necessary to know the gas composition and select the corresponding pump for the extracted gas. If the gas contains vapor, particles, and corrosive gases, it should be considered to install auxiliary equipment such as condensers, dust collectors, etc. on the inlet pipeline of the pump.
2、 The working pressure of the Roots vacuum unit should meet the maximum vacuum and working pressure requirements of the vacuum equipment. For example, a certain vacuum drying process requires a working pressure of 10mmHg (absolute pressure), and the maximum pressure of the selected vacuum pump should be at least 2mmHg, preferably lower than 1mmHg. Usually, the maximum pressure of the pump selected should be half to one order of magnitude higher than the working pressure of the vacuum equipment.
3、 Choose the correct operating point for the Roots vacuum unit. The normal operating range of Roots vacuum unit is from the maximum suction pressure to the ultimate pressure multiplied by 5. Example: The normal working range of JZJ2B150-2.1 Roots water ring vacuum unit is 6000Pa to 125Pa, which is the normal working pressure range after the main pump is turned on. The unit has the best efficiency within this working range.
4、 The vacuum unit should be able to discharge all the gas generated during the vacuum equipment process under its working pressure.
5、 Select appropriate unit configuration based on actual working conditions. For example, the maximum pumping rate and ultimate pressure of JZJ2B300-4.1 unit and JZJ2B300-2.1 unit are the same, but their working range and power consumption are different. The normal working range of JZJ2B300-4.1 unit is 2000Pa~125Pa, while the normal working range of JZJ2B300-2.1 unit is 5000Pa~125Pa. It is obvious that the normal working range of JZJ2B300-2.1 unit is wider, but the power consumption is also greater. If it can be confirmed that the working pressure of the extracted system is less than 2000Pa, priority should be given to using the JZJ2B300-4.1 unit to save energy. If the unit is required to have strong pre pumping capability for the system and needs to work at higher pressure for a long time, Wanjing Pump Industry will choose the JZJ2B300-2.1 unit with a larger front-end pump, which is more suitable.

4、 Main performance parameters of Roots water ring vacuum unit

Note: 1. The above table is a series of industry recommended standards. Due to different working conditions in actual production applications, the suction gas pressure may vary greatly. Therefore, when selecting, Wanjing Pump Industry should verify and calculate based on the actual pumping process, gas release process, suspicious gas condensation situation, suction pressure change time, etc., or refer to the existing equipment usage situation for selection.
2. The technical specifications of a single pump are detailed in the parameter tables of each pump.
3. The maximum suction pressure refers to the maximum pressure at which the main pump can be started. If the main pump is started above this pressure, it may cause overload of the main pump.
4. If the vacuum pump motor, electric contact vacuum gauge, and electric control cabinet need to be explosion-proof, please specify when ordering. The 2BV2 series in the above table should be changed to the 2BV2 Ex series, and the 2BV5 series should be changed to the 2BV6 series accordingly.

5、 Operation process of Roots water ring vacuum unit

1、 Secondary unit (Roots pump+water ring pump)

The main pump of this vacuum unit is a V2 type Roots vacuum pump, with a V1 type liquid ring vacuum pump as the front stage pump (as shown in system diagram 1). To ensure the normal operation of each pump, the following procedure should be followed: 1. Before installation, check the integrity of the equipment and familiarize yourself with the user manuals of each pump provided. 2. Place the vacuum unit in position and fix the bottom corner, and connect the pipelines as required. Attention: When connecting the intake pipeline, a 20-40 mesh filter should be installed in the pipeline above the unit to prevent foreign objects such as welding slag from entering the vacuum unit. It can be removed after the pipeline has passed the vacuum test and successfully tested. It is best to install a Y-shaped filter. A valve should be installed above the intake port of the Roots pump and at the connection point with the system, so that it can be closed before stopping, separating the unit from the vacuum system; A ball valve should be installed between the liquid ring pump and the supply pipeline to control the amount of liquid supplied to the liquid ring pump. Before starting the unit, check for any leaks in the system's pipelines; Before starting the liquid ring pump, please start the vehicle and check if it is stuck; Before starting, the oil level in the Roots pump oil tank and cup should be filled to the specified level according to the "Roots Vacuum Pump User Manual"; And connect the cooling pipeline of the Roots pump to ensure the cooling effect of the shaft seal end of the Roots pump. 4. Assemble the control cabinet and connect the motor and electric contact vacuum gauge according to the electrical schematic diagram. 5. Before powering on the electrical control cabinet, its insulation resistance should also be measured remotely to be ≮ 10M Ω, and the frame and each motor should be well grounded; Before starting the unit, check whether the rotation direction of each pump is correct and make other preparations before starting. 6. Adjust the lower limit of the vacuum degree on the electric contact vacuum gauge to -0.092MPa and the upper limit to the maximum; Attention: When adjusting the upper and lower limits of the electric contact vacuum gauge, the main power supply must be cut off first to prevent electric shock! 7. Power on the electrical control cabinet, open the liquid supply valve to inject water into the liquid ring pump, press the start button, and the liquid ring vacuum pump will run; The electric contact vacuum gauge controls the Roots pump to start automatically, and the unit starts working, driving the entire system. During operation, if the vacuum level falls below the limit due to certain factors, the Roots pump will automatically stop running. When the vacuum level returns to the limit, the Roots pump will restart; Before shutting down, the butterfly valve connecting the system and the unit should be closed, and then the stop button should be pressed to stop the operation of the vacuum unit.

2、 Three stage unit (Roots pump+Roots pump+water ring pump)

The main pump of this vacuum unit is the V3 type Roots vacuum pump, which consists of the V2 type Roots vacuum pump and the V1 type liquid ring vacuum pump as the front stage pumps (as shown in system diagram 2). To ensure the normal operation of each pump, the following procedures should be followed: 1. Before installation, check the integrity of the equipment and familiarize yourself with the user manuals of each pump provided. 2. Place the unit in position and fix the bottom corner, and connect the pipelines as required. Attention: When connecting the intake pipeline, a 20-40 mesh filter should be installed in the pipeline above the unit to prevent foreign objects such as welding slag from entering the vacuum unit. It can be removed after the pipeline has passed the vacuum test and successfully tested. It is best to install a Y-shaped filter. Install a valve above the intake port of the Roots pump and at the connection point with the system, in order to close it first during parking and isolate the unit from the vacuum system; A ball valve should be installed between the liquid ring pump and the liquid supply pipeline to control the amount of liquid supplied to the liquid ring pump. Before starting the unit, check whether there are any leaks in the system's pipelines; Before starting the liquid ring pump, please start the vehicle and check if it is stuck; Before starting, the oil level in the Roots pump oil tank and cup should be filled to the specified level according to the "Roots Vacuum Pump User Manual"; And connect the cooling pipeline of the Roots pump to ensure the cooling effect of the shaft seal end of the Roots pump. 4. Assemble the control cabinet and connect the motor and electric contact vacuum gauge according to the electrical schematic diagram. Before supplying power to the electrical control cabinet, its insulation resistance should also be remotely measured to be ≮ 10M Ω, And the rack and each motor have good grounding; Before starting the unit, check whether the rotation direction of each pump is correct and make other preparations before starting. 6. Adjust the lower limit and upper limit of the vacuum degree on the electric contact vacuum gauge to -0.092MPa and -0.096MPa, respectively; Attention: When adjusting the upper and lower limits of the electric contact vacuum gauge, the main power supply must be cut off first to prevent electric shock! 7. Power on the electrical control cabinet and open the liquid supply valve to supply water to the liquid ring pump. No load test: manually start V1, then start V2 and V3 in sequence. After each pump is running normally, stop V3, V2, and V1 in sequence; Load test: Manually start V1, pre pump the system to -0.092MPa, start V2 to pump to -0.096MPa, start V3. After the system works normally for about 0.5 hours, the parking sequence is the same as the no-load test operation. After the above test run units are normal, the steering switch can be adjusted to the automatic position, the start button can be pressed, V1 runs to -0.092MPa, the electric contact vacuum gauge controls the Roots pump to automatically start, V2 draws to -0.096MPa, V3 starts, and the entire unit enters normal working state after 20 minutes of normal operation of each pump in the unit. During operation, if the vacuum level falls below the limit due to certain factors, the Roots pump will automatically stop running. When the vacuum level returns to the limit, the Roots pump will restart. Before shutting down, the butterfly valve connecting the system and the unit should be closed, and then the stop button should be pressed to stop the operation of the vacuum unit.

3、 Four stage unit (Roots pump+Roots pump+Roots pump+water ring pump)

The main pump of this vacuum unit is the V4 Roots vacuum pump, which is composed of V3, V2 Roots vacuum pumps and V1 liquid ring vacuum pump as the front stage pumps (as shown in system diagram 3). To ensure the normal operation of each pump, the following procedure should be followed: 1. Before installation, check the integrity of the equipment and familiarize yourself with the user manuals of each pump provided. 2. Place the unit in position and fix the bottom corner, and connect the pipelines as required. Attention: When connecting the intake pipeline, a 20-40 mesh filter should be installed in the pipeline above the unit to prevent foreign objects such as welding slag from entering the vacuum unit. It can be removed after the pipeline has passed the vacuum test and successfully tested. It is best to install a Y-shaped filter. A valve should be installed above the intake port of the Roots pump and at the connection point with the system, so that it can be closed before stopping, separating the unit from the vacuum system; A ball valve should be installed between the liquid ring pump and the liquid supply pipeline to control the amount of liquid supplied to the liquid ring pump. Before starting the unit, check whether there are any leaks in the system's pipelines; Before starting the liquid ring pump, please start the vehicle and check if it is stuck; Before starting, the oil level in the Roots pump oil tank and cup should be filled to the specified level according to the "Roots Vacuum Pump User Manual"; Assemble the control cabinet and connect the motor and electrical contact vacuum gauge according to the electrical schematic diagram; Before supplying power to the electrical control cabinet, its insulation resistance should also be remotely measured to be ≮ 10M Ω, and the frame and each motor should have good grounding; Adjust the lower limit of electric contact vacuum gauge B1 to -0.092MPa and the upper limit to 0, and adjust the lower limit of B2 to -0.096MPa and the upper limit to -0.098MPa. Connect the water and gas sources to ensure the cooling effect of the shaft seal end of each Roots pump; Check if the rotation direction of each pump is correct and make other preparations before starting the vehicle. 4. Power on the electrical control cabinet and open the liquid supply valve to supply water to the liquid ring pump. No load test: Manually start V1, start V2, V3, V4 pumps in sequence, and then stop V4, V3, V2, V1 in sequence after normal operation; Load test: Manually start V1, while opening valve F2 pre pumping system to -0.092MPa, close valve F2 to start V2 pumping to -0.096MPa, start V3 pumping to -0.098MPa, and start V4. After the system works normally for about 0.5 hours, close valve F1 and open valve F4; the parking sequence is the same as the no-load test operation, close all valves. After the above test run units are normal, the steering switch can be adjusted to the automatic position, and the start button can be pressed to start V1, F1, F2, F3 to -0.092MPa. Valve F2 will automatically close, and the electric contact vacuum gauge will control the Roots pump to start automatically. When V2 draws to -0.096MPa, V3 will automatically start to -0.098MPa, and then V4 will automatically start until all pumps in the unit work normally for 20 minutes. The manual start valve F4 will interlock and close F1, and the entire unit will enter normal working state. Before shutting down, the butterfly valve connecting the system and the unit should be closed, and then the stop button should be pressed to stop the operation of the vacuum unit.

notes

When the working fluid of the liquid ring pump is water, cyclic use will reduce the vacuum degree due to the increase in water temperature, which will affect the normal operation of the pump; Therefore, cold water should be supplied regularly, hot water should be replaced, and it is best to directly drain cold water into the pump; When the vacuum machine is not in use for a long time, the water inside the pump should be drained to avoid rust and other accidents such as getting stuck during the next start-up.

2. Pay attention to the sound and current changes of the pump. If there are significant changes, stop the machine immediately for inspection.

6、 Electrical Control Instructions for Roots Water Ring Vacuum Unit

The electrical control system of this unit is designed strictly according to the working program of each pump. For the convenience of users, a manual debugging section and an automatic working section are generally set up. If used in explosion-proof systems, explosion-proof control columns can be installed. If the user needs it, a microcomputer control program can be used.

7、 Fault analysis and troubleshooting of Roots water ring vacuum unit

Fault Analysis and Troubleshooting Table