Light well point device for lowering multi-layer soil texture

Abstract

The utility model relates to the technical field of building related equipment, and discloses a light well point device for reducing multi-layer soil texture, which comprises a vertical water suction pipe, a water collection negative pressure tank and a vacuum drainage all-in-one machine, a floating ball switch a and a floating ball switch b are arranged in the water collection negative pressure tank, the upper portion and the lower portion of the water collection negative pressure tank are connected with the vacuum drainage all-in-one machine through a vacuum anti-explosion pipe and a water pumping pipe respectively, an electromagnetic valve is arranged in the vacuum anti-explosion pipe, and a cooling fan and a power failure alarm are arranged in the vacuum drainage all-in-one machine. And a low-pressure alarm is arranged at the top of the water collection negative-pressure tank through a self-control negative-pressure vacuum meter. The water permeable area can be increased through the blind pipe wrapping the vertical water pipe, underground water can enter the vertical water pipe more quickly, the drainage efficiency is improved, workers can be informed in time through the power failure alarm, and when the pressure in the negative pressure water collecting tank does not reach the standard, alarming and maintenance are conducted in time.

Description

Technical Field

[0001] The utility model relates to the technical field of construction-related equipment, in particular to a light well point device for lowering multi-layer soil. Background Art

[0002] When digging foundation pits, a large amount of groundwater will appear and it is necessary to pump the groundwater. In the past, when pumping groundwater, because the pipes were buried in the soil and only holes were made on the pipes, groundwater could only be drained through the small holes on the pipes. The water permeability was small and the speed was slow, which seriously affected the progress of the project. When pumping the negative pressure water collection tank, if the oil-free vacuum machine is powered off and the staff cannot be notified in time, the groundwater level will increase. The site for digging foundation pits is often very large, and dozens of devices are required to work at the same time. Due to the huge site, the staff cannot take care of each device, so it often happens that the pressure in the negative pressure water collection tank of a certain device does not meet the standard and cannot be pumped.

[0003] In the document CN202222603826, an air pump integrated energy-saving precipitation device is disclosed, including a negative pressure tank connected to a piston air pump, a piston air pump connected to a pressure air storage tank, a pressure air storage tank connected to a pipe well pneumatic energy-saving pump, a negative pressure tank connected to a water pump, a water outlet pipeline connected to the water pump, an air outlet pipe of the pressure air storage tank connected to an air inlet pipeline of the pipe well pneumatic energy-saving pump, an end of the water outlet pipeline of the pipe well pneumatic energy-saving pump located above the waterproof membrane of the drainage ditch, and a drainage pipeline of the well point precipitation pipe connected to the negative pressure tank. This structure only covers the filter screen outside the drainage pipeline, has a small permeable area, and has a low pumping efficiency. If the pressure in the negative pressure tank does not meet the standard, it is impossible to promptly alert the staff and perform timely maintenance, which affects the overall precipitation efficiency.

[0004] Therefore, a new technical solution is needed to solve the above technical problems. Summary of the invention

[0005] In order to solve the above problems, the utility model discloses a lightweight well point device for reducing multi-layer soil. The blind pipe coated on the outside of the vertical water pipe can increase the permeable area, allowing groundwater to enter the vertical water pipe more quickly, thereby accelerating the drainage efficiency. The staff can be notified in time through the power-off alarm. When the pressure in the negative pressure water collection tank does not meet the standard, an alarm can be issued in time for maintenance.

[0006] The technical solution of the utility model is: a light well point device for lowering multi-layer soil, including a vertical water suction pipe, a water collecting negative pressure tank, and a vacuum drainage integrated machine. The vertical water suction pipe is connected to the water collecting negative pressure tank through a horizontal water collecting pipe, and a water-permeable blind pipe and a water-permeable filter are respectively provided on the outside of the vertical water suction pipe. A float switch a and a float switch b are provided in the water collecting negative pressure tank. The upper and lower parts of the water collecting negative pressure tank are respectively connected to the vacuum drainage integrated machine through a vacuum explosion-proof pipe and a water pumping pipe. A solenoid valve is provided in the vacuum explosion-proof pipe. A low pressure alarm is provided on the top of the water collecting negative pressure tank through an automatic negative pressure vacuum gauge. A cooling fan is provided in the vacuum drainage integrated machine, and a power-off alarm is provided in the vacuum drainage integrated machine.

[0007] By adopting the above technical solution, the oil-free vacuum unit starts to work, and the vacuum explosion-proof pipe creates negative pressure in the water collecting negative pressure tank. Then the water in the vertical suction pipe flows upward toward the water collecting negative pressure tank, and is discharged from the drain pipe through the suction pipe by the horizontal centrifugal water pump, thereby draining water.

[0008] Preferably, a plurality of through holes are opened in the lower part of the vertical suction pipe near the bottom, the permeable blind pipe is wrapped around the two-thirds outside the vertical suction pipe, the through holes are located inside the permeable blind pipe, the permeable blind pipe is wrapped with a permeable filter screen, the part of the bottom of the permeable filter screen that exceeds the permeable blind pipe and the vertical suction pipe, and the position of the permeable filter screen located at the upper part of the permeable blind pipe are all tied with cable ties.

[0009] By adopting the above technical solution, only through holes are opened in the lower part, so that the negative pressure in the vertical water suction pipe can be guaranteed. The through holes in the lower part can allow groundwater to enter the vertical water suction pipe, and then the negative pressure in the vertical water suction pipe will suck the water into the water collecting negative pressure tank. The permeable blind pipe outside the vertical water suction pipe can effectively increase the permeable area. There is no through hole in the upper part of the vertical water suction pipe. The groundwater passes through the permeable blind pipe and flows downward along the permeable blind pipe, and finally enters the position of the through hole and enters the vertical water suction pipe. The permeable filter screen provided on the outside of the permeable blind pipe can block impurities such as clay, and prevent it from falling by using cable ties.

[0010] Preferably, the upper part of the vertical water suction pipe is exposed to the ground and is connected to the water inlet pipe at the upper part of the water collecting negative pressure tank through the horizontal water collecting pipe. A sealing clay layer is added to the pre-buried outlet of the vertical water suction pipe, and the clay layer is located at the upper part of the permeable blind pipe.

[0011] By adopting the above technical solution, the horizontal water collecting pipe can transport the water in the vertical water suction pipe. Adding a clay layer on the upper part of the vertical water suction pipe can increase the overall sealing of the vertical water suction pipe and increase the negative pressure inside the pipe, making it easier to suck up the water in the pipe.

[0012] Preferably, the float switch a is located at the upper part of the connection between the horizontal water collecting pipe and the water collecting negative pressure tank, the float switch b is located at the lower part of the float switch a, and the float switch a and the float switch b are connected to an external controller. By adopting the above technical solution, the float switch a and the float switch b are used to detect whether the water level in the water collecting negative pressure tank meets the discharge requirements. When the water level in the water collecting negative pressure tank reaches the float switch b, the float switch b sends a signal to the controller, and the controller transmits a signal to the control box to make the horizontal centrifugal water pump work. When the water level in the negative pressure water collecting tank reaches the float switch a, the float switch a sends a signal to the control box to turn off the oil-free vacuum unit and open the solenoid valve to connect the water collecting negative pressure tank to the outside world, so that the water collecting negative pressure tank has no negative pressure.

[0013] Preferably, a one-way valve b is further provided between the solenoid valve in the vacuum explosion-proof pipe and the water collecting negative pressure tank, and the vacuum explosion-proof pipe is connected to the oil-free vacuum unit of the vacuum drainage integrated machine.

[0014] By adopting the above technical solution, the water in the vacuum explosion-proof pipe can be prevented from flowing back, so that the internal water can only flow from the water pumping pipe to the vacuum drainage integrated machine.

[0015] Preferably, both ends of the water pumping pipe are respectively connected to the lower part of the water collecting negative pressure tank and the horizontal centrifugal pump of the vacuum drainage integrated machine. A one-way valve a is provided in the water pumping pipe, and an ultrasonic flowmeter is also provided between the one-way valve a and the horizontal centrifugal water pump. The horizontal centrifugal water pump discharges water through the drainage pipe.

[0016] Preferably, the power failure alarm is connected to the oil-free vacuum unit, the oil-free vacuum unit is connected to the horizontal centrifugal water pump and the control electric box, and the control electric box is connected to the controller.

[0017] By adopting the above technical solution, the control electric box is used to control the start and stop of the oil-free vacuum unit and the bedroom centrifugal water pump.

[0018] Preferably, the oil-free vacuum unit, horizontal centrifugal water pump, control electrical box and controller are all located in the vacuum drainage integrated machine and connected to a power supply. The vacuum drainage integrated machine is a box body with a mesh at the bottom. The cooling fan is located on the side wall of the box body, and the cooling fan is connected to a power supply.

[0019] By adopting the above technical solution, the cooling fan can cool the oil-free vacuum unit, the horizontal centrifugal water pump, and the control electrical box to prevent the machine from being damaged by excessive temperature, and the mesh at the bottom of the box can further dissipate the high temperature inside.

[0020] Preferably, an automatic negative pressure vacuum gauge is provided on the top of the negative pressure water collecting tank, and a low pressure alarm is connected to the automatic negative pressure vacuum gauge. When the value in the automatic negative pressure vacuum gauge is less than 0.04MPa, the low pressure alarm sounds an alarm.

[0021] By adopting the above technical solution, through the low-pressure alarm provided on the top of the negative pressure water collection tank, when the internal value is less than 0.04MPa, it is impossible to pump water out of it. The low-pressure alarm will sound, which can quickly notify the staff to check the entire device.

[0022] The benefits of the utility model are as follows: 1. The utility model increases the permeable area of ​​the entire vertical pumping pipe by adding a whole permeable blind pipe outside the vertical suction pipe, effectively improving the precipitation effect of multi-layer soil and other complex soils. During the drainage process, the water in the permeable blind pipe can be quickly discharged into the vertical suction pipe, and the groundwater can be accelerated to gather and discharge to the bottom of the vertical suction pipe, which greatly improves the precipitation effect.

[0023] 2. The utility model only opens a through hole at the lower part of the vertical water suction pipe, and arranges a clay layer at the upper part of the vertical water suction pipe, which can accelerate the formation of a negative pressure state in the vertical water suction pipe, accelerate the water absorption inside the vertical water suction pipe, and improve the precipitation effect.

[0024] 3. The utility model is provided with a solenoid valve in the vacuum explosion-proof pipe. When the float switch a detects the water level, the solenoid valve receives a signal and opens the solenoid valve to connect the water collecting negative pressure tank with the outside world, so as to prevent the water level in the water collecting negative pressure tank from being too high and flowing back into the oil-free vacuum unit, causing damage to the equipment.

[0025] 4. The utility model can timely find out which device's negative pressure water collecting tank's pressure value does not meet the standard through the low-pressure alarm, and promptly give an alarm, and can notify the staff to promptly inspect and repair the device.

[0026] 5. The utility model connects a power-off alarm to the oil-free vacuum unit. When the power-off alarm detects that the oil-free vacuum unit is not working, an alarm is sounded, and the staff can repair it in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the utility model;

[0028] Figure 2 This is a structural schematic diagram of a three-dimensional view of a vertical water suction pipe of the utility model;

[0029] Figure 3 This is a schematic diagram of the structure of the vertical water suction pipe of the utility model;

[0030] Figure 4 It is a structural schematic diagram of the negative pressure water collection tank and vacuum drainage integrated machine of the utility model.

[0031] Among them: 1. Vertical suction pipe; 1-1. Through hole; 2. Clay layer; 3. Permeable blind pipe; 4. Permeable filter; 5. Horizontal water collecting pipe; 6. Cable tie; 7. Water collecting negative pressure tank; 7-1. Float switch a; 7-2. Float switch b; 8. Vacuum explosion-proof pipe; 9. Suction pipe; 10. One-way valve a; 10-1. One-way valve b; 11. Solenoid valve; 12. Vacuum drainage integrated machine; 12-1. Oil-free vacuum unit; 12-2. Horizontal centrifugal water pump; 12-3. Cooling fan; 12-4. Power off alarm; 12-5. Drain pipe; 13. Ultrasonic flowmeter; 14. Low pressure alarm; 15. Automatic pressure vacuum gauge. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] like Figure 1-4 As shown, a light well point device for reducing multi-layer soil includes a vertical water suction pipe 1, a water collecting negative pressure tank 7, and a vacuum drainage integrated machine 12. The vertical water suction pipe 1 is connected to the water collecting negative pressure tank 7 through a horizontal water collecting pipe 5. A water-permeable blind pipe 3 and a water-permeable filter screen 4 are respectively arranged outside the vertical water suction pipe 1. A float switch a7-1 and a float switch b7-2 are arranged inside the water collecting negative pressure tank 7. The water-permeable blind pipe 3 is made of PLA degradable or plastic material. The upper and lower parts of the water collecting negative pressure tank 7 are connected to the vacuum drainage integrated machine 12 through a vacuum explosion-proof pipe 8 and a water pumping pipe 9 respectively. A low pressure alarm 14 is provided on the top of the water negative pressure tank 7 through an automatic negative pressure vacuum gauge 15, a solenoid valve 11 is provided in the vacuum explosion-proof pipe 8, a cooling fan 12-3 is provided in the vacuum drainage integrated machine 12, and more than two water inlet pipes 7-3 are provided on the water collecting negative pressure tank 7. The oil-free vacuum unit 12-1 starts to work, and the vacuum explosion-proof pipe 8 generates negative pressure in the water collecting negative pressure tank 7. Then the water in the vertical water suction pipe 1 flows upward toward the water collecting negative pressure tank 7, and is discharged from the drainage pipe 12-5 by the horizontal centrifugal water pump 12-2 through the suction pipe 9, thereby draining.

[0034] A plurality of through holes 1-1 are provided at the lower part of the vertical water suction pipe 1 near the bottom, and the water-permeable blind pipe 3 is wrapped at two-thirds of the outer part of the vertical water suction pipe 1. The through holes 1-1 are located inside the water-permeable blind pipe 3, and the water-permeable blind pipe 3 is wrapped with a water-permeable filter 4. The bottom of the water-permeable filter 4 exceeds the part of the water-permeable blind pipe 3 and the vertical water suction pipe 1, and the position of the water-permeable filter 4 located at the upper part of the water-permeable blind pipe 3 is tied by a cable tie 6. Only the through holes 1-1 are provided at the lower part, so that the negative pressure in the vertical water suction pipe 1 can be ensured. The through holes 1-1 at the lower part can make the ground The sewage enters the vertical suction pipe 1, and then the negative pressure in the vertical suction pipe 1 sucks the water into the water collecting negative pressure tank 7. The permeable blind pipe 3 outside the vertical suction pipe 1 can effectively increase the permeable area. There is no through hole 1-1 on the upper part of the vertical suction pipe 1. The groundwater passes through the permeable blind pipe 3 and flows downward along the permeable blind pipe 3, and finally enters the through hole 1-1 and enters the vertical suction pipe 1. The permeable filter screen 4 provided on the outside of the permeable blind pipe 3 can block impurities such as clay, and prevent it from falling by using cable ties 6 and the like.

[0035] The upper part of the vertical water suction pipe 1 is exposed to the ground and is connected through the horizontal water collecting pipe 5 and the water inlet pipe 7-3 on the upper part of the water collecting negative pressure tank 7. A sealing clay layer 2 is added to the pre-buried outlet of the vertical water suction pipe 1. The clay layer 2 is located on the upper part of the permeable blind pipe 3. The horizontal water collecting pipe 5 can transport the water in the vertical water suction pipe 1. The addition of the clay layer 2 on the upper part of the vertical water suction pipe 1 can increase the overall sealing of the vertical water suction pipe 1, increase the negative pressure inside the pipe, and facilitate the water in the pipe to be sucked up.

[0036] The float switch a7-1 is located at the upper part of the connection between the horizontal water collecting pipe and the water collecting negative pressure tank, and the float switch b7-2 is located at the lower part of the float switch a7-1. The float switch a7-1 and the float switch b7-2 are connected to an external controller. The float switch a7-1 and the float switch b7-2 are used to detect whether the water level in the water collecting negative pressure tank 7 meets the discharge requirements. When the water level in the water collecting negative pressure tank 7 reaches the float switch b7-2, the float switch b7-2 sends a signal to the controller, and the controller transmits a signal to the control box to make the horizontal centrifugal water pump 12-2 work. When the water level in the negative pressure water collecting tank 7 reaches the float switch a7-1, the float switch a7-1 gives a signal to the control box to close the oil-free vacuum unit 12-1 and open the solenoid valve 11 at the same time to connect the water collecting negative pressure tank 7 with the outside world, so that the water collecting negative pressure tank 7 has no negative pressure.

[0037] A one-way valve b10-1 is also provided between the solenoid valve 11 in the vacuum explosion-proof pipe 8 and the water collecting negative pressure tank 7. The vacuum explosion-proof pipe 8 is connected to the oil-free vacuum unit 12-1 of the vacuum drainage integrated machine 12, which can prevent the water in the vacuum explosion-proof pipe 8 from flowing back, so that the internal water can only flow from the water pumping pipe 9 to the vacuum drainage integrated machine 12.

[0038] The two ends of the water pumping pipe 9 are respectively connected to the lower part of the water collecting negative pressure tank 7 and the horizontal centrifugal pump 12-2 of the vacuum drainage integrated machine 12. A one-way valve a10 is provided in the water pumping pipe 9. An ultrasonic flowmeter 13 is also provided between the one-way valve a10 and the horizontal centrifugal water pump 12-2. The ultrasonic flowmeter 13 can monitor the flow of water in the water pumping pipe 9 and reflect the flow situation in the water pumping pipe 9 in real time. The horizontal centrifugal water pump 12-2 discharges water through the drain pipe 12-5. The power-off alarm 12-4 is connected to the oil-free vacuum unit 12-1, and the oil-free vacuum unit 12-1 is connected to the horizontal centrifugal water pump 12-2 and the control electric box. The control electric box is connected to the controller. The control electric box is used to control the start and stop of the oil-free vacuum unit 12-1 and the bedroom centrifugal water pump 12-2.

[0039] The oil-free vacuum unit 12-1, the horizontal centrifugal water pump 12-2, the control electric box and the controller are all located in the vacuum drainage integrated machine 12 and connected to a power source. The vacuum drainage integrated machine 12 is a box body with mesh holes at the bottom. The cooling fan 12-3 is located on the side wall of the box body. The cooling fan 12-3 is connected to a power source. The cooling fan 12-3 can cool the oil-free vacuum unit 12-1, the horizontal centrifugal water pump 12-2 and the control electric box to prevent the machine from being damaged by excessive temperature. The mesh holes at the bottom of the box body can further dissipate the internal high temperature.

[0040] An automatic negative pressure vacuum gauge 15 is provided on the top of the negative pressure water collecting tank 7. The automatic negative pressure vacuum gauge 15 is used to detect the pressure inside the negative pressure water collecting tank 7. The low pressure alarm 14 is connected to the automatic negative pressure vacuum gauge. When the value in the automatic negative pressure vacuum gauge 15 is less than 0.04MPa, the low pressure alarm 14 will alarm. Since the pumping site is very large and dozens of devices are working at the same time, the staff cannot check them in time. Through the low pressure alarm 14 provided on the top of the negative pressure water collecting tank 7, when the internal value is less than 0.04MPa, it is impossible to pump water. The low pressure alarm 14 will alarm and can quickly notify the staff to check the entire device.

[0041] When the oil-free vacuum unit 12-1 starts working, negative pressure is generated in the water collection negative pressure tank 7 through the vacuum explosion-proof pipe 8, and the water in the light well point pipe is sucked into the water collection negative pressure tank 7. When the water level in the water collection negative pressure tank 7 reaches the position of the float switch b7-2, the float switch b7-2 gives a signal to the control electric box to start the horizontal centrifugal water pump 12-3 to drain the water in the water collection negative pressure tank 7 to the designated drainage ditch or sedimentation tank; if the horizontal centrifugal water pump or the one-way valve a10 cannot be opened normally, the water collection negative pressure tank 7 When the internal water level continues to rise to the upper end float switch a7-1, the float switch a7-1 sends a signal to the control box to shut down the oil-free vacuum unit 12-1 and open the solenoid valve 11 to connect the water collecting negative pressure tank 7 with the outside world, so that the water collecting negative pressure tank 7 has no negative pressure to prevent the water level in the water collecting negative pressure tank 7 from being too high and flowing back into the oil-free vacuum unit 12-1, causing equipment damage, and adding a cooling fan 12-3 in the vacuum drainage integrated machine 12 to adjust the working temperature of the entire unit and effectively extend the service life of the unit.

[0042] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention, and the purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and the implementation methods of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A light well point device for reducing multi-layer soil, comprising a vertical water suction pipe, a water collection negative pressure tank, and a vacuum drainage integrated machine, wherein the vertical water suction pipe is connected to the water collection negative pressure tank through a horizontal water collection pipe, and is characterized in that: The outside of the vertical water suction pipe is respectively provided with a water-permeable blind pipe and a water-permeable filter, the water collecting negative pressure tank is provided with a float switch a and a float switch b, the upper and lower parts of the water collecting negative pressure tank are respectively connected to the vacuum drainage integrated machine through a vacuum explosion-proof pipe and a water suction pipe, the vacuum explosion-proof pipe is provided with a solenoid valve, the vacuum drainage integrated machine is provided with a cooling fan, the vacuum drainage integrated machine is provided with a power-off alarm, and the top of the water collecting negative pressure tank is provided with a low pressure alarm through an automatic negative pressure vacuum gauge.

2. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: A plurality of through holes are provided at the lower portion of the vertical water suction pipe near the bottom, the permeable blind pipe is wrapped around two-thirds of the outside of the vertical water suction pipe, the through holes are located inside the permeable blind pipe, a permeable filter is wrapped around the outside of the permeable blind pipe, and the portion of the bottom of the permeable filter that exceeds the permeable blind pipe and the vertical water suction pipe, as well as the position of the permeable filter located at the upper portion of the permeable blind pipe are all tied with cable ties.

3. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: The upper part of the vertical water suction pipe is exposed to the ground and is connected to the water inlet pipe at the upper part of the water collecting negative pressure tank through the horizontal water collecting pipe. A sealing clay layer is added to the pre-buried outlet of the vertical water suction pipe, and the clay layer is located at the upper part of the permeable blind pipe.

4. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: The float switch a is located at the upper part of the connection between the horizontal water collecting pipe and the water collecting negative pressure tank, and the float switch b is located at the lower part of the float switch a. The float switch a and the float switch b are connected to an external controller.

5. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: A one-way valve b is also provided between the solenoid valve in the vacuum explosion-proof pipe and the water collecting negative pressure tank, and the vacuum explosion-proof pipe is connected to the oil-free vacuum unit of the vacuum drainage integrated machine.

6. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: The two ends of the water pumping pipe are respectively connected to the lower part of the water collecting negative pressure tank and the horizontal centrifugal pump of the vacuum drainage integrated machine. A one-way valve a is provided in the water pumping pipe. An ultrasonic flow meter is also provided between the one-way valve a and the horizontal centrifugal water pump. The horizontal centrifugal water pump discharges water through the drainage pipe.

7. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: The power failure alarm is connected to the oil-free vacuum unit, the oil-free vacuum unit is connected to the horizontal centrifugal water pump and the control electric box, and the control electric box is connected to the controller.

8. A light well point device for reducing multi-layer soil according to claim 7, characterized in that: The oil-free vacuum unit, horizontal centrifugal water pump, control electrical box and controller are all located in the vacuum drainage integrated machine and connected to a power supply. The vacuum drainage integrated machine is a box body with mesh holes at the bottom. The cooling fan is located on the side wall of the box body and is connected to a power supply.

9. A light well point device for reducing multi-layer soil according to claim 1, characterized in that: An automatic negative pressure vacuum gauge is provided on the top of the water collecting negative pressure tank, and the low pressure alarm is connected to the automatic negative pressure vacuum gauge. When the value in the automatic negative pressure vacuum gauge is less than 0.04MPa, the low pressure alarm will sound an alarm.

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