Pulsed pneumatic groundwater extraction and treatment device

Abstract

The utility model relates to soil and groundwater remediation technical field discloses a kind of pulsed pneumatic groundwater extraction processing device, including air compressor, PLC controller and clay sealing layer, the bottom end of the clay sealing layer is provided with quartz sand layer, the inner wall top of the quartz sand layer is fixedly connected with open well pipe, the upper and lower ends of the open well pipe are fixedly connected with real pipe, one end of the air compressor is communicated with air inlet pipe, the other end of the air inlet pipe is communicated with pneumatic extraction device, the bottom end of the pneumatic extraction device is communicated with pumping pipe, the other end of the pumping pipe is communicated with pressure water pipe.In the utility model, by air compressor to generate compressed gas to flow into air inlet pipe, make pneumatic extraction device work to produce suction, when pumping, because there is sealed wellhead in well, when water level in well drops, air pressure reduces, float drops, well is under negative pressure, to improve contaminant capture efficiency, reduce disturbance to groundwater environment.

Description

Technical Field

[0001] This utility model relates to the field of soil and groundwater remediation technology, and in particular to a pulse-type pneumatic groundwater extraction and treatment device. Background Technology

[0002] In the field of soil and groundwater remediation, the pulsed pneumatic groundwater extraction and treatment device, as an innovative pollution control equipment, drives groundwater flow through periodically changing air pressure, changing the stable state of water flow under the traditional continuous pumping mode. This enables pollutants in groundwater to migrate and diffuse more fully, achieving efficient capture and collection of polluted groundwater, and has important application value in improving the quality of groundwater environment.

[0003] Early groundwater extraction and treatment devices employed a simple continuous pumping mode, consisting of a pump, pumping pipelines, and some basic components. During operation, the stable and continuous water flow made it difficult for pollutants in the groundwater to migrate and diffuse sufficiently, resulting in limited extraction efficiency. Furthermore, prolonged pumping caused significant disturbance to the groundwater environment and resulted in high energy consumption. To address these issues, some improved structures emerged, such as optimized pipeline design and the use of variable frequency pumps to regulate the pumping rate. However, existing devices still rely on pumps as the core power source. During pumping, the water flow direction is unidirectional and the flow velocity is stable, making it difficult for pollutants in the groundwater to migrate and diffuse sufficiently. Especially in poorly permeable strata, the stable water flow is insufficient to create a pressure gradient to drive pollutants towards the pumping well. Consequently, pollutants far from the pumping well cannot be effectively captured, greatly limiting the scope and efficiency of remediation. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a pulse-type pneumatic groundwater extraction and treatment device, which aims to improve the problem that pollutants in the pumping well area cannot be effectively captured in the prior art.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a pulse-type pneumatic groundwater extraction and treatment device, comprising an air compressor, a PLC controller, and a clay sealing layer. A quartz sand layer is provided at the bottom of the clay sealing layer. A screened well pipe is fixedly connected to the top of the inner wall of the quartz sand layer. Solid pipes are fixedly connected to both the upper and lower ends of the screened well pipe. One end of the air compressor is connected to an air inlet pipe, and the other end of the air inlet pipe is connected to a pneumatic extraction device. A water pumping pipe is connected to the bottom of the pneumatic extraction device, and a pressure-resistant water pipe is connected to the other end. Sealed wellheads are fixedly connected to both the upper and lower ends of the inner wall of the top solid pipe. The other end of the pressure-resistant water pipe passes through the tops of both sealed wellheads and is connected to a liquid level control mechanism. The PLC controller is electrically connected to the air compressor and the pneumatic extraction device for controlling the pulse-type extraction operation of the device.

[0006] As a further description of the above technical solution:

[0007] The bottom end of the air inlet pipe is connected to an air injection pipe, the other end of the air injection pipe is connected to the top end of the pressure-resistant water pipe, a second solenoid valve is fixedly connected to the outer wall of the air inlet pipe, a first solenoid valve is fixedly connected to the outer wall of the air injection pipe, a third solenoid valve is fixedly connected to the right end of the outer wall of the water pumping pipe, and a pressure gauge is connected to the left side of the outer wall of the water pumping pipe.

[0008] As a further description of the above technical solution:

[0009] The liquid level control mechanism includes a liquid level control unit, the outer wall of which is connected to the other end of the pressure-resistant water pipe, and a float is slidably connected to the inner wall of the liquid level control unit.

[0010] As a further description of the above technical solution:

[0011] The sealed wellhead is connected to the solid pipe via a flange connection, and the connection between the sealed wellhead and the pressure-resistant water pipe is designed with a seal.

[0012] As a further description of the above technical solution:

[0013] The float can move up and down inside the liquid level control unit under the action of gravity and buoyancy. The liquid level control unit has holes at both the upper and lower ends.

[0014] As a further description of the above technical solution:

[0015] The PLC controller is electrically connected to the pressure gauge, solenoid valve one, solenoid valve two, and solenoid valve three respectively. The pneumatic extraction device is a QBY type pneumatic diaphragm pump, which has the characteristics of corrosion resistance and high suction lift.

[0016] As a further description of the above technical solution:

[0017] It also includes multiple repair wells, each of which is equipped with a corresponding open screen well pipe, solid pipe and sealed well head. The PLC controller is configured to control the on and off states of solenoid valve one, solenoid valve two and solenoid valve three corresponding to each repair well according to a preset time program, so that the multiple repair wells alternately perform extraction operations in sequence.

[0018] As a further description of the above technical solution:

[0019] The PLC controller adjusts the switching interval of each repair well to ensure that the output air pressure fluctuation of the air compressor does not exceed ±5% and the total pumping flow fluctuation of the device does not exceed ±10%.

[0020] As a further description of the above technical solution:

[0021] The single air compressor is connected to multiple repair wells via an intake pipe branch, and the PLC controller reduces the instantaneous load of the air compressor by more than 30% through timing switching control.

[0022] As a further description of the above technical solution:

[0023] The PLC controller can store at least three different time switching programs, and the duration of a single cycle of the time switching program can be adjusted within the range of 1-60 minutes.

[0024] This utility model has the following beneficial effects:

[0025] 1. In this utility model, compressed gas generated by an air compressor flows into the air inlet pipe, causing the pneumatic extraction device to work and generate suction, which draws polluted groundwater out of the well through the pumping pipe. At this time, the groundwater level is high, and the float in the liquid level control unit floats up due to buoyancy. The pressure-resistant water pipe inlet opens, and the groundwater in the well enters through the screen hole at the bottom of the liquid level control unit and is discharged from the outlet under the action of the pneumatic extraction device. During pumping, because there is a sealed wellhead in the well, when the water level in the well drops and the air pressure decreases, the float descends, and the well is under negative pressure, thereby improving the pollutant capture efficiency and reducing the disturbance to the groundwater environment.

[0026] 2. In this utility model, the PLC controller outputs a signal to close solenoid valves two and three, stopping the pneumatic extraction device. Solenoid valve one is opened, and compressed air from the air compressor is injected into the well through the air inlet pipe and the air injection pipe. A large amount of air is released, and groundwater, under atmospheric pressure, sprays out from the well through the screen openings of the well pipe to the surrounding area. The water level in the well drops, the float sinks to the bottom, and the high-pressure air carrying water flows to flush the screen openings and the quartz sand filter material, clearing away impurities and blockages. The well is continuously pressurized, and the pressure rises. After reaching the set value, all solenoid valves are closed, and the high-pressure air in the well pipe is released through the formation pores, slowly replenishing the surrounding groundwater. The water level in the well rises, thus performing pulse-like reciprocating pumping. Attached Figure Description

[0027] Figure 1 This is a perspective view of a pulse-type pneumatic groundwater extraction and treatment device proposed in this utility model.

[0028] Figure 2 This is a front view of a pulse-type pneumatic groundwater extraction and treatment device proposed in this utility model;

[0029] Figure 3 This is a cross-sectional view of a pulse-type pneumatic groundwater extraction and treatment device proposed in this utility model;

[0030] Figure 4 This is a cross-sectional view of the liquid level control unit of a pulse-type pneumatic groundwater extraction and treatment device proposed in this utility model.

[0031] Legend:

[0032] 1. Air compressor; 2. PLC controller; 3. Clay sealing layer; 4. Quartz sand layer; 5. Open-screen well pipe; 6. Solid pipe; 7. Float; 8. Liquid level control unit; 9. Pressure-resistant water pipe; 10. Sealed well head; 11. Pressure gauge; 12. Solenoid valve one; 13. Solenoid valve two; 14. Pneumatic extraction device; 15. Solenoid valve three; 16. Air inlet pipe; 17. Air injection pipe; 18. Water pumping pipe. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] Reference Figure 1 , Figure 3 and Figure 4 This utility model provides an embodiment of a pulse-type pneumatic groundwater extraction and treatment device, comprising an air compressor 1, a PLC controller 2, and a clay sealing layer 3. A quartz sand layer 4 is provided at the bottom of the clay sealing layer 3. A screened well pipe 5 is fixedly connected to the top of the inner wall of the quartz sand layer 4. Solid pipes 6 are fixedly connected to both the upper and lower ends of the screened well pipe 5. One end of the air compressor 1 is connected to an air inlet pipe 16, and the other end of the air inlet pipe 16 is connected to a pneumatic extraction device 14. When the air compressor 1 is started, compressed gas is generated and flows into the air inlet pipe 16, allowing the compressed gas to enter the pneumatic extraction device 14. When it starts working, it generates suction. The bottom end of the pneumatic extraction device 14 is connected to the water pumping pipe 18, and the other end of the water pumping pipe 18 is connected to the pressure-resistant water pipe 9. The upper and lower ends of the inner wall of the top solid pipe 6 are fixedly connected to the sealing head 10. The sealing head 10 is located at the ground position and the junction of the solid pipe 6 and the open screen pipe 5, respectively, to ensure that external gas will not enter the well. The other end of the pressure-resistant water pipe 9 passes through the top of the two sealing heads 10 and is connected to the liquid level control mechanism. The PLC controller 2 is electrically connected to the air compressor 1 and the pneumatic extraction device 14 to control the pulse extraction operation of the device.

[0035] The liquid level control mechanism includes a liquid level control unit 8, the outer wall of which is connected to the other end of the pressure-resistant water pipe 9. A float 7 is slidably connected to the inner wall of the liquid level control unit 8. The float 7 can move up and down inside the liquid level control unit 8 under the action of gravity and buoyancy. Holes are opened at both the upper and lower ends of the liquid level control unit 8. When the groundwater level is high, the float 7 in the liquid level control unit 8 floats up to the upper part of the liquid level control unit 8 under the action of buoyancy, and the inlet of the pressure-resistant water pipe 9 opens, allowing groundwater in the well to enter through the screen holes at the bottom of the liquid level control unit 8. The sealed well head 10 is connected to the solid pipe 6 by a flange connection, and the connection between the sealed well head 10 and the pressure-resistant water pipe 9 is designed to be sealed.

[0036] Specifically, the air compressor 1 starts, generating compressed gas, which flows into the air inlet pipe 16, causing the compressed gas to enter the pneumatic extraction device 14 and start working, generating suction to extract the polluted groundwater from the well through the water extraction pipe 18. At this time, the groundwater level is at a high position, and the float 7 in the liquid level control unit 8 floats to the top of the liquid level control unit 8 under the action of buoyancy. The inlet of the pressure-resistant water pipe 9 is opened, and the groundwater in the well enters through the screen hole at the bottom of the liquid level control unit 8. Under the action of the pneumatic extraction device 14, it is continuously discharged from the outlet. During the continuous pumping process, because the well is equipped with a sealed well head 10, which is located at the ground position and the junction of the solid pipe 6 and the open screen well pipe 5, the water level in the well drops and the air pressure continues to decrease. The float 7 gradually descends, and the well presents a negative pressure.

[0037] Reference Figure 2 , Figure 3 and Figure 4 The bottom end of the air inlet pipe 16 is connected to the air injection pipe 17, and the other end of the air injection pipe 17 is connected to the top end of the pressure-resistant water pipe 9. A solenoid valve 2 13 is fixedly connected to the outer wall of the air inlet pipe 16, and a solenoid valve 12 is fixedly connected to the outer wall of the air injection pipe 17. A solenoid valve 3 15 is fixedly connected to the right end of the outer wall of the water extraction pipe 18. The PLC controller 2 outputs a signal to close solenoid valves 2 13 and 3 15, stopping the pneumatic extraction device 14. It then opens solenoid valve 12, allowing compressed air generated by the air compressor 1 to flow from the air inlet pipe 16 and the air injection pipe 17. 7. When the water is injected into the well, a large amount of air is released. Under atmospheric pressure, the groundwater is sprayed out from the well through the screen openings of the well pipe 5 to the surrounding area. The water level in the well drops further. The left side of the outer wall of the pumping pipe 18 is connected to a pressure gauge 11, which can provide the PLC controller 2 with information on the pressure changes in the well. The PLC controller 2 is electrically connected to the pressure gauge 11, solenoid valve 12, solenoid valve 13, and solenoid valve 15. The pneumatic extraction device 14 is a QBY type pneumatic diaphragm pump, which has the characteristics of corrosion resistance and high suction lift.

[0038] Specifically, the PLC controller 2 outputs a signal to close solenoid valves 13 and 15, stopping the pneumatic extraction device 14. It then opens solenoid valve 12, allowing compressed air from the air compressor 1 to be injected into the well through the inlet pipe 16 and injection pipe 17. At this time, a large amount of air is released, and groundwater, under atmospheric pressure, is ejected from the well through the screen openings of the open-screen pipe 5 to the surrounding area. The water level in the well further decreases, and the float 7 sinks to the bottom. The screen openings of the open-screen pipe 5 and the filter material in the quartz sand layer 4 are washed away by the high-pressure air carrying water, clearing impurities and blockages. During the continuous pressurization process, the pressure inside the well continues to rise, and the injection pipe 17... The pressure gauge 11 connected to the PLC controller 2 gradually increases the value. Once the set value is reached, the PLC controller 2 outputs a signal to switch to stop mode. Solenoid valves 12, 13, and 15 are all closed. The high pressure in the well pipe is released through the pores of the formation. Groundwater from the surrounding formation slowly replenishes the well, and the water level in the well gradually rises. Under the action of buoyancy, the float 7 in the level control unit 8 gradually floats up to the top. The pressure gauge 11 connected to the pressure-resistant water pipe 9 gradually approaches 0. The PLC controller 2 receives the signal. Once the value reaches the set value, the device switches to pumping mode.

[0039] Reference Figure 1 , Figure 2 and Figure 3It also includes multiple repair wells, each equipped with a corresponding open-screen pipe 5, solid pipe 6, and sealed well head 10. The PLC controller 2 is configured to control the on / off states of solenoid valves 12, 13, and 15 corresponding to each repair well according to a preset time program, allowing multiple repair wells to alternately perform extraction operations. Multiple repair wells exist on-site, each equipped with an independent open-screen pipe 5, solid pipe 6, and sealed well head 10, forming a complete downhole structural unit. Air compressor 1, as the core air source device, forms an air path network through the intake pipe 16, connecting to each repair well to provide compressed air for the pneumatic extraction operation of each well. Simultaneously, the PLC controller 2, through its internally preset time program, controls the on / off states of the corresponding solenoid valves 12, 13, and 15 for each repair well, realizing alternating extraction operations between multiple wells. The PLC controller 2 adjusts the switching interval time of each repair well to ensure that the output air pressure fluctuation of air compressor 1 does not exceed ±5%. The PLC controller 2 has adjustment capabilities. By adjusting the switching interval of each repair well, it monitors and adjusts the output air pressure of the air compressor 1 in real time, keeping its fluctuation range within ±5% and the total pumping flow fluctuation within ±10%. It coordinates the pumping flow of each well to ensure that the total pumping flow fluctuation does not exceed ±10%, maintaining the stability of the groundwater extraction process. Each air compressor 1 is connected to multiple repair wells through the intake pipe 16. The PLC controller 2 reduces the instantaneous load of the air compressor 1 by more than 30% through time-sequence switching control. The time-sequence switching control also significantly reduces the operating load of the air compressor 1. Compared with traditional simultaneous operation, the instantaneous load of a single air compressor 1 is reduced by more than 30%. The PLC controller 2 can store at least 3 different time switching programs, allowing the device to select or customize the switching program according to the actual working conditions such as the site pollution level and formation permeability. The single cycle duration of the time switching program can be adjusted within the range of 1-60 minutes to meet the differentiated needs of different repair scenarios.

[0040] Specifically, when multiple repair wells exist on-site, each repair well is equipped with an independent open-screen well pipe 5, solid pipe 6, and sealed well head 10, forming a complete downhole structural unit. Air compressor 1 serves as the core air source device, forming an air path network through inlet pipe 16, connecting to each repair well to provide compressed air for pneumatic extraction operations in each well. During operation, PLC controller 2, through its internally preset time program, controls the on / off state of the corresponding solenoid valves 12, 13, and 15 for each repair well, achieving multi-stage operation. Alternating extraction operations between wells: For example, when the first repair well is in the pumping stage, the PLC controller 2 outputs a signal to open the corresponding solenoid valves 13 and 15, close solenoid valve 12, and start the pneumatic extraction device 14 to pump water. At the same time, the pneumatic extraction devices 14 of the other repair wells are in the closed state. Once the first well reaches the set parameters, such as water level or gas pressure threshold, the PLC controller 2 quickly switches the signal, closing solenoid valves 13 and 15 and opening solenoid valve 12 to enter the injection stage. During the gasification phase, the pumping program of the next repair well is simultaneously initiated, and so on, to achieve orderly cyclical operation of the well group. To ensure stable system operation, the PLC controller 2, with its controllability, monitors and adjusts the output air pressure of the air compressor 1 in real time by controlling the switching interval of each repair well, keeping its fluctuation range within ±5%. At the same time, it coordinates the pumping flow of each well to ensure that the total pumping flow of the device does not fluctuate by more than ±10%, maintaining the stability of the groundwater extraction process. Furthermore, the time-sequence switching control significantly reduces the operating load of the air compressor 1. Compared with the traditional simultaneous operation mode, the instantaneous load of a single air compressor 1 is reduced by more than 30%, improving equipment lifespan and reducing energy consumption. Moreover, the PLC controller 2 supports the storage of at least 3 different time-sequence switching programs, allowing the device to select or customize switching programs according to the actual working conditions such as the degree of site contamination and the permeability of the formation. The single cycle duration of each program can be flexibly adjusted within the range of 1-60 minutes to meet the differentiated needs of different repair scenarios, achieving efficient and precise operation of groundwater repair work.

[0041] Working principle: First, the air compressor 1 starts, generating compressed gas. This compressed gas flows into the intake pipe 16. At this time, the PLC controller 2 outputs a signal to close solenoid valve 12 and open solenoid valves 13 and 15. The compressed gas enters the pneumatic extraction device 14, causing it to start operating and generating suction to extract the contaminated groundwater from the well through the pumping pipe 18. At this time, the groundwater level is at a high position, and the float 7 in the level control unit 8 floats to the top of the level control unit 8 under the action of buoyancy. The inlet of water pipe 9 is opened, and the groundwater in the well enters through the screen hole at the bottom of the liquid level control unit 8. Under the action of the pneumatic extraction device 14, it is continuously discharged from the outlet. During the continuous pumping process, since the well is equipped with a sealed well head 10, which is located at the ground position and the junction of the solid pipe 6 and the open screen well pipe 5, the water level in the well drops, the air pressure continues to decrease, the float 7 gradually descends, and the well presents a negative pressure. The pressure gauge 11 on the pumping pipe 18 displays a negative value. The PLC controller 2 receives the signal and will enter the air injection process after the set value is reached.

[0042] At this time, the PLC controller 2 outputs a signal to close solenoid valves 13 and 15, stopping the pneumatic extraction device 14. Simultaneously, solenoid valve 12 opens, and compressed air generated by the air compressor 1 is injected into the well through the air inlet pipe 16 and the air injection pipe 17. At this point, a large amount of air is released, and under atmospheric pressure, groundwater sprays from the well through the screen openings of the open-screen pipe 5 to the surrounding area, further lowering the water level. The float 7 sinks to the bottom, and the screen openings of the open-screen pipe 5 and the filter material in the quartz sand layer 4 are washed away by the water flow carried by the high-pressure air. Impurities and blockages are flushed out. During the continuous pressurization process in the well, the pressure inside the well continues to rise, and the air injection pipe... The pressure gauge 11 connected to 17 gradually increases in value. The PLC controller 2 receives the signal. After reaching the set value, the PLC controller 2 outputs a signal and switches to stop mode. Solenoid valves 12, 13, and 15 are all closed. The high air pressure in the well pipe is released through the pores of the formation. Groundwater from the surrounding formation slowly replenishes the well, and the water level in the well gradually rises. Under the action of buoyancy, the float 7 in the liquid level control unit 8 gradually floats to the top. The pressure gauge 11 connected to the pressure-resistant water pipe 9 gradually approaches 0. The PLC controller 2 receives the signal. After the value reaches the set value, the device switches to pumping mode.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pulse-type pneumatic groundwater extraction and treatment device, comprising an air compressor (1), a PLC controller (2), and a clay sealing layer (3), characterized in that: The bottom end of the clay sealing layer (3) is provided with a quartz sand layer (4). The top of the inner wall of the quartz sand layer (4) is fixedly connected to a screen well pipe (5). The upper and lower ends of the screen well pipe (5) are fixedly connected to solid pipes (6). One end of the air compressor (1) is connected to an air inlet pipe (16). The other end of the air inlet pipe (16) is connected to a pneumatic extraction device (14). The bottom end of the pneumatic extraction device (14) is connected to a water pumping pipe (18). The other end of the water pumping pipe (18) is connected to a pressure-resistant water pipe (9). The upper and lower ends of the inner wall of the top solid pipe (6) are fixedly connected to a sealing well head (10). The other end of the pressure-resistant water pipe (9) passes through the top of the two sealing well heads (10) and is connected to a liquid level control mechanism. The PLC controller (2) is electrically connected to the air compressor (1) and the pneumatic extraction device (14) and is used to control the pulse extraction operation of the device.

2. The pulse-type pneumatic groundwater extraction and treatment device according to claim 1, characterized in that: The bottom end of the air inlet pipe (16) is connected to the air injection pipe (17), and the other end of the air injection pipe (17) is connected to the top end of the pressure-resistant water pipe (9). The outer wall of the air inlet pipe (16) is fixedly connected to the second solenoid valve (13), the outer wall of the air injection pipe (17) is fixedly connected to the first solenoid valve (12), the right end of the outer wall of the water pumping pipe (18) is fixedly connected to the third solenoid valve (15), and the left side of the outer wall of the water pumping pipe (18) is connected to the pressure gauge (11).

3. The pulse-type pneumatic groundwater extraction and treatment device according to claim 1, characterized in that: The liquid level control mechanism includes a liquid level control unit (8), the outer wall of which is connected to the other end of the pressure-resistant water pipe (9), and a float (7) is slidably connected to the inner wall of the liquid level control unit (8).

4. The pulse-type pneumatic groundwater extraction and treatment device according to claim 1, characterized in that: The sealed wellhead (10) is connected to the solid pipe (6) by a flange connection, and the connection between the sealed wellhead (10) and the pressure-resistant water pipe (9) is designed with a seal.

5. The pulse-type pneumatic groundwater extraction and treatment device according to claim 3, characterized in that: The float (7) can move up and down inside the liquid level control unit (8) under the action of gravity and buoyancy. The liquid level control unit (8) has holes at both the upper and lower ends.

6. The pulse-type pneumatic groundwater extraction and treatment device according to claim 1, characterized in that: The PLC controller (2) is electrically connected to the pressure gauge (11), solenoid valve one (12), solenoid valve two (13) and solenoid valve three (15) respectively. The pneumatic extraction device (14) is a QBY type pneumatic diaphragm pump, which has the characteristics of corrosion resistance and high suction lift.

7. The pulse-type pneumatic groundwater extraction and treatment device according to claim 6, characterized in that: It also includes multiple repair wells, each of which is equipped with a corresponding open screen well pipe (5), solid pipe (6) and sealed well head (10). The PLC controller (2) is configured to control the on / off state of the corresponding solenoid valve one (12), solenoid valve two (13) and solenoid valve three (15) of each repair well according to a preset time program, so that the multiple repair wells can perform extraction operations in turn.

8. The pulse-type pneumatic groundwater extraction and treatment device according to claim 7, characterized in that: The PLC controller (2) adjusts the switching interval time of each repair well so that the output air pressure fluctuation of the air compressor (1) does not exceed ±5% and the total pumping flow fluctuation of the device does not exceed ±10%.

9. A pulse-type pneumatic groundwater extraction and treatment device according to claim 7, characterized in that: The single air compressor (1) is branched to multiple repair wells through an intake pipe (16), and the PLC controller (2) controls the instantaneous load of the air compressor (1) by more than 30% through timing switching control.

10. A pulse-type pneumatic groundwater extraction and treatment device according to claim 7, characterized in that: The PLC controller (2) can store at least 3 different time switching programs, and the single cycle duration of the time switching program can be adjusted within the range of 1-60 minutes.

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