Heat extraction device and remediation system for in-situ joule heat soil heavy metal remediation

Abstract

The application relates to a heat taking device and a remediation system for in-situ joule heat soil heavy metal remediation, the heat taking device comprising a U-shaped heat exchange unit, a circulating pump and a thermoelectric power generation module. The U-shaped heat exchange unit is provided with an injection pipe vertically arranged in soil, a fractal stepped heat absorption pipe and a U-shaped reversing pipe horizontally arranged at the bottom of a soil remediation area and connected between the injection pipe and the fractal stepped heat absorption pipe, the injection pipe is used for conveying a heat conducting medium to the soil remediation area, and the injection pipe is coated with a heat insulation layer, the fractal stepped heat absorption pipe has a multi-stage symmetrical bifurcation structure from bottom to top and is used for absorbing waste heat diffused outward by the soil remediation area in stages. The circulating pump is connected in series in a circulating loop formed by the injection pipe and the fractal stepped heat absorption pipe and is used for driving the heat conducting medium to flow in circulation. The thermoelectric power generation module comprises a plurality of thermoelectric power generation sheets, the thermoelectric power generation sheets are attached to the outer wall of the exposed end of the fractal stepped heat absorption pipe extending out of the ground and are used for converting heat energy into electric energy.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology, specifically to a heat extraction device and remediation system for in-situ Joule heating soil heavy metal remediation. Background Technology

[0002] Existing soil heavy metal remediation technologies mostly employ electrothermal remediation using flat or mesh electrodes, primarily powered by an external power grid. During the remediation process, a significant amount of heat generated by the electrodes diffuses and dissipates into deeper soil layers and surrounding uncontaminated areas. This not only results in severe energy waste and directly increases the operating costs of remediation projects, but also, traditional U-shaped buried pipes commonly suffer from uneven heat exchange and dead zones within the pipes when recovering waste heat. More importantly, when transporting low-temperature media, traditional heat extraction pipelines easily absorb the core heat generated by the metal rod electrode array, thereby disrupting the stable temperature field within the soil remediation area, leading to a decrease in heavy metal desorption efficiency and severely impacting the final remediation outcome. Summary of the Invention

[0003] The purpose of this invention is to provide a heat recovery device and remediation system for in-situ Joule heating soil heavy metal remediation, which can recover only the waste heat that diffuses outward without disturbing the remediation thermal field, thus achieving a virtuous cycle of energy.

[0004] To achieve the above objectives, according to a first aspect of the present invention, a heat extraction device for in-situ Joule heating soil heavy metal remediation is provided, comprising: The U-shaped heat exchange unit is equipped with an injection pipe vertically arranged in the soil, a fractal ladder heat absorption pipe, and a U-shaped reversing pipe horizontally arranged at the bottom of the soil remediation area and connected between the injection pipe and the fractal ladder heat absorption pipe. The injection pipe is used to deliver heat-conducting medium to the soil remediation area and is covered with a heat insulation layer. The fractal ladder heat absorption pipe has a multi-level symmetrical branching structure from bottom to top and is used to absorb the residual heat diffused outward from the soil remediation area in stages. A circulating pump, connected in series in the circulation loop formed by the injection pipe and the fractal ladder heat absorption pipe, is used to drive the heat transfer medium to circulate. The thermoelectric power generation module includes several thermoelectric power generation plates that are electrically connected to each other. The thermoelectric power generation plates are attached to the outer wall of the exposed end of the fractal ladder heat absorption tube extending out of the ground and are used to convert thermal energy into electrical energy.

[0005] Optionally, the lower half of the fractal ladder heat absorber tube includes, from bottom to top, a main pipe, a first-level branch pipe, a second-level branch pipe, and a third-level branch pipe connected in sequence, and the upper half of the fractal ladder heat absorber tube is mirrored in arrangement with the lower half.

[0006] Optionally, the diameter of each segment of the lower half of the fractal stepped heat absorber tube decreases progressively from bottom to top.

[0007] Optionally, the heat extraction device for in-situ Joule heating soil heavy metal remediation further includes: A controllable DC power supply is electrically connected to the thermoelectric power generation module and is used to store the electrical energy output by the thermoelectric power generation module and provide auxiliary DC power supply for the metal rod electrode array.

[0008] According to a second aspect of the present invention, a remediation system for in-situ Joule-thermal soil heavy metal remediation is provided, comprising: The soil pretreatment module is used to adjust the moisture content and conductivity of the soil remediation area; A metal rod electrode array is deployed in the soil remediation area for heated remediation. The exhaust gas treatment module is used to collect and purify the heavy metal vapors that volatilize during the heating and repair process. The data monitoring module is used to monitor soil temperature, humidity, and resistivity in real time during the heat remediation process; The central control module is electrically connected to the soil pretreatment module, the metal rod electrode array, the exhaust gas treatment module, and the data monitoring module, respectively. The heat extraction device has a controllable DC power supply that is electrically connected to the metal rod electrode array to provide auxiliary DC power to the metal rod electrode array.

[0009] Optionally, the metal rod electrode array includes several electrode bodies. The outer wall of the working section of each electrode body inserted into the soil is provided with anti-slip threads and covered with an insulating protective sleeve with vent holes. The lower end of the insulating protective sleeve is open so that the bottom of the electrode body is exposed and in conductive contact with the soil. The upper end of the electrode body is provided with a wire connection end for connecting the controllable DC power supply.

[0010] Optionally, the soil pretreatment module includes a storage tank, a booster pump, and a spray pipe assembly connected in sequence; The storage tank is used to store an aqueous solution containing conductive additives and the pressure of the aqueous solution is delivered to the spray pipe assembly by the booster pump. The spray pipe assembly is used to apply the aqueous solution to the soil remediation area by surface spraying or shallow injection to adjust the soil moisture content and resistivity.

[0011] Optionally, the exhaust gas treatment module includes a gas collection hood, a vacuum pump, a staged condensation assembly, and a composite adsorption tower connected in series. The gas collection hood covers the soil remediation area and forms a negative pressure in the system through the vacuum pump. The staged condensation component recovers heavy metals with different boiling points through staged cooling. The composite adsorption tower is connected to the rear end of the staged condensation component to purify the exhaust gas to meet emission standards.

[0012] Optionally, the data monitoring module includes a temperature sensor, a humidity sensor, and a resistance sensor buried within the soil remediation area and electrically connected to the central control module.

[0013] The beneficial effects of this invention are as follows: by covering the outer periphery of the injection pipe with a heat insulation layer, the heat exchange between the downward heat-conducting medium and the soil remediation area can be blocked, preventing it from absorbing the core remediation heat generated by the metal rod electrode array, thereby ensuring the stability and uniformity of the temperature field in the soil remediation area and ensuring the efficient desorption of heavy metals; at the same time, the fractal stepped heat-absorbing pipe adopts a biomimetic structure with multi-level symmetrical branching from bottom to top, which maximizes the heat exchange contact area with minimal flow resistance in the limited space of the vertical borehole. Through the stepped heat absorption of the heat-conducting medium from the bottom of the well to the ground, only the waste heat that diffuses outward is recovered without interfering with the remediation heat field, thus achieving a virtuous cycle of energy.

[0014] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic structural diagram of a heat extraction device for in-situ Joule heating soil heavy metal remediation according to an embodiment of the present invention. Figure 2 This is a schematic structural diagram of a remediation system for in-situ Joule-thermal soil heavy metal remediation according to an embodiment of the present invention. Figure 3 This is a schematic structural diagram of the electrode body of a remediation system for in-situ Joule heating soil heavy metal remediation according to an embodiment of the present invention. In the diagram: 1. Heat extraction device; 11. U-shaped heat exchange unit; 111. Injection pipe; 1111. Thermal insulation layer; 112. Fractal cascade heat absorption pipe; 1121. Main pipe; 1122. First-stage branch pipe; 1123. Second-stage branch pipe; 1124. Third-stage branch pipe; 113. U-shaped reversing pipe; 12. Circulation pump; 13. Thermoelectric power generation module; 14. Controllable DC power supply; 2. Soil pretreatment module; 21. Storage tank; 22. [Unclear text - possibly related to heat exchange] 23. Pressure pump; 3. Spray pipe assembly; 3. Metal rod electrode array; 31. Electrode body; 311. Anti-slip thread; 312. Insulating protective sleeve; 313. Vent hole; 314. Wire connection end; 4. Tail gas treatment module; 41. Gas collection hood; 42. Vacuum pump; 43. Staged condensation assembly; 44. Composite adsorption tower; 5. Data monitoring module; 51. Temperature sensor; 52. Humidity sensor; 53. Resistance sensor; 6. Central control module. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0019] Please see Figure 1 A preferred embodiment of this application shows a heat extraction device 1 for in-situ Joule heating soil heavy metal remediation, comprising a U-shaped heat exchange unit 11, a circulating pump 12, and a thermoelectric power generation module 13. The U-shaped heat exchange unit 11 is equipped with an injection pipe 111 vertically arranged in the soil, a fractal stepped heat absorption pipe 112, and a U-shaped reversing pipe 113 horizontally arranged at the bottom of the soil remediation area and connecting the injection pipe 111 and the fractal stepped heat absorption pipe 112. The injection pipe 111 is used to deliver a heat-conducting medium to the soil remediation area, and is covered with a heat-insulating layer 1111. The fractal stepped heat absorption pipe 112 has a multi-level symmetrical branching structure from bottom to top and is used to absorb residual heat diffused outward from the soil remediation area in stages. The circulating pump 12 is connected in series in the circulation loop formed by the injection pipe 111 and the fractal stepped heat absorption pipe 112 to drive the circulating flow of the heat-conducting medium. The thermoelectric power generation module 13 includes several thermoelectric power generation plates that are electrically connected to each other. The thermoelectric power generation plates are attached to the outer wall of the exposed end of the fractal ladder heat absorption tube 112 that extends out of the ground, and are used to convert thermal energy into electrical energy.

[0020] According to the embodiment of the present invention, by covering the outer periphery of the injection pipe 111 with a heat insulation layer 1111, the heat exchange between the downward heat-conducting medium and the soil remediation area can be blocked, preventing it from absorbing the core remediation heat generated by the metal rod electrode array 3, thereby ensuring the stability and uniformity of the temperature field in the soil remediation area and ensuring the efficient desorption of heavy metals; at the same time, the fractal stepped heat-absorbing pipe 112 adopts a biomimetic structure with multi-level symmetrical branching from bottom to top, which maximizes the heat exchange contact area with minimal flow resistance in the limited space of the vertical borehole. Through the stepped heat absorption of the heat-conducting medium from the bottom of the well to the ground, only the waste heat that diffuses outward is recovered without interfering with the remediation heat field, realizing a virtuous cycle of energy, and reducing the overall energy consumption of the system by 30% to 50% compared with traditional thermal remediation technology.

[0021] The following detailed description uses specific examples: Please see Figure 1 The lower half of the fractal ladder-type heat absorber 112 comprises, from bottom to top, a main pipe 1121, a first-stage branch pipe 1122, a second-stage branch pipe 1123, and a third-stage branch pipe 1124 connected sequentially. The upper half of the fractal ladder-type heat absorber 112 is mirrored in its arrangement. By establishing a three-stage symmetrical branching structure along the vertical direction of the main pipe 1121 corresponding to the formation temperature gradient, the flow of the heat transfer medium within the fractal ladder-type heat absorber 112 is ensured to be smooth and free of dead zones throughout its flow. With the main pipe 1121 as its core main vein, the fractal ladder-type heat absorber 112 branches into lateral veins at each stage, maximizing the heat exchange contact area with minimal water flow resistance within the limited space of a vertical borehole, thus adapting to the installation space limitations of standard boreholes.

[0022] Furthermore, the diameter of each segment of the lower half of the fractal ladder heat absorber 112 decreases progressively from bottom to top. In a specific embodiment, the bottommost main pipe 1121 of the fractal ladder heat absorber 112 has a diameter of 40 mm, and branches upwards into a first-stage branch pipe 1122 with a diameter of 32 mm, a second-stage branch pipe 1123 with a diameter of 25 mm, and a third-stage branch pipe 1124 with a diameter of 20 mm. This diameter reduction design can effectively compensate for the flow loss after diversion, ensuring that the flow velocity of the heat transfer medium in the branch pipes can still be maintained in the preset high-speed range as the heat transfer medium approaches the high-temperature region of the ground surface. This significantly improves the heat exchange efficiency between the heat transfer medium and the pipe wall by maintaining a high flow velocity, and, combined with the increased heat exchange length of the branch pipes, maximizes the absorption of waste heat diffused outward from the ground.

[0023] Please see Figure 1 The heat extraction device 1 also includes a controllable DC power supply 14, which is electrically connected to the thermoelectric power generation module 13. In one specific embodiment, the controllable DC power supply 14 is a conventional energy storage DC power supply in the art, used to store the electrical energy output by the thermoelectric power generation module 13 and provide auxiliary DC power supply for the metal rod electrode array 3.

[0024] Please see Figure 2 This application also provides a remediation system for in-situ Joule heating soil heavy metal remediation, including a soil pretreatment module 2, a metal rod electrode array 3, an exhaust gas treatment module 4, a data monitoring module 5, a central control module 6, and a heat extraction device 1. The soil pretreatment module 2 is used to adjust the moisture content and conductivity of the soil remediation area. The metal rod electrode array 3 is deployed in the soil remediation area for heating and remediation. The exhaust gas treatment module 4 is used to collect and purify the heavy metal vapors volatilized during the heating and remediation process. The data monitoring module 5 is used to monitor the soil temperature, humidity, and resistivity in real time during the heating and remediation process. The central control module 6 is electrically connected to the soil pretreatment module 2, the metal rod electrode array 3, the exhaust gas treatment module 4, and the data monitoring module. The controllable DC power supply 14 of the heat extraction device 1 is electrically connected to the metal rod electrode array 3 to provide auxiliary DC power. Other modules of the remediation system use conventional industrial power supplies. The central control module 6 receives feedback data in real time and dynamically adjusts the heating power and heating rate, achieving a high-efficiency remediation index of no less than 85% removal rate for a single heavy metal and no less than 80% removal rate for composite heavy metals.

[0025] Please see Figure 2 and Figure 3 The metal rod electrode array 3 includes several electrode bodies 31. Each electrode body 31 has an anti-slip thread 311 on the outer wall of its working section inserted into the soil and is covered by an insulating protective sleeve 312 with ventilation holes 313. The lower end of the insulating protective sleeve is open to expose the bottom of the electrode body 31 for conductive contact with the soil. The upper end of the electrode body 31 has a wire connection end 314 for connecting to a controllable DC power supply 14. In one specific embodiment, the electrode body 31 is made of corrosion-resistant materials such as copper-titanium composite alloy, and the surface is provided with anti-slip threads 311 to enhance contact stability with the soil. The insulating protective sleeve 312, in conjunction with 3-5 ventilation holes 313 with a diameter of 1-3 mm spaced at 10 cm intervals, ensures the smooth escape of heavy metal vapors. The length of the electrode body 31 is set between 0.5 m and 3 m, and the diameter is 10 mm to 30 mm, ensuring the applicability of the metal rod electrode array 3 in contaminated layers of different depths in the soil remediation area.

[0026] Please see Figure 2The soil pretreatment module 2 includes a storage tank 21, a booster pump 22, and a spray pipe assembly 23 connected in sequence. The storage tank 21 stores an aqueous solution containing a conductive additive, and the booster pump 22 pressurizes the solution to the spray pipe assembly 23. The spray pipe assembly 23 applies the aqueous solution to the soil remediation area via surface spraying or shallow injection to adjust the soil moisture content and resistivity. In one specific embodiment, the soil pretreatment module 2 can precisely control the soil moisture content to an optimal range of 15%-25%. For low-conductivity soils with resistivity greater than 150 Ω·m, adding a conductive additive at a ratio of 0.1%-0.5% of the soil dry weight can significantly improve the Joule heating efficiency.

[0027] Please see Figure 2 The exhaust gas treatment module 4 includes a gas collection hood 41, a vacuum pump 42, a staged condensation assembly 43, and a composite adsorption tower 44 connected in series. The gas collection hood 41 covers the soil remediation area and forms a system negative pressure through the vacuum pump 42. The staged condensation assembly 43 recovers heavy metals with different boiling points through staged cooling. The composite adsorption tower 44 is connected to the rear end of the staged condensation assembly 43 to purify the exhaust gas to meet emission standards. The gas collection hood 41 is inserted into the surface soil 0.5m deep through a double-layer seal of water-stop walls and geotextile fabric at its edges, forming a sealed negative pressure cavity. The vacuum pump 42 provides a system negative pressure of -0.03MPa to -0.06MPa, guiding the volatilized vapor to the staged condensation assembly 43. The staged condensation assembly 43 uses a first-stage high-temperature condensation (120℃-150℃) to recover heavy metals such as lead and cadmium, a second-stage low-temperature condensation (5℃-10℃) to recover heavy metals such as mercury and arsenic, and finally, the exhaust gas is deeply purified by the composite adsorption tower 44 to ensure that the exhaust gas meets emission standards.

[0028] Please see Figure 2 The data monitoring module 5 includes a temperature sensor 51, a humidity sensor 52, and a resistance sensor 53, which are buried within the soil remediation area and electrically connected to the central control module 6. By burying the temperature sensor 51, humidity sensor 52, and resistance sensor 53 at different depths within the soil remediation area, the system can collect core parameters in real time and upload them to the central control module 6 for real-time adjustment of the heating remediation process.

[0029] During operation, the remediation system of this application first uses the data monitoring module 5 to survey the initial soil parameters and geothermal resources of the soil remediation area. Based on the survey results, the central control module 6 drives the booster pump 22 and spray pipe assembly 23 of the soil pretreatment module 2 to regulate the moisture content and conductivity, and then allows the system to stand for 12 to 24 hours. Subsequently, the central control module 6 starts the metal rod electrode array 3 to execute a segmented gradient heating program. The generated heavy metal vapor, under the negative pressure created by the vacuum pump 42, enters the graded condensation assembly 43 through the gas collection hood 41 for classified recovery, and the exhaust gas is purified by the composite adsorption tower 44. During this period, the heat extraction device 1 starts simultaneously, and the circulating pump 12 drives the heat transfer medium into the injection pipe 111 covered with a heat insulation layer 1111. Due to the presence of the heat insulation layer 1111, the low-temperature medium does not absorb the core heat generated by the metal rod electrode array 3 in the soil remediation area. After being guided by the U-shaped reversing pipe 113, the medium enters the fractal ladder heat absorption pipe 112, absorbing only the waste heat diffused outwards. Thermoelectric module 13 converts the absorbed heat energy into electrical energy and stores it in controllable DC power supply 14, providing auxiliary DC power supply for metal rod electrode array 3 until data monitoring module 5 reports that the soil heavy metal concentration meets the standard, and central control module 6 triggers system shutdown.

[0030] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A heat extraction device for in-situ Joule heating soil heavy metal remediation, characterized in that, include: The U-shaped heat exchange unit is equipped with an injection pipe vertically arranged in the soil, a fractal ladder heat absorption pipe, and a U-shaped reversing pipe horizontally arranged at the bottom of the soil remediation area and connected between the injection pipe and the fractal ladder heat absorption pipe. The injection pipe is used to deliver heat-conducting medium to the soil remediation area and is covered with a heat insulation layer. The fractal ladder heat absorption pipe has a multi-level symmetrical branching structure from bottom to top and is used to absorb the residual heat diffused outward from the soil remediation area in stages. A circulating pump, connected in series in the circulation loop formed by the injection pipe and the fractal ladder heat absorption pipe, is used to drive the heat transfer medium to circulate. The thermoelectric power generation module includes several thermoelectric power generation plates that are electrically connected to each other. The thermoelectric power generation plates are attached to the outer wall of the exposed end of the fractal ladder heat absorption tube extending out of the ground and are used to convert thermal energy into electrical energy.

2. The heat extraction device for in-situ Joule heating soil heavy metal remediation according to claim 1, characterized in that, The lower half of the fractal ladder heat absorber tube includes, from bottom to top, a main pipe, a first-level branch pipe, a second-level branch pipe, and a third-level branch pipe connected in sequence. The upper half of the fractal ladder heat absorber tube is mirrored in arrangement with the lower half.

3. The heat extraction device for in-situ Joule heating soil heavy metal remediation according to claim 2, characterized in that, The diameter of each section of the lower half of the fractal stepped heat absorber tube decreases progressively from bottom to top.

4. The heat extraction device for in-situ Joule heating soil heavy metal remediation according to claim 1, characterized in that, Also includes: A controllable DC power supply is electrically connected to the thermoelectric power generation module and is used to store the electrical energy output by the thermoelectric power generation module and provide auxiliary DC power supply for the metal rod electrode array.

5. A remediation system for in-situ Joule-thermal soil heavy metal remediation, characterized in that, include: The soil pretreatment module is used to adjust the moisture content and conductivity of the soil remediation area; A metal rod electrode array is deployed in the soil remediation area for heated remediation. The exhaust gas treatment module is used to collect and purify the heavy metal vapors that volatilize during the heating and repair process. The data monitoring module is used to monitor soil temperature, humidity, and resistivity in real time during the heat remediation process; The central control module is electrically connected to the soil pretreatment module, the metal rod electrode array, the exhaust gas treatment module, and the data monitoring module, respectively. The heat extraction device according to any one of claims 1 to 4, wherein the controllable DC power supply of the heat extraction device is electrically connected to the metal rod electrode array, and is used to provide auxiliary DC power supply to the metal rod electrode array.

6. The remediation system for in-situ Joule-thermal soil heavy metal remediation according to claim 5, characterized in that, The metal rod electrode array includes several electrode bodies. The outer wall of the working section of each electrode body inserted into the soil is provided with anti-slip threads and covered with an insulating protective sleeve with ventilation holes. The lower end of the insulating protective sleeve is open so that the bottom of the electrode body is exposed and in conductive contact with the soil. The upper end of the electrode body is provided with a wire connection end for connecting the controllable DC power supply.

7. The remediation system for in-situ Joule-thermal soil heavy metal remediation according to claim 5, characterized in that, The soil pretreatment module includes a storage tank, a booster pump, and a spray pipe assembly connected in sequence. The storage tank is used to store an aqueous solution containing conductive additives and the pressure of the aqueous solution is delivered to the spray pipe assembly by the booster pump. The spray pipe assembly is used to apply the aqueous solution to the soil remediation area by surface spraying or shallow injection to adjust the soil moisture content and resistivity.

8. The remediation system for in-situ Joule-thermal soil heavy metal remediation according to claim 5, characterized in that, The exhaust gas treatment module includes a gas collection hood, a vacuum pump, a staged condensation component and a composite adsorption tower connected in series. The gas collection hood covers the soil remediation area and forms a negative pressure in the system through the vacuum pump. The staged condensation component recovers heavy metals with different boiling points through staged cooling. The composite adsorption tower is connected to the rear end of the staged condensation component to purify the exhaust gas to meet emission standards.

9. The remediation system for in-situ Joule-thermal soil heavy metal remediation according to claim 5, characterized in that, The data monitoring module includes a temperature sensor, a humidity sensor, and a resistance sensor buried within the soil remediation area and electrically connected to the central control module.

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