Soil remediation treatment device, system and method

Abstract

The present application relates to the technical field of soil remediation, and the present application discloses a soil remediation treatment device, system and method. Among them, the soil remediation treatment device includes a heating component, a reaction chamber and an exhaust gas recovery system, the heating component includes a heating base and a gas supply component, the heating base is provided with a heating chamber, and the gas supply component is used to supply gas to the heating chamber; in the direction away from the heating base, the reaction chamber is provided with a smoldering reaction chamber, a thermal desorption reaction chamber and an exhaust gas collection chamber connected by air in sequence, the heating chamber is connected by air to the smoldering reaction chamber, and the exhaust gas recovery system includes a recovery pipe, one end of the recovery pipe is connected to the exhaust gas collection chamber, and the other end is connected to the heating chamber. Compared with the prior art, the waste heat generated during the smoldering reaction can be fully utilized to improve the treatment efficiency of contaminated soil and save energy consumption.

Description

Technical Field

[0001] The present application relates to the technical field of soil remediation, and in particular to a soil remediation treatment device, system and method. Background Art

[0002] Smoldering remediation technology has gradually been applied in the field of organic contaminated soil remediation, especially when treating high-concentration organic contaminated soil. Smoldering remediation technology is a slow combustion reaction carried out in a high-temperature, oxygen-deficient environment. Smoldering has two major advantages: on the one hand, it can achieve complete oxidation of organic pollutants and meet strict remediation target requirements; on the other hand, the reaction process uses the heat released by the oxidation of pollutants to maintain the smoldering reaction, which saves energy compared to thermal desorption, incineration and other technologies. However, the smoldering reaction releases a lot of heat, which also makes the smoldering reaction temperature higher, usually above 800°C, and the waste heat in the generated high-temperature flue gas is usually not effectively utilized, resulting in heat waste. Summary of the invention

[0003] In order to solve the technical problem of heat waste in smoldering remediation technology, the main purpose of the present application is to provide a soil remediation treatment device, system and method that can effectively utilize the waste heat generated during the smoldering remediation process.

[0004] In order to achieve the above invention objectives, this application adopts the following technical solutions:

[0005] According to one aspect of the present application, a soil remediation device is provided, comprising:

[0006] A heating assembly, comprising a heating base and a gas supply assembly, wherein the heating base is provided with a heating cavity, and the gas supply assembly is used to supply gas to the heating cavity;

[0007] A reaction chamber is arranged on the heating base, and in a direction away from the heating base, the reaction chamber is provided with a smoldering reaction chamber, a thermal desorption reaction chamber and an exhaust gas collection chamber which are gas-connected in sequence, the heating chamber is gas-connected with the smoldering reaction chamber, soil with a first calorific value Q1 is arranged in the smoldering reaction chamber, and soil with a second calorific value Q2 is arranged in the thermal desorption reaction chamber, wherein Q1>Q2;

[0008] The waste gas recovery system comprises a recovery pipe, one end of which is connected to the waste gas collecting chamber, and the other end of which is communicated with the heating chamber.

[0009] According to one embodiment of the present application, the air supply component includes an air supply pipe and a fan, one end of the air supply pipe is connected to the heating chamber, and the other end is connected to the fan, and the fan is used to drive the gas from the air supply pipe to the heating chamber.

[0010] According to one embodiment of the present application, the heating component also includes an electric heating tube, which is arranged in the heating chamber. The heating base is provided with a connecting hole, and one end of the electric heating tube extends out of the connecting hole to be connected to an external power source.

[0011] According to one embodiment of the present application, the heating component also includes a support plate arranged on a side facing the reaction chamber, the heating base and the support plate form the heating chamber, a plurality of ventilation holes are opened on the support plate, and the heating chamber is connected to the smoldering reaction chamber through the ventilation holes.

[0012] According to one embodiment of the present application, the reaction chamber further comprises:

[0013] A combustion-supporting chamber, the combustion-supporting chamber is arranged on a side close to the heating chamber;

[0014] A filler is arranged in the combustion-supporting cavity, wherein a ventilation gap is provided in the filler, and a diameter of the filler is greater than a diameter of the ventilation hole.

[0015] According to one embodiment of the present application, it also includes:

[0016] A heat-insulating shell, wherein the heat-insulating shell is provided with a heat-insulating cavity, and the reaction chamber is arranged in the heat-insulating cavity;

[0017] A connecting piece, the heat-insulating shell is connected to the heating base through the connecting piece.

[0018] According to one embodiment of the present application, it also includes multiple heating components and multiple clamping components, and the multiple heating components are detachably connected through the clamping components.

[0019] According to another aspect of the present application, a soil remediation system is provided, comprising the soil remediation device.

[0020] According to another aspect of the present application, a soil remediation method is provided, comprising the soil remediation system, and further comprising the steps of:

[0021] Get the current calorific value Q0 of the current contaminated soil;

[0022] Filling the reaction chamber comprises:

[0023] If Q0>Q1, the contaminated soil is added into the smoldering reaction chamber.

[0024] Q0≤Q2, then when the contaminated soil is added into the thermal desorption reaction chamber;

[0025] Preheating: starting the heating base to heat the reaction chamber;

[0026] Ignition: when the temperature in the heating chamber reaches a preset temperature, the gas supply component is started to supply gas to the heating chamber;

[0027] Reaction repair;

[0028] Exhaust gas treatment: start the exhaust gas recovery system to introduce the exhaust gas in the exhaust gas collection chamber into the heating chamber.

[0029] According to one embodiment of the present application, after obtaining the current calorific value Q0 of the current contaminated soil, the following steps are included:

[0030] Preprocessing:

[0031] Obtain the boundary calorific value Q3 between the smoldering reaction and the thermal desorption reaction;

[0032] When Q0<Q3, combustible materials are added to the contaminated soil.

[0033] It can be seen from the above technical solutions that the advantages and positive effects of the soil remediation treatment device, system and method of the present application are:

[0034] A smoldering reaction chamber, a thermal desorption reaction chamber and an exhaust gas collecting chamber are sequentially arranged in the reaction chamber to treat the contaminated soil in different areas. After the heating component heats the heating chamber to ignite the contaminated soil in the smoldering reaction chamber, the smoldering reaction continues to release heat externally. The high-temperature flue gas passes through the thermal desorption reaction chamber to cause the contaminated soil in the thermal desorption reaction chamber to undergo a thermal desorption reaction, and further repairs the contaminated soil in the thermal desorption reaction chamber. The high-temperature exhaust gas is collected in the exhaust gas collecting chamber, and is guided to the heating chamber through a recovery pipe of the exhaust gas recovery system, and enters the smoldering reaction chamber through the air guide hole, and further heats the smoldering reaction chamber. At the same time, organic pollutants in the exhaust gas burn and release heat in the smoldering reaction chamber, thereby making full use of the waste heat to treat the contaminated soil. On the basis of improving the efficiency of contaminated soil treatment, energy consumption is saved and the amount of exhaust gas generated is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1A schematic diagram of the structure of a heating component in a soil remediation treatment device provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the structure of a reaction chamber in a soil remediation treatment device provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of the overall structure of a soil remediation treatment device provided in an embodiment of the present application;

[0040] Figure 4 Another structural schematic diagram of a heating component in a soil remediation treatment device provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of the structure of a clamping assembly in a soil remediation device provided in an embodiment of the present application;

[0042] Figure 6 A schematic diagram of the process structure of a soil remediation treatment method provided in an embodiment of the present application;

[0043] Figure 7 Another schematic diagram of the process structure of a soil remediation method provided in an embodiment of the present application;

[0044] Figure 8 A schematic diagram of the gas circulation structure in a soil remediation treatment method provided in an embodiment of the present application.

[0045] in:

[0046] 10. Heating assembly; 11. Heating base; 111. Heating chamber; 112. Connecting hole; 113. Air distribution hole; 12. Air supply assembly; 121. Air supply pipeline; 122. Fan; 13. Electric heating tube; 14. Support plate; 141. Air vent;

[0047] 20. reaction chamber; 21. smoldering reaction chamber; 211. first gap area; 22. thermal desorption reaction chamber; 221. second gap area; 23. exhaust gas collection chamber;

[0048] 30. Waste gas recovery system; 31. Recovery pipeline;

[0049] 40. snap-fit ​​assembly; 41. female buckle; 42. male buckle;

[0050] 50. Insulation shell;

[0051] 60. Connectors. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0053] Thermal desorption technology heats the contaminated soil to the designed temperature through direct or indirect heat exchange. The organic pollutants adsorbed in the soil are volatilized by heat and desorbed from the soil particles into the gas phase, thereby separating the pollutants from the soil and achieving the purpose of purifying the soil. Taking ex situ thermal desorption as an example, this technology and equipment are often used to treat semi-volatile organic contaminated soil. The boiling point of semi-volatile organic matter is usually above 260°C. In order to ensure that the pollutants in the soil are removed within the effective residence time, the designed heating temperature must be higher than 260°C. In order to meet the process requirements, more natural gas needs to be consumed. In addition, when treating high-concentration organic contaminated soil, it is usually necessary to increase the heating temperature or extend the residence time to achieve the purpose of qualified remediation, which is bound to increase energy consumption and treatment costs.

[0054] Smoldering is a slow combustion reaction in a high-temperature, oxygen-deficient environment. In recent years, it has been gradually applied in the field of organic contaminated soil remediation, especially for high-concentration organic contaminated soil. The flammability of organic pollutants in the soil is used to burn the pollutants into carbon dioxide, carbon monoxide and water, thereby achieving harmless treatment of contaminated soil.

[0055] Smoldering has two major advantages:

[0056] 1. It can achieve complete oxidation of organic pollutants and meet the stringent remediation target value requirements;

[0057] 2. The process uses the heat released by the oxidation of pollutants to maintain the smoldering reaction, which saves energy compared to technologies such as thermal desorption and incineration. Many common NAPLs are highly flammable, and some even have a combustion calorific value that exceeds that of combustible materials.

[0058] However, the reaction conditions required by smoldering technology are generally harsh, requiring sufficient combustibles to continuously burn and release heat to maintain the smoldering reaction. However, soil pollution is heterogeneous, and the concentration of pollutants in the soil varies greatly, so the calorific value content in each part of the soil is also different, which is not conducive to the smoldering reaction. It is easy to cause smoldering faults and discontinuous reactions, resulting in incomplete remediation of contaminated soil and affecting the acceptance of remediation projects. Therefore, the promotion and application of smoldering technology in the remediation of organic contaminated soil is limited. In addition, the smoldering reaction will release a lot of heat, which also makes the smoldering reaction temperature higher, usually above 800°C. The waste heat in the high-temperature flue gas is usually not effectively utilized, resulting in heat waste.

[0059] Therefore, there is an urgent need for a method and system to ensure the restoration effect and reduce the energy consumption of restoration, so as to achieve green and low-carbon restoration of organic contaminated soil.

[0060] The purpose of this application is to provide a system and method for treating organic contaminated soil by coupling smoldering and thermal desorption technology, the main features of which are:

[0061] (1) Taking advantage of the high calorific value of highly organically contaminated soil, the smoldering reaction is carried out, the calorific value of the contaminated soil is utilized, and the advantages of the smoldering technology are fully utilized to achieve self-purification of highly organically contaminated soil, thus avoiding the problem of smoldering reaction interruption caused by insufficient soil calorific value;

[0062] (2) Using the high-temperature flue gas generated during the smoldering reaction to heat the soil with low concentration of organic pollution, the pollutants in the soil are desorbed, thereby achieving the purification of the soil with low concentration of organic pollution;

[0063] (3) By distinguishing the pollution concentration and calorific value of the soil, the two technologies are combined to achieve complementary advantages, solving the problems of discontinuous single smoldering reaction, waste of waste heat, and high energy consumption of thermal desorption technology;

[0064] (4) Recycling of waste gas reduces the load on the tail gas treatment equipment at the rear end, simplifies the tail gas treatment equipment, and reduces the treatment cost;

[0065] (5) Compared with the traditional thermal desorption system, this system has a simple structure and can be spliced ​​according to the project engineering requirements. It is easy to operate and can meet the needs of soil remediation projects of different scales.

[0066] In summary, this application can effectively solve the shortcomings of the existing technology through the implementation of the above methods and systems, such as unstable repair effect, high energy consumption, complex equipment structure, large footprint, etc., and provide new technical ideas for the repair of small contaminated sites.

[0067] refer to Figure 1-Figure 3As shown, according to one aspect of the present application, a soil remediation treatment device is provided, including a heating component 10, a reaction chamber 20, and an exhaust gas recovery system 30. The heating component 10 includes a heating base 11 and an air supply component 12. The heating base 11 is provided with a heating chamber 111. The air supply component 12 is used to supply gas to the heating chamber 111. The reaction chamber 20 is arranged on the heating base 11. In the direction away from the heating base 11, the reaction chamber 20 is sequentially provided with a smoldering reaction chamber 21, a thermal desorption reaction chamber 22 and an exhaust gas collecting chamber 23 that are gas-connected. The heating chamber 111 is gas-connected with the smoldering reaction chamber 21. Soil with a first calorific value Q1 is arranged in the smoldering reaction chamber 21, and soil with a second calorific value Q2 is arranged in the thermal desorption reaction chamber 22, wherein Q1>Q2. The exhaust gas recovery system 30 includes a recovery pipe 31, one end of the recovery pipe 31 is connected to the exhaust gas collecting chamber 23, and the other end is connected to the heating chamber 111.

[0068] In the present application, the calorific value of the uncontaminated soil is divided, and the contaminated soil that meets the calorific value conditions of the smoldering reaction is set in the smoldering reaction chamber 21, while the contaminated soil with the second calorific value Q2 is set in the thermal desorption reaction chamber 22, thereby effectively avoiding the problem of smoldering faults or discontinuous reactions during the smoldering reaction.

[0069] When the heating component 10 is used to ignite the contaminated soil in the smoldering reaction chamber 21, after ignition, the smoldering reaction will release a large amount of heat, which is then used as a heat source for the contaminated soil in the thermal desorption reaction chamber 22. At the same time, the exhaust gas will rise along the smoldering reaction chamber 21 and the thermal desorption reaction chamber 22 to the exhaust gas collecting chamber 23. Through the recovery pipe 31 in the exhaust gas recovery system 30, a part of the high-temperature exhaust gas is diverted from the reaction chamber 20 to the heating chamber 111, providing a high-temperature environment for the smoldering reaction, thereby making full use of the heat in the smoldering reaction process and reducing energy consumption.

[0070] In another embodiment of the present application, the exhaust gas recovery system 30 includes an exhaust gas treatment device, which can be connected to an activated carbon treatment device on one side of the exhaust gas collection chamber 23. After the exhaust gas is treated to meet the standards, the treated gas is discharged without being recovered to the heating chamber 111 through the recovery pipe 31.

[0071] According to one embodiment of the present application, the gas supply assembly 12 includes a gas supply pipe 121 and a fan 122. One end of the gas supply pipe 121 is connected to the heating chamber 111, and the other end is connected to the fan 122. The fan 122 is used to drive the gas from the gas supply pipe 121 to the heating chamber 111. The recovery pipe 31 is an open screen pipe with a screen gap width of 1 mm, a length of 2 cm, and an interval of 3 cm. It is arranged in the upper part of the thermal desorption reaction chamber 22 of the reaction chamber 20, that is, in the exhaust gas collection chamber 23, and is connected to the fan 122. The exhaust gas generated by thermal desorption migrates upward in the reaction chamber 20, is collected through the recovery pipe 31, enters the fan 122, and is re-introduced into the heating base 11, and finally reaches the smoldering reaction area. While realizing the utilization of waste heat of the exhaust gas, the high temperature and oxygen-deficient environment of the smoldering reaction zone is used to treat organic matter in the exhaust gas and achieve exhaust gas purification.

[0072] According to an embodiment of the present application, a first gap area 211 is formed between the soils of the first calorific value, and a second gap area 221 is formed between the soils of the second calorific value. The first gap area 211 is connected to the second gap area 221, and the exhaust gas flows through the second gap area 221 to the exhaust gas collection chamber 23 at the top, and the exhaust gas is guided to the heating chamber 111 through the recovery pipe 31. Figure 2 As shown, porous materials can be filled between the soils with the first calorific value to form a first gap area 211 in the smoldering reaction chamber 21 and a second gap area 221 in the thermal desorption reaction chamber 22, so that the airflow driven by the fan 122 in the heating chamber 111 can rise to the exhaust gas collecting chamber 23 along the first gap area 211 in the smoldering reaction chamber 21 and the second gap area 221 in the thermal desorption reaction chamber 22, thereby improving the circulation efficiency of the airflow.

[0073] The present application provides a thermal desorption coupled smoldering repair system, which includes: a heating base 11, a recovery pipe 31 and an insulation shell 50.

[0074] The heating assembly 10 includes a heating base 11 , a support plate 14 , an air vent 141 , an electric heating tube 13 , and an air supply assembly 12 . The heating base 11 is provided with a clamping assembly 40 and a connector 60 .

[0075] refer to Figure 1 , Figure 4 and Figure 5As shown, according to one embodiment of the present application, the heating component 10 also includes an electric heating tube 13, which is arranged in the heating chamber 111, and the heating base 11 is provided with a connecting hole 112. One end of the electric heating tube 13 extends out of the connecting hole 112 and is electrically connected to an external power supply. After the electric heating tube 13 in the heating component 10 smolders the contaminated soil in the smoldering reaction chamber 21, the electric heating tube 13 can be closed, and the exhaust gas in the recovery pipe 31 can be re-introduced into the heating base 11, and finally reaches the smoldering reaction chamber 21.

[0076] refer to Figure 1 and Figure 4 As shown, the electric heating tube 13 integrated in the heating base 11 is spirally wound to surround the heating base 11 to ensure that the soil in the smoldering reaction chamber 21 is evenly heated. The upper surface of the heating base 11 is a support plate 14, and ventilation holes 141 are arranged on the ventilation plate to supply air to the reaction chamber 20 to improve the repair efficiency of the smoldering reaction.

[0077] The heating base 11 has a structure as follows: Figure 1 As shown, each partition in the reaction chamber 20 is as follows Figure 2 As shown, the bottom is a smoldering reaction chamber 21, the upper part is a thermal desorption reaction chamber 22, and the top is an exhaust gas collection chamber 23.

[0078] In the present application, according to one embodiment of the present application, the heating assembly 10 further includes a support plate 14 disposed on one side facing the reaction chamber 20, the heating base 11 and the support plate 14 enclose a heating chamber 111, the filler is disposed in the heating chamber 111, a plurality of vents 141 are provided on the support plate 14, and the heating chamber 111 is in gas communication with the smoldering reaction chamber 21 through the vents 141. The fan 122 transmits the airflow from the heating chamber 111 to the reaction chamber 20 through the vents 141, and then drives the gas in the smoldering reaction chamber 21 and the thermal desorption reaction chamber 22 to converge into the exhaust gas collection chamber 23, a part of the high-temperature gas in the exhaust gas collection chamber 23 is recovered to the reaction chamber 20 through the fan 122 and the recovery pipe 31, and the other part is discharged after the exhaust gas is treated by the exhaust gas treatment device to meet the standards.

[0079] The front side elevation of the heating base 11 is provided with an air hole 113 for connecting an air supply pipe 121, which is connected to a fan 122. The fan 122 blows air into the heating base 11, and the air enters the reaction chamber 20 through the air vent 141 on the support plate 14, providing combustion-supporting gas for the smoldering reaction. The front side elevation of the heating base 11 is provided with a connection hole 112, through which the electric heating tube 13 passes, and is electrically connected to an external power source.

[0080] According to one embodiment of the present application, the reaction chamber 20 also includes a combustion-supporting chamber and a filling material, wherein the combustion-supporting chamber is arranged on a side close to the heating chamber 111; the filling material is arranged in the combustion-supporting chamber, and the filling material has a ventilation gap, and the diameter of the filling material is greater than the diameter of the ventilation hole 141.

[0081] The filler can be set to high temperature resistant granular materials such as quartz stone, so that the technical effects achieved by filling quartz stone include:

[0082] (1) The gas distribution is uniform. The combustion-supporting air flowing out of the gas distribution holes 113 can enter the smoldering reaction zone uniformly after being disturbed by the quartz stone layer, ensuring that the smoldering reaction proceeds uniformly;

[0083] (2) Preventing blockage of the air distribution holes 113 and the air vents 141 . The quartz stone layer can effectively prevent soil particles in the smoldering reaction zone from leaking downward into the heating base 11 , thereby blocking the air vents 141 and the air distribution holes 113 .

[0084] According to one embodiment of the present application, it also includes a heat preservation shell 50 and a connector 60. The heat preservation shell 50 is provided with a heat preservation cavity, and the reaction chamber 20 is arranged in the heat preservation cavity. The heat preservation shell 50 is connected to the heating base 11 through the connector 60. The heat preservation shell 50 is installed around and on the top of the heating base 11 to form the reaction chamber 20 for contaminated soil. Figure 3 As shown, the volume of the reaction chamber 20 and the number of heat-insulating shells 50 used match the combination of the heating base 11. The equipment has a simple structure, is easy to transport, and is easy to install and operate on site.

[0085] In the present application, the heating base 11 is a rectangular box-shaped structure, and the four edges of the heating base 11 are equipped with connecting parts 60. One end of the connecting part 60 is fixed on the insulation shell 50, and the other end is fixed on the side of the heating base 11. The insulation shell 50 can be rotated through the connecting part 60, wherein the connecting part 60 can be set as a loose-leaf, so that during the repair process, the insulation shell 50 and the heating base 11 are in a 90° vertical state.

[0086] A heat-insulating shell 50 is installed around and on the top of the heating base 11 to form a reaction chamber 20 for contaminated soil. Figure 4 As shown, the volume of the reaction chamber 20 and the number of heat-insulating shells 50 used match the combination of the heating base 11. The equipment has a simple structure, is easy to transport, and is easy to install and operate on site.

[0087] According to an embodiment of the present application, it also includes a plurality of heating components 10 and a plurality of snap-in components 40, and the plurality of heating components 10 are detachably connected through the snap-in components 40. Figure 1-Figure 5As shown, the snap-on assembly 40 includes a sub-buckle 42 and a female buckle 41. The sub-buckle 42 and the female buckle 41 can be placed on the left side facade, the right side facade and the rear side facade of the heating base 11 respectively. The sub-buckle 42 and the female buckle 41 on the same heating base 11 are on different surfaces.

[0088] As an example, the heating base 11 can be assembled as follows:

[0089] Combination form 1: The sub-button 42 on the right side of one heating base 11 is inserted into the female button 41 on the left side of another heating base 11, thereby fixing the sub-button 41, such as Figure 4 The above method can realize the combination of two heating bases 11, such as Figure 3 As shown; Combination form 2: By inserting the sub-buckle 42 of the rear side elevation of one heating base 11 into the rear side female buckle 41 of another heating base 11, the combination of the two heating bases 11 can be achieved;

[0090] Combination form three: According to the above two combination forms, a combination of 4 or more heating bases 11 can be realized to match the demand of the repair project; in addition, the sub-buckle 42 and the mother buckle 41 can be disassembled and adjusted and replaced to meet the combination requirements of multiple heating bases 11.

[0091] According to another aspect of the present application, a soil remediation system is provided, comprising a soil remediation device.

[0092] The present application also provides a thermal desorption coupled smoldering repair method, the method flow is as follows Figure 6 As shown, the specific steps are as follows:

[0093] According to another aspect of the present application, a soil remediation method is provided, including a soil remediation system, further comprising the steps of:

[0094] S10: Obtain the current calorific value Q0 of the current contaminated soil;

[0095] S20: Filling the reaction chamber 20, including:

[0096] If Q0>Q1, the contaminated soil is added into the smoldering reaction chamber 21;

[0097] If Q0≤Q2, then when the contaminated soil is added into the thermal desorption reaction chamber 22;

[0098] S30: preheating: starting the heating base 11 to heat the reaction chamber 20;

[0099] S40: Ignition: When the temperature in the heating chamber 111 reaches a preset temperature, the gas supply assembly 12 is started to supply gas to the heating chamber 111;

[0100] S50: reaction repair;

[0101] S60: Waste gas treatment: Start the waste gas recovery system 30 to introduce the waste gas in the waste gas collection chamber 23 into the heating chamber 111.

[0102] As an example, further,

[0103] S10: Preliminary investigation: The purpose of pretreatment is to make the contaminated soil meet the basic conditions required for smoldering and thermal desorption reactions. The calorific value of the contaminated soil can represent the content of organic pollutants in the soil to a certain extent. Before pretreatment, samples are taken to test the calorific value and pollutant content of the contaminated soil, and the pollutant concentration corresponding to the calorific value Q0>Q3=1MJ / kg is determined. This calorific value is used as the boundary for distinguishing the smoldering or thermal desorption reactions of the contaminated soil;

[0104] S70: Pretreatment: obtaining the boundary calorific value Q3 between the smoldering reaction and the thermal desorption reaction; when Q0<Q3, adding combustible substances to the contaminated soil.

[0105] As an example, during the pretreatment process, the remediation technology can be selected according to the pollutant concentration, and the contaminated soil can be classified according to the calorific value. The contaminated soil with Q0>1MJ / kg is remediated by the smoldering technology, where Q1>Q3, and for the soil with Q0≤1MJ / kg, the thermal desorption technology is used for remediation;

[0106] However, when the calorific value of all contaminated soils Q0 is less than 1MJ / kg, combustibles, porous aggregates and other materials can be added to the soil using mechanical mixing equipment to make the soil have the conditions for smoldering reaction; at the same time, the contaminated soil with Q0>1MJ / kg is remediated using smoldering technology, and the contaminated soil with Q0≤1MJ / kg, where Q2≤Q3, is remediated using thermal desorption technology;

[0107] S20: Filling the reaction chamber 20: Before filling the contaminated soil, quartz stone with a particle size of 5-10 mm should be laid in the smoldering reaction chamber 21, close to the surface of the heating base 11, with a laying thickness of 50 mm.

[0108] Among them, filled quartz stone can play:

[0109] (1) The gas distribution is uniform. The combustion-supporting air flowing out of the gas distribution holes 113 can enter the smoldering reaction zone uniformly after being disturbed by the quartz stone layer, ensuring that the smoldering reaction proceeds uniformly;

[0110] (2) Preventing the air distribution holes 113 from being blocked. The quartz stone layer can effectively prevent soil particles in the smoldering reaction zone from leaking downward into the heating base 11, thereby blocking the air distribution holes 113.

[0111] Fill the quartz stone layer with contaminated soil with a calorific value of >1MJ / kg to provide the materials required for the smoldering reaction, with a filling thickness of no less than 50cm;

[0112] On the basis of the quartz stone layer as filler, lay the contaminated soil with Q0>1MJ / kg as soil for smoldering remediation; then lay the contaminated soil with Q0≤1MJ / kg on the contaminated soil with Q0>1MJ / kg as soil for thermal desorption remediation, with a filling thickness of not less than 100cm;

[0113] In order to ensure that the hot flue gas generated by smoldering fully heats the upper layer of contaminated soil with a calorific value of ≤1MJ / kg, the material filling thickness of the thermal desorption reaction chamber 22: the material filling thickness of the smoldering reaction chamber 21 should be ≤2:1.

[0114] Preheating: Turn on the heating base 11 to preheat the contaminated soil and preheat the soil in the bottom smoldering reaction chamber 21;

[0115] Ignition: When the temperature of the bottom soil reaches the minimum temperature required for the smoldering reaction, which can be set to an ignition temperature of 450°C-500°C, the fan 122 is turned on to introduce air into the contaminated soil through the air supply pipeline, so that the contaminated soil is ignited and a smoldering reaction occurs;

[0116] Reaction remediation: The smoldering reaction chamber 21 ignites the contaminated soil, triggering the smoldering reaction. Under high temperature and oxygen-deficient conditions, the organic pollutants in the soil are oxidized and decomposed into CO2 / CO and H2O, and a large amount of heat is released, which diffuses upward in the form of high-temperature flue gas. On the one hand, it can preheat the soil in the smoldering reaction zone to ensure that the smoldering reaction continues; on the other hand, it heats the contaminated soil in the upper thermal desorption reaction chamber 22. After the contaminated soil in the upper thermal desorption zone 16 is heated, the organic pollutants are desorbed from the soil particles, thereby achieving thermal desorption treatment of the contaminated soil.

[0117] After the smoldering reaction is triggered, the heating tube 7 can be turned off without inputting additional energy into the reactor, thereby realizing the self-circulation of heat in the reactor.

[0118] Energy cycle: In addition to the smoldering reaction chamber 21 at the bottom of the reaction chamber 20, which needs to input energy to trigger the smoldering reaction, the energy consumption in the reaction process of this reactor comes from the heat released during the smoldering process of the smoldering reaction chamber 21 at the bottom of the reaction chamber 20. The high-temperature flue gas generated by the smoldering reaction enters the thermal desorption reaction chamber 22 upward in the reactor for heat exchange. After the heat exchange, the flue gas carries the organic pollutants desorbed from the soil through the recovery pipeline 31, and enters the activated carbon adsorption box at the tail end to meet the emission standards; the other part enters the fan 122, and is mixed and preheated with the fresh air in the fan 122. The preheated mixed gas enters the smoldering reaction zone 15 in the reactor 1, providing the combustion-supporting gas required for the smoldering reaction and reducing the heat loss. At the same time, the organic pollutants in the mixed gas are oxidized and decomposed under high temperature and oxygen-deficient conditions, thereby reducing the load of the exhaust gas treatment equipment.

[0119] According to one embodiment of the present application, after obtaining the current calorific value Q0 of the current contaminated soil, the following steps are included:

[0120] Exhaust gas treatment: The temperature of the smoldering reaction zone is monitored by a temperature sensor. When the temperature of the smoldering reaction chamber 21 rises and is higher than the initial heating temperature of 450°C, it indicates that the smoldering reaction is triggered, and the exhaust gas treatment system can be turned on at this time.

[0121] The waste gas in the reaction chamber 20 is collected through the recovery pipe 31 at the top, and the collected waste gas is mixed with the combustion air through the fan 122 and flows back into the reaction chamber 20. On the one hand, it can preheat the combustion air, improve the heat utilization rate, and reduce heat loss; on the other hand, it can use the high temperature of the smoldering reaction zone to catalytically burn the organic matter in the waste gas, thereby reducing the emission of waste gas during the repair process. The repair reaction process is as follows: Figure 7 shown.

[0122] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0123] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A soil remediation device, characterized in that: include: A heating assembly (10) comprises a heating base (11) and a gas supply assembly (12), wherein the heating base (11) is provided with a heating chamber (111), and the gas supply assembly (12) is used to supply gas to the heating chamber (111); A reaction chamber (20) is arranged on the heating base (11); in a direction away from the heating base (11), the reaction chamber (20) is provided with a smoldering reaction chamber (21), a thermal desorption reaction chamber (22) and an exhaust gas collection chamber (23) which are gas-connected in sequence; the heating chamber (111) is gas-connected with the smoldering reaction chamber (21); soil with a first calorific value Q1 is arranged in the smoldering reaction chamber (21); soil with a second calorific value Q2 is arranged in the thermal desorption reaction chamber (22), wherein Q1>Q2; And an exhaust gas recovery system (30), comprising a recovery pipe (31), one end of the recovery pipe (31) is connected to the exhaust gas collection chamber (23), and the other end is communicated with the heating chamber (111).

2. The soil remediation device according to claim 1, characterized in that: The air supply assembly (12) comprises an air supply pipeline (121) and a fan (122); one end of the air supply pipeline (121) is in communication with the heating chamber (111), and the other end is connected to the fan (122); the fan (122) is used to drive the gas to flow from the air supply pipeline (121) to the heating chamber (111).

3. The soil remediation device according to claim 1, characterized in that: The heating assembly (10) further comprises an electric heating tube (13), wherein the electric heating tube (13) is arranged in the heating chamber (111), the heating base (11) is provided with a connecting hole (112), and one end of the electric heating tube (13) extends out from the connecting hole (112) to be connected to an external power source.

4. The soil remediation device according to claim 1 or 3, characterized in that: The heating assembly (10) further comprises a support plate (14) arranged on a side facing the reaction chamber (20); the heating base (11) and the support plate (14) enclose the heating chamber (111); a plurality of ventilation holes (141) are provided on the support plate (14); and the heating chamber (111) is in gas communication with the smoldering reaction chamber (21) via the ventilation holes (141).

5. The soil remediation device according to claim 4, characterized in that: The reaction chamber (20) further comprises: A combustion-supporting chamber, the combustion-supporting chamber being arranged on a side close to the heating chamber (111); A filler is arranged in the combustion-supporting cavity, wherein a ventilation gap is provided in the filler, and a diameter of the filler is greater than a diameter of the ventilation hole (141).

6. The soil remediation device according to claim 1, characterized in that: Also includes: A heat-insulating shell (50), wherein the heat-insulating shell (50) is provided with a heat-insulating chamber, and the reaction chamber (20) is arranged in the heat-insulating chamber; A connecting piece (60), wherein the heat-insulating shell (50) is connected to the heating base (11) via the connecting piece (60).

7. The soil remediation device according to claim 1, characterized in that: It also comprises a plurality of heating components (10) and a plurality of snap-in components (40), wherein the plurality of heating components (10) are detachably connected to each other via the snap-in components (40).

8. A soil remediation system, characterized in that: A soil remediation treatment device comprising any one of claims 1 to 7.

9. A soil remediation method, characterized in that: The soil remediation system according to claim 8 further comprises the steps of: Get the current calorific value Q0 of the current contaminated soil; Filling the reaction chamber (20) comprises: If Q0>Q1, the contaminated soil is added into the smoldering reaction chamber (21) If Q0≤Q2, then when the contaminated soil is added into the thermal desorption reaction chamber (22); Preheating: starting the heating base (11) to heat the reaction chamber (20); Ignition: when the temperature in the heating chamber (111) reaches a preset temperature, starting the gas supply component (12) to supply gas to the heating chamber (111); Reaction repair; Waste gas treatment: starting the waste gas recovery system (30) to guide the waste gas in the waste gas collection chamber (23) into the heating chamber (111).

10. The soil remediation method according to claim 9, characterized in that: After obtaining the current calorific value Q0 of the current contaminated soil, the steps include: Preprocessing: Obtain the boundary calorific value Q3 between the smoldering reaction and the thermal desorption reaction; When Q0<Q3, combustible materials are added to the contaminated soil.

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