Whole-process soil thermal desorption waste heat recycling system

Abstract

The utility model relates to a full-process soil thermal desorption waste heat recycling system which comprises a first-stage waste heat recycling module, a second-stage waste heat recycling module and a third-stage waste heat recycling module. The first-stage waste heat recycling module is located at an outlet of the rotary kiln and recycles heat of high-temperature clean soil. The second-stage waste heat recovery module is located at the tail of the second combustion chamber and recovers high-temperature flue gas heat of an outlet of the second combustion chamber. The third-stage waste heat recovery module is located between the quenching chamber and the bag-type dust collector and recovers high-temperature flue gas heat at an outlet of the quenching chamber. The three stages of waste heat recovery all adopt air as a working medium. And the high-temperature air subjected to second-level and third-level heating is introduced into a rotary kiln combustor for combustion supporting. The vast majority of heat loss in the soil thermal desorption technological process can be collected through three-stage waste heat recovery and used for supporting combustion during soil pre-drying and combustion, and the energy consumption level of soil thermal desorption can be remarkably reduced. According to the method, the energy-saving efficiency can be improved to 29%, and 5968.2 kW of energy is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery, and specifically relates to a full-process soil thermal desorption waste heat recovery and utilization system. Background Art

[0002] Soil pollutants entering the soil ecosystem will destroy the ecological balance and seriously threaten the growth of plants and animals and human health. Soil thermal desorption technology is considered to be one of the main effective technologies for controlling soil pollution. Soil thermal desorption technology refers to heating the organic pollutants in the soil to a sufficient temperature through direct or indirect heat exchange under vacuum conditions or when a carrier gas is introduced, so that the organic matter volatilizes or separates from the polluted medium. This process requires a large amount of fuel combustion to provide heat for thermal desorption while maintaining a high temperature of more than 1000°C in the secondary combustion chamber. The energy consumption is huge and the heat loss is serious. Therefore, soil thermal desorption energy-saving and consumption-reducing measures are urgently needed.

[0003] In the soil thermal desorption device, the organic matter in the soil evaporates and decomposes at 200-650℃, and most of it is converted at 500℃ and less than 10min. The thermally desorbed soil is discharged from the pyrolysis furnace at about 500℃, so the soil after thermal desorption still has considerable heat, and these soils are usually cooled by watering or natural cooling, resulting in serious heat loss. At present, the soil thermal desorption waste heat recovery device usually only recovers the waste heat of the flue gas at the outlet of the secondary combustion chamber, and most of it uses water as the working medium. Considering pressure and safety issues, it is impossible to heat the water to a very high temperature. The device is huge, corrosive, and has high manufacturing and maintenance costs. In addition, the generation of carcinogenic dioxins in the process of recovering the waste heat of the flue gas at the outlet of the secondary combustion chamber is not considered, which will cause serious environmental pollution. In addition, the heat of other parts of the thermal desorption process is not recovered, and the waste heat recovery is not complete.

[0004] Therefore, the present application proposes a full-process soil thermal desorption waste heat recovery and utilization system. Utility Model Content

[0005] In view of the deficiencies in the prior art, the technical problem that the utility model intends to solve is to provide a full-process soil thermal desorption waste heat recovery and utilization system.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A full-process soil thermal desorption waste heat recovery and utilization system, the system comprising:

[0008] The primary waste heat recovery module is located at the clean soil outlet of the rotary kiln, which recovers the heat of the high-temperature clean soil to dry the contaminated soil;

[0009] The secondary waste heat recovery module is located at the tail of the secondary combustion chamber, recovering the heat of the high-temperature flue gas at the outlet of the secondary combustion chamber to heat the air as the high-temperature combustion-supporting gas of the rotary kiln;

[0010] The three-stage waste heat recovery module is located between the quench chamber and the bag filter, which recovers the heat of the relatively high-temperature flue gas at the outlet of the quench chamber to heat the air as the high-temperature combustion-supporting gas of the rotary kiln;

[0011] The above three levels of waste heat recovery all use air as the working medium.

[0012] Furthermore, the high-temperature air outlet of the secondary waste heat recovery module and the high-temperature air outlet of the tertiary waste heat recovery module are connected to the burner of the rotary kiln through corresponding pipelines for combustion support.

[0013] Furthermore, the primary waste heat recovery module includes a pre-drying module, an induced draft fan, a first air pump and a soil-air heat exchanger. The soil-air heat exchanger, the induced draft fan, the pre-drying module and the air pump are connected in sequence to form a working cycle. The primary soil recovery inlet of the soil-air heat exchanger 104 is connected to the clean soil outlet after thermal desorption treatment of the rotary kiln 2. The primary recovery gas inlet 1043 of the soil-air heat exchanger 104 is connected to the air outlet of the pre-drying module 101 through a pipeline. The first air pump 103 is connected to the road connecting the soil-air heat exchanger 104 and the pre-drying module 101; the air inlet of the pre-drying module 101 is connected to the primary recovery air outlet 1044 of the soil-air heat exchanger 104 through the induced draft fan 102;

[0014] The pre-dried contaminated soil outlet 1012 of the pre-drying module 101 is connected to the inlet of the rotary kiln, and the contaminated soil enters from the pre-dried contaminated soil inlet 1011 of the pre-drying module 101; the first air pump inlet is connected to the air.

[0015] Furthermore, the secondary waste heat recovery module 8 includes a first air heat exchanger 801, a secondary recovery flue gas inlet 8013 of the first air heat exchanger 801 is connected to the outlet of the second combustion chamber 7, and a secondary recovery air inlet 8011 of the first air heat exchanger 801 is connected to the second air pump 4 for pumping air for heat exchange with the high-temperature flue gas;

[0016] The secondary recovery air outlet 8012 of the first air heat exchanger 801 is connected to the combustion air inlet of the rotary kiln 2. The outlet temperature of the high-temperature flue gas of the secondary recovery flue gas outlet 8014 of the first air heat exchanger 801 is 850°C or above, and the secondary recovery flue gas outlet 8014 is connected to the quenching chamber.

[0017] Furthermore, the three-stage waste heat recovery module 11 includes a second air heat exchanger 111, the three-stage recovery air inlet 11102 of the second air heat exchanger 111 is connected to the third air pump, the three-stage recovery air outlet 11101 of the second air heat exchanger 111 is connected to the combustion air inlet of the rotary kiln, the three-stage recovery flue gas inlet of the second air heat exchanger 111 is connected to the outlet of the quenching chamber 10, and the three-stage recovery flue gas outlet of the second air heat exchanger 111 is connected to the bag dust collector.

[0018] Furthermore, the first air heat exchanger 801 is a plate heat exchanger, and the second air heat exchanger 111 is a fin-tube heat exchanger.

[0019] Furthermore, the secondary recovery air outlet 8012 of the secondary waste heat recovery module 8 and the tertiary recovery air outlet 11101 of the tertiary waste heat recovery module 11 are respectively connected to the primary air inlet and secondary air inlet of the burner at the tail of the rotary kiln; a first valve 5 and a second valve 6 are respectively arranged on the pipeline connecting the secondary recovery air outlet 8012 and the primary air inlet of the burner, and on the pipeline connecting the tertiary recovery air outlet 11101 and the secondary air inlet of the burner, for controlling the amount of high-temperature air introduced.

[0020] Furthermore, a valve and a thermostat 9 are also provided at the secondary recovered air outlet 8012 .

[0021] Furthermore, the equipment used for soil thermal desorption includes a rotary kiln 2, a cyclone dust collector 3, a secondary combustion chamber 7, a quenching chamber 10, a bag filter 13, a catalytic adsorption tower 14 and a leaching tower 15 which are connected in sequence.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] 1. Three-stage waste heat recovery to avoid energy waste. Using air as the heat exchange medium, the waste heat of the hot soil at the outlet of the rotary kiln, the high-temperature flue gas at the outlet of the secondary combustion chamber, and the relatively high-temperature flue gas at the outlet of the quenching chamber are recovered, and basically all the waste heat that can be recovered in the thermal desorption process has been recovered.

[0024] 2. Three-stage waste heat utilization: the first-stage soil waste heat is used for soil pre-drying to reduce its moisture content, the second- and third-stage flue gas waste heat heats the air, and the high-temperature air is introduced into the rotary kiln as combustion-supporting air to improve combustion efficiency. The two measures of pre-drying and combustion-supporting greatly reduce the fuel input for soil thermal desorption. According to calculations, compared with the existing thermal desorption process, the energy consumption level of the improved thermal desorption process is significantly reduced, and the energy saving effect reaches 29%.

[0025] 3. The secondary waste heat recovery module can avoid the generation of dioxins by controlling the outlet flue gas temperature of the heat exchanger when recovering heat. The tertiary waste heat recovery module can not only recover waste heat, but also prevent the flue gas from entering the bag filter and lowering its temperature, so that the water vapor in the flue gas condenses with dust to form sludge and block the bag filter.

[0026] 4. Using air instead of water as the working medium for waste heat recovery has obvious advantages. The existing thermal desorption process uses water for waste heat recovery. Considering the pressure problem, water cannot be heated to a very high temperature, so the heat recovery is limited; the water undergoes phase change during the heat exchange process, and water as a working medium causes serious corrosion of the device, resulting in high maintenance costs. Using air for heat exchange can effectively avoid these problems.

[0027] 5. Air is recycled during primary recovery to reduce energy consumption for air extraction. The air is heated when recovering waste heat from the soil and cooled when pre-drying the soil. The two processes are continuously carried out to form a cycle. During operation, only a small amount of air leakage needs to be supplemented, which can reduce energy consumption for air extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the installation and connection structure of the full-process soil thermal desorption waste heat recovery and utilization system of the utility model;

[0029] In the figure, 1. primary waste heat recovery module; 2. rotary kiln; 3. cyclone dust collector; 4. second air pump; 5. first valve; 6. second valve; 7. second combustion chamber; 8. secondary waste heat recovery module; 9. thermostat; 10. quenching chamber; 11. tertiary waste heat recovery module; 12. third air pump; 13. bag filter; 14. catalytic adsorption tower; 15. leaching tower;

[0030] 101. pre-drying module; 102. induced draft fan; 103. first air pump; 104. soil-air heat exchanger;

[0031] 1011. Inlet for pre-dried contaminated soil; 1012. Outlet for pre-dried contaminated soil;

[0032] 1041, primary soil recovery inlet; 1042, primary soil recovery outlet; 1043, primary air recovery inlet; 1044, primary air recovery outlet;

[0033] 801, first air heat exchanger; 8011, secondary recovery air inlet; 8012, secondary recovery air outlet; 8013, secondary recovery flue gas inlet; 8014, secondary recovery flue gas outlet;

[0034] 111. Second air heat exchanger; 11101. Third-stage recovered air outlet; 11102. Third-stage recovered air inlet; 11103. Third-stage recovered flue gas inlet; 11104. Third-stage recovered flue gas outlet. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The equipment used for soil thermal desorption in the utility model comprises a rotary kiln 2, a cyclone dust collector 3, a secondary combustion chamber 7, a quenching chamber 10, a bag dust collector 13, a catalytic adsorption tower 14 and a leaching tower 15 which are connected in sequence.

[0037] The utility model discloses a full-process soil thermal desorption waste heat recovery and utilization system (see Figure 1 ) includes a primary waste heat recovery module 1, a secondary waste heat recovery module 8, and a tertiary waste heat recovery module 9. The primary waste heat recovery module is located at the clean soil outlet of the rotary kiln to recover the heat of the high-temperature clean soil; the secondary waste heat recovery module is located at the tail of the secondary combustion chamber to recover the heat of the high-temperature flue gas at the outlet of the secondary combustion chamber; the tertiary waste heat recovery module is located between the quenching chamber and the bag filter to recover the heat of the relatively high-temperature flue gas at the outlet of the quenching chamber; the above three levels of waste heat recovery all use air as the working medium. The high-temperature air outlet of the secondary waste heat recovery module and the high-temperature air outlet of the tertiary waste heat recovery module are connected to the burner of the rotary kiln through corresponding pipelines for combustion assistance.

[0038] Furthermore, the primary waste heat recovery module includes a pre-drying module, an induced draft fan, an air pump and a soil-air heat exchanger. The soil-air heat exchanger, the induced draft fan, the pre-drying module and the air pump are connected in sequence to form a working cycle. The module uses the heat recovered from the hot soil to pre-dry the soil to reduce its moisture content, thereby reducing the energy consumption of thermal desorption.

[0039] The primary waste heat recovery module 1 includes a pre-drying module 101, an induced draft fan 102, a first air pump 103 and a soil-air heat exchanger 104. The soil-air heat exchanger 104 is installed at the outlet of the clean soil after thermal desorption treatment of the rotary kiln 2. The first air pump 103 is connected between the soil-air heat exchanger 104 and the pre-drying module 101. The pre-drying module 101 is connected to the induced draft fan 102, and the induced draft fan 101 is further connected to the soil-air heat exchanger 104 to form a working cycle. The pre-dried contaminated soil outlet 1012 of the pre-drying module 101 is connected to the inlet of the rotary kiln, and the pre-dried soil is sent into the rotary kiln for treatment.

[0040] The soil-air heat exchanger 104 is a waste heat recovery device of the primary waste heat recovery module 1, and is installed at the outlet of the clean soil after thermal desorption treatment of the rotary kiln 2. The clean soil outlet of the rotary kiln 2 is connected to the primary soil recovery inlet 1041 of the soil-air heat exchanger 104, and the soil is discharged from the primary soil recovery outlet 1042 after heat exchange and cooling in the soil-air heat exchanger 104. Both the pre-drying module 101 and the soil-air heat exchanger 104 are air heat exchangers for gas-solid heat exchange.

[0041] The first air pump 103 extracts normal-temperature gas from the atmosphere and pumps it into the soil-air heat exchanger 104 through the primary recovery air inlet 1043 of the soil-air heat exchanger 104. The high-temperature soil and the normal-temperature air form a countercurrent heat exchange in the soil-air heat exchanger 104. The high-temperature soil is discharged after cooling down, and the normal-temperature air is discharged from the primary recovery air outlet 1044 of the soil-air heat exchanger 104 after heating up and sent to the pre-drying module 101 through the induced draft fan 102. The first air pump extracts normal-temperature gas from the atmosphere when the working cycle is started. When the amount of air in the working cycle is sufficient, the first air pump 103 can stop extracting air from the atmosphere, and the induced draft fan 102 can drive the normal operation of the working cycle.

[0042] The pre-drying module 101 can use soil drying equipment such as a disc hot air dryer. The contaminated soil enters the pre-drying module from the pre-drying contaminated soil inlet 1011, and the pre-drying contaminated soil outlet 1012 is connected to the inlet of the rotary kiln 2. After the high-temperature air is sent into the pre-drying module 101 through the induced draft fan 102, the untreated contaminated soil can be pre-dried to reduce its moisture content. In this process, the air temperature is continuously reduced, and then the air is returned to the soil air heat exchanger 104 through the primary recovery gas inlet 1043 to be used again to recover the heat of the hot soil and perform a cyclic operation. The contaminated soil after pre-drying enters the rotary kiln 2 for thermal desorption treatment.

[0043] This working cycle completes the process of recovering the waste heat of the high-temperature clean soil after thermal desorption treatment and using the recovered heat for soil pre-drying.

[0044] The secondary waste heat recovery module 8 is located at the outlet of the secondary combustion chamber 7, and the first air heat exchanger 801 is installed at the tail of the secondary combustion chamber 7. The first air heat exchanger 801 is the recovery equipment of the secondary waste heat recovery module 8. In the traditional soil thermal desorption process, the temperature of the secondary combustion chamber 7 needs to be controlled above 1000°C. The high-temperature flue gas at the outlet of the secondary combustion chamber 7 flows into the first air heat exchanger 801 through the secondary recovery flue gas inlet 8013. At the same time, the air is pumped into the first air heat exchanger 801 through the second air pump 4 through the secondary recovery air inlet 8011 of the first air heat exchanger 801 to exchange heat with the high-temperature flue gas. The high-temperature air after heat exchange flows out from the secondary recovery air outlet 8012 of the first air heat exchanger 801. The secondary recovery air outlet 8012 of the first air heat exchanger 801 is connected to the combustion air inlet of the rotary kiln 2. The high-temperature air after heat exchange is passed into the rotary kiln 2 through the corresponding pipeline as the secondary combustion air for fuel combustion. The secondary recovery flue gas outlet 8014 of the first air heat exchanger 801 should control the outlet temperature of the high-temperature flue gas to be 850°C or above to avoid the generation of dioxins during the waste heat recovery process. The secondary recovery flue gas outlet 8014 is connected to the quenching chamber, and then the relatively high-temperature flue gas after heat exchange is passed into the quenching chamber 10 for quenching, so as to achieve the purpose of avoiding the generation of dioxins while recovering the waste heat of the flue gas. The temperature of the high-temperature air coming out of the secondary recovery air outlet 8012 is about 460-500°C. The first air heat exchanger adopts a plate heat exchanger to improve the heat exchange efficiency under high heat exchange conditions.

[0045] The three-stage waste heat recovery module 11 is located between the quench chamber 10 and the bag filter 13. The second air heat exchanger 111 is a recovery device for the three-stage waste heat recovery module 11. The flue gas temperature at the outlet of the quench chamber 10 reaches 200°C. In order to prevent the water vapor in the flue gas from condensing in the bag filter 13 to form droplets, mixing with impurities and adsorbing on the inner wall of the bag filter to cause blockage, the flue gas is recovered and cooled in advance. The three-stage recovery flue gas inlet 11103 of the second air heat exchanger 111 is connected to the outlet of the quench chamber 10, and the three-stage recovery flue gas outlet 11104 of the second air heat exchanger 111 is connected to the bag filter, and the outlet flue gas of the quench chamber 10 flows into the second air heat exchanger 111. At the same time, the air is pumped into the second air heat exchanger 111 through the three-stage recovery air inlet 11102 of the second air heat exchanger 111 through the third air pump 12 to exchange heat with the flue gas. The high-temperature air after heat exchange flows out from the third-stage recovery air outlet 11101 of the second air heat exchanger 111, which is connected to the combustion air inlet of the rotary kiln. The high-temperature air flowing out of the third-stage recovery air outlet 11101 is passed into the rotary kiln 2 through the corresponding pipeline as the primary combustion air for fuel combustion. The temperature of the high-temperature air at the third-stage recovery air outlet 11101 is about 130-150°C. The second air heat exchanger adopts a finned tube heat exchanger.

[0046] The secondary recovery air outlet 8012 of the secondary waste heat recovery module 8 and the tertiary recovery air outlet 11101 of the tertiary waste heat recovery module 11 are respectively connected to the primary air port and the secondary air port of the burner at the tail of the rotary kiln as high-temperature combustion-supporting air. The combustion-supporting air of the secondary waste heat recovery module 8 is introduced into the rotary kiln burner through the primary air inlet 161 as the primary combustion-supporting air, and the combustion-supporting air of the tertiary waste heat recovery module 11 is introduced into the rotary kiln burner through the secondary air inlet 162 as the secondary combustion-supporting air. The combustion efficiency is improved by introducing high-temperature combustion-supporting air twice, thereby realizing the effect of two-stage combustion-supporting. The higher the combustion-supporting temperature, the more significantly the combustion efficiency is improved. A first valve 5 and a second valve 6 are respectively arranged on the pipeline connecting the secondary recovery air outlet 8012 and the primary air port of the burner, and on the pipeline connecting the tertiary recovery air outlet 11101 and the secondary air port of the burner, for controlling the amount of high-temperature air introduced, so that the utilization rate of the fuel in the rotary kiln is optimized.

[0047] According to the volume of natural gas in the rotary kiln, the amount of primary air outlet and secondary air outlet is adjusted, and the high-temperature air supply of primary air and secondary air can be the same. A valve and a thermostat 9 can also be set at the secondary recovery air outlet 8012 to control the amount of high-temperature air entering the thermostat. The thermostat can fine-tune the temperature of the high-temperature air entering the burner.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0049] Anything not described in the present invention is applicable to the prior art.

Claims

1. A full-process soil thermal desorption waste heat recovery and utilization system, characterized in that: The system comprises: The primary waste heat recovery module is located at the clean soil outlet of the rotary kiln, which recovers the heat of the high-temperature clean soil to dry the contaminated soil; The secondary waste heat recovery module is located at the tail of the secondary combustion chamber, recovering the heat of the high-temperature flue gas at the outlet of the secondary combustion chamber to heat the air as the high-temperature combustion-supporting gas of the rotary kiln; The three-stage waste heat recovery module is located between the quench chamber and the bag filter, which recovers the heat of the relatively high-temperature flue gas at the outlet of the quench chamber to heat the air as the high-temperature combustion-supporting gas of the rotary kiln; The above three levels of waste heat recovery all use air as the working medium.

2. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 1 is characterized in that: The high-temperature air outlet of the secondary waste heat recovery module and the high-temperature air outlet of the tertiary waste heat recovery module are connected to the burner of the rotary kiln through corresponding pipelines for combustion support.

3. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 1 is characterized in that: The primary waste heat recovery module includes a pre-drying module, an induced draft fan, a first air pump and a soil-air heat exchanger. The soil-air heat exchanger, the induced draft fan, the pre-drying module and the air pump are connected in sequence to form a working cycle. The primary soil recovery inlet of the soil-air heat exchanger is connected to the clean soil outlet after thermal desorption treatment of the rotary kiln. The primary recovery gas inlet of the soil-air heat exchanger is connected to the air outlet of the pre-drying module through a pipeline. The first air pump is connected to the road connecting the soil-air heat exchanger and the pre-drying module; the air inlet of the pre-drying module is connected to the primary recovery air outlet of the soil-air heat exchanger through the induced draft fan; The pre-dried contaminated soil outlet of the pre-drying module is connected to the inlet of the rotary kiln, and the contaminated soil enters from the pre-dried contaminated soil inlet of the pre-drying module; the first air pump inlet is connected to the air.

4. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 1 is characterized in that: The secondary waste heat recovery module comprises a first air heat exchanger, the secondary recovery flue gas inlet of the first air heat exchanger is connected to the outlet of the second combustion chamber, and the secondary recovery air inlet of the first air heat exchanger is connected to the second air pump for pumping air to exchange heat with the high-temperature flue gas; The secondary recovery air outlet of the first air heat exchanger is connected to the combustion air inlet of the rotary kiln, the outlet temperature of the high-temperature flue gas at the secondary recovery flue gas outlet of the first air heat exchanger is 850°C or above, and the secondary recovery flue gas outlet is connected to the quenching chamber.

5. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 4 is characterized in that: The three-stage waste heat recovery module includes a second air heat exchanger, the three-stage recovery air inlet of the second air heat exchanger is connected to the third air pump, the three-stage recovery air outlet of the second air heat exchanger is connected to the combustion air inlet of the rotary kiln, the three-stage recovery flue gas inlet of the second air heat exchanger is connected to the outlet of the quenching chamber, and the three-stage recovery flue gas outlet of the second air heat exchanger is connected to the bag dust collector.

6. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 4 is characterized in that: The first air heat exchanger is a plate heat exchanger, and the second air heat exchanger is a fin-tube heat exchanger.

7. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 4 is characterized in that: The secondary recovery air outlet of the secondary waste heat recovery module and the tertiary recovery air outlet of the tertiary waste heat recovery module are respectively connected to the primary air inlet and secondary air inlet of the burner at the tail of the rotary kiln; a first valve and a second valve are respectively arranged on the pipeline connecting the secondary recovery air outlet and the primary air inlet of the burner, and on the pipeline connecting the tertiary recovery air outlet and the secondary air inlet of the burner, for controlling the amount of high-temperature air introduced.

8. The full-process soil thermal desorption waste heat recovery and utilization system according to claim 4 is characterized in that: A valve and a thermostat are also provided at the secondary recovered air outlet.

9. The full-process soil thermal desorption waste heat recovery system according to any one of claims 1 to 8, characterized in that: The equipment used for soil thermal desorption includes a rotary kiln, a cyclone dust collector, a secondary combustion chamber, a quenching chamber, a bag dust collector, a catalytic adsorption tower and a leaching tower which are connected in sequence.

Images