Improved wet oxidation reaction device for wastewater treatment and wastewater treatment method

Abstract

The invention discloses an improved wet oxidation reaction device for wastewater treatment and a wastewater treatment method.The improved wet oxidation reaction device comprises a homogenizing tank, a heat exchanger, a gas-liquid mixer, an oxidation tower, a gas-liquid separator, an air compressor, an air preheater and a liquid receiving tank which are sequentially connected, and a gas outlet of the gas-liquid separator and the air compressor are connected with the air preheater; a gas outlet of the air preheater is connected with a gas inlet of the gas-liquid mixer, and the liquid receiving tank is connected with the heat exchanger; wastewater in the homogenizing tank can enter the heat exchanger to be preheated, then is mixed with air in the gas-liquid mixer, then enters the oxidation tower to be subjected to a wet oxidation reaction, can enter the gas-liquid separator to be subjected to gas-liquid separation after the reaction is finished, and separated gas can enter the air preheater to heat the air and then is discharged for treatment. And the separated liquid can flow back into the heat exchanger to exchange heat with the wastewater and finally flows into the liquid receiving tank. The device is low in cost, high in heat efficiency, good in oxidation effect and safe in reaction process.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and specifically relates to an improved wet oxidation reaction device for wastewater treatment and a wastewater treatment method. Background Art

[0002] With the rapid development of the national economy, the rapid development of industries such as petroleum, chemical, pharmaceutical, papermaking, and food has been driven. At the same time, the discharge of high-concentration macromolecular organic matter and ammonia nitrogen compounds that are difficult to biodegrade has doubled at a more rapid rate. This problem has attracted more and more attention from all walks of life and government environmental protection departments. High-concentration organic wastewater has the characteristics of high pollutant content, high toxicity, scattered discharge points, small water volume, complex treatment process, high investment and operation costs, and difficult management. High-concentration industrial organic wastewater is the main pollutant that causes serious water pollution, ecological environment deterioration, and threatens human health. Since conventional physical, chemical, and biochemical treatment methods are difficult or unable to meet the technical and economic requirements for the purification and treatment of such wastewater, the development of efficient treatment technology for high-concentration organic industrial wastewater that is difficult to degrade has become a problem that needs to be solved urgently at home and abroad at this stage.

[0003] At present, the main methods for treating high-concentration organic wastewater are chemical oxidation, H 2 O 2 Oxidation, Fenton reagent oxidation, catalytic oxidation, wet oxidation, activated carbon adsorption, SBR and other methods. Wet oxidation is a kind of advanced oxidation method, that is, using air or oxygen as an oxidant, in a liquid phase system, the macromolecular organic matter in the wastewater is oxidized and decomposed into small molecular organic matter, carbon dioxide, water and other small molecular inorganic matter to achieve the purpose of purification.

[0004] At present, there are still some problems in the practical application of wet oxidation technology:

[0005] 1. Wet oxidation needs to be carried out at a certain temperature and pressure, so it places certain requirements on the material of the equipment. Currently, the commonly used material is titanium, which is relatively expensive and has a high overall manufacturing cost;

[0006] 2. The overall thermal efficiency of the current wet oxidation device is not high, resulting in great energy waste, which also leads to high processing costs of wet oxidation technology;

[0007] 3. The contact efficiency among wastewater, air and catalyst is not high, and the oxidation rate and efficiency of organic matter in wastewater need to be improved;

[0008] 4. The equipment as a whole operates under a high temperature and high pressure state, and the safety and reliability of the equipment need further consideration;

[0009] 5. Since the wet oxidation process involves a long process and many equipments, the overall equipment occupies a large area and the investment is high. Summary of the invention

[0010] Purpose of the invention: In view of the problems existing in the prior art, the present invention provides an improved wet oxidation reaction device for wastewater treatment and a wastewater treatment method, which can achieve lower manufacturing cost of wet oxidation equipment, higher thermal efficiency, better oxidation effect, smaller footprint and safer reaction process.

[0011] Technical solution: To achieve the above purpose, the present invention adopts the following technical solution:

[0012] An improved wet oxidation reaction device for wastewater treatment comprises a homogenizing tank, a heat exchanger, a gas-liquid mixer, an oxidation tower and a gas-liquid separator, as well as an air compressor, an air preheater and a liquid receiving tank connected in sequence, wherein the gas outlet of the gas-liquid separator and the air compressor are respectively connected to the air preheater, the gas outlet of the air preheater is connected to the gas inlet of the gas-liquid mixer, and the liquid receiving tank is connected to the heat exchanger; the wastewater in the homogenizing tank can enter the heat exchanger for preheating, then be mixed with air in the gas-liquid mixer, and then enter the oxidation tower for wet oxidation reaction, after the reaction is completed, it can enter the gas-liquid separator for gas-liquid separation, the separated gas can enter the air preheater to heat the air, and then be discharged for treatment, the separated liquid can flow back to the heat exchanger for heat exchange with the wastewater, and finally flow into the liquid receiving tank.

[0013] As a specific implementation scheme, the homogenizing tank is provided with a stirring device, which can evenly stir the wastewater in the tank to keep the physical and chemical properties of the wastewater uniform, so as to prevent the water quality of the wastewater entering the oxidation tower from fluctuating drastically; temperature, pressure and liquid level detectors are also arranged inside the homogenizing tank, and relevant operations are performed according to the detection results.

[0014] As a specific implementation scheme, several heat exchangers are arranged in series to form a multi-stage heat exchanger with different heat exchange temperature regions to achieve the purpose of step-by-step heat exchange.

[0015] As a specific implementation scheme, the heat exchanger is a horizontal heat exchanger, including a cooling pipe, a heating pipe, a heat-conducting layer, an auxiliary heating layer and a thermal insulation layer. The cooling pipe is arranged in the middle position, and a plurality of heating pipes are arranged around it, which wrap the intermediate cooling pipe in a spiral shape. The heat-conducting layer is filled around the two pipes, and the auxiliary heating layer is arranged on the periphery of the heat-conducting layer, and the thermal insulation layer is arranged on the periphery of the auxiliary heating layer. Preferably, the heat-conducting layer material is thermally conductive silica gel or graphite, etc., and the thermal insulation layer material is polyurethane, aluminum silicate or nano aerogel, etc. The heat exchanger structure can reduce heat loss, improve heat exchange efficiency, heat evenly, and the heat utilization efficiency can reach more than 90%, and reduce the volume of the heat exchange unit. The wastewater to be treated is heated here by heat exchange and temperature rise to form hot wastewater, and the high-temperature liquid after the reaction is cooled by heat exchange here. In the initial stage of the device, a heater is used to heat the wastewater to be treated, and auxiliary heating and temperature rise can also be performed during the operation of the device. The heat exchanger can adopt intelligent temperature control, which can not only intelligently adjust the temperature range of each heat exchanger, but also reasonably control the heat exchange state of the material according to the material conditions, reduce the rapid temperature changes of the material in the heat exchanger, and reduce scaling in the heat exchange tubes.

[0016] As a specific implementation scheme, a water inlet pipeline is arranged at the upper part of the oxidation tower, and the wastewater enters tangentially from the tower body after being fully mixed by the front-end gas-liquid mixer, generating vortex flow, increasing the frequency of gas-liquid collision, and increasing the reaction efficiency; an intermittently operated scraping mechanism is arranged inside the oxidation tower, including a motor, a rotating shaft and a scraping plate, the motor is arranged outside the oxidation tower, one end of the rotating shaft is connected to the motor, and the other end is inserted into the oxidation tower, and a number of scraping plates are arranged on the rotating shaft, and the scraping plates are inclined relative to the inner wall of the oxidation tower and in contact with the inner wall; a slag discharge port is arranged at the bottom of the oxidation tower for regular slag discharge; preferably, the scraping plate is made of heat-resistant silicone material. The intermittent operation of the scraping mechanism can reduce the occurrence of high-salinity wastewater in the inner wall structure of the tower body.

[0017] As a specific implementation plan, according to the wastewater quality, several oxidation towers (usually 2 to 3) are connected in series. This arrangement can reduce the height of a single oxidation tower, and multi-stage series connection can also achieve better oxidation effect; the oxidation tower is made of duplex stainless steel as a whole, and 3 to 8 layers of high-pressure, corrosion-resistant and anti-explosion coating materials are sprayed on the inside; preferably, the coating material is a nano-composite ceramic coating or a nano-composite titanium coating, which makes it have better high-pressure, corrosion-resistant and anti-explosion capabilities than traditional titanium materials, while greatly reducing manufacturing costs.

[0018] As a specific implementation scheme, temperature, pressure and liquid level detectors are arranged inside the liquid receiving tank to dynamically and accurately adjust the heat exchange rate and heat exchange temperature range in real time according to the water output indicators.

[0019] As a specific implementation plan, the device uses temperature joint control, pressure joint control, liquid level joint control, and AI intelligent simulation prediction to monitor the entire device, detect changes in each link in real time, and can be adjusted through a remote system. Once the device detection value exceeds the set allowable range or the simulation has a deviation, the system can be warned and respond according to the preset event level, including adjusting material in and out, adjusting inlet and outlet temperature and pressure, cutting off feed, rapid cooling, emergency pressure relief, etc.

[0020] As a specific implementation scheme, each component in the device is a frame structure, highly modularized and integrated, and can be quickly assembled like building blocks. On-site installation can adopt a multi-layer truss form to optimize the overall layout of the equipment.

[0021] The present invention also provides a method for treating wastewater using the improved wet oxidation device, comprising the following steps:

[0022] Step 1, the wastewater to be treated enters the homogenization tank for pretreatment to keep the water quality in the tank stable;

[0023] Step 2: The wastewater in the homogenization tank enters the heat exchanger, and after being heated, enters the gas-liquid mixer through a pipeline to be fully mixed with the compressed air provided by the air compressor;

[0024] Step 3, the compressed air provided by the air compressor enters the air preheater for heating, and then enters the gas-liquid mixer through the pipeline to be fully mixed with the wastewater;

[0025] Step 4, the fully mixed gas-water mixture enters the oxidation tower from the tangential direction of the tower body, forming eddy disturbance and increasing the collision frequency;

[0026] Step 5, after the gas-water mixture is separated by the gas-liquid separator, the liquid enters the heat exchanger for cooling and is discharged into the liquid receiving tank, and then enters the back-end biochemical system for disposal;

[0027] Step 6: The gas after gas-liquid separation enters the air preheater to heat the compressed air and then is discharged for treatment.

[0028] Beneficial effects: Compared with the prior art, the improved wet oxidation device of the present invention has lower manufacturing cost, higher thermal efficiency, better oxidation effect, smaller footprint, and safer reaction process. Multi-stage heat exchange is adopted, and different heat exchange temperature zones are set to achieve the purpose of step-by-step heat exchange; a heat exchanger with a specific structure is adopted, with less heat loss, high heat exchange efficiency, uniform heating, and heat utilization efficiency of more than 90%, and the volume of the heat exchange unit is reduced; a water inlet pipeline is set on the upper part of the oxidation tower, so that the wastewater enters tangentially from the tower body, generating vortex flow, increasing the frequency of gas-liquid collision, and increasing the reaction efficiency; each component is a frame structure, a modular unit, highly integrated, and can be quickly assembled on site like a building block. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of the improved wet oxidation reaction device of the present invention.

[0030] Figure 2 It is a diagram of the internal structure of the heat exchanger in the improved wet oxidation reaction device of the present invention.

[0031] Figure 3 It is a schematic diagram of the frame structure of the improved wet oxidation reaction device of the present invention (taking the tank body as an example). DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The experimental methods used in the examples are conventional methods unless otherwise specified, and the materials and reagents used are all commercially available unless otherwise specified.

[0033] Example 1

[0034] An improved wet oxidation reaction device for wastewater treatment, such as Figure 1 As shown, it includes a homogenizing tank 1, a heat exchanger 2, a gas-liquid mixer 3, an oxidation tower 4 and a gas-liquid separator 5, as well as an air compressor 6, an air preheater 7 and a liquid receiving tank 8 which are connected in sequence. The gas outlet of the gas-liquid separator 5 and the air compressor 6 are respectively connected to the air preheater 7, the gas outlet of the air preheater 7 is connected to the gas inlet of the gas-liquid mixer 3, and the liquid receiving tank 8 is connected to the heat exchanger 2; the wastewater in the homogenizing tank 1 can enter the heat exchanger 2 for preheating, and then be mixed with the air in the gas-liquid mixer 3, and then enter the oxidation tower 4 for wet oxidation reaction. After the reaction is completed, it can enter the gas-liquid separator 5 for gas-liquid separation, the separated gas can enter the air preheater 7 to heat the air, and then be discharged for treatment, the separated liquid can flow back to the heat exchanger 2 for heat exchange with the wastewater, and finally flow into the liquid receiving tank 8.

[0035] Among them, the homogenizing tank 1 is used to mix and adjust the physical and chemical properties of the wastewater to be treated; the heat exchanger 2 is used to heat the wastewater to be treated and cool the wastewater after the reaction; the liquid receiving tank 8 is used to receive the reacted wastewater after cooling; the gas-liquid mixer 3, the wastewater and compressed air are fully mixed by the gas-liquid mixer and then enter the oxidation tower for oxidation reaction; the oxidation tower 4 is used to mix air and wastewater and carry out wet oxidation reaction; the air compressor 6 is used to compress the air and transport it to the air preheater through a pipeline; the air preheater 7 is used to heat the compressed air and transport it to the oxidation tower for wet oxidation reaction after reaching the set reaction temperature; the gas-liquid separator 5, the gas-water mixture discharged after wet oxidation in the oxidation tower is separated into gas and liquid by the gas-liquid separator, the gas after separation enters the air preheater to use the waste heat to heat the air, and the liquid enters the heat exchanger for heat exchange and cooling.

[0036] The homogenizing tank 1 is provided with a stirring device 11, which can evenly stir the wastewater in the tank to keep the physical and chemical properties of the wastewater uniform and prevent the water quality of the wastewater entering the oxidation tower from fluctuating violently; the homogenizing tank 1 is also provided with temperature, pressure and liquid level detectors to perform relevant operations according to the detection results.

[0037] Three heat exchangers 2 are arranged in series to form a multi-stage heat exchanger with different heat exchange temperature regions to achieve the purpose of step-by-step heat exchange. Figure 2 As shown, the heat exchanger 2 is a horizontal heat exchanger, including a cooling pipe 21, a heating pipe 22, a heat-conducting layer 23, an auxiliary heating layer 24 and a heat-insulating layer 25. The cooling pipe 21 is arranged in the middle position, and a plurality of heating pipes 22 are arranged around it, which wrap the intermediate cooling pipe 21 in a spiral shape. The heat-conducting layer 23 is filled around the two pipes, and the auxiliary heating layer 24 is arranged on the periphery of the heat-conducting layer 23. The heat-insulating layer 25 is arranged on the periphery of the auxiliary heating layer 24. Preferably, the material of the heat-conducting layer 23 is heat-conducting silica gel or graphite, etc., and the material of the heat-insulating layer 25 is polyurethane, aluminum silicate or nano aerogel, etc. The heat exchanger structure can reduce heat loss, improve heat exchange efficiency, heat evenly, and the heat utilization efficiency can reach more than 90%, and reduce the volume of the heat exchange unit. The wastewater to be treated is heated here by heat exchange and temperature rise to form hot wastewater, and the high-temperature liquid after the reaction is cooled by heat exchange here. In the initial stage of the device, a heater is used to heat the wastewater to be treated, and auxiliary heating and temperature rise can also be performed during the operation of the device. The heat exchanger 2 can adopt intelligent temperature control, which can not only intelligently adjust the temperature range of each heat exchanger, but also reasonably control the heat exchange state of the material according to the material conditions, reduce the rapid temperature change of the material in the heat exchanger, and reduce scaling in the heat exchange tubes.

[0038] A water inlet pipeline is arranged on the upper part of the oxidation tower 4. After being fully mixed by the front-end gas-liquid mixer 3, the wastewater enters tangentially from the tower body, generating a vortex flow, increasing the frequency of gas-liquid collision, and increasing the reaction efficiency. The gas-water mixture enters the tower tangentially from the tower body, so that a certain wall-adhering vortex is generated in the tower. On the one hand, the frequency of gas-liquid collision can be increased, and on the other hand, the newly formed salt scale on the inner wall of the tower that is better cleaned can be cleaned, thereby reducing the degree of scaling on the inner wall and increasing the service life. An intermittently operated wall scraping mechanism is arranged inside the oxidation tower 4, including a motor 41, a rotating shaft 42 and a scraping plate 43. The motor 41 is arranged outside the oxidation tower 4, one end of the rotating shaft 42 is connected to the motor 41, and the other end is inserted into the oxidation tower 4. A plurality of scraping plates 43 are arranged on the rotating shaft 42, and the scraping plates 43 are inclined relative to the inner wall of the oxidation tower 4 and in contact with the inner wall. A slag discharge port 44 is arranged at the bottom of the oxidation tower 4 for regular slag discharge. Preferably, the scraping plate 43 is made of heat-resistant silicone material. The scraping mechanism operates intermittently, which can remove salt scale that is difficult to remove by tangential gas-liquid vortex, and can reduce the occurrence of high-salinity wastewater in the inner wall structure of the tower body. Two oxidation towers 4 are arranged in series; the oxidation tower 4 is made of duplex stainless steel as a whole, and 3 to 8 layers of high-pressure, corrosion-resistant and anti-explosion coating materials are sprayed inside; preferably, the coating material is a nano-composite ceramic coating or a nano-composite titanium coating, which makes it have better high-pressure, corrosion-resistant and anti-explosion capabilities than traditional titanium materials, while significantly reducing the manufacturing cost.

[0039] Temperature, pressure and liquid level detectors are arranged inside the liquid receiving tank 8 to dynamically and accurately adjust the heat exchange speed and heat exchange temperature range in real time according to the water output index.

[0040] The device uses temperature joint control, pressure joint control, liquid level joint control, and AI intelligent simulation prediction to monitor the entire device, detect changes in each link in real time, and can be adjusted through the remote system. Once the device detects values ​​that exceed the set allowable range or the simulation has deviations, the system can be warned and respond according to the preset event level, including adjusting material in and out, adjusting inlet and outlet temperature and pressure, cutting off feed, rapid cooling, emergency pressure relief, etc.

[0041] like Figure 3 As shown, all components in the device are frame-type structures, highly modularized and integrated, and can be quickly assembled like building blocks. On-site installation can adopt multi-layer trusses to optimize the overall layout of the equipment.

[0042] The method for treating wastewater using the improved wet oxidation device comprises the following steps:

[0043] Step 1, the wastewater to be treated enters the homogenization tank 1 for pretreatment to keep the water quality in the tank stable;

[0044] Step 2, the wastewater in the homogenizing tank 1 enters the heat exchanger 2, and after being heated, enters the gas-liquid mixer 3 through the pipeline to be fully mixed with the compressed air provided by the air compressor 6;

[0045] Step 3, the compressed air provided by the air compressor 6 enters the air preheater 7 for heating, and then enters the gas-liquid mixer 3 through the pipeline to be fully mixed with the wastewater;

[0046] Step 4, the fully mixed gas-water mixture enters the oxidation tower 4 from the tangential direction of the tower body, forming eddy disturbance and increasing the collision frequency;

[0047] Step 5, after the gas-water mixture is separated by the gas-liquid separator 5, the liquid enters the heat exchanger 2 for cooling and is discharged into the liquid receiving tank 8, and then enters the back-end biochemical system for disposal;

[0048] Step 6, the gas after gas-liquid separation enters the air preheater 7 to heat the compressed air, and then is discharged for treatment.

[0049] Example 2

[0050] The wastewater treatment was carried out using the device and method of Example 1, as follows:

[0051] This embodiment is a 10t / d improved wet oxidation reaction device, which occupies an area of ​​about 50m 2 , 12 meters high, three-layer truss layout, greatly reducing the floor space. The external frame structure is used for layout, which is simple to construct, convenient and quick to assemble, saving labor and time.

[0052] The oxidation tower is made of duplex stainless steel, with 5 layers of nano-ceramic coating sprayed on the inside, and 3 sets of stirring scrapers built in. The scraper is made of heat-resistant silicone material, with a gap of 2 to 5 mm from the inner wall, which can ensure that the inner wall residue is removed without damaging the inner wall coating and keep the internal structure free of compaction and blockage.

[0053] Wastewater from a pharmaceutical factory (COD is 108000mg / L) and compressed air first enter the gas-liquid mixer to be fully mixed, and then enter the oxidation tower in the tangential direction of the tower body to present vortex mixing, which can not only increase the collision frequency, but also make the oxidation reaction more uniform. At the same time, a certain air flow rate can blow some solids sticking to the inner wall to the bottom of the oxidation tower and discharge them through the slag discharge port. The slag discharge port is based on the amount of slag, and the slag is discharged about once every 30 days.

[0054] The heat exchange unit adopts three-stage heat exchange, and the heat exchanger adopts three-stage heat exchange. Different heat exchange temperature areas are set, such as 140-220℃, 80-140℃, and 30-80℃, to control the flow rate of wastewater and achieve the purpose of step-by-step cooling. The heat exchange structure uses a larger pipe diameter in the middle as a cooling pipe, and 5 heating pipes are set around it. The middle cooling pipe is wrapped in a spiral shape. The pipe is filled with heat-conductive silicone and a heater is set. At the same time, the outer layer is wrapped with insulation material nano aerogel to reduce heat loss, improve heat exchange efficiency, and heat evenly. The heat utilization efficiency reaches 90.4%, and the volume of the heat exchange unit is reduced. The wastewater to be treated is heated here to form hot wastewater, and the high-temperature liquid after the reaction is cooled by heat exchange here. In the initial stage of the device, a heater is used to heat the wastewater to be treated, and it can also be auxiliary heated and heated during the operation of the device.

[0055] This device uses temperature joint control, pressure joint control, liquid level joint control, and AI intelligent simulation prediction to monitor the entire device, detect changes in each link in real time, and can be adjusted through the remote system. Once the detection value exceeds the set allowable range or the simulation is biased, the system can be warned and respond according to the preset event level, including adjusting material in and out, adjusting inlet and outlet temperature and pressure, cutting off feed, rapid cooling, emergency pressure relief, etc. The entire device is remotely controlled, which greatly ensures the safety of personnel in emergencies and prevents safety accidents.

[0056] After the wastewater is treated by the above device, the COD concentration is 6500 mg / L, the COD removal rate reaches 94%, and the effluent B / C is 0.39.

[0057] According to the prediction of the on-site implementation process, the effective service life of this equipment is 20 years, and the comprehensive thermal efficiency is 89%. After the initial startup, it can rely on the heat generated by the reaction process to operate, and rarely provides additional heat sources, which greatly reduces energy consumption.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 2 is that this embodiment is an 80t / h improved wet oxidation reaction device, which occupies an area of ​​about 300m 2, a total of four trusses, 16m high. The oxidation tower is made of duplex stainless steel. The inner wall is sprayed with 12 layers of nano-titanium coating according to the inlet water quality of wastewater (the COD of a chemical wastewater is 49000mg / L) to ensure the overall stable operation and corrosion resistance of the device. This oxidation tower is 15 meters high, equipped with 5 sets of stirring scrapers, and the bottom slag outlet is discharged about once every 10 to 15 days. The heat exchange unit adopts three-stage heat exchange. The heat exchange structure uses the cooling pipe with a larger diameter in the middle. 10 heating pipes are set around it, and the intermediate cooling pipe is wrapped in a spiral shape. The pipe is filled with thermal conductive graphite and a heater is set. At the same time, the outer layer is wrapped with thermal insulation material nano aerogel to reduce heat loss, improve heat exchange efficiency, and heat evenly. The heat utilization efficiency reaches 91.3%.

[0060] The rest are the same as those in Example 2.

[0061] After the wastewater is treated by the above device, the COD concentration is 3600 mg / L, the COD removal rate reaches 92.6%, and the effluent B / C is 0.43.

[0062] According to the prediction of the on-site implementation process, the effective service life of this equipment is 17 years, and the comprehensive thermal efficiency is 90.2%. After the initial startup, it can rely on the heat generated by the reaction process to operate, and very little additional heat source is provided, which greatly reduces energy consumption.

[0063] The above embodiments are the best implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An improved wet oxidation reaction device for wastewater treatment, characterized in that: The invention comprises a homogenizing tank (1), a heat exchanger (2), a gas-liquid mixer (3), an oxidation tower (4) and a gas-liquid separator (5), as well as an air compressor (6), an air preheater (7) and a liquid receiving tank (8) which are connected in sequence. The gas outlet of the gas-liquid separator (5) and the air compressor (6) are respectively connected to the air preheater (7), the gas outlet of the air preheater (7) is connected to the gas inlet of the gas-liquid mixer (3), and the liquid receiving tank (8) is connected to the heat exchanger (2). The wastewater in the homogenizing tank (1) can enter the heat exchanger (2) for preheating, then be mixed with air in the gas-liquid mixer (3), and then enter the oxidation tower (4) for wet oxidation reaction. After the reaction is completed, the wastewater can enter the gas-liquid separator (5) for gas-liquid separation. The separated gas can enter the air preheater (7) to heat the air, and then be discharged for treatment. The separated liquid can flow back to the heat exchanger (2) for heat exchange with the wastewater, and finally flow into the liquid receiving tank (8).

2. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: The homogenizing tank (1) is provided with a stirring device (11); temperature, pressure and liquid level detectors are also provided inside the homogenizing tank (1), and relevant operations are performed according to the detection results.

3. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: A plurality of the heat exchangers (2) are arranged in series to form a multi-stage heat exchanger.

4. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: The heat exchanger (2) is a horizontal heat exchanger, comprising a cooling tube (21), a heating tube (22), a heat-conducting layer (23), an auxiliary heating layer (24) and a thermal insulation layer (25); the cooling tube (21) is arranged in the middle position, and a plurality of heating tubes (22) are arranged around the cooling tube (21) to wrap the middle cooling tube (21) in a spiral shape; the heat-conducting layer (23) is filled around the two tubes; the auxiliary heating layer (24) is arranged around the heat-conducting layer (23); and the thermal insulation layer (25) is arranged around the auxiliary heating layer (24).

5. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: A water inlet pipeline is arranged at the upper part of the oxidation tower (4), and wastewater enters tangentially from the tower body after being fully mixed by the front gas-liquid mixer (3), thereby generating vortex flow, increasing the frequency of gas-liquid collision, and increasing the reaction efficiency; an intermittently operated wall scraping mechanism is arranged inside the oxidation tower (4), comprising a motor (41), a rotating shaft (42) and a scraping plate (43); the motor (41) is arranged outside the oxidation tower (4), one end of the rotating shaft (42) is connected to the motor (41), and the other end is inserted into the oxidation tower (4); a plurality of scraping plates (43) are arranged on the rotating shaft (42), and the scraping plates (43) are inclined relative to the inner wall of the oxidation tower (4) and in contact with the inner wall; a slag discharge port (44) is arranged at the bottom of the oxidation tower (4) for regular slag discharge; preferably, the scraping plate (43) is made of heat-resistant silica gel.

6. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: A plurality of oxidation towers (4) are arranged in series; the oxidation tower (4) is made of duplex stainless steel as a whole, and 3 to 8 layers of high-pressure, corrosion-resistant and anti-explosion coating materials are sprayed on the inside; preferably, the coating material is a nano-composite ceramic coating or a nano-composite titanium coating.

7. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: The liquid receiving tank (8) is internally provided with temperature, pressure and liquid level detectors, and the heat exchange speed and heat exchange temperature range are dynamically and accurately adjusted in real time according to the water output index.

8. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: The device uses temperature joint control, pressure joint control, liquid level joint control, and AI intelligent simulation prediction to monitor the entire device, detect changes in each link in real time, and can be adjusted through a remote system.

9. The improved wet oxidation reaction device for wastewater treatment according to claim 1, characterized in that: All components in the device are frame-type structures and can be quickly assembled in a building block-like manner.

10. A method for treating wastewater using the improved wet oxidation reaction device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, the wastewater to be treated enters the homogenization tank (1) for pretreatment to keep the water quality in the tank stable; Step 2, the wastewater in the homogenizing tank (1) enters the heat exchanger (2), and after being heated, enters the gas-liquid mixer (3) through a pipeline to be fully mixed with the compressed air provided by the air compressor (6); Step 3, the compressed air provided by the air compressor (6) enters the air preheater (7) for heating, and then enters the gas-liquid mixer (3) through a pipeline to be fully mixed with the wastewater; Step 4, the fully mixed gas-water mixture enters the oxidation tower (4) from the tangential direction of the tower body, forming eddy disturbance and increasing the collision frequency; Step 5, after the reaction, the gas-water mixture is separated by the gas-liquid separator (5), and the liquid enters the heat exchanger (2) for cooling and is then discharged into the liquid receiving tank (8), and then enters the back-end biochemical system for disposal; Step 6, the gas after gas-liquid separation enters the air preheater (7) to heat the compressed air, and then is discharged for treatment.

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