Micro-evaporation liquid-phase oxidation system and working method

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a micro-evaporation liquid-phase oxidation system which comprises a gas supply module, a wastewater module, a mixed reaction module and a recovery module, the mixed reaction module comprises a mixer and a reactor, the mixer injects micro bubbles into a water body through a micro-nano bubble technology, the dissolved oxygen content of the water body is increased, and the water body is recycled. The reactor provides an environment for stable oxidation reaction of organic wastewater and facilitates collection of evaporated gas and heat generated by oxidation, a protective coating is arranged on the inner wall of the reactor, an electric heating device is arranged on the outer side of the reactor, and a temperature control and pressure regulation assembly is arranged at the top of the reactor. The recovery module comprises a reversing valve, a cooler and a heat exchanger; micro-evaporation liquid phase oxidation is carried out in the reactor, the reaction temperature is 150-170 DEG C, the reaction pressure is 0.55-0.65 MPa, low pressure and safety are achieved, the equipment investment cost is reduced, the reactor can adopt a reaction tank or a reaction tube, selection is diversified, and the adaptability of the system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a micro-evaporation liquid phase oxidation system and a working method. Background Art

[0002] In recent years, with the development of industrialization, the water resources that humans rely on for survival have become increasingly polluted. A major source of water quality deterioration is the discharge of organic wastewater, especially wastewater from the petroleum, pesticide, chemical and other industries. These wastewaters have complex chemical compositions, are difficult to degrade, have high toxicity, and have high COD content, making them difficult to remove.

[0003] At present, biofilm method, aerobic activated sludge method, ozone oxidation technology, etc. are usually used for organic wastewater, among which wet oxidation process (WAO) has developed most rapidly. Wet oxidation process, which can oxidize organic matter in wastewater into small molecular inorganic matter under high temperature and high pressure conditions, has the advantages of wide application range, fast oxidation rate and slight secondary pollution.

[0004] However, there are also some problems in the industrial application of wet oxidation process, mainly the following points: 1. The huge investment capital of wet oxidation equipment is the biggest obstacle to its development, mainly because the wastewater wet oxidation reactor must be resistant to corrosion and pressure; the pressure in the reactor increases and the energy consumption is too high.

[0005] 2. Energy recovery: When the heat of reaction in the wet oxidation process is large, directly cooling the treated gas and liquid phases will consume most of the energy, which does not meet the requirements of energy conservation and environmental protection. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a micro-evaporation liquid phase oxidation system and a working method.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A micro-evaporation liquid phase oxidation system, comprising a gas supply module, a wastewater module, a mixing reaction module and a recovery module, wherein the gas supply module is used to provide an oxidant and deliver the oxidant at a certain pressure, the wastewater module is used to temporarily store organic wastewater and deliver the organic wastewater after pre-treatment, the mixing reaction module is used to increase the gas-liquid mixing rate and ensure stable and reliable oxidation of the wastewater, and the recovery module is used to recover the heat generated during the oxidation process, reduce energy consumption, and improve resource utilization; The mixed reaction module includes a mixer and a reactor. The mixer injects tiny bubbles into the water body through micro-nano bubble technology to increase the dissolved oxygen content of the water body. The reactor provides an environment for stable oxidation reaction of organic wastewater and is convenient for collecting evaporated gas and heat generated by oxidation. The inner wall of the reactor is provided with a protective coating, the outer side of the reactor is provided with an electric heating device, and the top of the reactor is provided with a temperature control and pressure regulating component. The recovery module includes a reversing valve, a cooler and a heat exchanger.

[0008] Preferably, the gas supply module is used to provide pure oxygen, air, oxygen-enriched or ozone, and the gas supply module comprises an air compressor, and the air outlet of the air compressor is connected to the air inlet of the mixer; The wastewater module includes a liquid storage tank, a pressure pump, a filter and a heater. The outlet of the heater is connected to the liquid inlet of the mixer. The mixer adopts a micro-nano bubble generator. The outlet of the mixer is connected to the lower side of the reactor. The upper middle part of the reactor side wall is connected to a discharge pipe.

[0009] Preferably, the discharge pipe is in contact with the heater, the temperature control and pressure regulating assembly includes a temperature sensor and a stop valve, the top of the reactor is connected to a reversing valve through the stop valve, and the reversing valve is connected to a cooler and a heat exchanger; Pure water is introduced into the heat exchanger to recover the heat of the evaporated gas in the reactor. The condensed water formed after the evaporated gas in the reactor is cooled is used for recycling and diluting organic wastewater or flushing pipelines and tanks.

[0010] Preferably, the reactor adopts a reaction tube, the diameter of the reaction tube is less than 150 mm, and there are multiple reaction tubes, which are arranged in parallel.

[0011] Preferably, the micro-evaporation liquid-phase oxidation system is connected in series with at least one secondary system, the structure of the secondary system is the same as that of the micro-evaporation liquid-phase oxidation system, and the discharge pipe of the micro-evaporation liquid-phase oxidation system is connected to the secondary heater of the secondary system.

[0012] Preferably, the working steps include: S1, the organic wastewater in the storage tank, with a COD of 20000-100000 mg / L, is sent out through a pressure pump, the filter filters the impurities in the organic wastewater, and the electric heating device preheats the reactor; S2, organic wastewater flows into the mixer through the heater, and the gas supply module sends the oxidant into the mixer. The gas and liquid are fully mixed in the mixer to form micro-nano bubbles. The mixed liquid enters the reactor for oxidation reaction. The reaction temperature is 150-170°C and the reaction pressure is 0.55-0.65MPa. S3. The organic matter in the wastewater is oxidized and generates heat in the reactor, and the wastewater is in a state of slight evaporation and slight boiling. New wastewater flows into the lower side of the reactor, and the wastewater after the reaction floats up and is discharged through the discharge pipe; The discharge pipe exchanges heat with the heater to preheat the wastewater sent out by the pressure pump, while the steam rises and stays in the cavity above the reactor; S4. If the heat generated is limited and the reaction time is short, the reversing valve will direct the steam into the cooler to reduce the temperature and recover the condensed water; If sewage treatment continues and more heat is generated, the reversing valve switches the pipeline, directing the steam into the heat exchanger, passing pure water, and recovering the heat in the steam; S5. If the primary oxidation cannot completely solve the problem of organic pollutants, then according to the pollutant removal efficiency of the primary system, at least one secondary system is connected in series, and the wastewater discharged from the discharge pipe is sent to the secondary heater of the secondary system, and steps S2 to S4 are repeated.

[0013] Preferably, the heater can be replaced by a mixing valve, and a pressure relief valve is connected in parallel to the mixing valve. The mixing valve mixes a portion of the treated wastewater in the discharge pipe into the untreated wastewater sent out from the storage tank in a certain proportion, dilutes the untreated organic wastewater, and preheats it at the same time.

[0014] Preferably, a COD detector is provided on the discharge pipe or the reactor to detect the COD content of the wastewater after the reaction, which serves as a basis for adjusting data of the mixing valve and the pressure relief valve.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The reactor of the present invention is a micro-evaporation liquid phase oxidation, the reaction temperature is 150-170°C, the reaction pressure is 0.55-0.65MPa, the low pressure is safe, and the equipment investment cost is reduced. The reactor can adopt a reaction tank or a reaction tube, and the selection is diversified to improve the adaptability of the system. The reaction tank can be applied to large-scale organic wastewater treatment, and the reaction tube can be skid-mounted into an integrated device, which is convenient for mobile transportation and improves the convenience of equipment use; 2. The inner wall of the reactor of the present invention adopts PPESK plus ceramic coating to replace titanium, palladium and rhodium, thereby reducing equipment costs. At the same time, a recovery module is provided to recover the heat generated by oxidation in the reactor, thereby reducing production costs and being economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of a first embodiment of a micro-evaporation liquid phase oxidation system proposed by the present invention; Figure 2 This is a structural schematic diagram of a second embodiment of a micro-evaporation liquid phase oxidation system proposed by the present invention; Figure 3This is a schematic structural diagram of a third embodiment of a micro-evaporation liquid phase oxidation system proposed by the present invention; Figure 4 This is a working diagram of the third embodiment of a micro-evaporation liquid phase oxidation system proposed by the present invention; Figure 5 This is a working flow chart of Example 4 of a micro-evaporation liquid phase oxidation system proposed by the present invention; Figure 6 This is a structural schematic diagram of Example 4 of a micro-evaporation liquid-phase oxidation system proposed by the present invention.

[0017] In the figure: 1. air compressor; 2. heater; 20. secondary heater; 3. mixer; 4. reactor; 40. reaction tube; 41. electric heating device; 42. temperature sensor; 43. stop valve; 5. reversing valve; 6. cooler; 7. heat exchanger; 8. pressure relief valve; 9. mixing valve. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0019] Reference Figure 1-6 , a micro-evaporation liquid phase oxidation system and working method, including a gas supply module, a wastewater module, a mixing reaction module and a recovery module; The gas supply module is used to provide an oxidant and deliver the oxidant at a certain pressure. The oxidant provided by the gas supply module includes pure oxygen, air, oxygen-enriched gas or ozone. In order to improve the oxidation effect and reduce the reaction temperature, the oxidant can be ozone plus hydrogen peroxide. The gas supply module includes an air compressor 1. The gas supply module is selected according to the type of oxidant used. If pure oxygen or oxygen-enriched gas is used, a gas cylinder is used. If air is used directly, an air filter is used. If ozone is used, an ozone machine can be used. The air outlet of the air compressor 1 is connected to the air inlet of the mixer 3; The wastewater module is used to temporarily store organic wastewater and send it out after pre-treatment. The micro-evaporation liquid phase oxidation system and method can be used to treat organic wastewater with a COD of 20,000 to 100,000 mg / L. Refractory organic wastewater needs to be treated under a high temperature and high pressure environment. Conventional organic wastewater can adopt a micro-evaporation liquid phase oxidation scheme. The wastewater module includes a liquid storage tank, a pressure pump, a filter and a heater 2; The mixing reaction module is used to improve the gas-liquid mixing rate and ensure stable and reliable oxidation of wastewater. The mixing reaction module includes a mixer 3 and a reactor 4. The outlet of the heater 2 is connected to the liquid inlet of the mixer 3, and the outlet of the mixer 3 is connected to the lower side of the reactor 4. The mixer 3 adopts a micro-nano bubble generator or a venturi ejector. When the venturi ejector is adopted, a micro-nano breathable membrane is added. One side of the membrane is oxygen, air or ozone, and the other side is the material. The gas that passes through the membrane is nanometer-level and directly enters the water. The mixer 3 injects tiny bubbles into the water body through the micro-nano bubble technology to increase the dissolved oxygen content of the water body. The reactor 4 provides an environment for the stable oxidation reaction of organic wastewater, and is convenient for collecting the evaporated gas and the heat generated by oxidation. An inspection port can be provided at the bottom of the reactor 4 for regular inspection of the reactor 4 or cleaning of sediments. A protective coating is provided on the inner wall of the reactor 4. The protective coating adopts a high-temperature resistant anti-corrosion coating. PPESK plus ceramics can be used to replace precious metals such as titanium, palladium, and rhodium to reduce the cost of the reactor 4. An electric heating device 41 is provided on the outside of the reactor 4. When the equipment is started, the reactor 4 is preheated to ensure that the oxidation reaction proceeds stably. A discharge pipe is connected to the upper middle part of the side wall of the reactor 4. The discharge pipe is in contact with the heater 2 for heat transfer. After the reaction proceeds normally, the wastewater in the discharge pipe is used as the heat source of the heater 2 for preheating to reduce the energy consumption of the electric heating device 41. A temperature control and pressure regulating assembly is provided on the top of the reactor 4. The temperature control and pressure regulating assembly includes a temperature sensor 42 and a stop valve 43. The steam discharge of the reactor 4 is regulated according to the temperature of the reactor 4 to ensure that the internal pressure and temperature of the reactor 4 are maintained within a stable range. The recovery module is used to recover the heat generated during the oxidation process, reduce energy consumption, and improve resource utilization. The recovery module includes a reversing valve 5, a cooler 6 and a heat exchanger 7. The top of the reactor 4 is connected to the reversing valve 5 through a stop valve 43, and the reversing valve 5 is connected to the cooler 6 and the heat exchanger 7; pure water is introduced into the heat exchanger 7 to recover the heat of the evaporated gas in the reactor 4. The condensed water formed after the evaporated gas in the reactor 4 is cooled is used for recycling and reuse, diluting organic wastewater or flushing pipelines and tanks, or using the heat of steam to heat the gas of the gas supply module.

[0020] In the first embodiment, the reactor 4 is a reaction tank, and the working steps include: S1, organic wastewater in the storage tank, COD is 20000~100000mg / L, sent out by the pressure pump, the filter filters the debris in the organic wastewater to avoid clogging the pipeline and affecting the operation of the equipment, the organic wastewater passes through the heater 2, when the equipment is just started, there is no discharge, so the heater 2 has no heating effect, and the electric heating device 41 needs to be turned on to preheat the reaction tank; S2, organic wastewater flows into the mixer 3, and the gas supply module sends the oxidant into the mixer 3 at the same time. The gas and liquid are fully mixed in the mixer 3 to form micro-nano bubbles. The mixed liquid enters the reaction tank for oxidation reaction. The reaction temperature is 150-170°C, preferably 159°C, and the reaction pressure is 0.55-0.65MPa, preferably 0.6MPa. Low pressure is safe and there is no need to work in a high temperature and high pressure environment; S3, the organic matter in the wastewater is oxidized and generates heat in the reaction tank, the wastewater is in a state of micro-evaporation and micro-boiling, the material contact is strengthened, most of the organic matter is oxidized into CO2, H2O or small molecular organic matter that is easy to biodegrade, new wastewater flows into the lower side of the reaction tank, the wastewater after the reaction floats up and is discharged through the discharge pipe, the discharge pipe exchanges heat with the heater 2, preheats the wastewater sent out by the pressure pump, reduces the workload of the electric heating device 41, and at the same time, the steam rises and stays in the cavity above the reaction tank; S4. If the generated heat is limited and the reaction time is short, the reversing valve 5 directs the steam into the cooler 6 to cool it down and recover the condensed water; If sewage treatment continues and more heat is generated, the reversing valve 5 switches the pipeline to introduce the steam into the heat exchanger 7, into which pure water is passed to recover the heat in the steam.

[0021] In the second embodiment, the reactor 4 adopts a reaction tube 40, the diameter of which is less than 150 mm, which circumvents the pressure vessel standard, reduces the equipment cost, realizes miniaturization and integration, and is easy to move and transport. There are multiple reaction tubes 40, which are arranged in parallel. Each reaction tube 40 performs oxidation reaction in small batches and separately, ensuring the efficiency and reliability of the oxidation reaction.

[0022] The working steps include: S1, the organic wastewater in the storage tank, COD is 20000~100000mg / L, is sent out by the pressure pump, the filter filters the debris in the organic wastewater to avoid clogging the pipeline and affecting the operation of the equipment, the organic wastewater passes through the heater 2, when the equipment is just started, there is no discharge, so the heater 2 has no heating effect, and the electric heating device 41 needs to be turned on to preheat the reaction tube 40; S2, the organic wastewater flows into the mixer 3, and the gas supply module sends the oxidant into the mixer 3, the gas and the liquid are fully mixed in the mixer 3 to form micro-nano bubbles, the mixed liquid is divided and enters multiple reaction tubes 40, and the oxidation reaction is carried out separately, the reaction temperature is 150-170°C, preferably the reaction temperature is 159°C, the reaction pressure is 0.55-0.65MPa, and the preferred reaction pressure is 0.6MPa; S3, the organic matter in the wastewater is oxidized and generates heat in the reaction tube 40, the wastewater is in a state of micro-evaporation and micro-boiling, the material contact is strengthened, most of the organic matter is oxidized into CO2, H2O or small molecular organic matter that is easy to biodegrade, new wastewater flows into the lower side of the reaction tube 40, the wastewater after the reaction floats up and is discharged through the discharge pipe, the discharge pipe exchanges heat with the heater 2, preheats the wastewater sent out by the pressure pump, reduces the workload of the electric heating device 41, and at the same time, the steam rises and stays in the cavity above the reaction tube 40; S4. If the generated heat is limited and the reaction time is short, the reversing valve 5 directs the steam into the cooler 6 to cool it down and recover the condensed water; If sewage treatment continues and more heat is generated, the reversing valve 5 switches the pipeline to introduce the steam into the heat exchanger 7, into which pure water is passed to recover the heat in the steam.

[0023] Embodiment 3: A micro-evaporation liquid-phase oxidation system is connected in series with at least one secondary system, and the structure of the secondary system is the same as that of the micro-evaporation liquid-phase oxidation system. The discharge pipe of the micro-evaporation liquid-phase oxidation system is connected to the secondary heater 20 of the secondary system. The two or more systems may use different oxidants. The primary system uses ozone or pure oxygen, and the secondary system uses enriched oxygen or air, which reduces costs, avoids material waste, or performs targeted oxidation reactions, thereby improving equipment efficiency and reliability. The working steps include: S1, the organic wastewater in the storage tank is sent out by a pressure pump, and the filter filters the debris in the organic wastewater to avoid clogging the pipeline and affecting the operation of the equipment. The organic wastewater passes through the heater 2. When the equipment is just started, there is no discharge, so the heater 2 has no heating effect, and the electric heating device 41 needs to be turned on to preheat the reactor 4; S2, the organic wastewater flows into the mixer 3, and the gas supply module sends the oxidant into the mixer 3, the gas and the liquid are fully mixed in the mixer 3 to form micro-nano bubbles, and the mixed liquid enters the reactor 4 for oxidation reaction, the reaction temperature is 150-170°C, preferably the reaction temperature is 159°C, the reaction pressure is 0.55-0.65MPa, and the preferred reaction pressure is 0.6MPa; S3, the organic matter in the wastewater is oxidized and generates heat in the reactor 4, the wastewater is in a state of micro-evaporation and micro-boiling, the material contact is strengthened, most of the organic matter is oxidized into CO2, H2O or small molecular organic matter that is easy to biodegrade, new wastewater flows into the lower side of the reactor 4, the wastewater after the reaction floats up and is discharged through the discharge pipe, the discharge pipe exchanges heat with the heater 2, preheats the wastewater sent out by the pressure pump, reduces the workload of the electric heating device 41, and at the same time, the steam rises and stays in the cavity above the reactor 4; S4. If the generated heat is limited and the reaction time is short, the reversing valve 5 directs the steam into the cooler 6 to cool it down and recover the condensed water; If sewage treatment continues and more heat is generated, the reversing valve 5 switches the pipeline to introduce steam into the heat exchanger 7, into which pure water is passed to recover the heat in the steam; S5. If the primary oxidation cannot completely solve the problem of organic pollutants, an estimate is made based on the pollutant removal efficiency of the primary system, and at least one secondary system is connected in series to form a multi-stage oxidation system. The wastewater discharged from the discharge pipe is sent to the secondary heater 20 of the secondary system, and steps S2 to S4 are repeated.

[0024] Embodiment 4: If the primary system cannot treat the wastewater to a qualified discharge standard, a secondary system is used, which wastes resources. The heater 2 can be replaced by a mixing valve 9, and a pressure relief valve 8 is connected in parallel to the mixing valve 9. The mixing valve 9 mixes a portion of the treated wastewater in the discharge pipe into the untreated wastewater sent out of the storage tank in a certain proportion, dilutes the untreated organic wastewater, reduces the COD content of the organic wastewater, and preheats the mixture at the same time. In order to avoid the liquid level in the reactor 4 from rising, the flow rate of the organic wastewater delivered by the pressure pump is slowed down, and the ratio between the treated wastewater and the untreated wastewater is adjusted; After a period of circulation and reflux, the organic wastewater is treated and qualified, and the pressure relief valve 8 discharges the wastewater. A COD detector is set on the discharge pipe or the reactor 4 to detect the COD content of the wastewater after the reaction, which serves as the adjustment data basis for the mixing valve 9 and the pressure relief valve 8; Working steps: a. The organic wastewater in the liquid storage tank is pressurized by a pressure pump and sent out through the water inlet pipe. The electric heating device 41 is turned on to preheat the reactor 4. At this time, the mixing valve 9 does not mix the flow; b. The organic wastewater flows into the mixer 3, and the gas supply module delivers the oxidant into the mixer 3. The gas and liquid are fully mixed in the mixer 3 to form micro-nano bubbles. The mixed liquid enters the reactor 4 for oxidation reaction. The reaction temperature is 150-170° C., preferably 159° C., and the reaction pressure is 0.55-0.65 MPa, preferably 0.6 MPa. c. The organic matter in the wastewater is oxidized and generates heat in the reactor 4. New wastewater flows into the lower side of the reactor 4. The wastewater after the reaction floats up and is discharged through the discharge pipe. The COD content of the wastewater after the reaction is detected by a COD detector, with the wastewater treatment discharge standard as a reference point; If it exceeds the discharge standard, the mixing valve 9 is opened to mix the treated wastewater into the wastewater to be treated in the water inlet pipe. The mixing ratio of the two wastewaters is adjusted according to the COD content of the treated wastewater. The higher the COD content of the treated wastewater in the discharge pipe, the higher the proportion of the treated wastewater in the mixed liquid, and the untreated wastewater in the water inlet pipe is diluted; The treated wastewater is returned, and the flow of untreated wastewater into the reactor 4 can be slowed down, ensuring that there is sufficient time to react the organic pollutants in the wastewater; d. The mixed wastewater is re-oxidized in the reactor 4 and discharged again. The COD detector re-detects the COD content of the wastewater after the reaction. If it does not meet the standard, repeat step c. In this process, the mixing valve 9 is adjusted according to the COD content to gradually reduce the proportion of the treated wastewater reflux. During the cycle, a dynamic balance is achieved until the COD content of the wastewater in the discharge pipe reaches the discharge standard. The pressure relief valve 8 is opened to discharge the treated wastewater for subsequent treatment or reuse. In addition, this scheme is also applicable to the secondary system mentioned in Example 3. If the COD content of the wastewater treated by the secondary system does not meet the standard, the discharged wastewater can be returned and sent to the primary system or the secondary system, or two reactors 4 of different sizes can be configured according to the actual production situation to reduce the equipment investment cost and ensure the reliability of organic wastewater treatment; e. During the reflux cycle reaction, the steam is processed normally. If the heat generated is limited, the reversing valve 5 will guide the steam into the cooler 6 to recover the condensed water. If more heat is generated, the reversing valve 5 will switch the pipeline to guide the steam into the heat exchanger 7, pass pure water, and recover the heat in the steam.

[0025] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

Claims

1. A micro-evaporation liquid phase oxidation system, characterized in that: It includes an air supply module, a wastewater module, a mixing reaction module and a recovery module. The air supply module is used to provide an oxidant and deliver the oxidant at a certain pressure. The wastewater module is used to temporarily store organic wastewater and deliver it after pre-treatment. The mixing reaction module is used to increase the gas-liquid mixing rate and ensure stable and reliable oxidation of the wastewater. The recovery module is used to recover the heat generated during the oxidation process, reduce energy consumption, and improve resource utilization. The mixed reaction module comprises a mixer (3) and a reactor (4); the mixer (3) injects tiny bubbles into a water body through micro-nano bubble technology to increase the dissolved oxygen content of the water body; the reactor (4) provides an environment for a stable oxidation reaction of the organic wastewater and facilitates the collection of evaporated gas and heat generated by oxidation; the inner wall of the reactor (4) is provided with a protective coating; the outer side of the reactor (4) is provided with an electric heating device (41); the top of the reactor (4) is provided with a temperature control and pressure regulating component; and the recovery module comprises a reversing valve (5), a cooler (6) and a heat exchanger (7).

2. A micro-evaporation liquid phase oxidation system according to claim 1, characterized in that: The air supply module is used to provide pure oxygen, air, oxygen-enriched air or ozone, and the air supply module comprises an air compressor (1), wherein an air outlet of the air compressor (1) is connected to an air inlet of a mixer (3); The wastewater module comprises a liquid storage tank, a pressure pump, a filter and a heater (2); the outlet of the heater (2) is connected to the liquid inlet of a mixer (3); the mixer (3) uses a micro-nano bubble generator; the outlet of the mixer (3) is connected to the lower side of a reactor (4); and a discharge pipe is connected to the upper middle portion of the side wall of the reactor (4).

3. A micro-evaporation liquid phase oxidation system according to claim 2, characterized in that: The discharge pipe is in contact with the heater (2); the temperature control and pressure regulating assembly comprises a temperature sensor (42) and a stop valve (43); the top end of the reactor (4) is connected to a reversing valve (5) via the stop valve (43); and the reversing valve (5) is connected to a cooler (6) and a heat exchanger (7); Pure water is introduced into the heat exchanger (7) to recover the heat of the evaporated gas in the reactor (4). Condensed water formed after the evaporated gas in the reactor (4) is cooled is used for recycling and reuse to dilute organic wastewater or flush pipelines and tanks.

4. A micro-evaporation liquid phase oxidation system according to claim 3, characterized in that: The reactor (4) adopts a reaction tube (40), the diameter of the reaction tube (40) is less than 150 mm, and a plurality of the reaction tubes (40) are provided and are arranged in parallel.

5. A micro-evaporation liquid phase oxidation system according to claim 3, characterized in that: The micro-evaporation liquid-phase oxidation system is connected in series with at least one secondary system, the structure of the secondary system is the same as that of the micro-evaporation liquid-phase oxidation system, and the discharge pipe of the micro-evaporation liquid-phase oxidation system is in communication with the secondary heater (20) of the secondary system.

6. A working method of the micro-evaporation liquid phase oxidation system according to any one of claims 1 to 5, characterized in that: The working steps include: S1, organic wastewater in the storage tank, with a COD of 20,000 to 100,000 mg / L, is pumped out through a pressure pump, the filter filters out impurities in the organic wastewater, and the electric heating device (41) preheats the reactor (4); S2, the organic wastewater flows into the mixer (3) through the heater (2), and at the same time, the gas supply module sends the oxidant into the mixer (3), the gas and the liquid are fully mixed in the mixer (3) to form micro-nano bubbles, and the mixed liquid enters the reactor (4) to undergo an oxidation reaction, the reaction temperature is 150 to 170° C., and the reaction pressure is 0.55 to 0.65 MPa; S3, the organic matter in the wastewater is oxidized and generates heat in the reactor (4), and the wastewater is in a state of slight evaporation and slight boiling. New wastewater flows into the lower side of the reactor (4), and the wastewater after the reaction floats up and is discharged through the discharge pipe; The discharge pipe exchanges heat with the heater (2) to preheat the wastewater delivered by the pressure pump, while steam rises and is retained in the cavity above the reactor (4); S4. If the heat generated is limited and the reaction time is short, the reversing valve (5) directs the steam into the cooler (6) to reduce the temperature and recover the condensed water; If sewage treatment continues and more heat is generated, the reversing valve (5) switches the pipeline to direct the steam into the heat exchanger (7), where pure water is passed to recover the heat in the steam; S5. If the primary oxidation cannot completely solve the organic pollutant problem, then at least one secondary system is connected in series according to the pollutant removal efficiency of the primary system, and the wastewater discharged from the discharge pipe is sent to the secondary heater (20) of the secondary system, and steps S2 to S4 are repeated.

7. A micro-evaporation liquid phase oxidation system according to claim 5, characterized in that: The heater (2) can be replaced by a mixing valve (9), and the mixing valve (9) is connected in parallel with a pressure relief valve (8). The mixing valve (9) mixes a portion of the treated wastewater in the discharge pipe into the untreated wastewater sent out from the liquid storage tank in a certain proportion, thereby diluting the untreated organic wastewater and performing preheating at the same time.

8. A micro-evaporation liquid phase oxidation system according to claim 7, characterized in that: The discharge pipe or the reactor (4) is provided with a COD detector for detecting the COD content of the wastewater after the reaction, which serves as a basis for adjusting the mixing valve (9) and the pressure relief valve (8).

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