A multi-stage vertical oxidation reactor

Abstract

The utility model provides a kind of multilayer vertical oxidation reactor, including main reactor and respectively with main reactor connection oxidant tank, catalyst tank, raw material tank and gas source, the main reactor includes coaxial sleeve and is equipped with multilayer sleeve, there is interval between adjacent two sleeves, the interval between sleeve and the space in the sleeve cylinder located in center are annular flow channel, adjacent two annular flow channel upper end or lower end are connected, and the upper and lower staggered distribution of multiple annular flow channel communication end, the height position of annular flow channel communication port located in upper end is gradually reduced from main reactor interior to outside, the main reactor top is equipped with with the reaction liquid outlet of outermost annular flow channel intercommunication, and each annular flow channel is fixed with helical flow guide vane, and the helical flow guide vane diameter is from small to big along material flow direction. The utility model can effectively reduce material backmixing in oxidation reaction process, ensure reaction efficiency, while equipment volume is small, save cost.

Description

Technical Field

[0001] This utility model relates to the field of oxidation reactor technology, specifically to a multi-layer vertical oxidation reactor. Background Technology

[0002] In the chemical industry, many compounds need to be prepared through oxidation reactions, such as PXA (1,1'-dicyclohexylamine peroxide), cyclohexanol, and cyclohexanone. Oxidation reactions typically need to be carried out in an oxidation reactor. Currently, to improve preparation efficiency, multi-layer oxidation reactors and multiple reactors connected in series are used for oxidation reactions, but many shortcomings still exist. GB1284181A initially prepared PXA through the oxidation reaction of cyclohexanone and H2O2, using single-reactor and double-reactor series reactors respectively. Although the residence time of the double-reactor reactor was increased compared to the single-reactor reactor, the overall impurities were more numerous due to severe backmixing during the reaction, resulting in a less than ideal PXA yield of only about 89%, and thus low production efficiency. CN107497374B designs a novel cyclohexane oxidation reactor, which adopts a multi-layered guide tube structure to divide the reactor shell into multi-level annular regions. Through the design of the central guide tube and annular regions, the liquid phase cyclohexane is flowed stepwise and the gas is introduced in stages, simulating multiple fully mixed reactors in series, which improves the flow mode and increases the selectivity of oxidation intermediates to a certain extent. However, due to the water gap between the bottom of the guide tube and the reactor shell, half of the material enters the next set of tubes from the bottom, and there is still some back-mixing phenomenon. CN106552577B discloses a multi-layer flow guide tube bubbling reactor and its usage method. The reactor shell is fitted with multiple layers of flow guide tubes. By improving the flow conditions in the reactor, the selectivity of cyclohexane oxidation is improved in a manner similar to plug flow. However, the overflow between the flow guide tubes will cause a certain flow dead zone at the bottom of each flow guide tube after the second flow guide tube, which will affect the reaction efficiency. CN116637583A discloses a flow guide tube bubbling reactor, which increases the gas-liquid contact surface, enhances gas-liquid phase mass transfer, and improves the gas-liquid separation effect of the reactor. However, the single-layer reactor structure results in a short overall residence time and low single-pass conversion rate, which affects the reaction efficiency. Existing oxidation reactors suffer from problems such as large number of devices, high initial investment, and deterioration of the flow state of reactants, resulting in low selectivity of target products. Therefore, it is necessary to develop a high-efficiency reactor that can effectively reduce material backmixing during the oxidation reaction, ensure reaction efficiency, and at the same time reduce the size of the equipment and the investment. Utility Model Content

[0003] To address the problems in the background technology, this utility model proposes a multi-layer vertical oxidation reactor, including a main reactor and an oxidant tank, a catalyst tank, a raw material tank, and a gas source, all connected to the main reactor. The main reactor includes multiple coaxially sleeved layers with gaps between adjacent sleeves. The gaps between the sleeves and the space inside the central sleeve form a circulation channel. The upper or lower ends of adjacent circulation channels are connected, and the connecting ends of multiple circulation channels are staggered vertically. The height of the upper circulation channel connection port gradually decreases from the inside of the main reactor to the outside. The top of the main reactor is provided with a reaction liquid outlet connected to the outermost circulation channel. Each circulation channel has a fixed spiral guide vane, and the diameter of the spiral guide vane increases from small to large along the material flow direction. Preferably, the number of sleeves is n, where n > 2 and n is an odd number. The bottom ends of the odd-numbered sleeves are located on the same horizontal plane. The height of the top ends of the odd-numbered sleeves decreases gradually from the inside of the main reactor to the outside. The top ends of the odd-numbered sleeves are open and located below the top ends of their adjacent even-numbered sleeves. There is a gap between the top ends of the odd-numbered sleeves and the inner walls of the top ends of their adjacent even-numbered sleeves. The bottom ends of the even-numbered sleeves are open and located above the bottom ends of the odd-numbered sleeves. There is a gap between the planes where the bottom ends of the even-numbered sleeves and the bottom ends of the odd-numbered sleeves are located.

[0004] Preferably, a one-way valve is provided at the end opening of the sleeve, and the opening pressure of the one-way valve is 0.05 MPa.

[0005] Preferably, the one-way valve plate has multiple grooves on the side near the material flow direction, the grooves having a diameter of 30μm and a depth of 10μm.

[0006] Preferably, the inner diameter of the central sleeve is not less than 50 mm, the distance between two adjacent sleeves is not less than 50 mm, the height difference between the tops of two adjacent odd-numbered sleeves is 30-500 mm, the outer diameter of the main reactor is 800-5000 mm, the ratio of the height to the outer diameter of the main reactor is 1-30, the pitch of the spiral guide vanes is 30-150 mm, and the angle α between the line connecting the outermost point of the smallest diameter blade and the largest diameter blade of the spiral guide vanes and the axis of the spiral guide vanes is 30°-60°.

[0007] Preferably, the inner or outer wall of the even-numbered sleeve is provided with a heat exchange coil, and the heat exchange coil is respectively connected to a circulating cooling water outlet pipe and a circulating cooling water inlet pipe.

[0008] Preferably, the main reactor has a feed inlet at the bottom, which is located inside the central sleeve. The feed inlet is connected to the catalyst tank via a first feed pump and to the raw material tank via a second feed pump. The oxidant tank is connected to multiple delivery pipes via a third feed pump. The end of each delivery pipe away from the third feed pump is connected to a corresponding circulation channel. Each circulation channel has a gas inlet at the bottom of the main reactor. The gas source is connected to multiple gas inlets via gas delivery pipes.

[0009] Preferably, the system also includes a dissolved oxygen probe and a controller. Each circulation channel is equipped with a dissolved oxygen probe, each gas delivery pipe is equipped with an airflow regulating valve, and the circulating cooling water outlet pipe and the circulating cooling water inlet pipe are equipped with water flow regulating valves. The controller is electrically connected to the dissolved oxygen probe, the airflow regulating valve, the water flow regulating valve, the first feed pump, the second feed pump, and the third feed pump.

[0010] Preferably, each gas inlet is bolted to a gas distributor, which has multiple air holes evenly distributed at the bottom of the circulation channel. The pore diameter is 0.1-10 mm, and the opening ratio of each gas distributor is 5-30%.

[0011] Preferably, each of the circulation channels is connected to a non-condensable gas discharge port at the top.

[0012] The beneficial effects of this utility model are as follows: 1. This application employs a multi-layered sleeve design to form the main reactor. A circulation channel is formed between the multiple sleeves, with the upper or lower ends of adjacent circulation channels connected. The connecting ends of multiple circulation channels are staggered vertically, forming a three-dimensional baffled flow channel. The sleeve walls act as baffles between the circulation channels, forcing the material to flow along a specific path (changing the material flow direction upwards along the main reaction axis). Simultaneously, 30-60° asymmetric three-dimensional twisted spiral guide vanes are installed within the circulation channels. The diameter of the spiral guide vanes increases from small to large along the material flow direction, forcing the gas-liquid two-phase flow to generate a spiral acceleration flow field within the channel. This design uses centrifugal force to cause the liquid phase containing bubbles to diffuse and collide towards the wall surface, enhancing gas-liquid mass transfer and increasing the gas holdup in the liquid phase. The swirling flow field increases the gas holdup to over 25% (compared to approximately 15% in traditional structures). Through the combined action of baffles and swirling flow, a spiral upward composite flow path is formed within the reactor. Compared to the two-dimensional planar flow of traditional baffles, this design effectively solves the backmixing problem of traditional reactors while ensuring gas-liquid mixing and maintaining reaction efficiency.

[0013] 2. The sleeve of this application is equipped with a one-way valve plate made of Hastelloy C276, with an opening pressure of 0.05MPa. It allows forward flow while completely blocking reverse flow, reducing material back mixing. The surface of the valve plate is treated with laser micro-texturing (dimples with a diameter of 30μm and a depth of 10μm), which can further reduce flow resistance.

[0014] 3. This application is equipped with a dissolved oxygen probe, an airflow regulating valve, and a circulating water flow regulating valve, which can more accurately control the progress of the oxidation reaction and improve the reaction yield.

[0015] This application employs a unique sleeve-type structure, a three-dimensional twisted spiral guide vane, and a synergistic effect of one-way valve plates, resulting in an oxidation efficiency improvement (6-8%) that far exceeds the simple summation of the effects of various technical features. At the same time, this application features a compact vertical layout, which can reduce the floor space by 40-60% and the amount of steel structure used by 35% compared to traditional multi-reactor series systems under the same reaction requirements. The equipment is small in size and the investment is relatively reduced, solving the problem of "scale-up effect" in industrial scale-up. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the structure of the main reactor with a three-layer sleeve according to this utility model; Figure 3 This is a schematic diagram of the structure of the main reactor with a five-layer sleeve according to this utility model; Figure 4 This is a three-dimensional schematic diagram showing the relationship between the main reactor and the spiral guide vanes of this utility model; Figure 5 This is a schematic diagram showing the relationship between the sleeve and the spiral guide vane of this utility model.

[0017] Labels in the diagram: 1. Oxidant tank; 2. Catalyst tank; 3. Raw material tank; 4. Main reactor; 5. Delivery pipe; 6. First feed pump; 7. Second feed pump; 8. Circulating cooling water inlet pipe; 9. Circulating cooling water outlet pipe; 10. Reaction liquid outlet; 11. Sleeve; 12. Feed inlet; 13. One-way valve; 14. Circulation channel; 15. Vent; 16. Third feed pump; 17. Spiral guide vane. Detailed Implementation

[0018] To make this utility model clearer and more understandable, the technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are only one of the implementation methods and do not represent all embodiments.

[0019] In this article, terms such as "inner," "outer," "upper," and "lower" are established based on the positional relationships shown in the attached drawings. Depending on the attached drawings, the corresponding positional relationships may also change. Therefore, they should not be interpreted as an absolute limitation on the scope of protection.

[0020] Combined with appendix Figure 1 -Appendix Figure 5 A multi-layer vertical oxidation reactor includes a main reactor 4 and an oxidant tank 1, a catalyst tank 2, a raw material tank 3, and a gas source, all connected to the main reactor 4. The gas source is used to supply gas into the main reactor 4. The main reactor 4 includes multiple coaxially sleeved sleeves 11 with a gap between adjacent sleeves 11. The gap between the sleeves 11 and the space inside the central sleeve 11 form a circulation channel 14. The upper or lower ends of adjacent circulation channels 14 are connected. The connecting ends of multiple circulation channels 14 are staggered, forming a baffle flow channel. The height of the connecting port of the upper circulation channel 14 decreases gradually from the inside to the outside of the main reactor 4, so that when the material flows from the top connecting port of the circulation channel 14 to the next circulation channel 14, it cannot flow back from the connecting port of the circulation channel 14 at a higher height, thus avoiding back mixing between layers. The main reactor 4 is provided with a reaction liquid outlet 10 at the top, which is connected to the outermost circulation channel 14. The reaction liquid outlet 10 is located at the top to facilitate the discharge of gas from the gas-liquid reaction. Each circulation channel 14 is fixed with a spiral guide vane 17, and the diameter of the spiral guide vane 17 increases from small to large along the material flow direction. Specifically, the number of sleeves 11 is n, where n > 2 and n is an odd number. The bottom ends of the odd-numbered layers of sleeves 11 are located on the same horizontal plane. The height of the top ends of the odd-numbered layers of sleeves 11 decreases gradually from the inside of the main reactor 4 to the outside. The top ends of the odd-numbered layers of sleeves 11 are open and located below the top ends of their adjacent even-numbered layers of sleeves 11. There is a gap between the top ends of the odd-numbered layers of sleeves 11 and the inner walls of the top ends of their adjacent even-numbered layers of sleeves 11. The bottom ends of the even-numbered layers of sleeves 11 are open and located above the bottom ends of the odd-numbered layers of sleeves 11. There is a gap between the planes where the bottom ends of the even-numbered layers of sleeves 11 and the bottom ends of the odd-numbered layers of sleeves 11 are located.

[0021] The sleeve 11 located at the center of the main reactor 4 is the central cylinder, and the outermost sleeve 11 is the outer wall of the main reactor 4. The raw material tank 3 and the catalyst tank 2 are connected to the bottom of the central cylinder. During the reaction, the raw material enters the central cylinder from the bottom of the main reactor 4. The material flows from the top of the innermost sleeve 11 into the next sleeve 11, that is, into the next circulating channel 14, and then from the bottom of the next sleeve 11 into the third sleeve 11. This flow continues until it enters the outermost sleeve 11. The circulating channel 14 in the outermost sleeve 11 is connected to the reaction liquid outlet 10. The material that has completed the reaction is the reaction liquid, which is discharged from the reaction liquid outlet 10 and sent to the separation process.

[0022] More specifically, the inner diameter of the central sleeve 11 is not less than 50 mm, the distance between two adjacent sleeves 11 is not less than 50 mm, the height difference between the tops of two adjacent odd-numbered sleeves 11 is 30-500 mm, the outer diameter of the main reactor 4 is 800-5000 mm, the height-to-outer-diameter ratio of the main reactor 4 is 1-30, the pitch of the spiral guide vane 17 is 30-150 mm, and the angle α between the line connecting the outermost point of the smallest and largest diameter blades of the spiral guide vane 17 and the axis of the spiral guide vane 17 is 30°-60°. More specifically, the minimum diameter of the spiral guide vane 17 is not less than the inner diameter of the circulation channel 14 in which it is located, and the maximum diameter of the spiral guide vane 17 is not greater than the outer diameter of the circulation channel 14 in which it is located.

[0023] Specifically, a one-way valve plate 13 is provided at the end opening of the sleeve 11, and the opening pressure of the one-way valve plate 13 is 0.05 MPa. The one-way valve plate 13 restricts the material flow direction, further preventing material backflow and reducing material mixing.

[0024] More specifically, the one-way valve plate 13 has multiple grooves on the side near the material flow direction, each groove having a diameter of 30 μm and a depth of 10 μm. These grooves are formed by laser surface treatment of the one-way valve plate 13, reducing frictional resistance and pressure drop during material flow.

[0025] More specifically, the one-way valve plate 13 is made of Hastelloy C276 and has a thickness of 0.5 mm. The one-way flow control of the one-way valve plate 13 is achieved as follows: the one-way valve plate 13 is connected to its adjacent sleeve 11 via a spring, and the spring's extension / retraction direction is consistent with the axial direction of the sleeve 11. When the spring is in its natural state, the one-way valve plate 13 covers the opening of the circulation channel 14, and the one-way valve plate 13 is in contact with the end of its adjacent sleeve 11. When material passes through, the material pushes the one-way valve plate 13, opening the opening of the circulation channel 14. At this time, the spring is in a stretched state. When the material flows into the next circulation channel 14, the one-way valve plate 13 loses its pushing effect and returns to its original position under the action of the spring force, re-covering the circulation channel 14 to prevent material backflow. Furthermore, the end of the sleeve 11 in contact with the one-way valve plate 13 limits the movement of the one-way valve plate 13, preventing it from moving in the direction of spring contraction. In other words, the spring can only be stretched from its natural state, and cannot contract from its natural state. The opening pressure of the one-way valve plate 13 can be determined by the spring's elastic coefficient. The one-way flow control method of the one-way valve plate 13 is not limited to the above.

[0026] Specifically, the even-numbered sleeves 11 are provided with heat exchange coils on their inner or outer walls, and the heat exchange coils are respectively connected to the circulating cooling water outlet pipe 9 and the circulating cooling water inlet pipe 8. The heat exchange coils can avoid the problem of excessive temperature difference caused by the exothermic reaction of the reactor, ensure that the reaction temperature is controllable, and effectively prevent the reaction from getting out of control.

[0027] Specifically, the main reactor 4 has a feed inlet 12 at its bottom, located inside the central sleeve 11. The feed inlet 12 is connected to the catalyst tank 2 via a first feed pump 6 and to the raw material tank 3 via a second feed pump 7. The oxidant tank 1 is connected to multiple delivery pipes 5 via a third feed pump 16. Each delivery pipe 5, at its end furthest from the third feed pump 16, is connected to a corresponding circulation channel 14. Each circulation channel 14 has a gas inlet at its bottom corresponding to the main reactor 4. The gas source is connected to the multiple gas inlets via gas delivery pipes. During the reaction, the reactants and catalyst are fed from the bottom of the main reactor 4, gas is added via bottom bubbling, and the oxidant is continuously introduced.

[0028] Specifically, it also includes dissolved oxygen probes and controllers. Each circulation channel 14 is equipped with a dissolved oxygen probe, each gas delivery pipe is equipped with an airflow regulating valve, and the circulating cooling water outlet pipe 9 and circulating cooling water inlet pipe 8 are equipped with water flow regulating valves. The controller is electrically connected to the dissolved oxygen probes, airflow regulating valves, water flow regulating valves, the first feed pump 6, the second feed pump 7, and the third feed pump 16. After each layer of dissolved oxygen probes detects the oxygen content signal in the liquid phase of the reaction liquid, it feeds the liquid phase oxygen content signal back to the controller. The controller judges the oxidation reaction status of each layer based on the liquid phase oxygen content and controls the gas flow regulating valves and flow regulating valves of each layer, thereby controlling the gas inflow and circulating water outflow of each layer, matching the oxygen content and reaction temperature required for each stage of the reaction, and thus achieving the purpose of improving the reaction yield.

[0029] Meanwhile, each delivery pipe 5 can be equipped with a solenoid valve, which is connected to a controller. According to the different stages of the reaction process, the oxidant is introduced in stages by controlling the start and stop of the third feed pump 16 and the opening and closing of the solenoid valves on different delivery pipes 5. This avoids side reactions caused by excessive oxidant, reduces the self-decomposition of the oxidant itself and the loss of organic materials through gas phase venting, effectively solving the problem of excessive oxidant. Furthermore, the three-dimensional baffled flow channel design effectively solves the problem of material backmixing during the reaction process, improving reaction efficiency. This not only improves atom utilization but also solves the environmental problem of excessive organic gas content in the exhaust gas.

[0030] More specifically, each of the circulating channels may be equipped with a temperature sensor electrically connected to the controller, which monitors the temperature to ensure that the heat exchange coil can be adjusted to a suitable temperature.

[0031] Specifically, each gas inlet is bolted to a gas distributor, allowing for disassembly. After long-term operation, the vents 15 may become clogged with catalyst particles; this disassembly facilitates cleaning or replacement. The gas distributor has multiple vents 15 evenly distributed at the bottom of its corresponding circulation channel 14. This gas distributor is more conducive to the stepwise addition of gas during the reaction process, providing greater stability compared to multi-reactor series control. Gas enters the gas distributor through the gas inlet and then enters the circulation channel 14 through the vents 15, achieving bubbling gas addition from the bottom of the main reactor 4.

[0032] More specifically, the diameter of the pore 15 is 0.1-10mm, and the opening ratio of each gas distributor is 5-30%, with the specific opening ratio selected according to the pressure difference of each layer of circulation channel 14.

[0033] Specifically, each of the circulating channels 14 is connected to a non-condensable gas exhaust port at its top. For general reactions, the entire reactor is in a gas-liquid two-phase mixed state, and there is no gas-liquid separation phenomenon in the reactor, that is, there is no gas phase space at the top of the reactor. For special reactions in which there is a risk of gas accumulation in the reactor (for example, the reaction produces inert or non-condensable gases), a separate non-condensable gas exhaust port can be added to the top of each layer of circulating channels 14 in the reactor.

[0034] Specifically, a support plate is fixed between two adjacent sleeves 11 to strengthen the structure and ensure its strength. More specifically, the support plate is located within the circulation channel 14, and its two ends are fixedly connected to its two adjacent sleeves 11. There are at least two support plates, which are symmetrically distributed.

[0035] Although embodiments of the present invention have been shown and described, those skilled in the art will be able to make various changes, modifications, substitutions and alterations to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-stage vertical oxidation reactor characterized by: The reactor includes a main reactor (4) and an oxidant tank (1), a catalyst tank (2), a raw material tank (3), and a gas source, which are respectively connected to the main reactor (4). The main reactor (4) includes multiple sleeves (11) coaxially mounted. There is a gap between two adjacent sleeves (11). The gap between the sleeves (11) and the space inside the sleeve (11) located in the center are circulation channels (14). The upper or lower ends of two adjacent circulation channels (14) are connected. The connecting ends of multiple circulation channels (14) are staggered. The height of the connecting port of the circulation channel (14) located at the upper end decreases from the inside of the main reactor (4) to the outside. The top of the main reactor (4) is provided with a reaction liquid outlet (10) connected to the outermost circulation channel (14). Each circulation channel (14) is fixed with a spiral guide vane (17). The diameter of the spiral guide vane (17) increases from small to large along the material flow direction.

2. A multi-stage vertical oxidation reactor according to claim 1, characterized in that: The number of sleeves (11) is n, n>2 and n is an odd number. The bottom ends of the odd-numbered sleeves (11) are located on the same horizontal plane. The height of the top end of the odd-numbered sleeves (11) decreases gradually from the inside of the main reactor (4) to the outside. The top end of the odd-numbered sleeves (11) is open and located below the top end of its adjacent even-numbered sleeves (11). There is a gap between the top end of the odd-numbered sleeves (11) and the inner wall of the top end of its adjacent even-numbered sleeves (11). The bottom end of the even-numbered sleeves (11) is open and located above the bottom end of the odd-numbered sleeves (11). There is a gap between the plane where the bottom end of the even-numbered sleeves (11) and the bottom end of the odd-numbered sleeves (11) are located.

3. A multi-layer vertical oxidation reactor according to claim 2, characterized in that: The sleeve (11) is provided with a one-way valve plate (13) at the end opening, and the opening pressure of the one-way valve plate (13) is 0.05MPa.

4. A multi-layer vertical oxidation reactor according to claim 3, characterized in that: The one-way valve plate (13) has multiple grooves on the side near the material flow direction, the grooves having a diameter of 30μm and a depth of 10μm.

5. A multi-layer vertical oxidation reactor according to claim 2, characterized in that: The inner diameter of the sleeve (11) located at the center is not less than 50 mm, the distance between two adjacent sleeves (11) is not less than 50 mm, the height difference between the tops of two adjacent odd-numbered sleeves (11) is 30~500 mm, the outer diameter of the main reactor (4) is 800~5000 mm, the ratio of the height to the outer diameter of the main reactor (4) is 1-30, the pitch of the spiral guide vane (17) is 30-150 mm, and the angle α between the line connecting the outermost point of the smallest diameter blade and the largest diameter blade of the spiral guide vane (17) and the axis of the spiral guide vane (17) is 30°-60°.

6. A multi-layer vertical oxidation reactor according to claim 2, characterized in that: The inner or outer wall of the even-numbered sleeve (11) is provided with heat exchange coils, and the heat exchange coils are respectively connected to the circulating cooling water outlet pipe (9) and the circulating cooling water inlet pipe (8).

7. A multi-layer vertical oxidation reactor according to claim 6, characterized in that: The main reactor (4) is provided with a feed inlet (12) at the bottom. The feed inlet (12) is located inside the central sleeve (11). The feed inlet (12) is connected to the catalyst tank (2) through the first feed pump (6) and to the raw material tank (3) through the second feed pump (7). The oxidant tank (1) is connected to multiple conveying pipes (5) through the third feed pump (16). The end of each conveying pipe (5) away from the third feed pump (16) is connected to a corresponding circulation channel (14). Each circulation channel (14) is provided with a gas inlet at the bottom of the main reactor (4). The gas source is connected to multiple gas inlets through gas pipelines.

8. A multi-layer vertical oxidation reactor according to claim 7, characterized in that: It also includes a dissolved oxygen probe and a controller. Each circulation channel (14) is equipped with the dissolved oxygen probe. Each gas delivery pipe is equipped with an airflow regulating valve. The circulating cooling water outlet pipe (9) and the circulating cooling water inlet pipe (8) are equipped with water flow regulating valves. The controller is electrically connected to the dissolved oxygen probe, the airflow regulating valve, the water flow regulating valve, the first feed pump (6), the second feed pump (7), and the third feed pump (16).

9. A multi-layer vertical oxidation reactor according to claim 7, characterized in that: Each gas inlet is connected to a gas distributor by bolts. The gas distributor has multiple air holes (15) and the multiple air holes (15) are evenly distributed at the bottom of the circulation channel (14) where it is located. The pore diameter of the air hole (15) is 0.1-10 mm, and the opening ratio of each gas distributor is 5-30%.

10. A multi-layer vertical oxidation reactor according to claim 1, characterized in that: Each of the circulation channels (14) is connected at the top to a non-condensable gas discharge port.

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