Oxidation furnace

Abstract

An oxidizing furnace belongs to the technical field of titanium dioxide production equipment. According to the invention, the problems of intensified high-temperature corrosion of high-temperature gas to a refractory lining on the inner wall of a heating section due to non-uniform circumferential distribution of oxygen entering the heating section of an existing oxidation furnace and non-uniform circumferential pressure distribution of titanium tetrachloride in a reaction section of the existing oxidation furnace are solved; and the distribution uniformity of the particle size of the titanium dioxide product is influenced by non-uniform mixing with high-temperature oxygen. The sealing head bluff body, the special-shaped bluff body and the fireproof lining form an annular cavity with an opening in one end, a plurality of oxygen inlet pipes are inserted into the shell in the circumferential direction and penetrate through the fireproof lining to be communicated with the annular cavity, and the reaction section comprises a feeding cavity, a titanium tetrachloride inlet pipe, a reaction pipe, an inert gas spraying device and a plurality of rectifying plates. The method is used for preparing the titanium dioxide particles.

Description

Technical Field

[0001] This invention relates to an oxidation furnace, belonging to the technical field of titanium dioxide production equipment. Background Technology

[0002] Titanium dioxide is one of the three major inorganic chemical products, widely used in coatings, plastics, papermaking, chemical fibers, rubber, food, pharmaceuticals, cosmetics, and other fields. Its main component is titanium dioxide, which possesses stable physical and chemical properties. Compared to the traditional sulfuric acid process for titanium dioxide production, the chloride process offers advantages such as a shorter process, higher product quality, continuous production, and less pollution, making it more aligned with the low-carbon, green, and sustainable development direction of modern industry. However, because the chloride process for titanium dioxide production entered China relatively late, there is still a gap between domestic technology and equipment capabilities and those of foreign countries.

[0003] The oxidation process is the core step in the production of titanium dioxide using the chloride process. The oxidation furnace is the most critical piece of equipment in this process, and its design and operation directly affect the pigment properties and additional value of titanium dioxide.

[0004] The main reaction in the oxidation furnace is TiCl4 + O2 → TiO2 + 2Cl2, which is usually completed in a very short time at about 1300℃ and 3.5 bar. In industrial applications, oxygen is heated to 1600~1800℃ and titanium tetrachloride is heated to 350~450℃, after which the two are thoroughly mixed to react and produce titanium dioxide particles.

[0005] The oxidation furnace mainly consists of three parts: a heating section, a reaction section, and a cooling section. The heating section provides a stable and uniform high-temperature oxygen supply for subsequent processes, while protecting the internal refractory lining from high-temperature corrosion. Oxygen preheated to 850-950°C by an oxygen preheater is introduced into the heating section and then directly heated to 1600-1800°C using the heat generated by toluene combustion before entering the reaction section. The reaction section is the critical area of ​​the oxidation furnace. Here, oxygen at 1600-1800°C mixes thoroughly and uniformly with titanium tetrachloride gas at 350-450°C, reacting rapidly at approximately 1300°C within milliseconds to generate titanium dioxide particles. The uniformity of the mixture of titanium tetrachloride and oxygen has a decisive impact on the final quality characteristics of the titanium dioxide particles. The cooling section rapidly cools the high-temperature titanium dioxide particles to prevent them from agglomerating and growing at high temperatures, thus ensuring the quality of the finished product.

[0006] Currently, the existing oxidation furnaces still have the following main problems in actual operation: 1) In the heating section of the oxidizer, the preheated oxygen enters through a single inlet, resulting in uneven circumferential flow field distribution. After heating, the high-temperature oxygen deviates from the axis of the heating section, and at the same time, the high-temperature flue gas generated by the combustion of toluene also deviates. The uneven and axially symmetrical high-temperature gas exacerbates the high-temperature corrosion of the refractory lining at the deviated point, significantly shortening the service life of the equipment. 2) In the oxidation furnace reaction section, the circumferential pressure distribution of titanium tetrachloride in the cavity is uneven, which leads to unstable circumferential injection flow rate, resulting in uneven mixing with high-temperature oxygen, and ultimately affecting the uniformity of the particle size distribution of titanium dioxide products.

[0007] Therefore, there is an urgent need for a new type of oxidation furnace to solve the problems of uneven circumferential distribution of oxygen entering the heating section of existing oxidation furnaces, which leads to increased high-temperature corrosion of the refractory lining on the inner wall of the heating section by high-temperature gas, and uneven circumferential pressure distribution of titanium tetrachloride in the reaction section of existing oxidation furnaces, which leads to uneven mixing with high-temperature oxygen and affects the uniformity of titanium dioxide particle size distribution. Summary of the Invention

[0008] The present invention aims to solve the problems of uneven circumferential distribution of oxygen entering the heating section of existing oxidation furnaces, which leads to aggravated high-temperature corrosion of the refractory lining on the inner wall of the heating section by high-temperature gas, and uneven circumferential pressure distribution of titanium tetrachloride in the reaction section of existing oxidation furnaces, which leads to uneven mixing with high-temperature oxygen and affects the uniformity of titanium dioxide particle size distribution. Therefore, an oxidation furnace is provided.

[0009] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: An oxidation furnace includes a heating section, a reaction section, and a cooling section arranged sequentially along an axial axis. The heating section includes a shell, a refractory lining, a blunt end cap, a shaped blunt body, a toluene lance, and several oxygen inlet pipes. The refractory lining is laid on the inner wall of the shell. One end of the blunt end cap is fixed to the inner wall of the end cap of the refractory lining, and the shaped blunt body is installed at the other end of the blunt end cap. The toluene lance is sequentially and coaxially inserted into the shell, the refractory lining, the blunt end cap, and the shaped blunt body, extending into the combustion zone inside the heating section. The blunt end cap, the shaped blunt body, and the refractory lining form an annular cavity with one open end. Several oxygen inlet pipes are circumferentially inserted into the shell and pass through the refractory lining, communicating with the annular cavity. The reaction section includes a feeding chamber, a titanium tetrachloride inlet pipe, a reaction tube, an inert gas injection device, and several rectifier plates. The feeding chamber is coaxially fitted onto the oxygen outlet section of the heating section. The titanium tetrachloride inlet pipe is connected and installed on the feeding chamber. Several rectifier plates are respectively fixed on the outer wall of the oxygen outlet section and the inner wall of the feeding chamber, and are arranged in a staggered manner along the axial direction. One end of the reaction tube is connected and fixed to the feeding chamber through an annular end plate, and the two are coaxially arranged. A slit-type injection inlet is formed between the annular end plate and the oxygen outlet end of the heating section. The other end of the reaction tube is coaxially connected and fixed to the cooling section. The inert gas injection device is fitted onto the outside of the reaction tube, and nitrogen or chlorine gas is injected into the reaction tube through the inert gas injection device.

[0010] Furthermore, the irregular blunt body has a frustum structure, and its small-diameter end is fixedly inserted into the other end of the head blunt body.

[0011] Furthermore, the angle of inclination of the generatrix of the frustum relative to the central axis is 10°~25°.

[0012] Furthermore, the distance between the large-diameter end of the truncated cone and the inner wall of the refractory lining is 20mm~50mm.

[0013] Furthermore, the oxygen inlet pipe is inserted obliquely into the shell and refractory lining, and the angle between the central axis of the oxygen inlet pipe and the central axis of the shell is 55°~70°.

[0014] Furthermore, there are 3 to 6 oxygen inlet pipes, which are evenly distributed around the periphery of the shell.

[0015] Furthermore, the central axis of the titanium tetrachloride inlet pipe is arranged perpendicular to the central axis of the feeding chamber.

[0016] Furthermore, the inert gas injection device includes an annular cover and an inert gas inlet pipe that is connected and fixed to the annular cover. The interior of the annular cover and the interior of the reaction tube are connected through a plurality of inert gas injection ports opened on the reaction tube.

[0017] Furthermore, the feeding chamber includes a feeding body and an annular baffle. The feeding body has a cylindrical structure, and the annular baffle is fixed at one end of the feeding body and the inner wall of the annular baffle is sealed and fixed to the outer wall of the oxygen outlet section.

[0018] Furthermore, the cooling section includes a cooling pipe, a cooling jacket, a scarified salt inlet pipe, and a spiral baffle plate. The cooling pipe is coaxially and fixedly connected to the reaction pipe. The cooling jacket is fitted outside the cooling pipe. The spiral baffle plate is fixed between the cooling jacket and the cooling pipe. The cooling jacket is provided with a cooling water inlet and a cooling water outlet. The scarified salt inlet pipe passes through the cooling jacket and is connected and fixedly connected to the cooling pipe.

[0019] Compared with the prior art, the present invention has the following advantages: Titanium tetrachloride enters the feeding chamber through the titanium tetrachloride inlet pipe, initially flowing in a ring around the outside of the oxygen inlet section, and then entering the inert gas injection device in a wave-like pattern after passing through several rectifier plates. The rectifier plates improve the uniformity of the circumferential pressure distribution of the titanium tetrachloride gas.

[0020] Titanium tetrachloride gas is uniformly injected into high-temperature oxygen through a slit-type injection inlet formed between the annular end plate and the oxygen outlet of the heating section, promoting mixing and reaction.

[0021] The inert gas injection device is located downstream of the slit-type injection inlet. By injecting nitrogen or chlorine into the reaction tube, a gas curtain is formed on the inner wall of the reaction tube to prevent scaling.

[0022] In the heating section of the oxidation furnace of this invention, oxygen preheated to 850-950°C is injected into the annular cavity through an oxygen inlet pipe. After rectification in the annular cavity, the oxygen flows out uniformly along the laminar flow zone of the entire circumference, forming a stable low-temperature gas film at 850-950°C. This gas film covers the inner wall surface of the heating section, effectively blocking the direct thermal shock of the refractory lining from the 2500-3000°C high-temperature flue gas generated by toluene combustion. Due to the protection of this low-temperature gas film, the actual surface temperature of the refractory lining in the heating section is much lower than its allowable operating temperature (1500-1800°C), thereby significantly reducing the high-temperature corrosion of the refractory lining and extending its service life.

[0023] In the reaction section, titanium tetrachloride gas at 350-450°C enters the feeding chamber through the titanium tetrachloride inlet pipe. After being rectified by the internal rectifier plate, the uniformity of its circumferential pressure distribution is significantly improved. Subsequently, the gas is uniformly injected into the reaction tube through a slit-type injection port, achieving thorough mixing with the high-temperature oxygen injected from the heating section. This improvement effectively enhances the mixing uniformity of titanium tetrachloride and oxygen, thereby significantly improving the uniformity of the final titanium dioxide particle size.

[0024] In the cooling section, cooling water enters the cooling water jacket through the cooling water inlet, and the heat exchange efficiency is enhanced by the guiding effect of the spiral baffles. A precisely designed descaling salt inlet allows for accurate dosing of the descaling salt, effectively preventing scaling inside subsequent pipelines and equipment. Attached Figure Description

[0025] Figure 1 This is a cross-sectional schematic diagram of the oxidation furnace of the present invention; Figure 2 A cross-sectional view of the heating section (and) Figure 1 (The directions shown are different) Figure 3 for Figure 2 Schematic diagram of the AA section; Figure 4 This is a cross-sectional schematic diagram of the reaction section and the cooling section.

[0026] In the picture: 1. Shell; 2. Refractory lining; 3. Blunt head; 4. Irregularly shaped blunt body; 5. Toluene gun; 6. Oxygen inlet pipe; 7. Annular cavity; 8. Feeding cavity; 801. Feeding body; 802. Annular baffle; 9. Titanium tetrachloride inlet pipe; 10. Reaction tube; 11. Inert gas injection device; 111. Annular cover; 112. Inert gas inlet pipe; 12. Rectifier plate; 13. Annular end plate; 14. Inert gas injection inlet; 15. Cooling pipe; 16. Cooling jacket; 17. Scabbed salt inlet pipe; 18. Spiral baffle; 19. Cooling water inlet; 20. Cooling water outlet. Detailed Implementation

[0027] Specific implementation method one: Combining Figures 1-4 This description of embodiments provides a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] An oxidation furnace includes a heating section, a reaction section, and a cooling section arranged sequentially along an axial axis. The heating section includes a shell 1, a refractory lining 2, a blunt end cap 3, a shaped blunt end cap 4, a toluene gun 5, and several oxygen inlet pipes 6. The refractory lining 2 is laid on the inner wall of the shell 1. One end of the blunt end cap 3 is fixed to the inner wall of the end cap of the refractory lining 2. The shaped blunt end cap 4 is installed at the other end of the blunt end cap 3. The toluene gun 5 is sequentially and coaxially inserted into the shell 1, the refractory lining 2, the blunt end cap 3, and the shaped blunt end cap 4, extending into the combustion zone inside the heating section. The blunt end cap 3, the shaped blunt end cap 4, and the refractory lining 2 form an annular cavity 7 with one open end. Several oxygen inlet pipes 6 are inserted circumferentially into the shell 1 and pass through the refractory lining to communicate with the annular cavity 7. The reaction section includes a feeding chamber 8, a titanium tetrachloride inlet pipe 9, a reaction tube 10, an inert gas injection device 11, and several rectifier plates 12. The feeding chamber 8 is coaxially fitted onto the oxygen outlet section of the heating section. The titanium tetrachloride inlet pipe 9 is connected and installed on the feeding chamber 8. Several rectifier plates 12 are respectively fixed on the outer wall of the oxygen outlet section and the inner wall of the feeding chamber 8, and are arranged in a staggered manner along the axial direction. One end of the reaction tube 10 is connected and fixed to the feeding chamber 8 through an annular end plate 13, and the two are arranged coaxially. A slit-type injection inlet is formed between the annular end plate 13 and the oxygen outlet end of the heating section. The other end of the reaction tube 10 is coaxially connected and fixed to the cooling section. The inert gas injection device 11 is fitted onto the outside of the reaction tube 10, and nitrogen or chlorine gas is injected into the reaction tube 10 through the inert gas injection device 11.

[0029] The heating section, reaction section, and cooling section are connected sequentially from left to right via flanges.

[0030] The directions of up, down, left, and right in this invention are based on the directions shown in the figure.

[0031] The shell 1 is existing technology, and its shape and specific material will not be described in detail here.

[0032] One end of the shell 1 is the end cap, and the other end is the high-temperature oxygen outlet.

[0033] The shell 1 is made of steel. The end cap 3 and the irregularly shaped blunt body 4 are both made of refractory material.

[0034] Toluene fuel, oxygen, and nitrogen atomizing medium are injected into the combustion zone of the heating section of the oxidizer through toluene gun 5.

[0035] Titanium tetrachloride enters the feeding chamber 8 through the titanium tetrachloride inlet pipe 9, first flowing in a ring around the outside of the oxygen inlet section, and then entering the inert gas injection device 11 in a wave-like manner after passing through several rectifier plates 12. The rectifier plates 12 improve the uniformity of the circumferential pressure distribution of the titanium tetrachloride gas.

[0036] Titanium tetrachloride gas is uniformly injected into the high-temperature oxygen through a slit-type injection inlet formed between the annular end plate 13 and the oxygen outlet end of the heating section, promoting mixing and reaction.

[0037] The inert gas injection device 11 is located downstream of the slit-type injection inlet. By injecting nitrogen or chlorine into the reaction tube 10, a gas curtain is formed on the inner wall of the reaction tube 10 to prevent scaling on the inner wall of the reaction tube 10.

[0038] Since nitrogen and chlorine do not react with titanium tetrachloride and oxygen, in the oxidation furnace of this invention, nitrogen and chlorine are inert gases relative to titanium tetrachloride and oxygen, and are not chemically inert gases.

[0039] In the heating section of the oxidation furnace of this invention, oxygen preheated to 850-950°C is injected into the annular cavity 7 through the oxygen inlet pipe 6. After rectification in the annular cavity 7, the oxygen flows out uniformly along the laminar flow zone of the entire circumference, forming a stable low-temperature gas film at 850-950°C. This gas film covers the inner wall surface of the heating section and can effectively block the direct thermal shock of the refractory lining 2 from the high-temperature flue gas at 2500-3000°C generated by the combustion of toluene. Due to the protection of this low-temperature gas film, the actual surface temperature of the refractory lining 2 in the heating section is much lower than its allowable operating temperature (1500-1800°C), thereby significantly reducing the high-temperature corrosion of the refractory lining 2 and extending its service life.

[0040] In the reaction section, titanium tetrachloride gas at 350-450°C enters the feeding chamber 8 through the titanium tetrachloride inlet pipe 9. After being rectified by the internal rectifier plate 12, the uniformity of its circumferential pressure distribution is significantly improved. Subsequently, the gas is uniformly injected into the reaction tube 10 through a slit-type injection port, achieving thorough mixing with the high-temperature oxygen injected from the heating section. This improvement effectively enhances the mixing uniformity of titanium tetrachloride and oxygen, thereby significantly improving the uniformity of the final titanium dioxide particle size.

[0041] The shaped blunt body 4 has a frustum structure, and its small-diameter end is fixedly inserted into the other end of the head blunt body 3. This design makes it easier for oxygen to be evenly distributed and flow out along the laminar flow zone of the entire circumference.

[0042] The angle of inclination of the generatrix of the frustum relative to the central axis is 10° to 25°. In this design, the preferred angle of inclination of the generatrix is ​​20°.

[0043] The distance between the large-diameter end of the frustum and the inner wall of the refractory lining 2 is 20mm~50mm. With this design, a distance of 35mm is preferred.

[0044] The oxygen inlet pipe 6 is inserted obliquely into the shell and refractory lining 1, with the angle between the central axis of the oxygen inlet pipe 6 and the central axis of the shell 1 being 55° to 70°. This design allows oxygen to be directly blown into the annular cavity 7 formed by the blunt end cap 3, the shaped blunt body 4, and the refractory lining 2. The angle β between the central axis of the oxygen inlet pipe 6 and the central axis of the shell 1 is preferably 60°.

[0045] The number of oxygen inlet pipes 6 is 3 to 6, and these oxygen inlet pipes 6 are evenly distributed around the perimeter of the shell. This design makes the oxygen distribution more uniform. Considering both the oxygen flow rate and the requirements for flow field uniformity, it is preferable to set 3 oxygen inlet pipes 6.

[0046] The central axis of the titanium tetrachloride inlet pipe 9 is arranged perpendicular to the central axis of the feeding chamber 8.

[0047] The inert gas injection device 11 includes an annular cover 111 and an inert gas inlet pipe 112 that is connected and fixed to the annular cover 111. The interior of the annular cover 111 is connected to the interior of the reaction tube 10 through a plurality of inert gas injection ports 14 formed on the reaction tube 10. With this design, the number of inert gas injection devices 11 can be one, two, or more. When there is more than one, the multiple inert gas injection devices 11 are distributed along the axial direction of the reaction tube 10. The plurality of inert gas injection ports 14 on the reaction tube 10 are preferably evenly distributed along the circumference of the reaction tube 10 to make the gas curtain formed on the inner wall of the reaction tube 10 more uniform.

[0048] The feeding chamber 8 includes a feeding body 801 and an annular baffle 802. The feeding body 801 is a cylindrical structure, and the annular baffle 802 is fixed to one end of the feeding body 801, with its inner wall sealed to the outer wall of the oxygen outlet section. This design, by setting the annular baffle 802, achieves a seal at one end of the internal space of the feeding chamber 8.

[0049] The cooling section includes a cooling pipe 15, a cooling jacket 16, a scar-forming salt inlet pipe 17, and a spiral baffle 18. The cooling pipe 15 is coaxially and fixedly connected to the reaction pipe 10. The cooling jacket 16 is fitted outside the cooling pipe 15. The spiral baffle 18 is fixedly installed between the cooling jacket 16 and the cooling pipe 15. The cooling jacket 16 is provided with a cooling water inlet 19 and a cooling water outlet 20. The scar-forming salt inlet pipe 17 passes through the cooling jacket 16 and is connected and fixedly connected to the cooling pipe 15.

[0050] In this design, the cooling pipe 15 is made of nickel-based alloy. The titanium dioxide particles, chlorine gas, and unreacted working fluid discharged from the reaction pipe 10 are cooled by the cooling pipe 15 before being discharged. The cooling pipe 15 and the reaction pipe 10 are preferably connected via a flange. A spiral baffle 18 is fixed between the cooling jacket 16 and the cooling pipe 15. Cooling water enters the cooling jacket 16 from the cooling water inlet 19, flows spirally along the spiral baffle 18 to the cooling water outlet 20, and is then discharged. By setting the spiral baffle 18, the flow of the cooling medium and the heat exchange effect are enhanced. The cooling water inlet 19 is preferably located at the tail end of the cooling jacket 16, i.e., the end furthest from the reaction pipe 10, and the cooling water outlet 20 is preferably located at the head end of the cooling jacket 16, i.e., the end closest to the reaction pipe 10. A descaling salt inlet pipe 17 is used to spray descaling salt into the cooling pipe 15, effectively preventing scaling inside subsequent pipes and equipment.

[0051] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An oxidation furnace comprising a heating section, a reaction section and a cooling section arranged axially in succession, characterized in that: The heating section comprises a shell (1), a refractory lining (2), a head blunt body (3), a special-shaped blunt body (4), a toluene gun (5) and a plurality of oxygen inlet tubes (6), wherein the refractory lining (2) is laid on the inner wall of the shell (1), one end of the head blunt body (3) is fixedly installed in the inner wall of the head end of the refractory lining (2), the special-shaped blunt body (4) is installed at the other end of the head blunt body (3), the toluene gun (5) is coaxially and sequentially installed in the shell (1), the refractory lining (2), the head blunt body (3) and the special-shaped blunt body (4) and extends to the internal combustion zone of the heating section, the head blunt body (3), the special-shaped blunt body (4) and the refractory lining (2) form an annular cavity (7) with an open end, and the plurality of oxygen inlet tubes (6) are circumferentially inserted into the shell (1) and communicate with the annular cavity (7) through the refractory lining, The reaction section comprises a feeding cavity (8), a titanium tetrachloride inlet tube (9), a reaction tube (10), an inert gas injection device (11) and a plurality of rectifier plates (12), wherein the feeding cavity (8) is coaxially sleeved on the oxygen outlet section of the heating section, the titanium tetrachloride inlet tube (9) is communicatively installed on the feeding cavity (8), the plurality of rectifier plates (12) are respectively fixedly installed on the outer wall of the oxygen outlet section and the inner wall of the feeding cavity (8) and are arranged in an axial staggered manner, one end of the reaction tube (10) is fixedly connected with the feeding cavity (8) through an annular end plate (13) and is coaxially arranged with the feeding cavity (8), a gap type injection inlet is formed between the annular end plate (13) and the oxygen outlet end of the heating section, the other end of the reaction tube (10) is coaxially and fixedly connected with the cooling section, the inert gas injection device (11) is sleeved on the outside of the reaction tube (10), and nitrogen or chlorine is injected into the reaction tube (10) through the inert gas injection device (11).

2. An oxidation furnace according to claim 1, characterized in that: The special-shaped blunt body (4) is a circular truncated cone structure, and the small-diameter end thereof is fixedly inserted into the other end of the head blunt body (3).

3. An oxidation furnace according to claim 2, characterized in that: The inclination angle of the circular truncated cone generatrix relative to the central axis is 10°-25°.

4. An oxidation furnace according to claim 2, characterized in that: The spacing between the large-diameter end of the circular truncated cone and the inner wall of the refractory lining (2) is 20mm-50mm.

5. An oxidation furnace according to claim 1, characterized in that: The oxygen inlet tube (6) is obliquely inserted into the shell and the refractory lining (1), and the included angle between the central axis of the oxygen inlet tube (6) and the central axis of the shell (1) is 55°-70°.

6. An oxidation furnace according to claim 1, characterized in that: The number of the oxygen inlet tubes (6) is 3-6, and the plurality of oxygen inlet tubes (6) are circumferentially distributed on the shell (1).

7. An oxidation furnace according to claim 1, characterized in that: The central axis of the titanium tetrachloride inlet tube (9) is perpendicular to the central axis of the feeding cavity (8).

8. An oxidation furnace according to claim 1, characterized in that: The inert gas injection device (11) comprises an annular cover (111) and an inert gas inlet tube (112) fixedly connected with the annular cover (111), and the inside of the annular cover (111) is in communication with the inside of the reaction tube (10) through a plurality of inert gas injection ports (14) formed on the reaction tube (10).

9. An oxidation furnace according to claim 1, characterized in that: The feeding cavity (8) comprises a feeding body (801) and an annular baffle (802), the feeding body (801) is a cylindrical structure, and the annular baffle (802) is fixedly arranged at one end of the feeding body (801) and is sealingly fixedly connected with the outer wall of the oxygen outlet section.

10. An oxidation furnace according to claim 1, characterized in that: The cooling section comprises a cooling tube (15), a cooling jacket (16), a brine inlet pipe (17) and helical baffles (18), wherein the cooling tube (15) is coaxially fixed with the reaction tube (10), the cooling jacket (16) is sleeved outside the cooling tube (15), the helical baffles (18) are fixed between the cooling jacket (16) and the cooling tube (15), the cooling jacket (16) is provided with a cooling water inlet (19) and a cooling water outlet (20), and the brine inlet pipe (17) penetrates through the cooling jacket (16) and is fixedly connected with the cooling tube (15).

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