Igniter and gas-phase white carbon black reaction furnace for gas-phase white carbon black preparation

Abstract

This invention provides an igniter for the preparation of fumed silica, comprising: an igniter body, the igniter body having an air channel, a hydrogen channel, and a reactant gas channel; a detachable end cap assembly on the top of the igniter body, the end cap assembly having at least one ignition gun mounting port, each ignition gun mounting port being fitted with an ignition gun; the reactant gas channel having a closed top and a reactant gas inlet on its side, the outlet of the reactant gas channel being adjacent to a gas distribution structure; this invention also provides a fumed silica reactor, the top of the furnace body having a burner mounting interface for mounting the igniter; this invention transfers the ignition gun from the reactor to the nozzle, by setting a detachable end cap assembly on the top of the igniter and providing an ignition gun mounting port, using the ignition gun for ignition operation, simplifies ignition and maintenance, and does not affect other parts of the burner and reactor.

Description

Technical Field

[0001] This invention relates to the technical field of fumed silica production equipment, specifically to an igniter and a fumed silica reaction furnace for fumed silica preparation. Background Technology

[0002] Fumed silica (fumed silica) is one of the most important nanoscale inorganic raw materials. Due to its extremely small particle size, large specific surface area, strong surface adsorption force, large surface energy, high chemical purity, and good dispersion performance, it has unique properties in terms of thermal resistance and electrical resistance. With its superior stability, reinforcing properties, thickening properties, and thixotropic properties, it plays an irreplaceable role in many disciplines and fields such as rubber, coatings, adhesives, cosmetics, pharmaceuticals, and electronics.

[0003] In existing fumed silica production processes, silicon source materials (such as silicon tetrachloride), hydrogen, and air are introduced into a burner for ignition and combustion, and then injected into a reactor for hydrolysis to produce silica particles. The burner is typically a multi-channel nozzle structure, with gas introduced from the top and ejected from the bottom. Ignition is generally performed on the reactor.

[0004] A fumed silica igniter, also known as a fumed silica burner, is a type of burner that uses a top-inlet design. For example, Chinese patent application CN223191629U discloses a fumed silica burner designed to prevent sticking. This burner features a hydrogen inlet and an air inlet on one side of the burner body, and a reaction gas inlet at the top. The reaction gas enters from the top and exits directly downwards. However, this design lacks a separate ignition gun mounting structure, requiring external equipment for ignition. Furthermore, the opening at the top of the central channel allows the reaction gas to prematurely contact the combustion gas at the upper part of the channel, hindering control over the mixing position and timing. Additionally, the reactor typically has a water-cooled jacket; installing an ignition gun through a hole in the furnace body would disrupt the cooling channels, increasing structural complexity and manufacturing difficulty. Summary of the Invention

[0005] The present invention provides an igniter and a gas phase silica reaction furnace for the preparation of fumed silica, so as to solve the problems of inconvenient ignition of igniters and premature contact between reaction gas and combustion gas in the prior art.

[0006] On one hand, the present invention provides an igniter for the preparation of fumed silica, comprising: an igniter body, the igniter body having an air channel communicating with an air inlet and a hydrogen channel communicating with a hydrogen inlet; a gas distribution structure being provided at the outlet end of the hydrogen channel; a detachable end cap assembly being provided at the top of the igniter body, the end cap assembly having at least one ignition gun mounting port, each ignition gun mounting port being fitted with an ignition gun; a reaction gas channel being provided inside the igniter body, the top of the reaction gas channel being closed and having a reaction gas inlet communicating with it through its wall area, the outlet of the reaction gas channel being adjacent to the gas distribution structure, and the ignition end of the ignition gun passing through the reaction gas channel.

[0007] The igniter for preparing fumed silica provided by this invention features an ignition gun mounted on its top for direct and quick ignition. The gas intake method has been changed from top to side intake, with the top space used for the end cap assembly and ignition gun mounting port, achieving a rational spatial layout for both intake and ignition functions. The side intake uses a three-way structure to guide each gas into its corresponding annular flow channel, resulting in a compact structure that does not affect the original gas distribution function of the flow channel.

[0008] Furthermore, a detachable head assembly is installed on the top of the burner, with an ignition gun mounting port on the assembly, allowing for ignition operation using an ignition gun. The head assembly is bolted and detachable, and the ignition gun is mounted on the head assembly. Maintenance is simple; just unscrew the bolts and remove the head assembly. Maintenance is straightforward and does not affect other parts of the burner or reactor. Further, the igniter body includes a first shell, a second shell, and a third shell arranged coaxially from the outside in. An air passage is formed between the first and second shells, and a hydrogen passage is formed between the second and third shells. This three-layer wall structure separates the air and hydrogen passages into independent annular channels, allowing air and hydrogen to be transported to the combustion zone separately. This prevents premature mixing of the two gases during transport, ensuring that mixing and combustion only occur upon arrival at the combustion zone, thus improving combustion safety and controllability.

[0009] Furthermore, the head assembly is a flange cover, the third housing encloses and forms a reaction gas passage, the flange cover covers the top of the reaction gas passage, and the side of the igniter body has a reaction gas inlet that communicates with the reaction gas passage.

[0010] Furthermore, the end cap assembly is a downward-opening cylindrical shape, located within the cavity enclosed by the third component, with its upper part protruding above the top of the igniter body. A reactive gas inlet is provided on the side wall of the protruding upper portion of the end cap assembly, forming a reactive gas channel within the cylindrical interior of the end cap assembly. The upper part of the cylinder protruding above the top of the igniter body provides ample space for the reactive gas side wall inlet, resulting in minimal structural modifications and low modification costs.

[0011] Furthermore, a hollow guide cone is coaxially arranged at the gas outlet of the igniter body. The hollow channel inside the guide cone allows the ignition gun to pass through. The guide cone is coaxially arranged with the gas outlet and is fixed to the first housing by several connecting rods. The guide cone guides the gas to converge towards the center, improving airflow distribution and reducing eddies and wall adhesion. The hollow design of the guide cone provides space for the ignition gun to pass through, allowing it to pass through the hollow guide cone and extend downward into the furnace body, thus resolving the structural contradiction of the guide cone obstructing the ignition gun from entering the furnace.

[0012] Furthermore, the air inlet and hydrogen inlet are located on the side of the igniter body. Each gas enters its corresponding flow channel from the side, and the top is sealed with a head assembly, thus achieving spatial separation between the gas intake method and the ignition function.

[0013] Furthermore, the first and second housings, as well as the second and third housings, are detachably connected via connecting flanges. The split-type wall structure facilitates cleaning and maintenance of the interior of the annular flow channel.

[0014] Furthermore, the length of the ignition tip of the ignition gun extending into the igniter body is adjustable. By adjusting the insertion depth of the ignition gun, the ignition tip can be positioned at the optimal ignition position to meet the ignition requirements under different operating conditions.

[0015] Furthermore, the width of the bottom outlet of the air channel gradually decreases along the airflow direction. This narrowing of the outlet diameter accelerates the air ejection, further enhancing the encapsulation effect on the internal hydrogen and reactant gases and increasing the gas contact area.

[0016] Furthermore, the end cap assembly is equipped with two ignition gun mounting ports, which are symmetrically arranged relative to the central axis of the igniter body. This dual ignition gun design improves ignition reliability and ensures successful ignition on the first attempt.

[0017] On the other hand, the present invention also provides a fumed silica reactor, including a furnace body, a discharge port at the bottom of the furnace body, and multiple layers of protective gas inlets arranged side by side at the top of the furnace body, each layer of protective gas inlet corresponding to an annular guide plate; the top of the furnace body is provided with an igniter mounting interface for installing the aforementioned igniter provided in this technical solution. Furthermore, the ignition end of the ignition gun extends into the furnace body. Extending the ignition end of the ignition gun into the furnace body brings the ignition position closer to the combustion reaction zone, which is beneficial for the rapid and reliable ignition of the hydrogen-oxygen mixture, shortens the ignition response time, and improves the ignition success rate. At the same time, having the ignition end located inside the furnace avoids the accumulation of incompletely burned mixed gas at the igniter outlet during the initial ignition stage, reducing safety hazards.

[0018] The fumed silica reactor provided by this invention integrates the ignition function into the burner, eliminating the need for drilling holes in the reactor to install an igniter. This avoids damaging the cooling jacket channels of the reactor, maintains the integrity of the reactor structure, and reduces the difficulty and cost of equipment manufacturing. Simultaneously, it avoids additional drilling in the highly corrosive environment of the reactor, reducing corrosion risks and extending the service life of the reactor. Attached Figure Description

[0019] Figure 1 A schematic diagram of the internal structure of the igniter provided by the present invention; Figure 2 This is a schematic diagram of the internal structure of an igniter according to another embodiment of the present invention; Figure 3 This is a top view of the fumed silica reactor provided by the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Igniter body; 11. First housing; 12. Second housing; 13. Third housing; 14. Air inlet; 15. Air passage; 16. Hydrogen inlet; 17. Hydrogen passage; 18. Gas distribution structure; 19. Reaction gas passage; 20. Reaction gas inlet; 2. Head assembly; 21. Igniter gun mounting port; 22. Igniter gun; 23. Guide cone; 24. Connecting rod; 25. Flange; 100. Furnace body; 101. Discharge port; 102. Protective gas interface; 103. Ignition device installation interface. Detailed Implementation

[0021] The following will be combined with the appendix Figures 1-3 The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples and should not be used to limit the scope of protection of this application.

[0022] like Figure 1 As shown, this invention provides an igniter for the preparation of fumed silica, comprising an igniter body 1, an air channel 15 and a hydrogen channel 17, the air channel 15 being connected to an air inlet 14 and the hydrogen channel 17 being connected to a hydrogen inlet 16; a reaction gas channel 19 is provided inside the igniter body 1, the reaction gas channel 19 having a reaction gas inlet 20. A gas distribution structure 18 is provided at the outlet end of the hydrogen channel 17. A detachable end cap assembly 2 is provided at the top of the igniter body 1, the end cap assembly 2 having at least one ignition gun mounting port 21, the ignition end of the ignition gun 22 extending into the igniter body 1 through the ignition gun mounting port 21, and further extending downwards to pass through the outlet of the reaction gas channel 19 or into the interior of the furnace body 100. The outlet of the reaction gas channel 19 is adjacent to the gas distribution structure 18.

[0023] The igniter of this invention has a detachable end cap assembly 2 on its top, and an ignition gun mounting port 21 on the end cap assembly 2, allowing the ignition gun 22 to be directly mounted on the igniter for ignition, making installation, maintenance, and ignition more convenient. When vulnerable parts such as the ignition gun 22 need to be replaced, the end cap assembly 2 can be opened for operation without disassembling the entire igniter, shortening the maintenance cycle and improving production efficiency.

[0024] Specifically, the igniter body 1 includes a first housing 11, a second housing 12, and a third housing 13 arranged sequentially from the outside to the inside; an air passage 15 is formed between the first housing 11 and the second housing 12, and a hydrogen passage 17 is formed between the second housing 12 and the third housing 13. In this embodiment, the first housing 11, the second housing 12, and the third housing 13 are coaxially arranged, so that the air passage 15 and the hydrogen passage 17 are uniformly distributed in an annular shape, ensuring that the gas flows uniformly in the circumferential direction.

[0025] Furthermore, the bottom outlet width of the air channel 15 gradually decreases along the airflow direction, forming a narrowing section. Specifically, the narrowing section is formed by the inward contraction of the bottom of the first housing 11. The cross-section of the narrowing section has a gradually narrowing annular structure, and the inner diameter of the bottom of the first housing 11 gradually decreases along the airflow direction, making the outlet width of the air channel 15 smaller than the channel width above it. The outlet width is reduced to 0.5-0.8 times the original width along the airflow direction. When the air flows through the narrowing section, the flow cross-sectional area gradually decreases, and the flow velocity increases accordingly, forming an accelerating jet. This enhances the radial envelopment effect on the internal hydrogen and reactant gases, while simultaneously increasing the contact area and mixing uniformity between the air and hydrogen.

[0026] A gas distribution structure 18 is located at the outlet end of the hydrogen channel 17. In this embodiment, the gas distribution structure 18 is a gas distribution plate with flow holes. The gas distribution plate 18 is located at the bottom of the hydrogen channel 17 and has multiple evenly distributed flow holes. When hydrogen flows through the gas distribution plate 18, it is evenly dispersed into multiple gas streams through the flow holes, so that the hydrogen is evenly distributed across the combustion cross section.

[0027] The top of the reaction gas channel 19 is closed, and a reaction gas inlet 20 is provided on the side of the channel. The reaction gas (such as silicon tetrachloride vapor) enters the reaction gas channel 19 through the reaction gas inlet 20. Due to the closed top, the reaction gas can only flow downwards within the channel. The outlet of the reaction gas channel 19 extends downwards through a gas distribution plate, allowing the reaction gas to pass through the gas distribution plate before merging with the hydrogen gas dispersed by the distribution plate and external air, mixing in the area below the gas distribution plate.

[0028] As a preferred embodiment, see the attached document. Figure 1As shown, the third housing 13 encloses and forms a reaction gas channel 19. The end cap assembly 2 is a flange cover, which covers the top of the reaction gas channel 19. A reaction gas inlet 20 communicating with the reaction gas channel 19 is provided on the side of the igniter body 1. The flange cover has high connection strength and good sealing performance, and can withstand the high temperature and high pressure conditions inside the igniter, while also being easy to disassemble.

[0029] In another embodiment, as shown in the appendix Figure 2 As shown, the end cap assembly 2 is a cylindrical shape with its opening facing downwards, and is disposed in the cavity formed by the third housing 13. Specifically, the end cap assembly 2 is inserted into the space formed by the third housing 13 of the igniter body 1. The upper part of the end cap assembly 2 protrudes from the top of the igniter body 1, and the protruding part provides space for the setting of the reaction gas inlet 20 and the ignition gun mounting port 21.

[0030] The top of the head assembly 2 has a top wall that isolates its internal space from the outside, forming a closed reaction gas channel 19 inside the head assembly 2. The ignition gun mounting port 21 is located on the top wall of the head assembly 2, and the reaction gas inlet 20 is located on the side wall of the upper protruding part of the head assembly 2. The first housing of the head assembly 2 is provided with a flange 25 (or annular lug), which is detachably connected to the top of the igniter body 1 by bolts.

[0031] The bottom of the end cap assembly 2 is flush with the height of the gas distribution structure 18. Specifically, the gas distribution structure 18 is a gas distribution plate with flow holes, located at the bottom of the hydrogen channel 17, and the bottom end face of the end cap assembly 2 is approximately flush with the upper surface of the gas distribution plate. The reactant gas enters the cylindrical structure from the reactant gas inlet 20 on the side wall of the end cap assembly 2, flows downward along the cylindrical structure, and flows out from the bottom of the end cap assembly 2. There, it mixes with the hydrogen dispersed by the distribution plate and the outer air below the gas distribution plate.

[0032] The ignition gun 22 extends into the cylindrical structure through the ignition gun mounting port 21 on the top wall of the head assembly 2, and further extends downward. The ignition gun mounting port 21 is detachably and sealingly connected to the ignition gun 22 via a mounting flange to prevent the reaction gas from leaking from the gap between the top wall and the ignition gun.

[0033] The head assembly 2 does not require large-scale modification to the existing burner body. It only requires inserting a cylindrical structure into the central channel to add an ignition gun 22 and change the direction of the reactant gas inlet, thus facilitating ignition and preventing the reactant gas from contacting and reacting with the combustion gas in the upper part of the igniter. The head assembly 2 is detachably connected to the igniter body 1 via a flange 25, making installation convenient. When the head assembly 2 needs maintenance or replacement, the cylindrical structure along with the ignition gun can be removed as a whole by loosening the connecting bolts, making operation simple.

[0034] Furthermore, the end cap assembly 2 is provided with two ignition gun mounting ports 21, which are symmetrically arranged with respect to the central axis of the igniter body 1. Each of the two ignition gun mounting ports 21 is detachably and sealingly connected to its corresponding ignition gun 22 via a mounting flange. The ignition end of the ignition gun 22 extends into the igniter body 1 through the ignition gun mounting port 21 and extends further downwards.

[0035] Two symmetrically arranged ignition guns 22 can form symmetrical ignition sources, enabling the hydrogen-oxygen mixture to ignite synchronously in the circumferential direction, which is beneficial for forming a uniform and symmetrical annular flame. If one ignition gun 22 fails, the other ignition gun 22 can still maintain its ignition function, improving the operational reliability of the system.

[0036] In a preferred embodiment, the ignition end of the ignition gun 22 extends into the furnace body 100, bringing the ignition position closer to the combustion reaction zone. This facilitates rapid and reliable ignition of the hydrogen-oxygen mixture and shortens the ignition response time. The length of the ignition end of the ignition gun 22 extending into the igniter body 1 is adjustable, allowing for flexible adjustment of the ignition position according to actual operating conditions. A length adjustment mechanism is provided between the ignition gun 22 and the igniter body 1, allowing for adjustment of the length of the ignition gun 22 extending into the igniter body 1. The length adjustment mechanism can be, for example, a threaded adjustment structure, a set screw fixing structure, a clamping sleeve structure, or a slotted pin positioning structure.

[0037] Air inlet 14 and hydrogen inlet 16 are respectively located on the side of the igniter body 1, facilitating connection with external gas delivery pipelines and avoiding interference with the installation of the top end cap assembly 2 and ignition gun 22. The first housing 11 and the second housing 12, as well as the second housing 12 and the third housing 13, are detachably connected by connecting flanges, facilitating the disassembly, cleaning, and individual replacement of a wall layer of the igniter body.

[0038] Furthermore, a hollow guide cone 23 is coaxially provided at the gas outlet of the igniter body 1. The guide cone 23 adopts a hollow conical shell structure and is integrally formed. The hollow internal channel of the guide cone 23 allows the ignition gun 22 to pass through.

[0039] When the ignition end of the ignition gun 22 needs to extend into the furnace body, the ignition gun 22 passes sequentially through the ignition gun mounting port 21 on the end cap assembly 2, the internal channel of the igniter body 1, and the internal hollow channel of the guide cone 23, finally extending downwards into the furnace body. The hollow guide cone 23 serves both to guide and rectify the combustion gases and to provide space for the ignition gun 22 to pass through; the two structures do not interfere with each other. The hollow guide cone 23 is integrally formed, requiring no additional assembly parts or sealing, and exhibits good structural stability and sealing reliability under the high-temperature conditions of fumed silica preparation.

[0040] like Figure 1 and Figure 3 As shown, this embodiment also provides a fumed silica reactor, including a furnace body 100. The furnace body 100 has a discharge port 101 at its bottom and an igniter mounting interface 103 at its top. The igniter mounting interface 103 is used to mount the igniter as described in the above embodiment. The igniter is mounted on the top of the furnace body 100 via the igniter mounting interface 103. The high-temperature hydrogen-oxygen flame generated by the igniter enters the furnace body 100 downwards, providing a heat source for the hydrolysis reaction of silicon tetrachloride.

[0041] Furthermore, the upper part of the furnace body 100 is provided with a multi-layer protective gas interface 102, and each layer of protective gas interface 102 is provided with a corresponding annular guide plate. Protective gas (such as nitrogen) is introduced into the multi-layer protective gas interface 102 at different heights, and the protective gas is uniformly guided to the circumference of the third shell of the furnace body 100 through the annular guide plate, forming a multi-layer protective gas curtain at the furnace wall, effectively preventing fumed silica particles from adhering to the furnace wall.

[0042] Work process: Before starting the system, confirm that the igniter body 1, furnace body 100, and all pipeline connections are intact. Introduce protective gas into the furnace body 100. The protective gas enters the furnace body 100 through two channels: one channel enters through the multi-layer protective gas inlet 102 at the top of the furnace body 100, and is evenly guided to the circumference of the third shell of the furnace body 100 by the annular guide plates of each layer, forming a multi-layer protective gas curtain at the furnace wall. The multi-layer protective gas curtain, together with the rotating airflow, provides an inert protective environment for the reaction inside the furnace.

[0043] Install the ignition gun 22. The ignition end of the ignition gun 22 extends into the igniter body 1 through the ignition gun mounting port 21 on the end cap assembly 2, and further extends downward through the hollow guide cone 23 (when the guide cone 23 is provided) into the furnace body 100.

[0044] Air and hydrogen are introduced. Air enters the air passage 15 between the first housing 11 and the second housing 12 through the air inlet 14 on the side of the igniter body 1, and hydrogen enters the hydrogen passage 17 between the second housing 12 and the third housing 13 through the hydrogen inlet 16 on the side of the igniter body 1. Air and hydrogen are transported independently in their respective passages and do not mix.

[0045] Hydrogen gas is transported downward through hydrogen channel 17 to the bottom gas distribution plate 18. It is evenly dispersed into multiple gas streams through multiple flow holes on the gas distribution plate 18. The gas streams merge with the air flowing out of the outer air channel 15 at the igniter outlet to form a uniform hydrogen-oxygen mixture.

[0046] After the hydrogen-oxygen mixture stabilizes, a reaction gas is introduced. The reaction gas (such as silicon tetrachloride vapor) enters the reaction gas channel 19 through the reaction gas inlet 20. Since the top of the reaction gas channel 19 is closed, the reaction gas can only flow downwards after being introduced from the side. The reaction gas is conveyed downwards along the reaction gas channel 19, and extends downwards through the gas distribution plate 18 through the outlet of the reaction gas channel 19, mixing with the hydrogen-oxygen mixture in the area below the gas distribution plate 18.

[0047] As the hydrogen-oxygen mixture flows downwards, it is guided and rectified by the hollow guide cone 23, resulting in a smoother and more orderly flow and a more uniform gas distribution. Simultaneously, the rotating airflow formed by the protective gas tangentially introduced through the side wall of the furnace 100 ensures uniform mixing of the reaction products within the furnace, promoting a uniform temperature distribution and facilitating the complete hydrolysis reaction. The ignition gun 22 releases an electric spark within the furnace 100, providing an ignition source for the subsequently introduced hydrogen-oxygen mixture. Upon ignition by the ignition gun 22, in the high-temperature hydrogen-oxygen flame environment, silicon tetrachloride vapor undergoes a hydrolysis reaction, generating fumed silica particles and hydrogen chloride gas.

[0048] The reacted gas mixture continues to flow downwards within the furnace body 100. The generated fumed silica particles move with the airflow. Under the action of multiple protective air curtains, most of the particles remain suspended in the central area of ​​the furnace body 100, reducing adhesion to the furnace wall. Finally, the fumed silica particles are discharged through the discharge port 101 at the bottom of the furnace body 100 and enter the subsequent collection and separation system.

[0049] During shutdown, the supply of reactant gas, hydrogen, and air is sequentially cut off. Once the temperature inside the furnace body 100 decreases, the supply of protective gas and cooling medium is stopped. When it is necessary to replace easily worn parts such as the ignition gun 22, loosen the flange connection between the end cap assembly 2 and the igniter body 1, remove the end cap assembly 2, and then remove the ignition gun 22 from the ignition gun mounting port 21 for replacement. Because the ignition gun 22 is detachably and sealed via the mounting flange, and the length of the ignition gun 22 extending into the igniter body 1 is adjustable, the replacement operation is simple and quick, without the need to disassemble the entire igniter body 1, greatly shortening maintenance time.

[0050] When it is necessary to clean or replace the wall structure of the igniter body 1, the connecting flanges between the first housing 11 and the second housing 12, and between the second housing 12 and the third housing 13 can be loosened, and the body can be disassembled layer by layer for cleaning or replacement, thus reducing maintenance costs.

[0051] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An igniter for the preparation of fumed silica, comprising: The igniter body (1) is provided with an air passage (15) that connects to an air inlet (14) and a hydrogen passage (17) that connects to a hydrogen inlet (16); the outlet end of the hydrogen passage (17) is provided with a gas distribution structure (18). The feature is that: the top of the igniter body (1) is provided with a detachable end cap assembly (2), the end cap assembly (2) is provided with at least one ignition gun mounting port (21), and each ignition gun mounting port (21) is equipped with an ignition gun (22). The igniter body (1) is provided with a reaction gas channel (19); the top of the reaction gas channel (19) is closed and a reaction gas inlet (20) communicating with it is opened through its wall area; the outlet of the reaction gas channel (19) is adjacent to the gas distribution structure (18); the ignition end of the ignition gun (22) passes through the reaction gas channel (19).

2. The igniter according to claim 1, characterized in that, The igniter body (1) includes a first housing (11), a second housing (12) and a third housing (13) arranged coaxially from the outside to the inside; the air passage (15) is formed between the first housing (11) and the second housing (12), and the hydrogen passage (17) is formed between the second housing (12) and the third housing (13).

3. The igniter according to claim 2, characterized in that, The third housing (13) encloses and forms the reaction gas channel (19). The end cap assembly (2) is a flange cover, which covers the top of the reaction gas channel (19). The side of the igniter body (1) is provided with the reaction gas inlet (20) that communicates with the reaction gas channel (19).

4. The igniter according to claim 2, characterized in that, The end cap assembly (2) is a cylindrical shape with an opening facing downwards, located in the cavity formed by the third housing (13) and its upper part protrudes from the top of the igniter body (1); the side wall of the upper protruding part of the end cap assembly (2) is provided with the reaction gas inlet (20), and the cylindrical interior of the end cap assembly (2) forms the reaction gas channel (19).

5. The igniter according to claim 1, characterized in that, The igniter body (1) has a hollow guide cone (23) coaxially arranged at the air outlet, and the hollow channel inside the guide cone (23) allows the ignition gun (22) to pass through.

6. The igniter according to claim 1, characterized in that, The air inlet (14) and the hydrogen inlet (16) are respectively located on the side of the igniter body (1).

7. The igniter according to claim 2, characterized in that, The first housing (11) and the second housing (12), and the second housing (12) and the third housing (13) are detachably connected by connecting flanges.

8. The igniter according to claim 1, characterized in that, The length of the ignition end of the ignition gun (22) extending into the igniter body (1) is adjustable.

9. The igniter according to claim 1, characterized in that, The head assembly (2) is provided with two ignition gun mounting ports (21), which are arranged symmetrically with respect to the central axis of the igniter body (1).

10. A fumed silica reactor, comprising a furnace body (100), a discharge port (101) at the bottom of the furnace body (100), and multiple protective gas inlets (102) arranged in parallel on the upper part of the furnace body (100); characterized in that: The furnace body (100) is provided with an igniter mounting interface (103) on the top, and the igniter mounting interface (108) is used to install the igniter as described in any one of claims 1 to 9.

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