Inlet air distribution device and method of pre-oxidation furnace for carbon fiber production

Abstract

The invention provides an air inlet distribution device and method of a pre-oxidation furnace for carbon fiber production, and belongs to the technical field of carbon fiber production. The air inlet distribution device comprises an air inlet channel, and a first-stage uniform air distribution plate, a second-stage uniform air distribution plate, an air guide inclined plate and an air inlet distribution combined structure are sequentially arranged in the air inlet channel in the air moving direction. By arranging a multi-stage distribution structure, the uniformity of a wind field of the pre-oxidation furnace from a fan outlet to a hot wind flow field entering the wind inlet cavity of the oxidation furnace is realized, the pre-oxidation uniformity of carbon fiber precursors in the pre-oxidation furnace is ensured, and the pre-oxidation stability of tows is improved; meanwhile, the uniform wind speed field can take away reaction heat and reaction byproducts of the tows in time, and safe and reliable operation of equipment is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon fiber production, and in particular relates to an air inlet distribution device and method for a pre-oxidation furnace for carbon fiber production. Background Art

[0002] The pre-oxidation furnace is the core equipment in the carbon fiber production device. The uniformity of the wind velocity field inside its process cavity is a key factor affecting the stability of carbon fiber production. Uneven wind velocity field in the furnace cavity will lead to uneven pre-oxidation degree of the raw silk inside the pre-oxidation furnace. At the same time, in areas with excessive wind speed, the filament bundle will be shaken, seriously affecting the quality of the filament bundle. In areas with lower wind speed, the hot air cannot take away the reaction heat and reaction by-products inside the filament bundle in time, seriously affecting the quality of the filament bundle. In severe cases, local overheating may cause the filament bundle to catch fire, causing a safety accident.

[0003] In the existing oxidation furnace, the air speed and the air angle of the incoming air are mainly adjusted by the air regulating plate to achieve the purpose of uniform air speed. When the number of layers of the pre-oxidation furnace is large, the adjustment of the upper and lower air regulating plates will affect the uniformity of the wind speed field in the adjacent areas. In order to achieve uniform wind speed in the entire furnace cavity, the adjustment workload is very large, which is not conducive to on-site operation. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide an air inlet distribution device and method for a pre-oxidation furnace for carbon fiber production, which can ensure the uniformity of the air inlet speed of the pre-oxidation furnace, and further ensure the uniformity of the pre-oxidation degree of the carbon fiber precursor in the pre-oxidation furnace.

[0005] The present invention is achieved through the following technical solutions:

[0006] The first aspect of the present invention provides an air inlet distribution device for a pre-oxidation furnace for carbon fiber production, comprising an air inlet channel, in which a primary uniform air distribution plate, a secondary uniform air distribution plate, an air guide inclined plate and an air inlet distribution combination structure are sequentially arranged along the direction of wind flow in the air inlet channel.

[0007] A further improvement of the present invention is:

[0008] The air inlet of the air inlet channel is provided with an arc-shaped guide plate.

[0009] A further improvement of the present invention is:

[0010] The primary uniform air distribution plate comprises a stainless steel plate, and a plurality of primary circular holes are evenly arranged on the stainless steel plate;

[0011] Preferably, the diameter of the primary circular holes on the primary uniform air distribution plate is 8 to 12 mm, and the opening rate is 60 to 80%.

[0012] A further improvement of the present invention is:

[0013] The secondary air distribution plate comprises a stainless steel plate, and a plurality of secondary circular holes are evenly arranged on the stainless steel plate;

[0014] Preferably, the diameter of the secondary circular holes on the secondary air distribution plate is 8 to 12 mm, and the opening rate is 40% to 60%.

[0015] A further improvement of the present invention is:

[0016] The wind guide inclined plate is arranged at the bottom of the air inlet channel, and is a wind guide plate with an inclination angle, and the wind guide plate gradually inclines from top to bottom in the air inlet channel toward the air outlet of the air inlet channel;

[0017] Preferably, the inclination angle of the wind guide inclined plate is 10 to 15°.

[0018] A further improvement of the present invention is:

[0019] The air inlet distribution combined structure comprises an air inlet distribution plate and a wedge-shaped hole plate fixed on the air inlet distribution plate.

[0020] A further improvement of the present invention is:

[0021] The air inlet distribution plate is evenly provided with a plurality of circular through holes;

[0022] Preferably, the diameter of the circular through holes on the air inlet distribution plate is 8-12 mm, and the opening rate is 40-60%.

[0023] A further improvement of the present invention is:

[0024] The wedge-shaped orifice plate includes a plurality of support bars fixed on the air inlet distribution plate, the plurality of support bars are arranged parallel to each other, a plurality of parallel wedge bars are fixed on the plurality of support bars, and the plurality of wedge bars and the support bars are arranged perpendicular to each other.

[0025] A further improvement of the present invention is:

[0026] The tooth profile half angle of the wedge-shaped strip is 10° to 15°, the height is 6 to 9 mm, and the width is 2.5 mm to 5 mm.

[0027] A second aspect of the present invention provides an air distribution method for a pre-oxidation furnace for carbon fiber production, which uses the air distribution device for the pre-oxidation furnace for carbon fiber production as described above to distribute the air to the pre-oxidation furnace.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention utilizes a multiple distribution structure to achieve uniformity of the hot air flow field of the pre-oxidation furnace from the fan outlet to the air inlet chamber of the oxidation furnace, ensure uniformity of pre-oxidation of the carbon fiber precursor in the pre-oxidation furnace, and improve the stability of pre-oxidation of the tow. At the same time, the uniform wind speed field can take away the reaction heat and reaction by-products of the tow in time, ensuring the safe and reliable operation of the equipment.

[0030] The air inlet distribution device of the pre-oxidation furnace for carbon fiber production of the present invention realizes the initial uniformity of hot air distribution by arranging a primary uniform air distribution plate and a secondary uniform air distribution plate; and realizes the uniformity of the wind field inside the oxidation furnace cavity by arranging an air inlet distribution combined structure, thereby improving the stability of filament bundle pre-oxidation.

[0031] The air inlet distribution device of the present invention has a simple structure and is easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of an air inlet distribution device of a pre-oxidation furnace for carbon fiber production provided by the present invention;

[0033] Figure 2 is a schematic diagram of the air inlet distribution combination structure;

[0034] Figure 3 This is the simulation result of the combined structure of honeycomb plate and perforated plate;

[0035] Figure 4 It is a simulation result using the air inlet distribution combined structure of the present invention.

[0036] In the figure, 1. air inlet channel, 2. arc-shaped air guide plate, 3. primary uniform air distribution plate, 4. secondary uniform air distribution plate, 5. inclined air guide plate, 6. air inlet distribution combined structure. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0038] The present invention provides an air inlet distribution device for a pre-oxidation furnace for carbon fiber production, which is mainly used for wind field distribution in an air inlet cavity of the pre-oxidation furnace to achieve a uniform air inlet wind velocity field, thereby ensuring the uniformity of the pre-oxidation degree of the carbon fiber precursor in the pre-oxidation furnace and ensuring the safe and reliable operation of the pre-oxidation furnace.

[0039] The embodiments of the dispensing device are as follows:

[0040] [Example 1]

[0041] This embodiment provides an air inlet distribution device for a pre-oxidation furnace for carbon fiber production, such as Figure 1As shown, it includes an air inlet channel 1, in which a primary air uniform distribution plate 3, a secondary air uniform distribution plate 4, an air guide inclined plate 5 and an air inlet distribution combined structure 6 are sequentially arranged along the direction of wind flow.

[0042] Among them, an air inlet distribution combination structure 6 is provided in the air inlet channel 1, one end of which is connected to the air inlet chamber of the pre-oxidation furnace, and the other end is connected to the filament bundle reaction chamber of the oxidation furnace body. The hot air enters the air inlet channel 1 through the fan, passes through the first-level uniform air distribution plate 3, so that the originally chaotic wind velocity field is initially distributed, and then enters the second-level uniform air distribution plate 4 for redistribution to obtain a uniform wind velocity field, and then is guided by the wind guide inclined plate 5 and then passes through the air inlet distribution combination structure 6 to obtain a uniform wind velocity field, and finally enters the air inlet chamber of the oxidation furnace.

[0043] The present invention utilizes a multiple distribution structure to achieve uniformity of the hot air flow field of the pre-oxidation furnace from the fan outlet to the air inlet chamber of the oxidation furnace, ensure uniformity of pre-oxidation of the carbon fiber precursor in the pre-oxidation furnace, and improve the stability of pre-oxidation of the tow. At the same time, the uniform wind speed field can take away the reaction heat and reaction by-products of the tow in time, ensuring the safe and reliable operation of the equipment.

[0044] If the hot air does not pass through the primary uniform air distribution plate 3 and the secondary uniform air distribution plate 4, but is directly guided by the wind guide inclined plate 5 and then enters the pre-oxidation furnace through the air inlet distribution combination structure 6, a uniform effect cannot be achieved because the hot air has a disordered flow velocity distribution in the height direction of the channel after passing through the fan, and the gas flow rate cannot achieve a relatively uniform effect on each layer.

[0045] If the hot air is distributed by the first-level uniform air distribution plate 3 and then directly guided by the wind guide inclined plate 5 and then enters the pre-oxidation furnace through the air inlet distribution combination structure 6, the uniform air effect is not good. In the present invention, the two-level uniform air distribution plates can achieve a certain back pressure effect in structure. The hot air reaches a preliminary distribution after passing through the first-level uniform air distribution plate 3. There is a certain space between the first-level uniform air distribution plate and the second-level uniform air distribution plate. Due to the back pressure of the second-level uniform air plate, the gas can achieve a further uniform air effect in this space.

[0046] [Example 2]

[0047] An arc-shaped guide plate 2 is provided at the air inlet of the air inlet channel 1. The arc-shaped guide plate is a 90° arc-shaped plate, which plays a role in changing the gas flow direction. The radius of curvature needs to be determined according to the channel size of the pre-oxidation furnace. When the hot air enters the air inlet channel 1 through the fan, the arc structure of the arc-shaped guide plate 2 is used to rotate the hot air flow direction by 90°, so that the hot air can be smoothly turned and enter the air inlet channel 1. There will be no dead zone in the wind field, which can ensure that the hot air entering the air inlet channel can all enter the air inlet chamber of the pre-oxidation furnace without energy loss.

[0048] [Example 3]

[0049] The primary uniform air distribution plate 3 and the secondary uniform air distribution plate 4 are both orifice plate structures, specifically:

[0050] The first-level uniform air distribution plate 3 includes a stainless steel plate, on which a plurality of first-level circular holes are evenly arranged. The actual size of the first-level circular holes is determined according to the process wind speed and air volume of the entire oxidation furnace. Preferably, the aperture of the first-level circular holes on the first-level uniform air distribution plate 3 is 8 to 12 mm, and the opening rate is 60 to 80%.

[0051] The secondary uniform air distribution plate 4 includes a stainless steel plate on which a plurality of secondary circular holes are evenly arranged. The actual size of the secondary circular holes is determined according to the process wind speed and air volume of the entire oxidation furnace. Preferably, the aperture of the secondary circular holes on the secondary uniform air distribution plate 4 is 8 to 12 mm, and the opening rate is 40% to 60%.

[0052] Preferably, the opening rate of the secondary air distribution plate 4 should be smaller than the opening rate of the primary air distribution plate 3 .

[0053] The pressure difference of the first-level uniform air distribution plate 3 and the second-level uniform air distribution plate 4 needs to be reasonably configured according to the structural size, wind speed and other factors of the equipment. Specifically, the flow field simulation needs to be carried out according to the size, wind speed and air volume of the oxidation furnace to finally determine the opening size and opening rate and the spacing between the first-level uniform air distribution plate 3 and the second-level uniform air distribution plate 4. The opening rate of the first-level uniform air distribution plate 3 and the second-level uniform air distribution plate 4 should ensure that there is sufficient back pressure to ensure the uniformity of the wind field.

[0054] The hot air enters the air inlet channel 1 through the fan, passes through the first-level uniform wind distribution plate 3, so that the originally turbulent wind speed field is initially distributed, and then enters the second-level uniform wind distribution plate 4 for redistribution. After two-level distribution, a uniform wind speed field is finally obtained.

[0055] [Example 4]

[0056] The inclined air guide plate 5 is arranged at the bottom of the air inlet channel 1. It is an air guide plate with an inclination angle. The air guide plate is gradually inclined from top to bottom in the air inlet channel 1 toward the air outlet of the air inlet channel 1. The inclination angle is related to the width of the oxidation furnace body and the wind speed. In actual application, the fluid simulation software Fluent should be used to simulate the flow field.

[0057] Preferably, the inclination angle of the wind guide inclined plate is 10 to 15°.

[0058] The hot air is distributed by the primary uniform air distribution plate 3 and the secondary uniform air distribution plate 4, and then guided by the wind guide inclined plate 5 and then passed through the air inlet distribution combined structure 6 to obtain a uniform wind speed field.

[0059] [Example 5]

[0060] The function of the air inlet distribution assembly structure 6 is to ensure that the hot air enters the oxidation furnace cavity evenly after two-stage distribution, ensure the uniformity of pre-oxidation of the carbon fiber precursor in the pre-oxidation furnace, and improve the stability of the pre-oxidation of the tow. At the same time, the uniform wind speed field can take away the reaction heat and reaction by-products of the tow in time, ensuring the safe and reliable operation of the equipment.

[0061] like Figure 2 As shown, the air inlet distribution assembly structure 6 includes an air inlet distribution plate and a wedge-shaped hole plate fixed on the air inlet distribution plate, and a plurality of circular through holes are evenly arranged on the air inlet distribution plate; the air inlet distribution plate is a stainless steel plate;

[0062] The wedge-shaped orifice plate includes a plurality of support bars fixed on the air inlet distribution plate, the plurality of support bars are arranged parallel to each other, a plurality of parallel wedge bars are fixed on the plurality of support bars, the plurality of wedge bars and the support bars are arranged perpendicular to each other, and the wedge-shaped orifice plate is a combined structure with an opening rate of 30 to 45%.

[0063] The support strips should be arranged away from the circular through holes on the air inlet distribution plate.

[0064] Specifically, the aperture size and opening ratio of the circular through holes on the air inlet distribution plate, as well as the height, width and distance between two adjacent wedge bars are determined according to the process wind speed and air volume of the entire oxidation furnace. In actual application, the flow field simulation should be carried out using the fluid simulation software Fluent.

[0065] Preferably, the diameter of the circular through hole is 8-12 mm, and the opening rate is 40-60%.

[0066] Preferably, the tooth profile half angle of the wedge-shaped strip is 10° to 15°, the height is 6 to 9 mm, and the width is 2.5 mm to 5 mm.

[0067] The air inlet distribution combined structure 6 of the present invention is a combined structure of a circular orifice plate and a wedge-shaped orifice plate, which is a replaceable structure according to the change of wind speed. The distance between two adjacent wedge-shaped strips in the wedge-shaped orifice plate of the present invention can be adjusted according to actual needs to meet the requirement of uniform gas distribution.

[0068] The following simulations are respectively conducted on the combined structure 6 of the air inlet distribution of the present invention and the combined structure of the honeycomb plate and the orifice plate in the prior art, wherein the parameters of the two simulations are the same, such as the wind speed, air volume, the aperture of the air inlet distribution plate, the opening rate, etc. are all the same, and the final simulation results are as follows: Figure 3 and Figure 4 shown.

[0069] right Figure 3 and Figure 4 By comparing the displayed results of , it can be seen that the wind uniformity effect of the wedge-shaped plate in the present invention is significantly better than that of the honeycomb plate.

[0070] The present invention also provides an air inlet distribution method for a preoxidation furnace for carbon fiber production, which can ensure the uniformity of the preoxidation degree of the carbon fiber precursor in the preoxidation furnace and ensure the safe and reliable operation of the preoxidation furnace.

[0071] An embodiment of the method is as follows:

[0072] [Example 6]

[0073] The present embodiment provides an air inlet distribution method for a pre-oxidation furnace for carbon fiber production, and uses an air inlet distribution device for the pre-oxidation furnace for carbon fiber production to distribute the air in the pre-oxidation furnace.

[0074] like Figure 1 As shown, the air inlet distribution device of the pre-oxidation furnace for carbon fiber production includes an air inlet channel 1, in which a primary uniform air distribution plate 3, a secondary uniform air distribution plate 4, an air guide inclined plate 5 and an air inlet distribution combined structure 6 are sequentially arranged along the direction of wind flow.

[0075] Among them, an air inlet distribution combination structure 6 is provided in the air inlet channel 1, one end of which is connected to the air inlet chamber of the pre-oxidation furnace, and the other end is connected to the filament bundle reaction chamber of the oxidation furnace body. The hot air enters the air inlet channel 1 through the fan, passes through the first-level uniform air distribution plate 3, so that the originally chaotic wind velocity field is initially distributed, and then enters the second-level uniform air distribution plate 4 for redistribution to obtain a uniform wind velocity field, and then is guided by the wind guide inclined plate 5 and then passes through the air inlet distribution combination structure 6 to obtain a uniform wind velocity field, and finally enters the air inlet chamber of the oxidation furnace.

[0076] The first-level uniform air distribution plate 3 includes a stainless steel plate, on which a plurality of first-level circular holes are evenly arranged. The actual size of the first-level circular holes is determined according to the process wind speed and air volume of the entire oxidation furnace. Preferably, the aperture of the first-level circular holes on the first-level uniform air distribution plate 3 is 8 to 12 mm, and the opening rate is 60 to 80%.

[0077] The secondary uniform air distribution plate 4 includes a stainless steel plate on which a plurality of secondary circular holes are evenly arranged. The actual size of the secondary circular holes is determined according to the process wind speed and air volume of the entire oxidation furnace. Preferably, the aperture of the secondary circular holes on the secondary uniform air distribution plate 4 is 8 to 12 mm, and the opening rate is 40% to 60%.

[0078] The present invention utilizes a multiple distribution structure to achieve uniformity of the hot air flow field of the pre-oxidation furnace from the fan outlet to the air inlet chamber of the oxidation furnace, ensure uniformity of pre-oxidation of the carbon fiber precursor in the pre-oxidation furnace, and improve the stability of pre-oxidation of the tow. At the same time, the uniform wind speed field can take away the reaction heat and reaction by-products of the tow in time, ensuring the safe and reliable operation of the equipment.

[0079] If the hot air does not pass through the primary uniform air distribution plate 3 and the secondary uniform air distribution plate 4, but is directly guided by the wind guide inclined plate 5 and then enters the pre-oxidation furnace through the air inlet distribution combination structure 6, a uniform effect cannot be achieved because the hot air has a disordered flow velocity distribution in the height direction of the channel after passing through the fan, and the gas flow rate cannot achieve a relatively uniform effect on each layer.

[0080] If the hot air is distributed by the first-level uniform air distribution plate 3 and then directly guided by the wind guide inclined plate 5 and then enters the pre-oxidation furnace through the air inlet distribution combination structure 6, the uniform air effect is not good. In the present invention, the two-level uniform air distribution plates can achieve a certain back pressure effect in structure. The hot air reaches a preliminary distribution after passing through the first-level uniform air distribution plate 3. There is a certain space between the first-level uniform air distribution plate 3 and the second-level uniform air distribution plate 4. Due to the back pressure of the second-level uniform air plate, the gas can achieve a further uniform air effect in this space.

[0081] The wind guide inclined plate 5 is arranged at the bottom of the air inlet channel 1. It is an inclined wind guide plate. The wind guide plate is gradually inclined from top to bottom in the air inlet channel 1 toward the air outlet of the air inlet channel 1. Its inclination angle is related to the width of the oxidation furnace body and the wind speed. In actual application, the flow field simulation should be obtained by using the fluid simulation software Fluent. Preferably, the inclination angle of the wind guide inclined plate is 10-15°.

[0082] like Figure 2 As shown, the air inlet distribution assembly structure 6 includes an air inlet distribution plate and a wedge-shaped hole plate fixed on the air inlet distribution plate, and a plurality of circular through holes are evenly arranged on the air inlet distribution plate; the air inlet distribution plate is a stainless steel plate;

[0083] The wedge-shaped orifice plate includes a plurality of support bars fixed on the air inlet distribution plate, the plurality of support bars are arranged parallel to each other, a plurality of parallel wedge bars are fixed on the plurality of support bars, the plurality of wedge bars and the support bars are arranged perpendicular to each other, and the wedge-shaped orifice plate is a combined structure with an opening rate of 30 to 45%.

[0084] The support strips should be arranged away from the circular through holes on the air inlet distribution plate.

[0085] Specifically, the aperture size and opening ratio of the circular through holes on the air inlet distribution plate, as well as the height, width and distance between two adjacent wedge bars are determined according to the process wind speed and air volume of the entire oxidation furnace. In actual application, the flow field simulation should be carried out using the fluid simulation software Fluent.

[0086] Preferably, the diameter of the circular through hole is 8-12 mm, and the opening rate is 40-60%.

[0087] Preferably, the tooth profile half angle of the wedge-shaped strip is 10° to 15°, the height is 6 to 9 mm, and the width is 2.5 mm to 5 mm.

[0088] The function of the air inlet distribution assembly structure 6 is to ensure that the hot air enters the oxidation furnace cavity evenly after two-stage distribution, ensure the uniformity of pre-oxidation of the carbon fiber precursor in the pre-oxidation furnace, and improve the stability of the pre-oxidation of the tow. At the same time, the uniform wind speed field can take away the reaction heat and reaction by-products of the tow in time, ensuring the safe and reliable operation of the equipment.

[0089] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0090] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0091] The above technical solution is only one implementation mode of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. An air inlet distribution device for a pre-oxidation furnace for carbon fiber production, characterized in that: It comprises an air inlet channel, in which a primary air distribution plate, a secondary air distribution plate, an air guide inclined plate and an air inlet distribution combined structure are sequentially arranged along the running direction of the wind.

2. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 1, characterized in that: The air inlet of the air inlet channel is provided with an arc-shaped guide plate.

3. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 1, characterized in that: The primary uniform air distribution plate comprises a stainless steel plate, and a plurality of primary circular holes are evenly arranged on the stainless steel plate; Preferably, the diameter of the primary circular holes on the primary uniform air distribution plate is 8 to 12 mm, and the opening rate is 60 to 80%.

4. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 1, characterized in that: The secondary air distribution plate comprises a stainless steel plate, and a plurality of secondary circular holes are evenly arranged on the stainless steel plate; Preferably, the diameter of the secondary circular holes on the secondary air distribution plate is 8 to 12 mm, and the opening rate is 40% to 60%.

5. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 1, characterized in that: The wind guide inclined plate is arranged at the bottom of the air inlet channel, and is a wind guide plate with an inclination angle, and the wind guide plate gradually inclines from top to bottom in the air inlet channel toward the air outlet of the air inlet channel; Preferably, the inclination angle of the wind guide inclined plate is 10 to 15°.

6. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 1, characterized in that: The air inlet distribution combined structure comprises an air inlet distribution plate and a wedge-shaped hole plate fixed on the air inlet distribution plate.

7. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 6, characterized in that: The air inlet distribution plate is evenly provided with a plurality of circular through holes; Preferably, the diameter of the circular through holes on the air inlet distribution plate is 8-12 mm, and the opening rate is 40-60%.

8. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 7, characterized in that: The wedge-shaped orifice plate includes a plurality of support bars fixed on the air inlet distribution plate, the plurality of support bars are arranged parallel to each other, a plurality of parallel wedge bars are fixed on the plurality of support bars, and the plurality of wedge bars and the support bars are arranged perpendicular to each other.

9. The air inlet distribution device of the pre-oxidation furnace for carbon fiber production according to claim 6, characterized in that: The tooth profile half angle of the wedge-shaped strip is 10° to 15°, the height is 6 to 9 mm, and the width is 2.5 mm to 5 mm.

10. A method for distributing air in a pre-oxidation furnace for producing carbon fiber, characterized in that: The air inlet distribution device of the preoxidation furnace for carbon fiber production as described in any one of claims 1 to 9 is used to distribute the air inlet to the preoxidation furnace.

Images