A double-layer graphitization furnace for the engineering production of carbon fiber

Abstract

A double-layer graphitization furnace for carbon fiber engineering production relates to the technical field of carbon fiber engineering production equipment. The furnace comprises two parallel layers of muffle chambers, namely an independent upper muffle chamber (101) and a lower muffle chamber (102). The upper muffle chamber (101) and the lower muffle chamber (102) are all rectangular parallelepiped cavity structures composed of graphite muffle plates along the length direction. Three independent heating temperature zones are adopted: upper, middle and lower. The graphitization furnace comprises a double-layer muffle chamber, a heating element, an electric bridge, a support assembly, a heat preservation system, a waste outlet and a furnace shell. The double-layer muffle chamber is arranged in an upper and lower manner, and the muffle chamber is used for carbon fiber tow wire routing. The graphitization furnace can realize the wire routing of the upper and lower layers of carbon fiber tow. Under the condition of the same heat input as the traditional single-layer wire routing, the amount of carbon fiber tow processed by carbon fiber graphitization is increased, the production capacity of engineering production is improved, the energy consumption and operating costs are reduced, and the high-efficiency and low-cost rapid development of domestic carbon fiber is met.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber engineering production equipment, in particular to a double-layer graphitization furnace for carbon fiber engineering production. Background Art

[0002] Carbon fiber is a type of graphite fiber with a carbon content of over 99%. It has a series of excellent properties such as high tensile strength, low thermal expansion coefficient, light weight and dimensional stability. It is widely used in fields such as aerospace to reinforce composite structural parts. Among them, high-strength medium modulus carbon fiber (T series) has excellent mechanical properties such as high tensile strength and medium tensile modulus. High-strength high modulus carbon fiber (M series) is based on high-strength medium modulus carbon fiber and further ultra-high temperature graphitization treatment, which significantly improves the tensile modulus of carbon fiber.

[0003] In the engineering production of carbon fiber, high-temperature graphitization furnaces and ultra-high-temperature graphitization furnaces are one of the most critical processes for preparing high-performance carbon fiber. High-temperature graphitization undergoes structural transformation at 1000-1800°C, and ultra-high-temperature graphitization undergoes structural transformation at 2000-2800°C. For high-performance carbon fiber engineering production lines, high-temperature graphitization furnaces and ultra-high-temperature graphitization furnaces mostly use graphite as a heat source. In addition, the width of the production lines of domestic and foreign engineering carbon fiber manufacturers is basically 1m, 2m, and 3m. Due to the limitations of the graphite material's stress-bearing structure, the width of the production line cannot be expanded, which cannot meet the requirements of increasing the number of carbon fiber tows to increase production capacity. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a double-layer graphitization furnace for carbon fiber engineering production, which can meet the needs of carbon fiber engineering production.

[0005] To achieve the purpose of the present invention, the following technical solutions are provided:

[0006] A double-layer graphitization furnace for carbon fiber engineering production is characterized in that it comprises two parallel muffle cavities, namely an independent upper muffle cavity (101) and a lower muffle cavity (102), the upper muffle cavity (101) and the lower muffle cavity (102) are all rectangular cavity structures composed of graphite muffle plates along the length direction; there is an intermediate gap (103) between the lower graphite muffle plate corresponding to the upper muffle cavity (101) and the upper graphite muffle plate corresponding to the lower muffle cavity (102); the outer parts of the upper muffle cavity (101) and the lower muffle cavity (102) are integrally formed as a heat preservation system (5), that is, the upper part of the upper muffle cavity (101) is the heat preservation upper layer (501) of the furnace shell, and the upper part of the upper muffle cavity (101) is connected to the heat preservation layer of the furnace shell. There is a gap between the upper and lower layers (501) of the furnace shell, which is called an upper gap (1011); below the lower muffle cavity (102) is the furnace bottom insulation layer (506); there is a gap between the lower muffle cavity (102) and the furnace bottom insulation layer (506) which is called a lower gap (1012); on both sides of the upper and lower muffle cavities (101) as a whole and between the furnace shell insulation upper layer (501) and the furnace bottom insulation layer (506), a furnace shell insulation left layer (502) and a furnace shell insulation right layer (503) are correspondingly provided; there is a gap between the furnace shell insulation left layer (502) and the furnace shell insulation right layer (503) and the side graphite plates of the upper and lower muffle cavities (101) and the lower muffle cavity (102), which is correspondingly called a left gap ( 1013) and the right gap (1014); multiple support components (4) are provided in the upper gap (1011), the lower gap (1012), and the middle gap (103) for supporting the upper and lower structures of the corresponding gaps, and the support component (4) is composed of an upright solid graphite cylindrical structure (401) and a boron nitride sleeve (402), and the graphite solid cylindrical structure (401) is coaxially sleeved with a boron nitride sleeve (402); heating elements (2) are provided in the upper gap (1011), the lower gap (1012), and the middle gap (103), and the heating element (2) in the upper gap (1011) is closely attached to the upper graphite muffle plate corresponding to the upper muffle cavity (101), and the heating element (2) in the lower gap (1012) is closely attached to the upper graphite muffle plate corresponding to the upper muffle cavity (101). The component (2) is in close contact with the lower graphite muffle plate corresponding to the lower muffle cavity (102), and the upper and lower parts of the heating element (2) in the middle gap (103) are respectively in close contact with the lower graphite muffle plate corresponding to the upper muffle cavity (101) and the upper graphite muffle plate corresponding to the lower muffle cavity (102); an electric bridge (3) is provided in the left gap (1013) to connect the ends of the heating element in the upper gap (1011), the heating element in the lower gap (1012), and the heating element in the middle gap (103) into one; and an electric bridge (3) is provided in the right gap (1014) to connect the other ends of the heating element (2) in the upper gap (1011), the heating element in the lower gap (1012), and the heating element in the middle gap (103) into one;A heating element in the upper gap (1011), a heating element in the lower gap (1012), a heating element in the middle gap (103), an electric bridge connected to the right gap (1014), and an electric bridge connected to the left gap (1013) form an electric heating system. Multiple electric heating systems are provided along the length direction of the upper muffle cavity (101) and the lower muffle cavity (102).

[0007] The heating element (2) is an isostatically pressed hollow graphite rod.

[0008] At the front and rear ends of the double-layer graphitization furnace, a furnace shell insulation front layer (504) and a furnace shell insulation rear layer (505) are respectively used to block and seal the furnace shell insulation upper layer (501), the furnace bottom insulation layer (506), the furnace shell insulation left layer (502) and the furnace shell insulation right layer (503) to form an insulation system (5); the furnace shell insulation front layer (504) and the furnace shell insulation rear layer (505) are provided with cavities correspondingly connected to the upper muffle cavity (101) and the lower muffle cavity (102); and a waste discharge port (6) is provided outside the front end insulation system (5) of the double-layer graphitization furnace, that is, the upper muffle cavity (101) and the lower muffle cavity (102) are respectively provided with a waste discharge port (6) at the front end.

[0009] The outside of the heat preservation system (5) is a furnace shell (7), which is composed of a hollow water-cooled steel plate (701).

[0010] A throat-locking heat-insulating cavity (8) is provided between the upper muffle cavity (101) and the lower muffle cavity (102) corresponding to the front and rear ends of the double-layer graphitization furnace. The throat-locking heat-insulating cavity (8) is correspondingly nested in the middle of the furnace shell heat-insulating front layer (504) and the furnace shell heat-insulating rear layer (505).

[0011] The furnace shell insulation front layer (504), the furnace shell insulation rear layer (505), the furnace shell insulation upper layer (501), the furnace shell insulation left layer (502), and the furnace shell insulation right layer (503) are composed of three materials from the inside to the outside: graphite hard felt, graphite soft felt, and aluminum silicate felt. The furnace bottom insulation layer (506) is composed of a combination of aluminum silicate bricks and zirconia bricks from the inside to the outside.

[0012] The throat-locking heat-insulating chamber is divided into two symmetrical parts, the upper and lower parts. The throat-locking heat-insulating chamber is made of graphite hard felt. Two wire-running chambers are correspondingly arranged in the throat-locking heat-insulating chamber. The height H2 (100 mm) of the wire-running chamber is less than the height H1 of the upper muffle chamber (101) and the lower muffle chamber (102). The heights of the upper muffle chamber (101) and the lower muffle chamber (102) are equal to H1, and H1 is 120 mm. The wire-running chambers are respectively connected to the upper muffle chamber (101) and the lower muffle chamber (102).

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The graphitization furnace of the present invention can realize the wire routing of upper and lower layers of carbon fiber tows. Under the same heat input conditions as the traditional single-layer wire routing, the amount of processed fiber tows for high-temperature graphitization and ultra-high-temperature graphitization of carbon fiber is increased, the production capacity of engineering production is improved, the energy consumption and operating costs are reduced, and the high-efficiency and low-cost rapid development of domestic carbon fiber is met. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a front view of the double-layer graphitization furnace for carbon fiber engineering production of the present invention

[0016] Figure 2 For the present invention Figure 1 Corresponding right view of the double-layer graphitization furnace for carbon fiber engineering production

[0017] Figure 3 For the present invention Figure 1 The corresponding AA diagram of a double-layer graphitization furnace for carbon fiber engineering production;

[0018] Among them, 101 is the upper muffle cavity; 102 is the lower muffle cavity; 103 is the middle gap; 1011 is the upper gap; 1012 is the lower gap; 1013 is the left gap; 1014 is the right gap; 2 is the heating element; 3 is the bridge; 4 is the support assembly; 401 is the graphite solid cylindrical structural member; 402 is the boron nitride sleeve; 5 is the insulation system; 501 is the upper insulation layer of the furnace shell; 502 is the left insulation layer of the furnace shell (); 503 is the right insulation layer of the furnace shell (); 504 is the front insulation layer of the furnace shell (); 505 is the rear insulation layer of the furnace shell; 506 is the bottom insulation layer of the furnace; 6 is the waste outlet; 7 is the furnace shell; 701 is the hollow water-cooled steel plate; 8 is the throat insulation cavity; DETAILED DESCRIPTION

[0019] The present application will be further described below with reference to the following examples, but the present invention is not limited to the following examples.

[0020] Example 1

[0021] Combined with attachment Figure 1 、 Figure 2 and Figure 3 The specific embodiments of the present invention are described in detail.

[0022] A double-layer graphitization furnace for carbon fiber engineering production, characterized in that:

[0023] ①The maximum design temperature of the graphitization furnace is 3000℃, with three independent heating zones, corresponding to each set of electric heating systems, and each zone adopts three-phase power supply.

[0024] ② The graphitization furnace includes a double-layer muffle cavity, a heating element, an electric bridge, a support assembly, a thermal insulation system, a waste outlet and a furnace shell.

[0025] ③ The double-layer muffle cavity of the graphitization furnace is divided into upper and lower layers. Each layer of the muffle cavity is composed of four graphite muffle plates (upper, lower, left and right). The muffle cavity is used for carbon fiber tow wire routing. The inner height of the muffle cavity (wire path height H1) is 120 mm.

[0026] Multiple electric heating systems are evenly distributed in the length direction (along the carbon fiber wire running direction) in each heating temperature zone.

[0027] The heating elements are isostatically pressed hollow graphite rods, and each phase of heating elements consists of three graphite rods, which are alternately distributed with the double-layer muffle cavity, that is, from bottom to top, they are heating graphite rod, lower muffle cavity, heating graphite rod, upper muffle cavity, and heating graphite rod.

[0028] The left and right ends of each phase heating graphite rod are respectively connected to the electric bridge through threads.

[0029] The support assembly is composed of a solid graphite cylindrical structure with a boron nitride sleeve insulating member nested outside. The support assembly and the heating element are alternately spaced along the carbon fiber wire feed direction. The support assembly is positioned at the left and right edges of the graphite muffle plate under each muffle cavity.

[0030] The insulation system consists of two parts: the furnace shell insulation layer and the furnace bottom insulation layer. The furnace shell insulation layer is specifically divided into upper, left, right, front, and rear insulation layers, and is composed of a combination of three materials from the inside to the outside: hard graphite felt, soft graphite felt, and aluminum silicate felt. The furnace bottom insulation layer is the lower insulation layer, and is composed of a combination of aluminum silicate bricks and zirconia bricks from the inside to the outside.

[0031] A throat-locking insulation cavity is provided in the middle of the front and rear insulation layers. The throat-locking insulation cavity is divided into two symmetrical parts, the upper and lower parts. The throat-locking insulation cavity is made of graphite hard felt. The wire height H2 (100mm) inside the throat-locking insulation cavity is smaller than the wire path height H1 of the muffle cavity.

[0032] The furnace shell is wrapped around the outer side of the insulation system, and the furnace shell is a hollow water-cooled steel plate structure. The waste outlet is symmetrically arranged on the inlet side of the graphitization furnace.

Claims

1. A double-layer graphitization furnace for carbon fiber engineering production, characterized in that: The invention comprises two layers of muffle cavities in parallel with each other, namely, an independent upper muffle cavity (101) and a lower muffle cavity (102), wherein the upper muffle cavity (101) and the lower muffle cavity (102) are all rectangular cavity structures composed of graphite muffle plates along the length direction; there is an intermediate gap (103) between the lower graphite muffle plate corresponding to the upper muffle cavity (101) and the upper graphite muffle plate corresponding to the lower muffle cavity (102); the outer portion of the upper muffle cavity (101) and the lower muffle cavity (102) is an insulation system (5), namely, the upper portion of the upper muffle cavity (101) is the furnace shell insulation upper layer (501), and there is a gap between the upper portion of the upper muffle cavity (101) and the furnace shell insulation upper layer (501) called the upper layer. The lower muffle cavity (102) is provided with a furnace bottom insulation layer (506) below the lower muffle cavity (102), and a gap between the lower muffle cavity (102) and the furnace bottom insulation layer (506) is called the lower gap (1012); the upper muffle cavity (101) and the lower muffle cavity (102) are provided with a furnace shell insulation left layer (502) and a furnace shell insulation right layer (503) on both sides of the upper muffle cavity (101) and the lower muffle cavity (102) as a whole and distributed between the furnace shell insulation upper layer (501) and the furnace bottom insulation layer (506); the furnace shell insulation left layer (502) and the furnace shell insulation right layer (503) are distributed with gaps between the graphite plates on the side surfaces of the upper muffle cavity (101) and the lower muffle cavity (102), and the distribution is called the left gap (1013) and the right gap (1014). 014); Multiple support assemblies (4) are provided in the upper gap (1011), the lower gap (1012), and the middle gap (103) for supporting the upper and lower structures of the corresponding gaps, and the support assembly (4) is composed of an upright solid graphite cylindrical structure (401) and a boron nitride sleeve (402), and the graphite solid cylindrical structure (401) is coaxially sleeved with a boron nitride sleeve (402); Heating elements (2) are provided in the upper gap (1011), the lower gap (1012), and the middle gap (103), and the heating element (2) in the upper gap (1011) is in close contact with the upper graphite muffle plate corresponding to the upper muffle cavity (101), and the heating element (2) in the lower gap (1012) is in close contact with the upper graphite muffle plate corresponding to the upper muffle cavity (101). The lower graphite muffle plate corresponding to the lower muffle cavity (102) and the heating element (2) in the middle gap (103) are respectively closely attached to the lower graphite muffle plate corresponding to the upper muffle cavity (101) and the upper graphite muffle plate corresponding to the lower muffle cavity (102) on the upper and lower sides; an electric bridge (3) is provided in the left gap (1013) to connect the ends of the heating element in the upper gap (1011), the heating element in the lower gap (1012), and the heating element in the middle gap (103) into one body; and an electric bridge (3) is provided in the right gap (1014) to connect the other ends of the heating element (2) in the upper gap (1011), the heating element in the lower gap (1012), and the heating element in the middle gap (103) into one body;A heating element in the upper gap (1011), a heating element in the lower gap (1012), a heating element in the middle gap (103), an electric bridge connected to the right gap (1014), and an electric bridge connected to the left gap (1013) form an electric heating system. Multiple electric heating systems are provided along the length direction of the upper muffle cavity (101) and the lower muffle cavity (102).

2. The double-layer graphitization furnace for carbon fiber engineering production according to claim 1, characterized in that: The heating element (2) is an isostatically pressed hollow graphite rod.

3. The double-layer graphitization furnace for carbon fiber engineering production according to claim 1 is characterized in that: At the front and rear ends of the double-layer graphitization furnace, a furnace shell insulation front layer (504) and a furnace shell insulation rear layer (505) are respectively used to seal the furnace shell insulation upper layer (501), the furnace bottom insulation layer (506), the furnace shell insulation left layer (502) and the furnace shell insulation right layer (503) to form an insulation system (5); the furnace shell insulation front layer (504) and the furnace shell insulation rear layer (505) are provided with cavities correspondingly connected to the upper muffle cavity (101) and the lower muffle cavity (102); a waste discharge port (6) is provided outside the front end insulation system (5) of the double-layer graphitization furnace, that is, the upper muffle cavity (101) and the lower muffle cavity (102) are respectively provided with a waste discharge port (6) at the front end.

4. The double-layer graphitization furnace for carbon fiber engineering production according to claim 1 is characterized in that: The outside of the insulation system (5) is a furnace shell (7), which is composed of a hollow water-cooled steel plate (701).

5. The double-layer graphitization furnace for carbon fiber engineering production according to claim 1 is characterized in that: A throat-locking heat-insulating cavity (8) is provided between the upper muffle cavity (101) and the lower muffle cavity (102) corresponding to the front and rear ends of the double-layer graphitization furnace. The throat-locking heat-insulating cavity (8) is correspondingly nested in the middle portion of the furnace shell heat-insulating front layer (504) and the furnace shell heat-insulating rear layer (505).

6. The double-layer graphitization furnace for carbon fiber engineering production according to claim 1, characterized in that: The furnace shell insulation front layer (504), the furnace shell insulation rear layer (505), the furnace shell insulation upper layer (501), the furnace shell insulation left layer (502) and the furnace shell insulation right layer (503) are composed of a combination of three materials from the inside to the outside: graphite hard felt, graphite soft felt and aluminum silicate felt; the furnace bottom insulation layer (506) is composed of a combination of aluminum silicate bricks and zirconia bricks from the inside to the outside.

7. The double-layer graphitization furnace for carbon fiber engineering production according to claim 5, characterized in that: The throat-locking heat-insulating chamber is divided into two symmetrical parts, the upper and lower parts. The throat-locking heat-insulating chamber is made of graphite hard felt. Two wire-running chambers are correspondingly provided in the throat-locking heat-insulating chamber. The height H2 of the wire-running chamber is less than the height H1 of the upper muffle chamber (101) and the lower muffle chamber (102). The heights of the upper muffle chamber (101) and the lower muffle chamber (102) are equal to H1. The wire-running chambers are respectively connected to the upper muffle chamber (101) and the lower muffle chamber (102).

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