JP6960845B2 - Muffle structure for cylindrical furnaces made of carbon / carbon composite material - Google Patents

Description

The present invention relates to a muffle structure made of a carbon / carbon composite material for a high temperature cylindrical furnace, and more specifically, a muffle structure of a polygonal columnar body formed by connecting plate members made of a carbon / carbon composite material. Related to.

In a cylindrical furnace (including a vertical cylindrical furnace and a horizontal cylindrical furnace) which is a kind of heat treatment equipment and is an indirect heating type furnace (also called an indirect heating furnace or a muffle furnace), a heat source or a heating element and a firing chamber are used. A partition wall (muffle) made of a refractory material having good thermal conductivity is provided between the two.

Conventionally, a metal material such as heat-resistant steel has been used as this partition wall structure (muffle structure), but since the metal muffle structure does not have sufficient heat resistance and has a large coefficient of thermal expansion, heating and cooling are repeated. There was a problem that the metal muffle was greatly deformed by thermal deformation and could not withstand long-term use.

Therefore, instead of the metal muffle structure, a carbon or graphite muffle structure (hereinafter, these are collectively referred to as graphite) has come to be used (see Patent Document 1). Graphite material has high heat resistance and chemical stability, and its coefficient of thermal expansion is lower than that of metal material, so it can be used repeatedly in a high temperature environment.

However, since the strength and rigidity of the graphite material are not so high and it is a brittle material, there is a problem that it is necessary to use a graphite material in a very thick state in order to use the graphite material as a muffle structure. was there. For this reason, the weight of the muffle structure becomes very large, and the heat capacity of the furnace becomes excessive. As a result, a large amount of heat energy is required to raise the temperature of the furnace body itself, and the thermal efficiency of the furnace is greatly reduced. There was a problem.

In addition, when adopting a graphite muffle structure in a cylindrical furnace, it is necessary to make the muffle structure cylindrical, but due to the characteristics (strength, brittleness) of the graphite material, the muffle structure is integrally molded into a cylindrical shape. I had to do it. In the case of graphite material, which has insufficient strength and rigidity and has brittle properties, it is sufficient even if it is constructed as a cylindrical muffle structure by mechanically joining several divided pieces. This is because it is difficult to construct a muffle structure having strength and rigidity.

Therefore, when the size of the cylindrical furnace is increased, the wall thickness is large and a large cylindrical graphite is required. As a result, the graphite manufacturing equipment is required to be increased in size, and the cost of the muffle structure is increased. rice field.

Japanese Unexamined Patent Publication No. 9-101086

The present invention has been made in view of the above-mentioned technical background, and is a cylindrical furnace (excellent in durability, low heat capacity, does not require large-scale manufacturing equipment, and can significantly reduce operating costs. It is an object of the present invention to provide a muffle structure for (including a vertical cylindrical furnace and a horizontal cylindrical furnace).

In order to solve the above problems, a plurality of carbon / carbon composite materials having high heat resistance, strength, rigidity, and high toughness, which are the simplest basic forms, are mechanically formed. We devised a muffle structure for a cylindrical furnace, which is composed of a polygonal columnar body having a pseudo-cylindrical shape by being coupled to.

That is, in the invention according to the first aspect, the muffle structure for a cylindrical furnace is composed of a plurality of shell structural elements and a plurality of connecting members made of a carbon / carbon composite material, and the shell structural elements are composed of a plurality of carbons. A plate member made of a carbon composite material is formed by joining through a rigid joining member having at least one stiffener to form a shell structure having a chevron-shaped cross section, and the plurality of shell structural elements are combined with each other. A muffle structure for a cylindrical furnace made of a polygonal columnar body formed by connecting through a plurality of connecting members was obtained.

In the invention according to the second aspect, a muffle structural cylindrical furnace of the invention according to the first or second aspect, the thickness of at least one plate member of said plurality of plate members, the other A muffle structure for a cylindrical furnace was formed, which was composed of polygonal columnar bodies having a structure different from the thickness of the plate members of.

In the invention according to the third aspect, a muffle structural cylindrical furnace of the invention according to any one of the first to third aspect, multiplanar of at least one plate member of said plurality of plate members A muffle structure for a cylindrical furnace is formed, which is composed of a polygonal columnar body whose circumferential length of a square is different from the circumferential length of a polygonal cross section of another plate member.

In the present invention, by adopting a muffle structure for a cylindrical furnace composed of polygonal columnar bodies having the above-mentioned configuration, the durability is excellent, the heat capacity is small, no large manufacturing equipment is required, and the operating cost is significantly reduced. It has become possible to provide a muffle structure for a cylindrical furnace that can be used.

In particular, the muffle structure for a cylindrical furnace according to the present invention uses a plurality of carbon / carbon composite material plate members, and the plurality of plate members are mechanically connected by a plurality of carbon / carbon composite material connecting members. Since the muffle structure for a cylindrical furnace is made of a pseudo-cylindrical polygonal columnar body by combining, the heat resistance and dimensional stability of the carbon / carbon composite material can be used as they are, and the muffle structure has excellent durability. It became possible to.

In addition, since the carbon / carbon composite material has the characteristics of high strength, high rigidity, and high toughness, the muffle structure can be made thinner and lighter, and the heat capacity of the muffle structure can be minimized. rice field. As a result, the thermal inertia of the entire furnace body can be reduced, and the thermal efficiency of the furnace body can be dramatically improved.

Further, in the muffle structure according to the present invention, since a flat plate-shaped carbon / carbon composite material is used as a main member, existing manufacturing equipment can be used, and no special large-scale manufacturing equipment is required.

As a result of having the above-mentioned effects, the muffle structure according to the present invention can not only reduce the manufacturing cost of the muffle structure, but also reduce the power consumption of the furnace body (operating cost of the furnace body), and can reduce the operating cost of the furnace body. It has become possible to reduce the repair cost (renewal cost of the muffle structure).

FIG. 1 shows a muffle structure for a cylindrical furnace made of a polygonal columnar body according to the first embodiment of the present invention. In detail, FIG. 1 (a) is a perspective view of a muffle structure assembly for a cylindrical furnace composed of polygonal columnar bodies, and FIG. 1 (b) shows an arrow X in FIG. 1 (a). FIG. 1 (c) shows the arrow Y seen in FIG. 1 (a). Further, FIG. 1 (d) is an exploded perspective view of a muffle structure for a cylindrical furnace composed of a polygonal columnar body, and FIG. 1 (e) shows an arrow X in FIG. 1 (d). (f) shows the arrow Y seen in FIG. 1 (d). FIG. 2 shows a muffle structure for a cylindrical furnace made of a polygonal columnar body according to a second embodiment of the present invention. In detail, FIG. 2 (a) is a perspective view of a muffle structure assembly for a cylindrical furnace composed of polygonal columnar bodies, and FIG. 2 (b) shows an arrow X in FIG. 2 (a). FIG. 2 (c) shows the arrow Y seen in FIG. 2 (a). Further, FIG. 2 (d) is an exploded perspective view of a muffle structure for a cylindrical furnace composed of a polygonal columnar body, and FIG. 2 (e) shows an arrow X in FIG. 2 (d). (f) shows the arrow Y seen in FIG. 2 (d). FIG. 3 shows a muffle structure for a cylindrical furnace made of a polygonal columnar body according to a third embodiment of the present invention. In detail, FIG. 3 (a) is a perspective view of a muffle structure assembly for a cylindrical furnace composed of polygonal columnar bodies, and FIG. 3 (b) shows an arrow X in FIG. 3 (a). FIG. 3 (c) shows the arrow Y seen in FIG. 3 (a). Further, FIG. 3 (d) is an exploded perspective view of a muffle structure for a cylindrical furnace composed of a polygonal columnar body, and FIG. 3 (e) shows an arrow X in FIG. 3 (d). (f) shows the arrow Y seen in FIG. 3 (d).

Hereinafter, the muffle structure for a cylindrical furnace (including a vertical cylindrical furnace and a horizontal cylindrical furnace) made of a polygonal columnar body made of a carbon / carbon composite material according to the present invention will be described.

A carbon / carbon composite material (also called a C / C composite) is a fiber-reinforced composite material in which carbon fibers, which are reinforcing fibers, are hardened with graphite or a carbon matrix, and is several times as much as a conventional carbon material or a graphite material. It is a material that has the strength and elasticity of the above, and also has excellent heat resistance, abrasion resistance, and toughness. Further, the carbon / carbon composite material is also known as a material having a high specific strength and a high specific rigidity because it has a small specific gravity and a high strength and rigidity (elastic modulus).

Furthermore, since the carbon / carbon composite material has high thermal conductivity and a small coefficient of thermal expansion, it has high thermal stability when used as a structural member, and is thermally stable even if heating and cooling are repeated. It has the characteristics of being high and difficult to deform.

In the muffle structure according to the present invention, a flat plate-shaped carbon / carbon composite material is mainly used, in which carbon fibers are oriented in two directions in a plane and carbon fibers (short fibers) are oriented in a plane at random. , Carbon fibers can be used as woven fabrics (plain weave or red woven fabric), which are laminated in the plate thickness direction.

Regarding the manufacturing method of carbon / carbon composite material, in addition to the resincher method, the CVD method, the manufacturing method using preformed yarn, etc., short fibrous carbon fiber, binder pitch powder, coke powder, and stickiness A manufacturing method using a sheet-like intermediate material composed of a binder can be adopted.

FIG. 1 shows a muffle structure 10 for a cylindrical furnace made of a polygonal columnar body according to a first embodiment of the present invention.
The muffle structure 10 is composed of eight carbon / carbon composite plate members 11 and eight carbon / carbon composite connecting members 12.

Each plate member 11 is connected to the connecting member 12 at both side ends thereof via a fastener. Further, the connecting member 12 is a member for connecting the side ends of adjacent plate members 11 to each other, and is a member extending in the axial direction of the muffle structure 10. The cross-sectional shape of the connecting member 12 may be, for example, a triangular shape, but the cross-sectional shape is not limited to this.

As the fastener for connecting each plate member 11 and each connecting member 12, for example, bolts and nuts made of heat-resistant steel can be used, or bolts and nuts made of carbon / carbon composite material can be used. can.

Further, the bolts and nuts may be used in combination with a heat-resistant adhesive (for example, a ceramic adhesive), or the heat-resistant adhesive may be used alone. When bolts and nuts are used as fasteners, one row or multiple locations or multiple rows and multiple locations are fixed to the joint portion of one plate member 11 and one connecting member along the central axis of the muffle structure. You may do so.

By constructing the muffle structure in this way, a pseudo-cylindrical muffle structure along the inner diameter of the cylindrical furnace can be obtained. The muffle structure 10 described here shows an example of the muffle structure of the present invention, and the number, dimensions, and the like of the plate member 11 and the connecting member 12 can be freely selected.

FIG. 2 shows a muffle structure 20 for a cylindrical furnace made of a polygonal columnar body according to a second embodiment of the present invention.
The muffle structure 20 is composed of four sets of carbon / carbon composite material shell structural elements 100 and four carbon / carbon composite material connecting members 22.

The shell structural element 100 according to the second embodiment of the present invention is composed of two plate members 21 made of carbon / carbon composite material and one rigid joining member 23 made of carbon / carbon composite material. There is. The rigid joining member 23 is a member for rigidly joining two plate members 21 made of carbon / carbon composite material in a form of abutting each other at a predetermined angle, in the axial direction of the muffle structure 20. It is a stretched member.

The cross-sectional shape of the rigid joining member 23 of the shell structural element 100 may be, for example, triangular as in the connecting member 22, but is not limited thereto. Further, in order to rigidly connect the two plate members 21 by the rigid joining member 23, it is desirable that the rigid joining member 23 is wider than the connecting member 22. Further, as shown in FIG. 2, the rigid joining member 23 may be provided with one or a plurality of stiffeners 23-1 extending in the circumferential direction.

As the fastener for connecting the two plate members 21, the rigid joining member 23 and the stiffener 23-1, for example, bolts and nuts made of heat-resistant steel can be used, or carbon / carbon composite material can be used. Bolts and nuts can also be used.

Further, in order to make the bond between the two plate members 21, the rigid joining member 23, and the stiffener 23-1 more rigid, bolts and nuts and a heat-resistant adhesive (for example, ceramic adhesive) may be used in combination. good. When bolts and nuts are used as fasteners, one row and multiple locations or multiple rows and multiple locations along the central axis of the muffle structure with respect to the joint portion of one plate member 21 and one rigid joint member 23. The location may be fixed.
The shell structural element 100 configured in this way has a chevron-shaped cross section (triangular chevron shape).

Next, a method of constructing the muffle structure 20 by connecting the four sets of shell structural elements 100 and the four connecting members 22 will be described.
Each shell structural element 100 is connected to the connecting member 22 at both side ends thereof via a fastener. Further, the connecting member 22 is a member for connecting the side ends of the plate members 21 of the adjacent shell structural elements 100 to each other, and is a member extending in the axial direction of the muffle structure 20. As the connecting member 22, the same connecting member 21 as that used in the muffle structure 10 according to the first embodiment can be used.

As the fastener for connecting each shell structural element 100 and the connecting member 22, for example, bolts and nuts made of heat-resistant steel can be used, or bolts and nuts made of carbon / carbon composite material can be used. can.

Further, the bolts and nuts may be used in combination with a heat-resistant adhesive (for example, a ceramic adhesive), or the heat-resistant adhesive may be used alone. When bolts and nuts are used as fasteners, the same method as the method described in the first embodiment can be adopted as the method of arranging the bolts and nuts.

By constructing the muffle structure 20 in this way, a pseudo-cylindrical muffle structure 20 along the inner diameter of the cylindrical furnace can be obtained. The muffle structure 20 described here is configured by connecting four sets of shell structural elements 100, and the two plate members 21 in each shell structural element 100 are firmly formed by the rigid joining member 23 ( Since it is rigidly coupled, the cross section of the muffle structure 20 has four corners, in other words, it has mechanically equivalent properties to the square structure and has excellent structural stability.

Although the muffle structure 20 has been described here as being formed by combining four sets of shell structural elements 100, the structure is not limited to this. For example, the muffle structure 20 may be constructed by connecting the three sets of shell structural elements 100 and the three connecting members 22.

In this case, the cross section of the muffle structure 20 has three corners, in other words, it has mechanically equivalent characteristics to the triangular structure, and further has excellent structural stability.

FIG. 3 shows a muffle structure 30 for a cylindrical furnace made of a polygonal columnar body according to a third embodiment of the present invention.
The muffle structure 30 is composed of three sets of carbon / carbon composite shell structural elements 200 and three carbon / carbon composite connecting members 32.

The shell structural element 200 according to the third embodiment of the present invention is composed of three carbon / carbon composite plate members 31 and two carbon / carbon composite rigid joint members 33. .. The rigid joining member 23 is a member for rigidly joining two adjacent plate members 31 made of carbon / carbon composite material in a form such that they abut each other at a predetermined angle, and is the axial center of the muffle structure 30. It is a member that extends in the direction.

The cross-sectional shape of the rigid joining member 33 of the shell structural element 200 may be, for example, triangular as in the connecting member 32, but is not limited thereto. Further, in order to rigidly connect the two adjacent plate members 31 by the rigid joining member 33, it is desirable that the rigid joining member 33 is wider than the connecting member 32. Further, as shown in FIG. 3, the rigid joining member 23 is provided with one or a plurality of stiffeners 33-1 extending in the circumferential direction so that the stiffeners 33-1 straddle two adjacent rigid joining members 33. You may place it.

As the fastener for connecting the three plate members 31, the two rigid joining members 33, and the stiffener 33-1, for example, heat-resistant steel bolts and nuts can be used, or a carbon / carbon composite. Material bolts and nuts can also be used.

Further, in order to make the bond between the three plate members 31 and the two rigid joining members 33 and the stiffener 33-1 more rigid, bolts and nuts and a heat resistant adhesive (for example, ceramic adhesive) should be used together. You can do it. When bolts and nuts are used as fasteners, one row and multiple locations or multiple rows and multiple locations are provided along the central axis of the muffle structure with respect to the joint portion of 1 plate member 31 and 1 rigid joint member 33. It may be fixed.
The shell structural element 200 configured in this way has a chevron-shaped cross section (trapezoidal chevron shape).

Next, a method of constructing the muffle structure 30 by connecting the three sets of shell structural elements 200 and the three connecting members 32 will be described.
Each shell structural element 200 is connected to the connecting member 32 at both side ends thereof via a fastener. Further, the connecting member 32 is a member for connecting the side ends of the plate members 31 of each shell structural element 200 to each other, and is a member extending in the axial direction of the muffle structure 30.
As the connecting member 32, the same connecting member 21 as that used in the muffle structure 10 according to the first embodiment can be used.

As the fastener for connecting each shell structural element 200 and the connecting member 32, for example, bolts and nuts made of heat-resistant steel can be used, or bolts and nuts made of carbon / carbon composite material can be used. can.

Further, the bolts and nuts may be used in combination with a heat-resistant adhesive (for example, a ceramic adhesive), or the heat-resistant adhesive may be used alone. When bolts and nuts are used as fasteners, the same method as the method described in the first embodiment can be adopted as the method of arranging the bolts and nuts.

By constructing the muffle structure 30 in this way, a pseudo-cylindrical muffle structure 30 along the inner diameter of the cylindrical furnace can be obtained. The muffle structure 30 described here is configured by connecting three sets of shell structural elements 200, and the three plate members 31 in each shell structural element 200 are firmly formed by the rigid joining member 33 ( Since it is rigidly coupled, the cross section of the muffle structure 30 has three corners, in other words, it has mechanically equivalent properties to the triangular structure and has excellent structural stability.

Although the muffle structure 30 has been described here as being formed by combining three sets of shell structural elements 200, the structure is not limited to this. For example, the muffle structure 30 may be constructed by connecting the four sets of shell structural elements 200 and the four connecting members 32.

In this case, the cross section of the muffle structure 30 has four corners, in other words, it has mechanically equivalent characteristics to the square structure and has excellent structural stability.

The plate thicknesses of the plate members 11, 21, and 31 used in the muffle structures 10, 20, and 30 according to the first to third embodiments described above and the length (width dimension) in the circumferential direction are all the same. However, the present invention is not limited to this. The thickness of at least one of the plurality of plate members 11, 21, 31 used in the same muffle structure 10, 20, 30 and / or the circumferential length of the polygonal cross section. However, it may be different from those of the other plate members 11, 21, and 31.

By doing so, in the circumferential direction of the cross-sectional polygons of the muffle structures 10, 20, and 30, the plate thicknesses of the plate members 11, 21, and 31 are changed to increase the strength of a part of the region, thereby increasing the muffle structure. Multiple cross-sections of the muffle structure 10, 20, 30 can be made to withstand asymmetrical loads acting on 10, 20, and 30 or by changing the circumferential length of the cross-sectional polygons of the plate members 11, 21, and 31. By flattening the square shape to some extent, it is possible to avoid interference with structures and the like outside the muffle structures 10, 20, and 30 and existing in the cylindrical furnace.

10, 20, 30 Muffle structure 11, 21, 31 Plate members 12, 22, 32 Connecting members 23, 33 Rigid joint members 23-1, 33-1 Stiffener 100, 200 Shell structural elements

Claims (3)

It has a muffle structure for cylindrical furnaces and has a muffle structure.
With multiple shell structure elements
Consists of multiple carbon / carbon composite connecting members
The shell structural element is formed by joining a plurality of carbon / carbon composite plate members via a rigid joining member having at least one stiffener, forming a shell structure having a chevron-shaped cross section.
A muffle structure for a cylindrical furnace composed of a polygonal columnar body formed by connecting the plurality of shell structural elements via the plurality of connecting members. The polygonal columnar structure according to claim 1, wherein the plate thickness of at least one of the plurality of plate members is different from the plate thickness of the other plate members. Muffle structure for cylindrical furnace consisting of body. The muffle structure for a cylindrical furnace according to any one of claims 1 or 2 , wherein the circumferential length of the polygonal cross section of at least one of the plurality of plate members is the cross section of the other plate member. A muffle structure for a cylindrical furnace composed of polygonal columnar bodies, which is characterized by having a different circumferential length from the polygon.

Images