JP2016125769A - Heat treatment furnace, heat insulation material unit, agitation fan, and method for building furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of heat insulation performance of a heat insulation material even when dew condensation is caused between the heat insulation material and an outer wall, which form a furnace wall, by influence of temperature and humidity differences between a furnace interior atmosphere and a furnace exterior atmosphere of a heat treatment furnace.SOLUTION: In a heat treatment furnace 1 that performs heat treatment of a workpiece W, a furnace wall 5 comprises an outer wall 6 and a heat insulation material unit 7. The heat insulation material unit 7 includes: a base material layer 7a formed by a heat insulation material; and a waterproof resin film 7b covering at least one surface of the base material layer 7a. The heat insulation material unit 7 is disposed so that the waterproof resin film 7b faces an inner surface of the outer wall 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat insulating material unit used in a heat treatment furnace in which the inside of the furnace becomes high temperature.

  In a heat treatment furnace in which the inside of the furnace becomes a high temperature (for example, 850 ° C. or more) like a carburizing furnace that performs a carburizing process on a workpiece, a heat insulating material is provided on an inner surface of an outer wall (iron skin) that constitutes the furnace wall. A pin is provided on the inner surface of the outer wall, and the pin is fixed so that the central axis is perpendicular to the outer wall. The heat insulating material is attached to the inner surface of the outer wall so as to penetrate the pins.

  As a heat insulating material for a heat treatment furnace, for example, there is a composite heat insulating material described in Patent Document 1. The composite heat insulating material described in Patent Document 1 has a multilayer structure, and a core portion made of a heat-expandable heat insulating material is covered with an alumina-based or alumina-silica-based ceramic fiber.

JP-A-6-271362

  However, in the heat treatment furnace, dew condensation may occur between the heat insulating material and the outer wall constituting the furnace wall due to the temperature difference and humidity difference between the furnace atmosphere and the outside atmosphere. The heat insulating material tends to be deformed or deteriorated by absorbing moisture. For this reason, generation | occurrence | production of dew condensation has become a factor which heat insulation performance falls. In particular, a high-performance heat insulating material (Roslim (registered trademark) board or the like) generally used in a heat treatment furnace has high hydrophilicity, and the problem is likely to occur.

  On the other hand, in the conventional heat insulating material structure like patent document 1, the dew condensation between a heat insulating material and an outer wall was not considered especially.

  This invention is made | formed in view of the said situation, Even if dew condensation arises between a heat insulating material and an outer wall, it aims at not reducing the heat insulation performance of a heat insulating material.

  The present invention for solving the above-mentioned problems is a heat treatment furnace for heat-treating a workpiece, wherein the furnace wall is composed of an outer wall and a heat insulating material unit, and the heat insulating material unit includes a base material layer made of a heat insulating material and the base material. A heat-resistant resin film covering at least one surface of the layer, and the heat insulating material unit is disposed so that the water-resistant resin film faces the inner surface of the outer wall.

  In the heat treatment furnace according to the present invention, since a water-resistant resin film exists between the heat insulating material and the outer wall, even if condensation occurs between the heat insulating material and the outer wall, generated water droplets are blocked by the water-resistant resin film. And does not reach the insulation.

  The present invention according to another aspect is a heat insulating unit for a heat treatment furnace, comprising a base material layer made of a heat insulating material and a water-resistant resin film covering at least one surface of the base material layer. To do.

  According to another aspect of the present invention, there is provided a stirring fan for stirring an atmosphere in a heat treatment furnace, wherein a rotating shaft of the stirring fan passes through a heat insulating material unit, and the heat insulating material unit includes a base material layer made of a heat insulating material, And a water resistant resin film covering at least one surface of the base material layer, and the heat insulating material unit so that the water resistant resin film faces an inner surface of an outer wall of the heat treatment furnace when attached to the heat treatment furnace. Is provided.

  According to another aspect of the present invention, there is provided a method for constructing a heat treatment furnace in which a furnace wall is composed of an outer wall and a heat insulating material for heat treatment of a workpiece, wherein a plurality of the heat insulating material units are prepared, and the water resistant resin film is provided. Each heat insulating unit is arranged so as to face the inner surface of the outer wall.

  According to the present invention, even if condensation occurs between the heat insulating material and the outer wall, the generated water droplets are blocked by the water-resistant resin film, and thus do not reach the heat insulating material. That is, moisture absorption of the heat insulating material can be prevented. Thereby, it becomes possible to suppress a deformation | transformation and deterioration of a heat insulating material, and can prevent the fall of heat insulation performance.

It is a top view showing a schematic structure of a heat treatment furnace concerning an embodiment of the present invention. It is AA sectional drawing in FIG. It is sectional drawing which shows schematic structure of the heat insulating material unit which concerns on embodiment of this invention. It is sectional drawing which shows schematic structure of the heat insulating material unit which concerns on another embodiment of this invention. It is sectional drawing which shows schematic structure of the heat insulating material unit which concerns on another embodiment of this invention. It is sectional drawing which shows schematic structure of the heat insulating material unit which concerns on another embodiment of this invention. It is sectional drawing which shows schematic structure of the heat insulating material unit which concerns on another embodiment of this invention. It is a figure which shows the heat processing furnace at the time of applying the heat insulating material unit which concerns on embodiment of this invention to a stirring fan.

  Hereinafter, a heat treatment furnace according to an embodiment of the present invention will be described with reference to the drawings. The heat treatment furnace of the present embodiment is a continuous heat treatment furnace that performs a series of heat treatments related to carburization. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, the heat treatment furnace 1 according to the present embodiment has a rectangular outer shape in plan view. In the hearth at one corner among the four corners of the heat treatment furnace 1, a carry-in port 2 for carrying the workpiece W is formed. As shown in FIGS. 1 and 2, a heat-resistant brick 3 is arranged at the center in the heat treatment furnace so as to extend from one side wall to the other side wall. The heat-resistant brick 3 is provided in contact with the hearth and the ceiling. The workpiece W carried in from the carry-in entrance 2 is conveyed along the periphery of the heat-resistant brick 3. A carry-out port 4 for carrying out the work W is formed in the side wall portion of the heat treatment furnace 1 downstream in the work transfer direction T.

  A furnace wall 5 of the heat treatment furnace 1 includes an outer wall 6 made of an iron skin or the like, and a heat insulating material unit 7 provided on the inner surface of the outer wall 6. Each heat insulating material unit 7 on the side surface and the bottom surface of the furnace wall 5 is fixed by being laid so as to fill a gap between each other. On the other hand, in the ceiling portion of the furnace wall 5, pins 8 are provided on the inner surface of the outer wall 6 so as to penetrate the outer wall 6. The pin 8 is fixed by being welded on the outer periphery of the outer wall 6 so that the central axis is perpendicular to the outer wall 6. The heat insulating material unit 7 in the ceiling has an opening that is approximately the same as the pin diameter. Further, a plate 9 made of ceramics or the like is provided on the ceiling, and is fixed to the ceiling surface by pins 8. The heat insulating material unit 7 in the ceiling portion is fixed by supporting its own weight by the plate 9.

  The heat treatment furnace 1 is provided with a plurality of stirring fans 10 for stirring the atmosphere in the furnace. A rotating shaft 11 is connected to the blade portion 10a of the stirring fan 10 located in the furnace. The rotary shaft 11 passes through the plate 9 and the furnace wall 5 and is connected to a drive source (not shown) outside the furnace.

  A plurality of stirring fans 10 are provided. Between each stirring fan 10, an elevating partition door 12 (not shown in FIG. 2) is provided. That is, when the partition door 12 is closed, a sealed space is formed by the partition door 12, the furnace wall 5, and the heat-resistant brick 3. Then, a desired heat treatment (temperature increase, carburization, diffusion, quenching, etc.) is sequentially performed in the sealed space, so that a series of heat treatments related to the carburization treatment is performed on the workpiece W.

  As shown in FIG. 3, the heat insulating material unit 7 according to this embodiment includes a base material layer 7 a made of a heat insulating material. The heat insulating material of the base material layer 7a has a rectangular shape in a plan view such as a rectangular parallelepiped or a cube. The heat insulating material of the base material layer 7a is a so-called high performance heat insulating material such as Roslim (registered trademark) board (for example, a heat-resistant temperature of 800 ° C. or higher and a thermal conductivity of 0.05 W / m · K or lower). It is preferable to adopt.

  A water-resistant resin film 7b is attached to one surface of the six base material layers 7a. The method for attaching the water-resistant resin film 7b to the base material layer 7a is such that the water-resistant resin film 7b is not displaced and the base material layer 7a is not exposed during the construction or use of the heat treatment furnace 1. If it is good. For example, the water resistant resin film 7b is attached to the base material layer 7a using a heat resistant adhesive.

  The water resistant resin film 7b is formed of a material that does not allow moisture to pass therethrough. Examples of the “water resistant resin film” include a synthetic resin film containing polyethylene. Moreover, in the case of the resin film containing polyethylene, it is preferable to contain 99% or more of polyethylene. Moreover, it is preferable that the thickness of a water-resistant resin film is 0.05 mm or more and 1 mm or less. Preferably they are 0.05 mm or more and 0.5 mm or less.

  As described above, the heat insulating material unit 7 according to this embodiment includes the base material layer 7a and the water-resistant resin film 7b. As shown in FIGS. 1 and 2, the heat insulating material unit 7 is disposed such that the water-resistant resin film 7 b faces the inner surface of the outer wall of the furnace wall 5. A plurality of heat insulating material units 7 are spread over the entire inner surface of the outer wall by such an arrangement method, whereby the furnace wall 5 of the heat treatment furnace 1 is configured.

  For this reason, the water-resistant resin film 7b exists between the base material layer 7a of the heat insulating material unit 7 constituting the furnace wall 5 and the outer wall 6. Thereby, even if dew condensation occurs on the inner surface of the outer wall due to the temperature difference or humidity difference between the furnace atmosphere and the atmosphere outside the furnace, the generated water droplets are blocked by the water resistant resin film 7b and reach the base material layer 7a. do not do.

  That is, according to the heat insulating material unit 7 according to the present embodiment, even when condensation occurs between the base material layer 7a and the outer wall 6, the base material layer 7a is configured by the presence of the water-resistant resin film 7b. The insulation does not absorb the generated water droplets. Thereby, the deformation | transformation and deterioration accompanying moisture absorption of a heat insulating material can be prevented, and it becomes possible to prevent the heat insulation performance from falling.

  The temperature of the furnace during the heat treatment is, for example, 850 ° C. or higher, but due to the heat insulating effect of the base material layer 7a, the temperature between the base material layer 7a and the outer wall 6 is such that the water-resistant resin film 7b is melted. It is not at temperature.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above-described embodiment, the heat insulating material unit 7 has a structure in which the water-resistant resin film 7b is attached to one surface of the base material layer 7a. However, as shown in FIG. It is good also as a structure covered with the conductive resin film 7b. In this case, the heat insulating material wrapped with the water resistant resin film 7b is put in a heating furnace, and the water resistant resin film 7b is thermally contracted by maintaining a temperature of about 200 ° C. Thereby, the water resistant resin film 7b is fixed to the heat insulating material constituting the base material layer 7a.

  Since the frictional force between the water-resistant resin films 7b is small, when covering the entire surface of the base material layer 7a with the water-resistant resin film 7b, the adjacent heat-insulating material units 7 are arranged when arranging the heat-insulating material units 7 in the furnace. The friction between 7 is reduced. Thereby, the attachment to the outer wall 6 of the heat insulating material unit 7 in a furnace construction stage becomes easy. As a result, it is possible to shorten the time required for the furnace building. In addition, since the entire surface of the base material layer 7a is covered with the water-resistant resin film 7b, moisture absorption of the heat insulating material during storage of the heat insulating material unit 7 after the heat insulating material unit 7 is manufactured until the furnace is built. Can be prevented. In addition, when covering the whole surface of the base material layer 7a with the water-resistant resin film 7b, the water-resistant resin film 7b is melted except for the surface facing the outer wall 6 due to heat during heat treatment in the furnace. Therefore, it is preferable to remove the film facing the inside of the furnace after stacking the heat insulating material units 7 covered with the water-resistant resin film 7b to form the furnace wall.

  Moreover, in the said embodiment, although the base material layer 7a was comprised with one heat insulating material, as shown in FIG. 5, it is good also as comprising the base material layer 7a with a some heat insulating material, for example. In this case, it is preferable to cover the entire surface of the base material layer 7a with the water resistant resin film 7b.

  In a heat treatment furnace, it is common that the heat insulating material has a multilayer structure. At the stage of building the heat insulating material, the heat insulating materials are attached to the outer wall 6 one by one, and it takes time to complete the furnace. However, as shown in FIG. 5, for example, if the heat insulating material unit 7 includes three heat insulating materials covered with the water-resistant resin film 7 b, three heat insulating materials can be transported and attached together. As a result, it is possible to significantly reduce the time spent for building a furnace.

  On the other hand, since the temperature in the furnace during the heat treatment is 850 ° C. or higher, the water resistant resin film 7 b of the heat insulating material unit 7 may be melted except for the surface facing the outer wall 6. In this case, since each heat insulating material of the base material layer 7a is not wrapped with the water-resistant resin film 7b, the position of each heat insulating material is not constrained. For this reason, the heat insulating material unit 7 attached to the side wall of the heat treatment furnace 1 has a concern that the heat insulating material may drop out inside the furnace due to vibration or the like.

  Therefore, as shown in FIG. 6, as the heat insulating material unit 7, the whole surface of the base material layer 7a is covered with a fibrous heat insulating material 7c, and the whole surface of the fibrous heat insulating material 7c is further covered with a water resistant resin film 7b. preferable. The fibrous heat insulating material 7c is formed of a material that does not melt depending on the furnace temperature. For this reason, even if the water-resistant resin film 7b melts due to the rise in the furnace temperature, the base material layer 7a of the heat insulating material unit 7 on the side wall is wrapped with the fibrous heat insulating material 7c, and the base material layer 7a The position of each heat insulating material is in a restrained state. That is, it is possible to prevent the respective heat insulating materials from falling off.

  Moreover, the force which bundles a several heat insulating material becomes strong by covering the whole surface of the base material layer 7a with the fibrous heat insulating material 7c. Thereby, it becomes possible to make the shape of the heat insulating material unit 7 difficult to collapse at the time of transportation and attachment of the heat insulating material unit 7 at the furnace building stage.

  Moreover, even if the several heat insulating material which comprises the heat insulating material unit 7 is the same dimension on design, it will not become the completely same shape by a product error. For this reason, when a plurality of heat insulating material units 7 are used to form the furnace wall, a gap may be generated between the heat insulating material units due to an accumulated error. In such a case, if the fibrous heat insulating material 7c is provided as a configuration of the heat insulating material unit 7, the gap between the heat insulating material units can be filled with the fibrous heat insulating material 7c having elasticity. Thereby, the heat insulation of a furnace wall can be improved. Examples of the “fibrous heat insulating material” include a blanket made of glass fiber.

  Moreover, although the heat insulating material unit 7 shown in FIG. 6 is comprised in order of the base material layer 7a, the fibrous heat insulating material 7c, and the water resistant resin film 7b, the order of the water resistant resin film 7b and the fibrous heat insulating material 7c is the order. It may be replaced. That is, it is good also as a structure which covers the base material layer 7a with the water-resistant resin film 7b, and also covers the fibrous heat insulating material 7c on it. Even in this case, it is possible to obtain the effect of preventing each heat insulating material from falling off.

  However, when the water-resistant resin film 7b is covered with the fibrous heat insulating material 7c, it is necessary to use an air tucker or the like when fixing the fibrous heat insulating material 7c to the base material layer 7a. In this case, the heat insulating material which comprises the base material layer 7a will be damaged, and there exists a possibility that original heat insulating performance and durability performance of a heat insulating material cannot be exhibited. Therefore, in order to fully exhibit the function as the heat insulating material unit 7 and to improve the furnace building property, it is preferable to adopt the configuration shown in FIG.

  Moreover, in order to obtain the effect of preventing moisture absorption of the heat insulating material according to the present invention, it is only necessary that the water-resistant resin film 7 b is provided on the surface of the heat insulating material unit 7 that faces the outer wall 6. For this reason, when covering the whole surface of the base material layer 7a with the fibrous heat insulating material 7c, as shown in FIG. 7, it is good also as providing the water resistant resin film 7b only in one surface of the fibrous heat insulating material 7c.

  The heat insulating unit 7 on the ceiling of the heat treatment furnace 1 is supported by a plate 9, and the heat insulating unit 7 on the hearth is supported by an outer wall 6 of the hearth. For this reason, about the heat insulating material unit 7 for ceiling parts, and the heat insulating material unit 7 for hearth parts, even if it does not use the fibrous heat insulating material 7c, the problem that a heat insulating material peels from the outer wall 6 does not arise. Accordingly, for example, the heat insulating material unit 7 for the hearth is not provided with the fibrous heat insulating material 7c, and the heat insulating material unit 7 for the side wall is provided with the fibrous heat insulating material 7c. It is also possible to construct a furnace by combining them.

  Further, as shown in FIG. 8, the rotating shaft 11 of the stirring fan 10 according to the present invention may pass through the heat insulating material unit 7, and the heat insulating material unit 7 may be provided so as to cover the rotating shaft 11 of the stirring fan 10. . When the heat insulating material unit 7 is applied to the stirring fan 10, the base material layer 7a may be formed in a columnar shape and the surface facing the outer wall 6 may be covered with the water resistant resin film 7b. Thereby, the moisture absorption of the base material layer 7a can be prevented. Moreover, when applying the heat insulating material unit 7 to the stirring fan 10, as described above, covering the entire surface of the base material layer 7a with the water-resistant resin film 7b, or forming the base material layer 7a into multiple layers, It is also possible to provide a fibrous heat insulating material 7c.

  In the above embodiment, the heat insulating material unit 7 is applied to a continuous carburizing furnace, but may be applied to a batch heat treatment furnace. Further, the heat treatment furnace is not limited to one for carburizing treatment.

  The present invention can be applied to a heat treatment furnace for performing a carburizing process on a workpiece.

DESCRIPTION OF SYMBOLS 1 Heat treatment furnace 2 Carry-in port 3 Heat-resistant brick 4 Carry-out port 5 Furnace wall 6 Outer wall 7 Heat insulation material unit 7a Base material layer 7b Water-resistant resin film 7c Fibrous heat insulation material 8 Pin 9 Plate 10 Stirring fan 10a Blade part 11 Rotating shaft 12 Partition Door T Workpiece transport direction W Workpiece

Claims (8)

A heat treatment furnace for heat treating a workpiece,
The furnace wall is composed of an outer wall and an insulation unit,
The insulation unit is
A base material layer made of heat insulating material;
A water-resistant resin film covering at least one surface of the base material layer,
The heat insulating unit is a heat treatment furnace in which the water-resistant resin film is disposed so as to face the inner surface of the outer wall. A base material layer made of heat insulating material;
A heat-insulating material unit for a heat treatment furnace, comprising a water-resistant resin film covering at least one surface of the base material layer.   The heat insulating material unit for heat treatment furnaces according to claim 2, wherein the entire surface of the base material layer is covered with the water-resistant resin film.   The said base material layer is a heat insulating material unit for heat processing furnaces of Claim 2 or 3 comprised by the some heat insulating material.   The heat insulation unit for heat treatment furnaces as described in any one of Claims 2-4 further provided with the fibrous heat insulating material which covers the whole surface of the said base material layer.   The heat insulating material unit for heat treatment furnaces according to claim 5, wherein the entire surface of the fibrous heat insulating material is covered with the water-resistant resin film. A stirring fan for stirring the atmosphere in the heat treatment furnace,
The rotating shaft of the stirring fan penetrates the heat insulating material unit,
The insulation unit is
A base material layer made of heat insulating material;
A water-resistant resin film covering at least one surface of the base material layer,
The agitation fan in which the heat insulating unit is provided so that the water-resistant resin film faces the inner surface of the outer wall of the heat treatment furnace when attached to the heat treatment furnace. A furnace construction method of a heat treatment furnace in which a furnace wall is composed of an outer wall and a heat insulating material, and heat-treats a workpiece,
Preparing a plurality of heat insulating material units according to any one of claims 2 to 6;
A method for constructing a heat treatment furnace, wherein each heat insulating unit is disposed so that the water-resistant resin film faces the inner surface of the outer wall.

Images