JP3527978B2 - heating furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating furnace, and more particularly to a heating furnace in which a belt-shaped heating element is held by a heat insulating material.

[0002]

2. Description of the Related Art Conventionally, as a heating furnace, it is preferable that the entire surface of the inside of the furnace is used as a heating element and the entire outer surface thereof is surrounded by a heat insulating material so that the temperature difference between the heating element and the inside of the heating element can be reduced. The temperature of the heating element can be reduced to a lower temperature to extend the life of the furnace, but in order to improve the soaking characteristics in the furnace, the temperature near the furnace edge can be set higher than that in the furnace. To increase the electric resistance value of the heating element to reduce the energizing current so that the commercial power source can be used as it is, the belt-shaped heating element is appropriately arranged as it is on the inner wall surface of the furnace, or the belt-shaped heating element is appropriately changed. A slit is provided and similarly arranged on the inner wall surface of the furnace.

In the method conventionally used for fixing the heating element to the inner wall of the furnace, a fibrous heat insulating material disposed on the outer surface of the heating element is used to hold the heating element.
A part of the holding material of the heat-resistant insulating material made of alumina is embedded, and the heating element is held by the remaining part that is projected to the inner surface of the furnace, or the heating element is bent in a wavy shape and the part protruding to the heat insulating material side A part of the fibrous heat insulating material is held by the solidified surface portion.

4 and 5 are explanatory views of the former, in which 1 is a fiber-shaped heat insulating material, 2 is a flat strip-shaped heating element,
Reference numeral 3 denotes a base member of the upper and lower holding members 3 which are provided with grooves for sandwiching the heating element 2 from above and below, for example, upper and lower holding members of a heat-resistant insulating material made of alumina, and 4 which are embedded and fixed in the fibrous heat insulating material 1. Reference numeral 5 denotes a dovetail-shaped recess and a projection formed to connect the bases 4 of the upper and lower holding members 3 to each other.

FIGS. 6 and 7 are explanatory views of the latter case, where 6 is a solidified portion of the surface of the fiber-shaped heat insulating material 1, 7 is a band-shaped heating element curved in a wave shape, and 8 is the surface of the heat insulating material 1. The band-shaped heating element portion embedded in the solidified portion 6 is shown.

[0006]

However, in the former case, the production cost of the holding material made of the heat-resistant insulating material is high, and in order to change the arrangement of the heating elements, it is necessary to change the shape of the holding material. It took a long time to change the mold and production, and it was difficult to respond in a short delivery time. In the latter case,
Since the hardness of the heating element material varies from lot to lot, it is difficult to control the corrugated shape, and the electric resistance value per unit length of the heating element varies between deep bending and shallow bending, In addition, even if there is little displacement in the direction of the adjacent heating element, there is almost no holding force in the direction of the center of the furnace on the surface of the heating element. Due to the change in shape due to the contraction, the protrusion of a part inside the furnace becomes large and there is a drawback that it cannot be used.

The present invention eliminates the above-mentioned drawbacks.

[0008]

The heating furnace of the present invention comprises a heat insulating material, a flat band-shaped heating element arranged on the core side of the heat insulating material, and a length of the band-shaped heating element on the surface on the heat insulating material side. Consisting of a plurality of hooks spaced apart from each other in the direction, and composed of two layers of heat insulating material integrally formed so that the above heat insulating materials overlap each other, and solidified layers are formed on the front surface and the back surface of each heat insulating material layer. The hook has a portion extending outwardly from the strip-shaped heating element and two portions orthogonal to this, and the bent portion of the strip-shaped heating element and the hook is the surface of the heat insulating material layer on the core side and It is characterized in that each is buried in the solidified layer on the back surface.

[0009]

The hook is a plate member bent in a U-shaped cross section.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIGS. 1 and 2, two fibrous heat insulating material layers 1a are formed by vacuum forming.
1b is used as a fibrous heat insulating material 1 and each of the heat insulating material layers 1a and 1b is impregnated with colloidal silica on the front surface and the back surface thereof to form a solidified layer 1c having a thickness of, for example, 3 mm. To form. Further, a plurality of hooks 9 are attached to the flat band-shaped heat generating element 2 while being separated from each other in the lengthwise direction by welding or the like, and the band-shaped heat generating element 2 and the hooks 9 are vacuum-molded, for example, to form the fibrous heat insulating material layer 1a. Embedded in the surface solidified layer 1a. The hook 9 is provided with, for example, a portion 9a extending outwardly from the belt-shaped heating element 2 and a bent portion 9b in a direction orthogonal to the portion 9a so that the cross section thereof has a substantially U-shape.

FIG. 3 shows another embodiment of the present invention in which the bent portion 9b on the inside of the hook 9 is embedded in a solidified layer 1c formed on the back surface of the heat insulating material layer 1a.

[0014]

Since the heating furnace of the present invention is constructed as described above, the strength of the fibrous heat insulating material 1 becomes extremely large, and the deformation as a whole is reduced.
The number of hooks 9 can be reduced by about 30% as compared with the case where the fibrous heat insulating material 1 is made of a single layer, and the shape change accompanying the thermal expansion / contraction of the heating element causes There is a great benefit of being able to reliably prevent a part of the material from jumping inside.

[Brief description of drawings]

FIG. 1 is a front view of a heating element portion of a heating furnace of the present invention.

FIG. 2 is a vertical sectional side view of a heating element portion of the heating furnace shown in FIG.

FIG. 3 is a vertical side view of a heating element portion of a heating furnace according to another embodiment of the present invention.

FIG. 4 is a front view of a heating element portion of a conventional heating furnace.

5 is a vertical side view of a heating element portion of the heating furnace shown in FIG.

FIG. 6 is a front view of a heating element portion of a conventional heating furnace.

7 is a bottom view of a heating element portion of the heating furnace shown in FIG.

[Explanation of symbols]

1 Fiber insulation 1a Fibrous insulation layer 1b Fibrous insulation layer 1c Solidified layer 2 band heating element 3 holding material 4 base 5 Dovetail recess and protrusion 6 Surface solidification part 7 Curved strip heating element 8 Embedded strip heating element 9 hooks 9a extension 9b Bent part

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H05B 3/62-3/66 F27D 11/02 H05B 3/10

Claims (2)

(57) [Claims] 1. A heat insulating material, a flat band-shaped heating element arranged on the core side of the heat insulating material, and a plurality of hooks provided on the surface of the band-shaped heating element on the heat insulating material side so as to be spaced apart from each other in the longitudinal direction. The heat insulating material is composed of two heat insulating material layers integrally formed so as to overlap each other, and a solidified layer is formed on each of the front surface and the back surface of each heat insulating material layer, and the hook is removed from the strip heating element. A part that extends away from and a direction orthogonal to this
And a bent portion of the hook and the hook are embedded in the solidified layers on the front and back surfaces of the heat insulating material layer on the core side, respectively. 2. The heating furnace according to claim 1, wherein the hook is a plate material bent in a U-shaped cross section.