JPH0638316Y2 - Holding device for resistance heating element for electric furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a holding device for a coil-shaped resistance heating element.

The resistance heating element holding device according to the present invention is useful for supporting a coil-shaped resistance heating element provided in a cylindrical electric furnace by adapting the expansion and contraction of the resistance heating element.

(Prior Art) Conventionally, in this type of electric furnace, a coil-shaped resistance heating element is disposed around a housing cylinder that accommodates an object to be heat-treated, and a heat insulating layer is disposed around the resistance heating element. At the same time, the resistance heating element is supported by the heat insulating layer via the holding member. At this time, the holding members generally shown in FIGS. 6 and 7 are provided. A part of the holding member (1) is immersed in the heat insulating layer (6), and in particular, as shown in FIG. 6, the cross section along the axial direction of the electric furnace housing is opened inward in the radial direction and is E-shaped. And are continuously provided along the axial direction of the housing cylinder and are spaced apart from each other in the circumferential direction. In this case, the coil-shaped resistance heating element (5) is housed and held in the recess (7) of the holding member (1).

Further, as shown in FIGS. 8 and 9, a holding member (1a) having a holding function similar to the above for the resistance heating element of the electric furnace.
Each of the holding members (1a) is provided with a recess (7a) on one side and a protrusion (7b) on the other side in the axial direction of the axis of the container to be heat treated, and the holding members are adjacent to each other. The projection (7b) is fitted in the recess (7a) of (1a) and is provided so as to be continuously provided. Furthermore, the concave part ( 7a ) of the holding member (1a)
And projections coiled resistance heating body when both are fitted to each other in (7b) notch for accommodating the (5a) (8a), ( 8
b ) is formed so that the resistance heating element (5a) can be housed and held between the recess ( 7a ) and the projection ( 7b ) in a state where the holding member (1a) is continuously provided.

(Problems to be solved by the invention) Among the above-mentioned conventional holding members (1) disclosed in FIGS. 6 and 7, the supporting function inward in the radial direction with respect to the container of the object to be processed is insufficient. For example, when the resistance heating element (5) is deformed at a high temperature, this cannot be suppressed, and there is a fear that the resistance heating element (5) may deviate from between the comb teeth (12). Also the 8th
Since the holding member (1a) shown in FIGS. 9 and 9 has a relatively complicated shape, the manufacturing surface and the assembly and manufacturing surface are extremely complicated, and the resistance heating element is arranged radially outward or inward. Although the bearing function is also achieved in the direction of, the margin around the resistance heating element is low, so there is a problem that the resistance heating element becomes elliptical due to plastic deformation.

Therefore, the object of the present invention is to support the resistance heating element of the electric furnace both in the radial direction outward and inward, and at the same time, the manufacturing is easy and the manufacturing and assembling can be performed smoothly. It is an object to provide a highly reliable holding device without wear due to plastic deformation of the body.

(Means for Solving the Problems) According to the present invention, for the above-mentioned purpose, a coil-shaped resistance heating element (15) is provided around a housing portion for housing an object to be heat treated. In the holding device which supports the resistance heating element (15) on the inner peripheral surface of the heat insulating layer (16) arranged around
Multiple teeth (12) with sufficient length in the radial direction of the housing
A large number of comb-teeth-shaped holding bodies (11) having a plurality of teeth are arranged along the axial direction of the holding portion, and the holding bodies extending in the axial direction of the holding portion with respect to the large number of tooth portions (12) of each holding body (11). Rod (1
It is overcome by being characterized in that 4) is penetrated.

(Operation) According to the holding device of the present invention configured as described above, the resistance heating element (15) is formed by the base surface (18) between the tooth portions (12) of the holding body (11) and the holding rod (14). ) Is prevented from deforming at high temperature inward and outward in the radial direction, the resistance heating element (15) can be held without deviating from the holding body (11), and the tooth portion (12) and the holding rod are retained. Since the resistance heating element (15) is fitted in the holding space (17) defined by (14) and
A sufficient margin can be provided around the resistance heating element (15), and a good holding action can be realized without causing wear due to plastic deformation of the resistance heating element (15).

(Embodiment) Referring to FIGS. 1 and 2, the holding device (10) includes a large number of comb-shaped holding bodies (11). In the illustrated embodiment, the holding body (11) has two teeth (12) each.
And the holding members (11) are arranged in a pair so as to face each other so that the tooth portions (12) of the holding members engage with each other. ) Are continuously arranged in the axial direction. Further, the holding body (11) rows are spaced apart from each other in the circumferential direction, and can be arranged, for example, every 60 degrees in rotation angle. In addition, a holding rod (14) extending in the axial direction of the accommodating cylinder (13) penetrates through the tooth portion (12) of each holding member (11) through each of the holding body (11) rows.

In this case, the coil-shaped resistance heating element (15) provided around the housing tube (13) has a holding device (on the inner peripheral surface of the heat insulating layer (16) provided around the resistance heating element (15). 10) will be supported. Here, the coiled resistance heating element (1
For each pitch of the spiral portion, 5) fits in a space (17) defined by the tooth portion (12) and the retaining rod (14) of the retaining body (11) extending sufficiently in the radial direction. Can be done. At this time, the resistance heating element (15) located in the void (17) has a tooth (1
The base surface (18) and the holding rod (14) between 2) prevent radial and inward displacements, and when the resistance heating element (15) is softened at high temperature, it partially sags or becomes elliptical and It can be effectively suppressed.

Further, through holes (19) are formed in the base surface (18) between the tooth portions (12) of the holding body (11), and these through holes (19) are used for heat radiation of the resistance heating element (15). A heat insulating layer (1) is provided in the through holes (19) of the holding body (11) which are arranged to contribute to the outside in the radial direction.
The tip end of the suspension bolt (20), whose base end is fixed to the outer circumference of (6), can be fixed via a nut. By the suspension bolts (20), the holding body (11) row on the outer side in the radial direction, and further the holding body (1) on the inner side in the radial direction via the holding rod (14).
1) The row, that is, the entire holding device (10) according to the present invention is pulled outward in the radial direction, and the holding function of the holding device (10) can be stabilized. Further, by disposing the heat-resistant member (21) at the end portion of the heat insulating layer (16), a so-called horizontal type tubular electric furnace body as shown in FIG. 2 can be constructed.

For an electric furnace, the holding device (10) according to the present invention may be used together with a known holding device (10a) as is clear from FIG. It is preferable to arrange them, but it has been found that the holding device (10) according to the present invention can achieve the intended purpose if it is arranged in at least one row. The holding body (11) has 2
Although the toothed portion (12) has a book shape and is formed in an F shape, the number of toothed portions (12) can be increased or decreased to select one of T-shaped or E-shaped various shapes. And the holding device (1
Although 0) shows a mode applied to a horizontal electric furnace, it can also be adopted to a vertical cylindrical electric furnace. Further, it can be effectively applied to the embodiment in which the coil-shaped resistance heating element (15) is formed to have a rectangular shape as shown in FIG. Moreover, the holding body (11) and the holding rod (14) are preferably made of high-purity alumina material, and the suspension bolt (20) is made of a heat-resistant metal such that a male screw for connecting the nut can be provided at the tip. It is preferable to create.

Further, in addition to the number of holding bodies (11) being increased or decreased, the holding bodies (11) are arranged only on the side of the housing cylinder (13) as shown in FIGS. 4 and 5 without facing each other and facing outward in the radial direction. The holding device (10a) may be configured by inserting a holding rod (14) extending in the axial direction through a large number of comb portions (12) extending in the direction of. Also in this case, the resistance heating element (15) is fitted in the space (17) defined by the tooth portion (12) of the holding body (11) and the holding rod (14). Although the number of comb portions (12) of the holding body (11) is shown as four in FIGS. 4 and 5, the number of comb portions (12) can be appropriately increased or decreased. Further, FIG. 5 shows a mode in which the holding device (10a) is adopted in a so-called vertical cylindrical electric furnace, but it can also be adopted in the horizontal type shown in FIG. 2 or 3.

In addition, in an electric furnace to which the holding device (10) of FIG. 1 and FIG. 2 is applied, the resistance heating element (15) is made of Kanthal A of 8.0 mmφ, the inner diameter is 268 mmφ, and the total length is 500 mm. When compared with an electric furnace using a well-known holding device regardless of the holding device (10) according to the present invention and using a similar resistance heating element, the temperature was raised at 1300 ° C. about 30 times every 10 hours, In the electric furnace using the holding device according to the present invention, the resistance heating element hardly drooped, whereas in the electric furnace using the conventional holding device, a large droop was observed, and the operating time was long. It was predicted that this tendency would increase if the situation changed.

(Effects of the Invention) According to the holding device of the present invention configured as described above, since the resistance heating element can be stably held, it is possible to suppress plastic deformation of the resistance heating element, and thus the resistance heating element sags. It is possible to effectively prevent uneven temperature distribution due to downhill, etc., to prolong the life of the resistance heating element, and to suppress plastic deformation even if the resistance heating element is made larger. Alternatively, it achieves remarkable practical effects such as contributing to higher temperatures.

[Brief description of drawings]

FIG. 1 is a partial perspective view of an embodiment of a holding device for a resistance heating element according to the present invention, FIG. 2 is a perspective view showing a partial cutaway of a horizontal electric furnace employing the holding device, and FIG. FIG. 4 is a partial perspective view of another embodiment of the present invention which employs a holding device, FIG. 4 is a partial perspective view of another embodiment of the present invention, and FIG. 5 is a partial incision of a vertical electric furnace which employs the holding device. FIG. 6 is a side view of a conventional holding device, FIG. 7 is a cross-sectional view taken at a position rotated 90 degrees from FIG. 6, and FIG. 8 is a side view of another conventional holding device. , FIG. 9 is a sectional view taken at a position rotated by 90 degrees from FIG. 11 ... Retaining body, 12 ... Tooth portion, 13 ... Retaining cylinder, 14 ... Retaining rod, 15 ... Resistance heating element, 16 ... Heat insulating layer, 17 ... Space, 18 ... Base surface, 19 ... Through hole, 20 ... Hanging bolt , 21 ... Heat resistant material

Claims (3)

[Scope of utility model registration request] 1. A heat-insulating layer (16) provided around a resistance heating element (15) in which a coil-shaped resistance heating element (15) is provided around a storage portion for storing an object to be processed. In a holding device that supports a resistance heating element (15) on its peripheral surface, a comb-teeth-shaped holding body (11) having a plurality of teeth (12) having a sufficient length in the radial direction of the housing is housed. The holding rods (14), which are arranged in a large number along the axial direction of the housing portion and which extend in the axial direction of the housing portion, penetrate through the numerous tooth portions of each holding body (11),
A holding device, characterized in that each spiral portion of a resistance heating element (15) is provided so as to be arranged in a space (17) formed by a tooth portion (12) and a holding rod (14). 2. The holding device according to claim 1, wherein the holding body (11) is formed in an F-shape, and the holding body (11) is arranged in pairs so that the tooth portions (12) mesh with each other. . 3. A base surface (1) between tooth portions (12) of a holding body (11).
8) is provided with a through hole (19), and the tip end of the hanging bolt (20) having the proximal end fixed to the outer peripheral portion of the heat insulating layer (16) can be fixed by being inserted into the through hole (19). The holding device according to claim 1 or 2, wherein the utility model registration is provided.