JP2016053466A - Heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment device capable of quickly raising a temperature of a muffle, and improving thermal uniformity in the muffle after the rise of temperature.SOLUTION: A heat treatment device 1 includes a furnace body 2 the inside of which is formed into the substantially rectangular shape, a muffle 3 disposed in the furnace body 2 while extending in an axial direction, and accommodating a heat treatment object, a high output heating element 4 for entirely heating the muffle 3 in the longitudinal direction, and planar heating elements 5a-5e heating the muffle 3 with an output lower than the high output heating element 4. A plurality of high output heating elements 4 are disposed in an axial direction of the muffle 3 at both outer sides in one direction substantially orthogonal to an axial direction of the muffle 3 at prescribed internals. The pair of planar heating elements 5b and 5c are disposed at both outer sides in one direction with respect to the high output heating elements 4.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat treatment apparatus for heat-treating an object to be processed with a high-power heating element.

  2. Description of the Related Art Conventionally, as a heat treatment apparatus for heating and heat-treating an object to be processed contained in a cylindrical muffle in a furnace body, one having a high-output heating element that heats at a high output such as a SiC heater is known (for example, , See Patent Document 1).

JP 10-141859 A

In the conventional heat treatment apparatus, although the muffle can be quickly heated by the high-power heating element, there is a problem that it is difficult to maintain the heat uniformity in the muffle after the temperature is raised.
The present invention has been made in view of the above problems, and provides a heat treatment apparatus capable of quickly raising the temperature of the muffle and improving the heat uniformity in the muffle after the temperature increase. Objective.

  The heat treatment apparatus of the present invention includes a furnace main body having an inside formed in a substantially rectangular shape, a muffle disposed in the furnace main body and extending in the axial direction and containing an object to be heat treated, A high-power heating element that heats the muffle over its entire length, and a sheet-like heating element that is formed in a substantially planar shape and heats the muffle at a lower output than the high-power heating element. A plurality of bodies are arranged on both outer sides in one direction substantially orthogonal to the axial direction of the muffle, with a predetermined gap therebetween along the axial direction of the muffle, and the planar heating element includes at least the A pair is arranged on both outer sides in the one direction with respect to the high-power heating element.

According to the present invention, since the muffle is heated by the high-power heating element and the planar heating element, the muffle can be quickly raised to the target temperature. Further, since the muffle is heated by the planar heating element at a low output, the heat uniformity in the muffle after the temperature rise can be improved.
Further, since the high-power heating element is disposed on the inner side (muffle side) than the planar heating element, the heat radiated from the high-output heating element is effectively transmitted to the muffle. Further, since the plurality of high-power heating elements are arranged with a predetermined gap between each other, the heat radiated from the planar heating element arranged outside the high-power heating element passes through the gap to the muffle. Effectively communicated. Thereby, a muffle can be heated effectively and a muffle can be heated uniformly.

In the heat treatment apparatus, the length of the planar heating element in the other direction, which is a direction substantially orthogonal to the axial direction of the muffle and a direction substantially orthogonal to the one direction, is larger than the outer diameter of the muffle. It is preferable to set it long.
In this case, since the planar heating element is formed wider than the outer diameter of the muffle, the muffle can be effectively heated by the planar heating element, and the muffle can be heated uniformly.

In the heat treatment apparatus, the muffle is formed in a substantially cylindrical shape, and the planar heating element has a direction substantially perpendicular to both outer sides of the one direction and the axial direction of the muffle with the muffle interposed therebetween. In addition, it is preferably arranged on both outer sides in the other direction, which is a direction substantially orthogonal to the one direction.
In this case, the planar heating element is disposed on both sides of the one direction and the other direction on both sides of the muffle, that is, the planar heating element is disposed so as to surround the entire outer periphery of the muffle. The muffle can be heated more effectively, and the muffle can be heated more uniformly.
Moreover, since the muffle is formed in a substantially cylindrical shape and has an excellent symmetry, it has excellent mechanical strength against a thermal load. Moreover, since the muffle has a shape with excellent symmetry, heat transfer can be performed uniformly, and the heat uniformity in the muffle can be further improved.

In the heat treatment apparatus, the high-power heating element is disposed so as to extend downward from the upper part of the furnace main body, and the lower end of the high-power heating element is disposed on the workpiece in the muffle. It is preferable to arrange below the arrangement position.
In this case, it is possible to uniformly raise the temperature of the entire object to be processed disposed in the muffle by the high output heating element.

In the heat treatment apparatus, it is preferable that an inner surface of the planar heating element facing the furnace body is substantially flush with an inner wall surface of the furnace body.
In this case, it can suppress that the inner surface which faces the furnace main body of a planar heating element protrudes inside rather than the inner wall surface of a furnace main body.

  According to the heat treatment apparatus of the present invention, it is possible to quickly raise the temperature of the muffle and to improve the heat uniformity in the muffle after the temperature rise.

It is a perspective view which shows the heat processing apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the inside of a heat processing apparatus. It is sectional drawing which shows the heat processing apparatus. It is a graph which shows the temperature distribution of a heat processing apparatus. It is explanatory drawing which shows the temperature measurement point of a heat processing apparatus.

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a heat treatment apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing the inside of the heat treatment apparatus. 1 and 2, the heat treatment apparatus 1 is used for heat-treating an object to be processed such as a CIGS solar cell, for example. The heat treatment apparatus 1 includes a furnace body 2 having a substantially rectangular shape inside, a substantially cylindrical muffle 3 having an opening / closing door 3a, a high-power heating element 4 and planar heating elements 5a to 5e for heating the muffle 3. And.
As shown in FIG. 1, in this specification, the front side of the furnace body 2 viewed from the entrance / exit 3a side is “front”, the rear side is “rear”, the right side is “right”, and the left side is Each component of the heat treatment apparatus 1 is described as “left”.

  The furnace body 2 is formed in a rectangular parallelepiped shape that is long in the front-rear direction by the front wall portion 6, the rear wall portion 7, the right wall portion 8, the left wall portion 9, the top wall portion 10, and the bottom wall portion 11, and these wall portions. A substantially rectangular space surrounded by 6 to 11 is the heating chamber 2a (see FIG. 3). In the heating chamber 2a of this embodiment, the width dimension in the left-right direction is set to about 1000 mm, the height dimension is set to about 850 mm, and the length dimension in the front-rear direction is set to about 1800 mm.

  The muffle 3 is formed to extend in the axial direction, and most of the muffle 3 is disposed in the heating chamber 2a with the axial direction as the front-rear direction. One end portion in the axial direction of the muffle 3 is supported in a state of penetrating the front wall portion 6 of the furnace body 2, and an opening / closing door 3 a that is opened and closed when the workpiece is accommodated in the muffle 3 on the end surface. Is provided. The muffle 3 is filled with an inert gas such as nitrogen gas or hydrogen gas. Thereby, the to-be-processed object accommodated in the muffle 3 is heat-processed in inert gas atmosphere. The muffle 3 in this embodiment has an inner diameter of about 750 mm and an axial direction (front-rear direction) length of about 2000 mm.

FIG. 3 is a cross-sectional view showing the heat treatment apparatus 1. 2 and 3, the high-power heating element 4 heats the muffle 3 with a high output over the entire length thereof, and is made of, for example, a rod-like SiC (silicon carbide) heater. The high-power heating element 4 is disposed on both outer sides in the left-right direction (one direction) of the muffle 3 disposed in the center portion in the heating chamber 2 a, and the upper end portion thereof is supported by the top wall portion 10. The length of the high-power heating element 4 in the vertical direction is set such that the lower end of the high-power heating element 4 is disposed below the position where the object to be processed in the muffle 3 is disposed.
A plurality of high-power heating elements 4 are arranged along the axial direction of the muffle 3 with a predetermined gap therebetween, and the outer peripheral surface of the muffle 3 is heated from both the left and right sides. Twelve high-power heating elements 4 of the present embodiment are arranged on each of the left and right sides.

  As shown in FIGS. 1 and 2, planar heating elements 5 a to 5 e are provided on the inner wall surfaces of the wall portions 7 to 11 of the furnace body 2. The planar heating elements 5a to 5e heat the muffle 3 with a lower output than the high-output heating element 4, and are formed in a substantially planar shape. Specifically, the planar heating elements 5a to 5e are, for example, flat plate-like mold thermother heaters, in which a heat insulating material made of ceramic fibers and a heating element made of a metal wire formed in a meandering shape are integrated by vacuum forming. (Product name of heater product manufactured and sold by Koyo Thermo System Co., Ltd.).

  In the sheet heating elements 5a to 5e, all the output ratios of the high-power heating elements 4 to all the sheet heating elements 5a to 5e are 5/7 or more in order to improve the heat uniformity in the furnace body 2. It is preferable to set as follows. The high-power heating element 4 and the planar heating element 5 maintain the heat treatment temperature by reducing both outputs while maintaining the output ratio after reaching the predetermined heat treatment temperature. ing.

  The planar heating elements 5a to 5e include a first planar heating element 5a fixed to the inner wall surface of the rear wall portion 7, a second planar heating element 5b fixed to the inner wall surface of the right wall portion 8, and a left The third planar heating element 5c fixed to the inner wall surface of the wall portion 9, the fourth planar heating element 5d fixed to the inner wall surface (lower wall surface) of the top wall portion 10, and the inner wall surface of the bottom wall portion 11 It consists of the 5th planar heating element 5e fixed to (upper wall surface).

  As shown in FIG. 2, the first sheet heating element 5a is constituted by a pair of first sheet heating parts 5a1 formed in a rectangular flat plate shape. These first sheet-like heat generating portions 5a1 are arranged at predetermined intervals in the left-right direction along the inner wall surface of the rear wall portion 7, with the longitudinal direction thereof being the vertical direction. The first sheet heating element 5 a is embedded in the rear wall 7, and the inner surface of the first sheet heating element 5 a facing the furnace body 2 is flush with the inner wall surface of the rear wall 7. Moreover, as shown in FIG. 3, each 1st planar heat-emitting part 5a1 is each arrange | positioned in the back wall part 7 so as to oppose each right and left both sides except the center part of the rear-end part of the muffle 3, The length in the vertical direction of the single sheet heating portion 5 a 1 is set longer than the outer diameter of the muffle 3. Thereby, the 1st planar heating element 5a heats the rear-end part of the muffle 3.

As shown in FIGS. 2 and 3, the second planar heating element 5 b is arranged on the right outer side of the high-power heating element 4 arranged on the right outer side of the muffle 3. The third planar heating element 5 c is disposed on the left outer side of the high-power heating element 4 disposed on the left outer side of the muffle 3.
Further, as shown in FIG. 3, the lengths of the second and third planar heating elements 5 b, 5 c in the vertical direction (other direction) are set longer than the outer diameter of the muffle 3.

  As shown in FIGS. 1 and 2, the second and third planar heating elements 5b and 5c are constituted by a plurality of second and third planar heating elements 5b1 and 5c1 formed in a rectangular flat plate shape. . A plurality of the second and third planar heating portions 5b1 and 5c1 are continuously arranged in the front-rear direction with the longitudinal direction as the vertical direction. As shown in FIG. 3, the second and third planar heating elements 5b and 5c are embedded in the right wall portion 8 and the left wall portion 9, respectively, and are placed in the furnace body 2 of the second planar heating element 5b. The inner surface facing the inner wall surface of the right wall portion 8 is disposed flush with the inner wall surface of the third wall heating element 5c, and the inner surface facing the furnace body 2 of the third planar heating element 5c is disposed flush with the inner wall surface of the left wall portion 9. Further, the second and third planar heating elements 5b, 5c are arranged in the center in the vertical direction of the right wall portion 8 and the left wall portion 9, and heat the outer peripheral surface of the muffle 3 from the left and right sides, respectively. ing.

As shown in FIG. 3, the fourth planar heating element 5 d is disposed on the upper and outer sides of the muffle 3. Further, the fifth planar heating element 5e is disposed on the lower outer side of the muffle 3.
The lengths of the fourth and fifth planar heating elements 5d, 5e in the left-right direction (one direction) are set longer than the outer diameter of the muffle 3.

  As shown in FIGS. 1 and 2, the fourth and fifth planar heating elements 5d, 5e are constituted by a plurality of fourth and fifth planar heating parts 5d1, 5e1 formed in a rectangular flat plate shape. . A plurality of the fourth and fifth planar heating portions 5d1 and 5e1 are continuously arranged in the front-rear direction with the longitudinal direction as the left-right direction. As shown in FIG. 3, the fourth and fifth planar heating elements 5d and 5e are embedded in the top wall 10 and the bottom wall 11, respectively, and are placed in the furnace body 2 of the fourth planar heating element 5d. The inner surface (lower surface) facing the inner wall surface (lower wall surface) of the top wall portion 10 is flush with the inner wall surface (upper surface) of the fifth planar heating element 5e. It is arranged flush with the (upper wall surface). Further, the fourth and fifth planar heating elements 5d and 5e are arranged at the center in the left-right direction of the top wall 10 and the bottom wall 11 so as to heat the outer peripheral surface of the muffle 3 from both the upper and lower sides. It has become.

FIG. 4 is a graph showing the temperature distribution of the heat treatment apparatus 1 under predetermined test conditions. FIG. 5 is an explanatory diagram showing temperature measurement points of the heat treatment apparatus 1 in the test.
In this test, the maximum output total value of the high-power heating element 4 is set to approximately 70 kW, the maximum output total value of the planar heating elements 5b to 5e is set to approximately 50 kW, The ratio of all the outputs of the high-power heating element 4 was set to be approximately 5/7. Then, the inside of the muffle 3 is heated to 600 ° C. by the high output heating element 4 and the planar heating elements 5b to 5e, and then controlled to soak for 90 minutes, and the measurement container disposed in the muffle 3 at that time Measure each temperature at a total of 5 points: C left upper left measurement point P1, right front upper measurement point P2, right rear lower measurement point P3, left front lower measurement point P4, and central measurement point P5. did. Note that the solid line in FIG. 4 indicates the temperature distribution outside the muffle 3, and the broken line in FIG. 4 indicates the average temperature distribution at the five points inside the muffle 3.

As shown in FIG. 4, the average temperature increase rate from 200 ° C. to 500 ° C. at the five points is 18.2 ° C./min, and the average temperature increase rate when heated only by the planar heating elements 5b to 5e is It can be seen that the value is higher than that of about 10 ° C./min.
In addition, as shown in FIG. 4, the temperature difference (width) between the maximum temperature and the minimum temperature inside the muffle 3 in the soaking 90 minutes is 2.5 ° C., and the soaking is carried out in a small width. I understand.
If the sheet heating element 5a is added to the sheet heating elements 5b to 5e and heated, the average temperature rise rate can be further increased.

According to the heat treatment apparatus 1 of the present embodiment configured as described above, the muffle 3 is heated by the high-power heating element 4 and the planar heating element 5, so that the muffle 3 is quickly raised to the target temperature. Can do. Further, since the muffle 3 is heated by the planar heating element 5 at a low output, the heat uniformity in the muffle 3 after the temperature rise can be improved.
Further, since the high output heating element 4 is arranged on the inner side (muffle 3 side) than the second and third planar heating elements 5b and 5c, the heat radiated from the high output heating element 4 is effectively applied to the muffle 3. Communicated. Further, since the plurality of high-power heating elements 4 are arranged with a predetermined gap therebetween, the heat radiated from the second and third planar heating elements 5b and 5c arranged outside the high-output heating element 4 is obtained. Is effectively transmitted to the muffle 3 through the gap. Thereby, the muffle 3 can be heated effectively and the muffle 3 can be heated uniformly.

  Further, the vertical lengths of the second and third planar heating elements 5b and 5c and the horizontal lengths of the fourth and fifth planar heating elements 5d and 5e are both larger than the outer diameter of the muffle 3. The sheet heating elements 5 b to 5 e are formed wider than the outer diameter of the muffle 3. Therefore, the muffle 3 can be effectively heated by the planar heating elements 5b to 5e, and the muffle 3 can be heated uniformly.

Further, the planar heating elements 5b to 5e are disposed on both sides in the left and right direction and both sides in the vertical direction with the muffle 3 interposed therebetween, that is, the planar heating elements 5b to 5e so as to surround the entire outer periphery of the muffle 3. Therefore, the muffle 3 can be heated more effectively and the muffle 3 can be heated more uniformly.
Moreover, since the muffle 3 is formed in a substantially cylindrical shape and has an excellent symmetry, the mechanical strength against a thermal load is excellent. Further, since the muffle 3 has a shape with excellent symmetry, heat transfer can be performed uniformly, and the heat uniformity in the muffle 3 can be further improved.

Further, the high-power heating element 4 is disposed so as to extend from the upper part of the furnace body 2 to the lower side in the furnace body 2, and the lower end of the high-power heating element 4 is located from the position of the workpiece in the muffle 3. Since the high-power heating element 4 can also raise the temperature of the entire object to be processed arranged in the muffle 3 uniformly.
Further, since the inner surface of the planar heating element 5 facing the inside of the furnace body 2 is disposed so as to be substantially flush with the inner wall surface of the furnace body 2, the inner surface of the planar heating element 5 facing the furnace body 2 is arranged. However, it can suppress projecting inside rather than the inner wall surface of the furnace main body 2.

  The present invention is not limited to the above embodiments. For example, the planar heating element of the present embodiment is disposed on both outer sides of the high-output heating element (both outer sides in the left-right direction of the muffle) and on both outer sides in the vertical direction of the muffle. It only has to be arranged on both outer sides of the body. Further, the number of the high-power heating elements 4 and the planar heating elements 5 can be arbitrarily set according to the heat treatment conditions.

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus 2 Furnace main body 3 Muffle 4 High output heating element 5a 1st planar heating element 5b 2nd planar heating element 5c 3rd planar heating element 5d 4th planar heating element 5e 5th planar heating element

Claims (5)

A furnace body whose inside is formed in a substantially rectangular shape;
A muffle that is disposed in the furnace body and extends in the axial direction and accommodates an object to be heat treated,
A high-power heating element that heats the muffle throughout its longitudinal direction;
A sheet heating element that is formed in a substantially planar shape and heats the muffle at a lower output than the high output heating element,
A plurality of the high-output heating elements are disposed on both outer sides in one direction substantially orthogonal to the axial direction of the muffle, with a predetermined gap therebetween along the axial direction of the muffle,
A pair of the planar heating elements is disposed at least on both outer sides in the one direction with respect to the high-power heating element.   In the planar heating element, the length in the other direction, which is a direction substantially orthogonal to the axial direction of the muffle and a direction substantially orthogonal to the one direction, is set longer than the outer diameter of the muffle. The heat treatment apparatus according to claim 1. The muffle is formed in a substantially cylindrical shape,
The planar heating element has both outer sides in the one direction across the muffle and both outer sides in the other direction that is a direction substantially orthogonal to the axial direction of the muffle and a direction substantially orthogonal to the one direction. The heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is disposed respectively. The high-power heating element is disposed so as to extend from the upper part of the furnace body to the lower part in the furnace body,
The heat processing apparatus of any one of Claims 1-3 with which the lower end of the said high output heat generating body is arrange | positioned below rather than the arrangement position of the to-be-processed object in the said muffle.   The heat processing apparatus of any one of Claims 1-4 arrange | positioned so that the inner surface which faces in the said furnace main body in the said planar heating element may become substantially flush with the inner wall surface of the said furnace main body.

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