JP5136543B2 - heating furnace - Google Patents

Description

  The present invention relates to a heating furnace provided with a heat treatment chamber having a plurality of stages of heat treatment spaces.

  Conventionally, a heating furnace described in Patent Document 1 below is known as a technique in such a field. This heating furnace accommodates a plurality of objects to be heated in multiple stages in the heat treatment chamber at intervals in the vertical direction, and heats the object to be heated by circulating the hot air generated in the hot air circulation channel to the heat treatment chamber. is there. In the vicinity of the ventilation holes for introducing hot air into the heat treatment chamber, there are a plurality of wind direction adjustment plates that can adjust the inclination, and this wind direction adjustment plate adjusts the air direction of the hot air to adjust the temperature distribution in the heat treatment chamber. It has been proposed to achieve uniformization.

Japanese Patent No. 3644849

  However, in the heating furnace of Patent Document 1, an airflow direction adjusting plate is arranged corresponding to each of the vent holes arranged in the upper and lower directions to suppress the temperature distribution variation of each multi-stage object to be heated. Is not enough. Therefore, for example, when the heating furnace having this configuration is applied to the degreasing treatment of the ceramic molded body, there is a possibility that a difference occurs in the degreasing state of each ceramic molded body arranged in multiple stages, and the ceramic molded body is fired after the degreasing treatment. Sometimes, there is a risk that defects typified by cracks and deformation occur.

  Therefore, an object of the present invention is to provide a heating furnace that makes the temperature distribution in the heat treatment space of each stage in the heat treatment chamber uniform.

The heating furnace of the present invention is arranged at a position where at least a part of the hot air circulating flow path for circulating hot air generated by the heater and the blower and at least a part of the heater or the blower is viewed from the vertical direction, and a horizontal partition wall. partitioned formed has a heat treatment space in a plurality of stages you accommodating the article to be heated, respectively, and a heat treatment chamber for passing the hot air hot air circulation passage is branched into the heat treatment space of each stage, a heat treatment of each stage On the upstream side of the space, a curved heat loss adjusting plate that protrudes longer toward the upstream side as the distance from the heater is larger, a first mesh material on the upstream side that sequentially passes the hot air introduced into the heat treatment space, and the downstream side A second mesh material on each side, the first mesh materials on each step are arranged at the same position as viewed from the vertical direction, and the second mesh material on each step Every time, adjust the position in the direction of hot air It is characterized by being adjustable .

In this case, the heat loss adjustment plate, the first and second mesh material is preferably made of stainless steel. The heat distribution compensation member is made of stainless steel having high heat retention (poor heat conduction), the heat loss adjusting plate as the heat distribution compensation member, and the first and second mesh materials , even if disturbance occurs. However, the temperature does not change abruptly and it is easy to maintain a constant temperature distribution in the heat treatment chamber.

Further, the first mesh material is located downstream of the heat loss adjusting plate and upstream of the heat treatment space, and passes the hot air before being introduced into the heat treatment space, and the second mesh material is Located downstream of the mesh material and upstream of the heat treatment space, the hot air that has passed through the first mesh material is allowed to pass between the first mesh material and the second mesh material. A heat distribution adjusting plate for adjusting the heat distribution in the horizontal direction may be provided.

  Moreover, it is preferable that the aperture ratios of the first and second mesh members of each step differ for each step. By adjusting the aperture ratios of the first and second mesh materials for each heat treatment space, the temperature distribution for each stage can be adjusted more precisely.

  According to the heating furnace of the present invention, the temperature distribution in the heat treatment space at each stage in the heat treatment chamber can be made uniform.

It is a front view which shows partially broken one Embodiment of the heating furnace of this invention. It is a horizontal sectional view along the II-II line of the heating furnace of FIG.

  Hereinafter, preferred embodiments of a heating furnace according to the present invention will be described in detail with reference to the drawings. A heating furnace 1 shown in FIGS. 1 and 2 is used as a degreasing furnace for performing a degreasing process by heating a ceramic molded body before a firing process in a manufacturing process of a ceramic electronic component. In the following description, the terms “front” and “rear” may be used in explaining the positional relationship between the respective parts of the heating furnace 1. In this case, the left in FIG. 1 is “front” and the right is “rear”. "

  The heating furnace 1 includes a heat treatment chamber 10 that is surrounded by a heat insulating wall and accommodates a workpiece W of a ceramic molded body, a heater 21 and a blower 23 that generate hot air, and a hot air circulation channel that supplies the generated hot air into the heat treatment chamber 10. 30. Hot air from the hot air circulation channel 30 blows through the heat treatment chamber 10 from the rear to the front, and the workpiece W in the heat treatment chamber 10 is heated and degreased by being exposed to the hot air. . By this degreasing treatment, the resin component (binder) in the ceramic molded body is removed prior to the firing treatment.

  The heat treatment chamber 10 is partitioned by a plurality of horizontal partition walls 11, and in the heat treatment chamber 10, multiple stages (here, five stages) of heat treatment spaces 13 a to 13 e overlapping in the vertical direction are formed. Yes. The partition wall 11 is a stainless steel plate, and can place the workpiece W on the upper surface. In this way, by allowing the workpieces W to be stored in the respective heat treatment spaces 13a to 13e, the workpiece W can be efficiently stored in the heat treatment chamber 10, and the processing efficiency in the heating furnace 1 can be improved. .

  The hot air circulation flow path 30 includes a downward flow path 31 for sending the hot air discharged forward from the heat treatment chamber 10 downward, a horizontal flow path 33 for sending the hot air from the downward flow path 31 further horizontally, and a horizontal flow path. And an ascending flow path 35 for sending hot air from 33 further upward and reintroducing it into the heat treatment chamber 10. On the horizontal flow path 33, the heater 21 and the blower 23 are installed as a source of hot air. The heater 21 and the blower 23 are located below the heat treatment chamber 10, and are arranged so that the outlines of the heater 21 and the blower 23 overlap with the heat treatment chamber 10 as viewed from above. By such a hot air circulation flow path 30, a hot air circulation indicated by an arrow A is generated, and the hot air can be circulated in the heat treatment chamber 10. As described above, since the heat treatment chamber 10 is divided into five stages of heat treatment spaces 13a to 13e, the hot air from the ascending flow path 35 branches and flows into the heat treatment spaces 13a to 13e of the respective stages and merges again. And discharged to the descending flow path 31.

  In general, the workpiece W of the ceramic molded body contains a resin component, and in the heating furnace 1, the resin component in the workpiece W is gradually removed over a long period of time. The removal rate of the resin component depends on the temperature of the atmospheric gas contacting the workpiece W as hot air, the air volume, and the resin concentration in the atmospheric gas. Here, when there are variations in the temperature of the atmospheric gas, the air volume, and the resin concentration for each position in the heat treatment chamber 10, the resin removal speed varies for each workpiece W arranged in each position in the heat treatment chamber 10. It will be. For example, if the resin removal rate is too fast, the workpiece W may crack. If the resin removal rate is too slow, the resin component remains on the workpiece W even after the processing is completed. Therefore, in order to perform uniform degreasing without unevenness for all the workpieces W in the heat treatment chamber 10, it is necessary to reduce variations in the temperature distribution, air volume distribution, and resin concentration distribution in the heat treatment chamber 10.

  Therefore, the heating furnace 1 includes stainless steel heat loss adjusting plates 51a to 51e corresponding to the five stages of heat treatment spaces 13a to 13e, respectively. Among these, the heat loss adjusting plates 51b to 51e are respectively provided behind the corresponding heat treatment spaces 13b to 13e (upstream side of hot air). The heat loss adjustment plates 51b to 51e are fixed to the rear end of the partition wall 11 that forms the upper wall that partitions the heat treatment spaces 13b to 13e, and the heat loss adjustment plates 51b to 51e are respectively ascending flow paths. It extends rearward so as to protrude into 35. The heat loss adjusting plates 51b to 51e are curved so that the tips are directed downward. Due to such a curved shape, each heat loss adjusting plate 51b to 51e guides the hot air in the vertical direction of the ascending flow path 35 into a horizontal hot air, and smoothly guides the hot air to each heat treatment space 13b to 13e. Put in. Although the heat loss adjusting plate 15a is fixed to the upper wall surface of the heat treatment chamber 10, hot air is smoothly introduced into the heat treatment space 13a with the same configuration as the other heat loss adjusting plates 51b to 51e.

  The length of the heat loss adjusting plates 51a to 51e protruding upstream of the hot air is longer in the order of the heat loss adjusting plates 51a, 51b, 51c, 51d, and 51e. That is, the lengths of the heat loss adjustment plates 51a to 51e are longer as they are positioned above. In other words, the heat loss adjustment plates 51a to 51e are longer as the distance from the heater 21 is larger. ing. The heat loss adjusting plates 51a to 51e all have the same width and thickness.

  Furthermore, in each heat processing space 13a-13e, the two mesh materials arrange | positioned doubly so that the inlet of a hot air may be plugged are provided. Of these, the upstream mesh material is the first mesh material 53, and the downstream mesh material is the second mesh material 55. The 1st mesh material 53 and the 2nd mesh material 55 are located between the mounting position of the workpiece | work W, and the heat loss adjustment plates 51a-51e. The first mesh material 53 and the second mesh material 55 are stainless steel wire mesh members having a predetermined opening ratio (about 60%), and the hot air introduced into the heat treatment spaces 13a to 13e is the first The first mesh material 53 and the second mesh material 55 are sequentially passed. The first mesh members 53 at each stage are all arranged at the same position as viewed from above. On the other hand, the second mesh material 55 at each stage is arranged so as to gradually shift forward as it goes down. Further, the second mesh material 55 of each step can be adjusted in the front-rear direction by a configuration that is detachably attached to the partition wall 11 by, for example, screwing or the like. The opening ratios of the first and second mesh members 53 and 55 in each step are adjusted for each step and are different from each other.

  Furthermore, in each of the heat treatment spaces 13a to 13e, a plurality of (here, six) stainless steel heat distribution adjusting plates 57 are provided in the space between the first mesh material 53 and the second mesh material 55. Is provided. The heat distribution adjusting plate 57 is provided on the upper surface of the partition wall 11 (or the bottom wall surface of the heat treatment chamber 10), and is arranged horizontally in the depth direction in FIG. The heat distribution adjusting plate 57 is slightly inclined when viewed from above, thereby affecting the flow of hot air at the position where the workpiece W is installed. That is, the heat distribution adjusting plate 57 is inclined so as to guide the hot air near the center to the outside as viewed from above. With this configuration, in each of the heat treatment spaces 13a to 13e, variation in the air volume in a plane orthogonal to the hot air is reduced.

  Then, the effect of the heating furnace 1 based on the above-mentioned structure is demonstrated.

  In this heating furnace 1, since the heat treatment chamber 10, the heater 21, and the blower 23 are arranged in a vertical positional relationship, it is easy to make the apparatus compact and reduce the installation area. On the other hand, due to such an arrangement, it is necessary to guide the upward hot air from the ascending flow path 35 into the heat treatment chamber 10 while being guided horizontally. The heat treatment spaces 13a to 13e of each stage have different distances from the heater 21, and the flow length of hot air from the heater to the heat treatment spaces 13a to 13e of each stage is the heat treatment spaces 13a, 13b, and 13c. , 13d, and 13e in this order, and as a result, the heat loss of the hot air from the heater is also in this order. Therefore, the temperature distribution is likely to vary between the heat treatment spaces at each stage.

  Therefore, in the heating furnace 1, as described above, the heat loss adjusting plates 51a to 51e protruding upstream are provided in correspondence with the heat treatment spaces 13a to 13e. Each of the heat loss adjustment plates 51a to 51e functions as a heat storage material. The longer the flow path length from the heater 21, the longer the heat loss adjustment plates 51a to 51e are set and the heat capacity increases. Therefore, the larger the amount of heat loss of hot air, the larger the amount of heat that is in contact with the heat loss adjusting plates 51a to 51e is introduced into the heat treatment spaces 13a to 13e of each stage. For example, the hot air introduced into the uppermost heat treatment space 13a has a large heat loss because the flow path length from the heater 21 is long. The hot air comes into contact with the heat loss adjusting plate 51a having a large heat capacity, and the hot air is introduced into the heat treatment space 13a in a state where the temperature is compensated. As described above, the heat loss adjusting plates 51a to 51e having different lengths and different amounts of heat for the respective stages make the temperature of the hot air introduced into the heat treatment spaces 13a to 13e of the respective stages uniform, and the heat treatment spaces 13a to 13e. The temperature distribution for each 13e is made uniform.

  Moreover, the 1st mesh material 53 makes temperature distribution equal as a result by disperse | distributing distribution of the hot air to pass. Further, the horizontal temperature variation remaining after passing through the first mesh material 53 is compensated by the heat distribution adjusting plate 57 functioning as a heat storage material, so that the horizontal temperature distribution in the heat treatment spaces 13a to 13e is made uniform. Is done. Further, the second mesh material 55 suppresses the direct influence of the radiant heat from the heat treatment spaces 13 a to 13 e on the heat distribution adjusting plate 57 and disperses the radiant heat within the surface of the second mesh material 55. Thereby, the temperature of the heat distribution adjusting plate 57 is stabilized without suddenly changing, and the temperature distribution of the cross section perpendicular to the flow in the hot air that has passed through the second mesh material 55 is made uniform.

  The heat loss adjusting plates 51a to 51e, the first and second mesh members 53 and 55, and the heat distribution adjusting plate 57 are made of stainless steel. As described above, the heat loss adjusting plates 51a to 51e as the heat distribution compensating members, the first and second mesh members 53 and 55, and the heat distribution adjusting plate 57 are made of stainless steel having high heat retention (poor heat conduction). Thus, even if a disturbance occurs, these heat distribution compensating members do not change in temperature rapidly, and it is easy to maintain a constant temperature distribution in the heat treatment chamber 10.

  In addition, since the first mesh material 53 at each stage is disposed at the same position when viewed from above, the position of the second mesh material 55 is adjusted by introducing hot air into each of the heat treatment spaces 13a to 13e under substantially the same conditions. Thus, even if the radiant heat from each of the heat treatment spaces 13a to 13e varies, the influence on the second mesh material 55 can be made common in the heat treatment spaces 13a to 13e of each stage.

  Moreover, the aperture ratios of the first and second mesh members 53 and 55 at each stage are adjusted for each stage and are different from each other. Thus, by adjusting the aperture ratio of the first and second mesh members 53 and 55 for each stage, the temperature distribution for each heat treatment space 13a to 13e of each stage can be adjusted more precisely.

  As described above, according to the heating furnace 1, the temperature distribution of each stage and each position of the heat treatment chamber 10 is made uniform, and the variation in the degreasing state of the workpieces W arranged at each position of each stage in the heat treatment chamber 10 is achieved. Can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Heating furnace, 10 ... Heat treatment chamber, 11 ... Partition wall, 13a-13e ... Heat treatment space, 21 ... Heater, 23 ... Blower, 30 ... Hot air circulation flow path, 51a-51e ... Heat loss adjustment plate, 53 ... 1st Mesh material, 55 ... second mesh material, 57 ... heat distribution adjusting plate.

Claims (4)

A hot air circulation passage for circulating the hot air generated by the heater and the blower;
Vertically from seeing disposed on at least partially overlap position and the heater or the blower has a heat treatment space in a plurality of stages you accommodating formed partitioned by a horizontal partition wall object to be heated, respectively, the hot air circulation A heat treatment chamber for branching and passing the hot air of the flow path to the heat treatment space of each stage, and
On the upstream side of the heat treatment space of each stage,
A curved heat loss adjustment plate that protrudes longer toward the upstream side as the distance from the heater increases,
An upstream first mesh material and a downstream second mesh material that sequentially pass the hot air introduced into the heat treatment space are provided, and
The first mesh members of each stage are arranged at the same position as seen from the vertical direction,
The heating furnace characterized in that the position of the second mesh material of each stage can be adjusted for each stage in the traveling direction of the hot air . The heating furnace according to claim 1, wherein the heat loss adjusting plate and the first and second mesh members are made of stainless steel. The first mesh material is located on the downstream side of the heat loss adjusting plate and upstream of the heat treatment space, and passes the hot air before being introduced into the heat treatment space,
The second mesh material is located downstream of the first mesh material and upstream of the heat treatment space, and allows the hot air that has passed through the first mesh material to pass through.
The heat distribution adjusting plate for adjusting the heat distribution in the horizontal direction of the heat treatment space is provided between the first mesh material and the second mesh material. The heating furnace described in 1. The heating furnace according to any one of claims 1 to 3, wherein the first and second mesh members of each stage have different opening ratios for each stage.

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