JP2019215141A - Heater unit in hot air heating device - Google Patents

Abstract

To provide a heater unit in a compact hot air heating device improved in a heat transfer coefficient.SOLUTION: A heater unit 101 is used in a hot air heating device which atmosphere heats a furnace inside by multiple heater shaft parts 11 provided in a corresponding state of the axial direction to an air flow direction A1 of circulation air or in a direction orthogonal to the air flow direction A1, and heats a workpiece in the furnace by generating the circulation air by an air fan. The heater unit 101 comprises the heater shaft parts 11, multiple air channels 30 and multiple disturbance structures 20. The heater shaft parts 11 are provided in parallel to two mutually orthogonal directions. The air channels 30 are formed between mutually adjacent heater shaft parts 11. The disturbance structures 20 are arranged in the air channels 30 and generate turbulence in the flow of the circulation air around the heater shaft parts 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heater unit in a hot-air heating device that heats a member to be processed disposed in a furnace.

  2. Description of the Related Art Conventionally, various types of heating furnaces as heating devices for heating a member to be processed are known. For example, a heating device described in Patent Literature 1 is a heat treatment furnace that supplies hot air by a centrifugal fan to a heating area inside a housing in which an electric heater is arranged to heat a member to be processed such as a header of a heat exchanger. It is.

  In addition, in a furnace in which an object to be heated is heated with hot air using an atmospheric gas, a radiant tube heater having a large protective tube around a heating element so that air does not enter the furnace in order to maintain an internal atmospheric gas concentration. Some are used.

JP-A-2005-201547

  Since such a heater has a tubular and long shape, when it is compactly arranged in a furnace, it must be arranged in parallel to the flow of circulating air. Since the heat transfer coefficient is reduced when the heat transfer coefficient is arranged in parallel with the flow, a method of increasing the heat transfer area has been adopted in order to secure a calorific value. For this reason, there has been a limitation on miniaturization of the apparatus. There is also a method of attaching heat-dissipating fins to secure the amount of heat generated.However, at high temperatures, performance cannot be maintained due to thermal deformation, so it is necessary to secure a heat transfer area by arranging many heaters. After all, there was a problem that the equipment became large.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a heater unit in a hot air heating device capable of improving a heat transfer coefficient and being compact.

  The heater unit in the hot-air heating device of the present invention comprises a plurality of heating elements (11, 13) provided in such a manner that the axial direction coincides with the direction of the circulating wind or the direction perpendicular to the direction of the circulating wind. ) Is heated in an atmosphere, and a circulating air is generated by a blowing unit (3) to heat a member to be processed (W) in a furnace. The heater unit includes a heating element, a plurality of air paths (30, 31, 32), and a plurality of disturbance structures (20-26, 13). A plurality of heating elements are provided in parallel in two directions orthogonal to each other. The air path is formed between adjacent heating elements. The disturbance structure is arranged in the air path, and generates a disturbance in the flow of the circulating wind around the heating element.

  The heater unit in the hot-air heating device of the present configuration has a disturbance structure that generates disturbance in the flow of the circulating wind in an air path formed between the heating elements. For this reason, the circulating wind does not go straight in the wind path, but hits the disturbance structure to change the flow direction. By providing a plurality of such disturbance structures in the air path, turbulence occurs in the flow around the heating element, and the heat transfer coefficient between the heating element and the circulating wind can be improved. As a result, a heating element having a smaller protective tube diameter can be employed as compared with the conventional case, and the number of heating elements can be reduced, so that the heater unit itself and the hot air heating device provided with the heater unit can be made more compact.

1 is an overall view of a hot-air heating device according to a first embodiment of the present invention. It is a perspective view of a heater unit by a 1st embodiment of the present invention. FIG. 3 is a view taken in the direction of the arrow III in FIG. 2. It is a front view of a heater unit by a 2nd embodiment of the present invention. It is a front view of a heater unit by a 3rd embodiment of the present invention. It is a figure which shows the heater unit by 4th Embodiment of this invention, (a) is a front view, (b) is a side view, (c) is a top view. It is a front view of a heater unit by a 5th embodiment of the present invention. It is a figure which shows the heater unit by 6th Embodiment of this invention, (a) is a front view, (b) is a side view. It is a figure which shows the heater unit by 7th Embodiment of this invention, (a) is a front view, (b) is a side view.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
[Constitution]
The configuration of the first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the hot-air heating device 1 of the present embodiment mainly includes a housing 2, a blower fan 3, a baffle 6, a heater unit 101, and a rectifying mechanism 7.

  The housing 2 is a box and forms a space inside. Hereinafter, the inside of the housing 2 is simply referred to as “furnace interior 8”. The blower fan 3 is located above the baffle 6 at the center of the furnace, and is fixed to an inner wall constituting a ceiling portion of the housing 2. The blower fan 3 is a centrifugal blower that generates circulating air in the furnace 8 by driving a motor (not shown). The blower fan 3 corresponds to an example of a “blower”.

  The baffle 6 is formed below the blower fan 3 and near the center of the furnace 8. The upper wall of the baffle 6 is open at a portion corresponding to the blower fan 3. A workpiece W corresponding to a member to be processed is transported by the transport conveyor 9 into the baffle 6.

  The heater units 101 are provided at three places on both sides and below the baffle 6 in the furnace 8. A rectifying mechanism 7 is provided above a heater unit 101 provided below the baffle 6.

  In the hot air heating device 1, as shown by a white arrow A 1 (hereinafter also referred to as “wind flow direction A 1”), the inside of the furnace 8 has a A circulating wind circulating clockwise in the right half and a circulating wind circulating counterclockwise in the left half of the furnace 8 are generated. The circulating air becomes hot air by passing through the plurality of heater units 101 during circulation, and is blown into the baffle 6 from an opening at a lower portion of the baffle 6.

(Detailed configuration of heater unit)
Next, the configuration of the heater unit 101 will be described with reference to FIG. The heater units located below the baffle 6 and the heater units located on both sides of the baffle 6 are different in size, but have the same configuration, and therefore are described with the same reference numerals. As shown in FIG. 2, the heater unit 101 includes a plurality of heaters 10 and a plurality of disturbance structures 20.

  The heater 10 is a sheathed heater having a coil-shaped heating wire in a metal sheath and filling the metal sheath with an inorganic insulator. One heater 10 is formed in a wave shape by appropriately bending a rod-shaped sheathed heater, and includes a heater shaft portion 11 and a curved portion 12 which are linear. As shown in FIG. 2, two directions that are parallel to each other and that are orthogonal to the heater shaft portion 11 are referred to as a first direction and a second direction.

  When the heater unit 101 is installed in the furnace 8, the heater shaft portion 11 is a portion formed to extend linearly in the air flow direction A1. The bending portion 12 connects the heater shaft portions 11 arranged in parallel in the second direction. The heater shaft portion 11 and the curved portion 12 are alternately continuous in the second direction, and are integrally formed so as to have a wavy shape as a whole. The corrugated heaters 10 are stacked in the first direction. That is, a plurality of heater shaft portions 11 are provided three-dimensionally in parallel in the first direction and the second direction.

  As shown in FIG. 3, an air passage 30 is formed between adjacent heater shaft portions 11. A disturbance structure 20 is provided in the air passage 30. The disturbance structure 20 is a columnar member having a rectangular cross section in the axial direction. A plurality of the disturbance structures 20 are arranged in one air path 30 at predetermined intervals in the air flow direction A1 with the long axial direction coinciding with the second direction. The separation distance of the disturbance structures 20 arranged in each wind path 30 in the wind flow direction A1 is the same for all the disturbance structures 20.

  The disturbance structures 20 are arranged at alternate positions for each of the air passages arranged in parallel in the first direction. The material of the disturbance structure 20 is carbon. Carbon has high radiation heat absorption, and also has excellent corrosion resistance at high temperatures. In addition, a material such as ceramic having such similar characteristics may be used. In addition, the arrangement intervals and the number of arrangements of the heater 10 and the disturbance structure 20 are appropriately set in consideration of the resistance of the circulating wind, clogging of foreign matter, and the like.

  The heater unit 101 is disposed in the furnace 8 in a state where the axial direction of the heater shaft portion 11 matches the wind direction A1 of the circulating wind. The heater 10 and the disturbance structure 20 are integrally formed in a case (not shown), and can be arranged at a predetermined position in the hot-air heating device 1 as one unit.

[Action]
The heater unit 101 in the hot-air heating device 1 of the present embodiment has a disturbance structure 20 in the air passage 30 formed between the heater shaft portions 11 to generate turbulence in the flow of the circulating wind. The disturbance structures 20 arranged in the air passages 30 adjacent to each other in the first direction orthogonal to the wind flow direction A1 are alternately arranged so as to have different positions.

  For this reason, the circulating wind does not travel straight along the air passage 30 along the axial direction of the heater shaft portion 11, but hits the disturbance structure 20 to change the flow direction, and as shown by the arrow A2, The contact is made in a direction orthogonal to or crossing the portion 11. By providing a plurality of such turbulence structures 20 in the air passage 30, turbulence occurs in the flow around the heater shaft 11 and the heat transfer coefficient between the heater shaft 11 and the circulating wind can be improved. .

  This makes it possible to employ the heater 10 having a smaller protective tube diameter as compared with the related art, and to further reduce the number of heaters, thereby making the heater unit 101 itself and the hot air heating device 1 provided with the heater unit 101 more compact. it can.

  Furthermore, since the disturbance structures 20 are provided alternately, the heat transfer coefficient can be improved without restricting the location where the circulating air flows.

  Further, the material of the disturbance structure 20 is carbon having a high radiation heat absorption rate. By using a material having a high radiation heat absorption rate, the amount of heat transfer is further increased. Heat is also transferred to the circulating wind from the disturbance structure 20 that has absorbed the radiant heat, and the heat transfer coefficient is improved. Further, as in the present embodiment, in a furnace that performs hot air atmosphere heating, even in a furnace environment where corrosion resistance such as 500 ° C. to 1000 ° C. is required, the disturbance structure 20 having high corrosion resistance may be used. Can be. The durability of the heater unit 101 itself can be improved.

Second Embodiment
Next, a heater unit 102 according to a second embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In addition, in FIGS. 4 to 9 described below, only a part around the heater shaft portion of the heater unit is simplified and schematically illustrated in order to easily understand the features of the configuration. In addition, in each of FIGS. 4 to 9, a hatch is shown in the heater 10. In the second embodiment, the shape of the disturbance structure is different from that of the first embodiment. As shown in FIG. 4, the axial cross-sectional shape of the disturbance structure 21 has a triangular shape that is convex on the upstream side in the wind direction A1 of the circulating wind.

  Also in the heater unit 102 of the second embodiment, as shown by the arrow A3, the circulating air can be blown in a direction orthogonal to or crossing the heater shaft portion 11, and the same effects as those in the first embodiment can be obtained. be able to.

<Third Embodiment>
Next, a heater unit 103 according to a third embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The third embodiment differs from the first embodiment in the shape of the disturbance structure. As shown in FIG. 5, the axial cross-sectional shape of the disturbance structure 22 is circular.

  Also in the heater unit 103 of the third embodiment, as shown by the arrow A4, the circulating air can be blown in a direction orthogonal to or crossing the heater shaft portion 11, and the same effects as those in the first embodiment can be obtained. be able to.

<Fourth embodiment>
Next, a heater unit 104 according to a fourth embodiment of the present invention will be described with reference to FIGS. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The fourth embodiment differs from the third embodiment in the arrangement of the disturbance structures. The shape of the disturbance structure itself is the same as in the third embodiment.

  As shown in FIGS. 6A to 6C, the disturbance structures 22, 23 are provided in a lattice shape in a plan view. That is, in addition to the disturbance structure 22 in the third embodiment, another disturbance structure 23 is spaced apart from the long axis direction by the predetermined direction in the wind flow direction A1 in a state where the long axial direction is aligned with the first direction. A plurality is arranged.

  Also in the heater unit 104 of the fourth embodiment, as shown by the arrow A5, the circulating air can be blown in a direction orthogonal to or intersecting with the heater shaft portion 11, and the same effect as in the first embodiment can be obtained. be able to. Further, by disposing the disturbance structures 22 and 23 in a stepwise lattice shape, the flow around the heater 10 is disturbed without significantly increasing the resistance of the circulating wind, thereby further improving the heat transfer coefficient. be able to.

<Fifth embodiment>
Next, a heater unit 105 according to a fifth embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the fifth embodiment, the shape of the disturbance structure is different from that of the first embodiment.

  As shown in FIG. 7, the disturbance structures 24 and 25 are plate-shaped, and one air passage is formed in a state where the long axial direction is aligned with the second direction (the depth direction in FIG. 7). 30 are arranged at predetermined intervals in the wind flow direction A1.

  For convenience, an arbitrary air path is referred to as a first air path 31, and an air path adjacent to the first air path 31 in the first direction is referred to as a second air path 32. At one end (the right end in FIG. 7) of the first disturbance structure 24 arranged in the first air passage 31, a plurality of semicircular notches 241 are appropriately formed in the second direction. The heater shaft 11 is located inside. At the other end (the left end in FIG. 7) of the second disturbance structure 25 disposed in the second air passage 32, a plurality of semicircular notches 251 are similarly formed in the second direction as appropriate. The heater shaft 11 is located inside the notch 251. Note that one end of the first disturbance structure 24 and the other end of the second disturbance structure 25 coincide with the center axis l of the heater shaft 11.

  As shown in FIG. 7A, since the first disturbance structures 24 and the second disturbance structures 25 are arranged alternately in the wind flow direction A1, the circulation is performed as indicated by an arrow A6. The wind passes between the heaters 10 while changing its direction while hitting each of the disturbance structures 24 and 25.

  In the heater unit 105 of the fifth embodiment, the same effects as those of the first embodiment can be obtained.

<Sixth embodiment>
Next, a heater unit 106 according to a sixth embodiment of the present invention will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the heater units 101 to 105 of the above embodiments, the heater shaft portion 11 coincides with the wind flow direction A1, but in the sixth embodiment, as shown in FIG. It coincides with a second direction orthogonal to the direction A1.

  The heaters 10 are composed of two types, a normal heater and a disturbance heater, and are provided alternately in the airflow direction A1 and shifted so as not to overlap in the first direction. The configuration of the wave-shaped heater 10 alone is the same as that of the first embodiment. The heater unit 106 is arranged in the furnace 8 in a state where the axial directions of the heater shaft portions 11 and 13 are aligned with a second direction orthogonal to the wind direction A1 of the circulating wind.

  In the sixth embodiment, the shaft of the normal heater is referred to as “normal heater shaft 11” and the shaft of the disturbance heater is referred to as “disturbance heater shaft 13” for convenience of description. Between the normal heater shaft portions 11 adjacent to each other in the wind flow direction A1, a disturbance heater shaft portion 13 also serving as a disturbance structure is located. The disturbance heater shaft 13 is provided such that the position in the first direction does not overlap with the normal heater. That is, a plurality of normal heater shaft portions 11 and disturbance heater shaft portions 13 are provided three-dimensionally in parallel in two directions orthogonal to each other (first direction and wind flow direction). The disturbance heater shaft portion 13 corresponds to an example of a “heating element” and a “disturbance structure”.

  In the heater unit 106 according to the sixth embodiment, the heater shaft portion 13 for disturbance acts as a disturbance structure to cause disturbance in the circulating wind as shown by an arrow A7, so that heat between the heater 10 and the circulating wind is generated. The transmission rate can be improved. Further, since heat transfer is performed between the disturbance heater shaft portion 13 and the circulating wind, the heat transfer coefficient can be further improved.

<Seventh embodiment>
Next, a heater unit 107 according to a seventh embodiment of the present invention will be described with reference to FIG. The same components as those in the sixth embodiment are denoted by the same reference numerals, and description thereof will be omitted. The seventh embodiment is different from the sixth embodiment in that a disturbance structure 26 (same as the third embodiment as a single unit) is provided separately from the disturbance heater. The disturbance structure 26 of the seventh embodiment is a rod-shaped member having a circular cross section in the axial direction.

  As shown in FIG. 9, a plurality of the disturbance structures 26 are provided in parallel with the second direction and the wind flow direction A <b> 1 in a state where the axial direction, which is the long direction, coincides with the first direction. In the wind flow direction A1, the disturbance structures 26 are arranged at alternate positions so that the positions in the second direction do not continuously overlap.

  In the heater unit 107 of the seventh embodiment, turbulence can be generated in the circulating wind as shown by an arrow A8 by the heater shaft portion 13 for disturbance and the disturbance structure 26. Accordingly, the same effect as that of the sixth embodiment can be obtained, and the heat transfer coefficient can be further improved because the disturbance structure 26 is provided separately.

<Other embodiments>
The material of the disturbance structure in each of the above-described embodiments may be a stainless alloy material or a nickel alloy material, depending on the corrosive environment of the furnace 8, other than carbon or ceramic. If it is a stainless alloy material, it can be used at 850 ° C. or lower in a normal corrosive environment. A nickel alloy-based material can be used even in a corrosive atmosphere at 1000 ° C. or lower.

  The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

1 Hot air heating device 3 Blowing fan (blowing section)
10: heater 11: heater shaft (heating element)
20: Disturbed structure 30: Air passage 101: Heater unit

Claims (8)

A furnace (8) is atmosphere-heated by a plurality of heating elements (11, 13) provided in such a manner that the axial direction coincides with the flow direction of the circulating wind or the direction perpendicular to the flow direction of the circulating wind, and the blowing section (3) is heated. A) a heater unit used in a hot-air heating device that generates the circulating air to heat the member to be processed (W) in the furnace;
A plurality of the heating elements provided in parallel in two directions orthogonal to each other;
A plurality of air paths (30, 31, 32) formed between the adjacent heating elements;
A plurality of disturbance structures (20-26, 13) that are arranged in the wind path and generate turbulence in the flow of the circulating wind around the heating element;
A heater unit in a hot air heating device comprising: When the two directions that are parallel directions of the heating elements and are orthogonal to each other are a first direction and a second direction,
The heater unit in the hot air heating device according to claim 1, wherein the disturbance structure is provided so as to be different from each other in the air passage adjacent in the first direction or the second direction.   The heater unit in the hot air heating device according to claim 2, wherein the disturbance structure is provided at an alternate position for each of the adjacent air paths in the first direction or the second direction.   The heater unit in the hot air heating device according to any one of claims 1 to 3, wherein the disturbance structure is a rod-shaped member.   The heater unit of the hot air heating device according to claim 4, wherein the disturbance structure has a circular or rectangular cross section in the axial direction.   The heater unit of the hot air heating device according to claim 4, wherein the disturbance structure has a triangular cross section in an axial direction.   The heater unit in the hot air heating device according to any one of claims 1 to 6, wherein the heating element is a sheathed heater.   The heater unit in the hot air heating device according to any one of claims 1 to 7, wherein the disturbance structure is formed of any one material of carbon and ceramic.

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