Heating device

Abstract

The present invention provides a heating device in which at least one of the heating temperature and heating efficiency is improved while suppressing the occurrence of malfunctions. [Solution] The heating device 1 comprises a furnace wall 4, an infrared heater unit 6 located inside the furnace wall 4 that generates infrared rays by electric power, and a blower unit 8 that forms air inside the furnace wall 4. The infrared heater unit 6 has one or more infrared heaters 60. Each infrared heater 60 has a quartz glass tube 61, which is a tube made of quartz glass. The blower unit 8 sends air heated to a temperature below the transition temperature of quartz glass (for example, 400°C or more and less than 1000°C) into the furnace wall 4.

Description

Technical Field

[0001] The present disclosure relates to a heating device for heating an object to be heated.

Background Art

[0002] As a heating device, a mold heating device described in Japanese Patent Application Laid-Open No. 2016-78112 (Patent Document 1) is known. This mold heating device includes a main body 2 having a through space 8, an infrared heater 3 disposed in the through space 8, and a plate-like closing member 5 vertically provided downward so as to surround an opening 14 on the lower surface of the main body 2. The infrared heater 3 includes a carbonaceous heating element 21 that emits infrared rays and a quartz glass tube 20 that covers the carbonaceous heating element 21. A lower mold 50 is disposed below this mold heating device, and an upper mold 51 is disposed above the lower mold 50 at a predetermined distance from the lower mold 50. The closing member 5 is placed on the opening edge of the first cavity 53 of the lower mold 50, and the upper part of the first cavity 53 is closed. Further, the upper mold 51 approaches the mold heating device with the upper surface of the main body 2 facing each other. By the operation of the infrared heater 3 in such an arrangement state, the lower mold 50 and the upper mold 51 are heated. At this time, a closed space is formed by the closing member 5 and the first cavity 53 of the lower mold 50, and the first cavity 53 is efficiently heated. On the other hand, since no closed space is formed between the main body 2 and the upper mold 51 and the space between the main body 2 and the upper mold 51 is open, heat does not accumulate in the infrared heater 3 itself.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] To further improve heating efficiency, it is conceivable to position the heating device inside the furnace wall to suppress the leakage of infrared radiation outside the furnace wall. However, if the temperature of the part of the furnace wall adjacent to the infrared heater exceeds approximately 1000°C, problems such as whitening and deformation may occur in the quartz glass tube of the infrared heater.

[0005] The main objective of this disclosure is to provide a heating device in which at least one of the heating temperature and heating efficiency is improved while suppressing the occurrence of malfunctions. [Means for solving the problem]

[0006] This specification discloses a heating device. This heating device may include a furnace wall. This heating device may include an infrared heater unit located within the furnace wall that generates infrared radiation by electric power. This heating device may also include a blower unit that forms air within the furnace wall. [Effects of the Invention]

[0007] The main effect of this disclosure is to provide a heating device in which at least one of the heating temperature and heating efficiency is improved while suppressing the occurrence of malfunctions. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the heating device related to this disclosure. [Figure 2] Figure 1 is an exploded perspective view of the heating device from the upper right rear. [Figure 3] Figure 1 is a disassembled perspective view of the heating device from the upper right rear. [Figure 4] Figure 1 is an exploded perspective view of the heating device from the lower left front. [Figure 5] Figure 1 is a disassembled perspective view of the heating device from the lower left front. [Figure 6]Figure 6A is a schematic cross-sectional view of the air duct and its surrounding area in the heating device shown in Figure 1, and Figure 6B is a schematic cross-sectional view of a modified example of the air duct in Figure 6A and its surrounding area. [Modes for carrying out the invention]

[0009] The embodiments and modifications thereof relating to this disclosure will be described below with reference to the drawings as appropriate. This disclosure is not limited to the following forms and variations.

[0010] Figure 1 is a perspective view of the heating device 1 according to the said configuration. Figure 2 is an exploded upper perspective view of the heating device 1 in Figure 1, viewed from the upper right rear. Figure 3 is an exploded lower perspective view of the heating device 1 in Figure 1, viewed from the upper right rear. Figure 4 is an exploded upper perspective view of the heating device 1 in Figure 1, viewed from the lower left front. Figure 5 is an exploded lower perspective view of the heating device 1 in Figure 1, viewed from the lower left front. The heating device 1 comprises a housing 2, a furnace wall 4, an infrared heater section 6, an air blower section 8, a terminal section 10, and a power supply connection section 12. For convenience, the various directions in the heating device 1 are as shown in each figure. However, these directions may be changed as appropriate by at least one of the following: movement due to the driving of a component or part, and / or its relationship with other devices. The heating device 1 heats the object to be heated, which is placed inside the furnace wall 4. Note that the infrared heater unit 6 and the air blower unit 8 in Figures 2 and 3 are the same. Also, the infrared heater unit 6 and the air blower unit 8 in Figures 4 and 5 are the same.

[0011] The housing 2 is a metal frame-like body and has a front frame portion 20 and a rear frame portion 22. The front frame portion 20 is box-shaped, open upwards and having a lower opening on its underside. Base portions 24 projecting radially outward are formed on the front, left, and right sides of the front frame portion 20. The front base portion 24 extends to the left and right. The left and right base portions 24 extend to the front and back, respectively. The rear frame section 22 is box-shaped, open to the top and rear, and has a communication section at the front that connects it to the front frame section 20. The lower surface of the front frame section 20 is continuous with the lower surface of the rear frame section 22. Multiple (two) housing handles 26 are provided on the lower left side of housing 2. Each housing handle 26 protrudes to the left, extends front to back, and is arranged in a front-to-back configuration. Multiple (two) housing handles 26 are provided on the lower right side of housing 2. Each housing handle 26 protrudes to the right, extends front to back, and is arranged in a front-to-back configuration. Furthermore, the configuration of housing 2 may be other than those described above. For example, the lower surface of the front frame portion 20 may be separated from the lower surface of the rear frame portion 22. Also, housing 2 may consist only of the front frame portion 20, or it may have three or more box-shaped portions. Moreover, at least one of each base portion 24 and each housing handle 26 may be omitted. The number of at least one of each base portion 24 and each housing handle 26 may be changed from the number described above. The arrangement of at least one of each base portion 24 and each housing handle 26 may be changed from the arrangement described above.

[0012] The furnace wall 4 has a central part 30, a right part 31, a left part 32, a rear part 33 that serves as a heater terminal protection part, an upper part (not shown), and a lower part (not shown). The central part 30 of the furnace wall has an upper frame part 34 and a lower frame part 35. The upper frame portion 34 at the central part of the furnace wall includes a frame-shaped body made of metal and ceramic furnace wall blocks overlapping in a plurality (two) of layers on the lower surface of the frame-shaped body. A front upper recess 36 is formed on the lower surface of the front portion of the upper frame portion 34 at the central part of the furnace wall. The front upper recess 36 is formed by arranging a plurality of recesses concave upward in a semi-cylindrical shape side by side. Each recess of the front upper recess 36 extends rearward from the central part in the front-rear direction of the front portion of the upper frame portion 34 at the central part of the furnace wall. A rear upper recess 37 is formed on the lower surface of the rear portion of the upper frame portion 34 at the central part of the furnace wall. The rear upper recess 37 is formed by arranging a plurality of recesses concave upward in a semi-cylindrical shape side by side. Each recess of the rear upper recess 37 extends in the front-rear direction over the entire lower surface of the rear portion of the upper frame portion 34 at the central part of the furnace wall. Incidentally, the furnace wall blocks of the upper frame portion 34 at the central part of the furnace wall may be one layer or three or more layers. The lower frame portion 35 at the central part of the furnace wall includes a plurality of ceramic furnace wall blocks assembled in a frame shape as a whole in one layer. A front lower recess 38 is formed on the upper surface of the front portion of the lower frame portion 35 at the central part of the furnace wall. The front lower recess 38 is formed by arranging a plurality of recesses concave downward in a semi-cylindrical shape side by side. Each recess of the front lower recess 38 extends rearward from the central part in the front-rear direction of the front portion of the lower frame portion 35 at the central part of the furnace wall. A rear lower recess 39 is formed on the upper surface of the rear portion of the lower frame portion 35 at the central part of the furnace wall. The rear lower recess 39 is formed by arranging a plurality of recesses concave downward in a semi-cylindrical shape side by side. Each recess of the rear lower recess 39 extends in the front-rear direction over the entire upper surface of the rear portion of the lower frame portion 35 at the central part of the furnace wall. The front upper recess 36 and the front lower recess 38 face each other symmetrically with respect to a virtual horizontal plane. The rear upper recess 37 and the rear lower recess 39 face each other symmetrically with respect to a virtual horizontal plane. Incidentally, the furnace wall blocks of the lower frame portion 35 at the central part of the furnace wall may be two or more layers. The central part 30 of the furnace wall is placed inside the front frame portion 20 of the housing 2. The central part 30 of the furnace wall is held by the front frame portion 20 of the housing 2.

[0013] The right part 31 of the furnace wall is a "U"-shaped member having a front plate portion, a right plate portion, and a rear plate portion when viewed from above downward. The right part 31 of the furnace wall is formed by fitting a plurality (three) of ceramic panels 45 into a furnace wall right part frame 44 made of metal. The left part 32 of the furnace wall is a "U"-shaped member having a front plate part, a left plate part, and a rear plate part, as viewed from above downward. The left part 32 of the furnace wall is formed by fitting a plurality (three) of ceramic panels 47 into a metal right part frame 46 of the furnace wall. The right part 31 and the left part 32 of the furnace wall are placed and held on the base part 24 and the front frame part 20 of the housing 2. The right part 31 and the left part 32 of the furnace wall surround the front, rear, left, and right above the central part 30 of the furnace wall.

[0014] A front handle 50 is attached to the upper left front surface of the front plate part of the left part 32 of the furnace wall. The front handle 50 protrudes forward and to the left. Also, a front attachment part 52 is provided across the front surfaces of the front plate part of the right part 31 of the furnace wall and the front plate part of the left part 32 of the furnace wall. The front attachment part 52 has a front magnet part 52M arranged on the left part 32 of the furnace wall and a front metal plate part 52P arranged on the right part 3i of the furnace wall. By the front magnet part 52M being detachably attached to the front metal plate part 52P, the front part of the left part 32 of the furnace wall and the front part of the right part 31 of the furnace wall are connected. A rear handle 54 is attached to the upper right rear surface of the rear plate part of the left part 32 of the furnace wall. The rear handle 54 protrudes rearward and to the left. Also, a rear attachment part 56 is provided across the rear surfaces of the rear plate part of the right part 31 of the furnace wall and the rear plate part of the left part 32 of the furnace wall. The rear attachment part 56 has a rear magnet part 56M arranged on the left part 32 of the furnace wall and a rear metal plate part 56P arranged on the right part 31 of the furnace wall. By the rear magnet part 56M being detachably attached to the rear metal plate part 56P, the rear part of the left part 32 of the furnace wall and the rear part of the right part 31 of the furnace wall are connected.

[0015] The rear part 33 of the furnace wall is arranged on the rear side of the rear surfaces of the right part 31 and the left part 32 of the furnace wall and is held at the front end part of the rear frame part 22 of the housing 2. The rear part 33 of the furnace wall is a plate-shaped member made of ceramics that spreads in the up, down, left, and right directions and has a plurality (six) of through holes 33H. Each through hole 33H is arranged side by side left and right at the lower edge of the rear part 33 of the furnace wall and extends forward and backward. The upper part of the furnace wall is, for example, a ceramic plate that covers the upper openings of the right part 31 and the left part 32 of the furnace wall. The lower part of the furnace wall is, for example, an open, box-shaped section that covers the lower openings of the central part 30 and the front frame part 20 of the furnace wall.

[0016] The furnace wall 4 forms a closed space that surrounds part or all of the infrared heater section 6, part or all of the air blower section 8, and the object to be heated. Furthermore, the furnace wall 4 does not have to be a single, integrally constructed furnace wall structure. The furnace wall 4 may be a structure that covers the periphery of the infrared heater section 6 on a specific surface or its entire surface by a shielding structure. The shielding structure may have at least one of the following effects: reducing infrared leakage and transmission, improving heating efficiency by reflecting infrared rays, and providing heat insulation. Various materials can be selected for the furnace wall 4, for example, ceramics, metals, glass, composite materials, or combinations thereof can be used. The shape and structure of the furnace wall 4 can be varied in various ways, for example, the shielding structure constituting the furnace wall 4 may include flat plates, curved plates, ribbed plates, mesh plates, or combinations thereof. The orientation of the shielding structure constituting the furnace wall 4 may be horizontal only, vertical only, or a combination of these orientations. The furnace wall 4 may have gaps, or it may be completely sealed without gaps. The furnace wall 4 can be modified and flexibly applied according to at least one of its design requirements and application, as well as the type of object being heated.

[0017] The infrared heater unit 6 has one or more (in this case, four) infrared heaters 60. The number of infrared heaters 60 may be three or fewer, or five or more. The infrared heater unit 6 may also have heaters other than the infrared heaters 60, either in place of or in conjunction with the infrared heaters 60. Each infrared heater 60 is similar to the others. Unless otherwise specified, one infrared heater 60 will be described as representative. In cases where the infrared heater unit 6 has multiple infrared heaters 60, some of the infrared heaters 60 may be of a different type than the others.

[0018] The infrared heater 60 includes a quartz glass tube 61, a heater front end 62, a heater rear end 63, a heater terminal 64, and a plurality (2) carbonaceous heating elements 65.

[0019] The quartz glass tube 61 is made of quartz glass and is translucent. The quartz glass tube 61 is cylindrical, extending from front to back. The front end of the quartz glass tube 61 is sealed by the heater front end 62. The rear end of the quartz glass tube 61 is sealed by the heater rear end 63. Heater terminals 64 are arranged both inside and outside the rear of the heater rear end 63. At least one of the shapes of the quartz glass tubes 61 may be other than cylindrical, such as a rectangular tube. In addition, multiple heater terminals 64 may be provided, for example, at the front end of the heater front end 62 and at the rear end of the heater rear end 63. An inert gas such as argon gas is sealed inside the quartz glass tube 61 to suppress the deterioration of the carbonaceous heating element 65 due to oxidation. However, the sealing of the inert gas may be omitted. Each quartz glass tube 61 is arranged side by side. Each quartz glass tube 61 is adjacent to one another.

[0020] Each carbonaceous heating element 65 extends in the front-to-back direction and is a plate-shaped member that spreads out in the front-to-back, left-to-right, and rear-to-back directions. Each carbonaceous heating element 65 is a carbonaceous plate. The orientation of the carbonaceous heating elements 65 is horizontal. However, at least one orientation of each carbonaceous heating element 65 may be other than horizontal. Also, at least one shape of each carbonaceous heating element 65 may be other than a plate. Each carbonaceous heating element 65 is held within a quartz glass tube 61. Each carbonaceous heating element 65 is arranged side by side within one quartz glass tube 61. The rear end of the right carbonaceous heating element 65 is connected to one of a pair of terminals in the heater terminal section 64, i.e., the first terminal. The front end of the right carbonaceous heating element 65 is connected to the front end of the right carbonaceous heating element 65 at the heater front section 62. The rear end of the left carbonaceous heating element 65 is connected to the other of a pair of terminals in the heater terminal section 64, i.e., the second terminal. Each carbonaceous heating element 65 generates heat by emitting infrared radiation when current is passed through a circuit consisting of a first terminal, the right carbonaceous heating element 65, the left carbonaceous heating element 65, and the second terminal. From the viewpoint of heating efficiency, the infrared radiation is preferably mid-infrared. However, at least one of near-infrared and far-infrared radiation may be used as infrared radiation instead of mid-infrared, or together with mid-infrared. Each carbonaceous heating element 65 is lighter than a metal of the same size, and therefore the infrared heater 60 is lighter than a heater using a metal heating element of similar size. Furthermore, since the carbonaceous heating element 65 emits infrared rays and heats the object to be heated by infrared rays, the infrared heater 60 can efficiently heat objects even from a distance, and can heat high-temperature objects while suppressing the reduction in heat transfer. In addition, since the carbonaceous heating element 65 instantly emits light (red-hot) in response to power application, the object to be heated begins to heat up immediately, and the user can easily understand the operating status of the infrared heater 60. The amount of infrared radiation emitted from the top and bottom surfaces of each carbonaceous heating element 65 is greater than the amount of infrared radiation emitted from the front, back, left, and right surfaces, which are the thicker surfaces of each carbonaceous heating element 65. In other words, infrared radiation from each carbonaceous heating element 65 is mainly emitted from the top and bottom surfaces, and the thermal radiation from each carbonaceous heating element 65 is directional. Furthermore, the number of carbonaceous heating elements 65 per infrared heater 60 may be one or three or more. If multiple infrared heaters 60 exist, the number of carbonaceous heating elements 65 in some infrared heaters 60 may differ from the number of carbonaceous heating elements 65 in other infrared heaters 60. In addition, the heating elements in at least one of the infrared heaters 60 may be replaced with, or used together with, a carbonaceous heating element 65, at least one of tungsten, iron-chromium, molybdenum disilide, and silicon carbide.

[0021] Each infrared heater 60 is installed within the central part 30 of the furnace wall, with its front and rear ends sandwiched between the upper frame 34 and lower frame 35 of the central part of the furnace wall. The front end of each infrared heater 60 is located within the corresponding upper front recess 36 and lower front recess 38. The rear end of each infrared heater 60 is located within the corresponding upper rear recess 37 and lower rear recess 39. The rear end of each infrared heater 60 also penetrates the corresponding through-hole 33H in the rear part 33 of the furnace wall. The rear end of each infrared heater 60 is positioned behind the rear surface of the rear part 33 of the furnace wall. In the heating device 1, multiple infrared heaters 60 are held adjacent to each other, so that the upper and lower surfaces of each carbonaceous heating element 65 within each quartz glass tube 61 are aligned in the left-right direction. Thus, a virtual plate-shaped heating surface is formed that extends in the front, back, left, and right directions. Infrared rays are mainly emitted upwards and downwards from the heating surface. Furthermore, at least one of a sheathed heater and a cartridge heater may be used as the infrared heater 60. The sheathed heater is an infrared heater that has a metal tube instead of a quartz glass tube 61 and has heater terminals 64 on both sides. The cartridge heater is an infrared heater that has a metal tube instead of a quartz glass tube 61 and has heater terminals 64 on one side.

[0022] The air blower unit 8 has one or more (in this case, two) air ducts 70. The air ducts 70 may be one or three or more. The air blower unit 8 may also have other air blowing mechanisms besides the air ducts 70, such as fans installed inside the furnace wall 4, either in place of or in conjunction with the air ducts 70. Each air duct 70 is similar to the others. Unless otherwise specified, one air duct 70 will be described as representative. In cases where the air supply unit 8 has multiple air ducts 70, some of the air ducts 70 may be of a different type than the others.

[0023] Figure 6A is a schematic cross-sectional view of the air supply duct 70 and its surrounding area. The air supply duct 70 includes an air supply pipe 72, an air supply hose 74, an air heating unit 76, and a lead wire 78. The air duct 72 is a heat-resistant tube and extends forward and downward. The front end of the air duct 72 is bent downward. When viewed from right to left, the air duct 72 is L-shaped. The air duct 72 is installed so that it extends into the central part of the furnace wall 30, with its rear end sandwiched between the upper frame 34 and the lower frame 35 of the central part of the furnace wall. The rear end of the air duct 72 is located in the corresponding upper rear recess 37 and lower rear recess 39. The rear end of the air duct 72 also passes through the corresponding through-hole 33H in the rear part of the furnace wall 33. The rear end of the air duct 72 is positioned behind the rear surface of the rear part of the furnace wall 33. The right air duct 72 is positioned to the right of the right infrared heater 60. The left air duct 72 is positioned to the left of the left infrared heater 60. Each air duct 72 sandwiches each infrared heater 60 in the left-right direction. Each air duct 72 is positioned outside each infrared heater 60 in the left-right direction. However, the arrangement of the air ducts 72 relative to each infrared heater 60 is not limited to that described above. For example, the air ducts 72 may be positioned above the infrared heaters 60. Also, the air ducts 72 do not have to be in an "L" shape when viewed from right to left. The air hose 74 is connected to a blower (not shown) and the rear end of the air duct 72, and sends the wind, i.e., the airflow, generated by the blower to the air duct 72. The blower may be provided for each air duct 70, or it may be a single common blower. The air hose 74 may have a rear end connected to one blower, and a front end with two branch hoses via a branching section. In this case, each branch hose is connected to supply air to the corresponding air duct 72. The air heating section 76 is a heat-generating component, i.e., a heating element, which is an electric heating wire, and is located inside the air supply pipe 72. The air heating section 76 heats the air flowing from the rear end to the front end inside the air supply pipe 72. The air is heated to a temperature lower than the temperature inside the furnace wall 4 brought about by each infrared heater 60. The temperature of the air is set to a temperature that suppresses damage to each infrared heater 60, such as a temperature that suppresses at least one of whitening and deformation of the quartz glass tube 61. The rear end of the air heating section 76 is located adjacent to the rear part 33 of the furnace wall (in the through hole 33H in Figure 6A). Note that the air heating section 76 may be made of a material other than an electric heating wire. Also, the arrangement of the air heating section 76 may be other than that described above. Furthermore, the temperature of the air may be other than that described above. If the infrared heater 60 is at least one of a sheathed heater and a cartridge heater, the temperature of the air may be set to a temperature that suppresses damage to the metal pipe, such as a temperature that suppresses at least one of deterioration and deformation of the metal pipe, or in other words, a temperature at which no damage to the metal pipe occurs. The lead wire 78 is connected to the air heating unit 76 to supply power for generating heat. The lead wire 78 extends rearward from the rear end of the air heating unit 76 and is drawn outward from the rear end of the air blower pipe 72. The arrangement of the lead wire 78 may be other than that described above.

[0024] Figure 6B is a schematic cross-sectional view of the air duct 70B and its surrounding area, relating to an example of a modification of the air duct 70. In the air duct 70B, the rear end of the air heating section 76B is located within the central part of the air pipe 72B in the front-rear direction. The lead wire 78B extends rearward from the rear end of the air heating section 76B and passes through the rear end of the air pipe 72B. The lead wire 78B is located inside the portion of the air pipe 72B that is positioned within the furnace wall 4. When heating, if air passes through the air pipe 72B of the air duct 70B, the temperature inside the air pipe 72B decreases compared to when no air passes through, and the lead wire 78B can be placed inside the air pipe 72B while heat damage is suppressed.

[0025] The terminal section 10 includes a heater terminal connection section 80, a base 82, an inner cover 84, and an outer cover 86. The heater terminal connection section 80 is connected to each heater terminal section 64 via heater lead wires (not shown). The base 82 holds the heater terminal connection portion 80. The base 82 is held by the rear frame portion 22. The inner cover 84 is positioned above and behind each heater terminal 64 to protect each heater terminal 64 from contact with other components. The inner cover 84 is held in place by the rear frame 22. The outer cover 86 is positioned on the upper and rear sides of the rear frame 22 to protect the components inside the rear frame 22 from contact with other components, etc.

[0026] The power connection section 12 is held on the right side of the rear frame section 22 and has a socket 90. The socket 90 is connected to a power line (not shown). The power connection unit 12 is connected to each infrared heater 60 via the heater terminal connection unit 80. The power connection unit 12 is connected to the heater terminal connection unit 80 by a lead wire (not shown). The power connection unit 12 is also connected to the lead wire 78 of the air heating unit 76 in each air duct 70. Note that the lead wire 78 may be connected to a power source other than the power connection unit 12. The power lines are connected to a power source such as commercial power, and can supply power to each infrared heater 60 and the air heating unit 76. Furthermore, the heating device 1 may be equipped with a switch for turning the power on and off. Also, the circuit of the heating device 1 can be modified in various ways, for example, by omitting the heater terminal connection part 80, or by connecting each air duct 70 to the power connection part 12 via the heater terminal connection part 80.

[0027] An example of the operation of such a heating device 1 is described below. The user places the object to be heated in at least one of the following locations: within the furnace wall 4 below the infrared heater unit 6, i.e., within the lower part of the furnace wall 4, and within the furnace wall 4 above the infrared heater unit 6. For example, the user places the lower object to be heated, such as a lower mold, within the lower part of the furnace wall 4, and installs the heating device 1 (excluding the lower and upper parts of the furnace wall) above the lower part of the furnace wall, and places the upper object to be heated, such as an upper mold, within the furnace wall 4 above the infrared heater unit 6, and installs the upper part of the furnace wall.

[0028] Next, the user connects the power line to the socket 90, causing the infrared heater section 6 of the heating device 1 to heat up, and also causing the blower section 8 to blow air and heat the air. Each blast of air entering the corresponding blast pipe 72 from each blast hose 74 is heated by the blast heating unit 76, enters the furnace wall 4, forms a blast within the furnace wall 4, and agitates the air inside the furnace wall 4. Part or all of each blast of air is directed downward by the blast pipe 72, which has a downward-curving front end, and then, by at least one of impact with the lower part of the furnace wall and convection, is directed mainly upward, more specifically upward and in the forward, backward, left, and right directions. Furthermore, the air inside the furnace wall 4 escapes gradually from the furnace wall 4 through gaps in the furnace wall 4, so the pressure inside the furnace wall 4 does not continue to increase.

[0029] Each airflow circulates the air within the furnace wall 4, suppressing heat buildup in the infrared heater section 6 and its adjacent areas. This improves the heating capacity of the infrared heater section 6, reducing self-damage and extending its lifespan. Furthermore, each airflow enables even higher output from the infrared heater 60, contributing to more efficient heating. Furthermore, the air inside the furnace wall 4 is agitated by each airflow, allowing the object to be heated to heat more efficiently. Heat that tends to accumulate in the upper part of the furnace wall 4 is moved more evenly within the furnace wall 4 by each airflow. In particular, objects to be heated below the infrared heater section 6 are heated much more efficiently than when there is no airflow from the air blower section 8. Moreover, since each airflow is heated by the air heating section 76, the temperature drop inside the furnace wall 4 is suppressed compared to when there is no heating. In addition, the convection generated inside the furnace wall 4 improves the heat transfer coefficient of the air inside the furnace wall 4 compared to when no convection occurs, further improving the heating efficiency. Furthermore, when heating is performed by the infrared heater unit 6, the airflow suppresses heat buildup in the air duct 72, keeping the temperature inside the air duct 72 lower than when there is no airflow. This reduces damage to at least one of the air heating unit 76 and the lead wire 78, thus extending the lifespan of at least one of them.

[0030] Translucent quartz glass undergoes a transition from a glassy state (amorphous) to cristobalite (crystalline) in environments with temperatures above its transition temperature (e.g., 1150°C), resulting in at least one of two changes: a decrease in translucency, such as whitening, or devitrification, and deformation. The deformation occurs due to softening caused by the transition in properties and can be caused by at least one of its own weight and external pressure. The transition temperature, which is the lower limit at which quartz glass can undergo this transition, can be lowered by at least one of the presence and adhesion of impurities, for example, to 1000°C. Each infrared heater 60 has a quartz glass tube 61 made of quartz glass that is transparent enough to transmit infrared rays. If the temperature inside the furnace wall 4 reaches above the transition temperature due to each infrared heater 60, and there is no airflow from the air blower 8, the temperature of the quartz glass tube 61 may exceed the transition temperature, potentially causing at least one of devitrification and deformation of the quartz glass tube 61. In such a case, the heating device 1 has airflow from the air blower 8, which suppresses the situation in which the temperature of the quartz glass tube 61 exceeds the transition temperature. In particular, if the airflow is adjusted to be below the transition temperature, the situation in which the temperature of the quartz glass tube 61 exceeds the transition temperature is sufficiently suppressed.

[0031] For example, if the air heating unit 76 heats the air to 800°C, which is below the transition temperature, then even if the inside of the furnace wall 4 can be heated to above the transition temperature in a windless state because each infrared heater 60 is surrounded by the furnace wall 4, the flow of 800°C air inside the furnace wall 4 sufficiently suppresses the situation in which the temperature of the quartz glass tube 61 exceeds the transition temperature, thereby suppressing the occurrence of malfunctions in each infrared heater 60. In addition, the temperature inside the air blower tube 72 is maintained at around 800°C by the passage of air at around 800°C, thereby suppressing damage to the air heating unit 76 and lead wires 78. If there is no air passing through the air blower tube 72, when the furnace temperature reaches above the transition temperature, such as 1000°C, the temperature inside the air blower tube 72 may also reach above the transition temperature, which increases the possibility of damage to the air heating unit 76 and lead wires 78. Furthermore, since the air is heated to 800°C, the temperature drop inside the furnace wall 4 is suppressed compared to when the air is not heated. In addition, as mentioned above, the air inside the furnace wall 4 is stirred by the blowing of heated air, improving heating efficiency. In view of at least one of the following: a cooling effect on the infrared heater 60 so that the temperature of the quartz glass tube 61 is below the transition temperature, and suppression of a decrease in the heating efficiency of the object being heated, the air is preferably heated to 400°C or more and less than 1000°C, more preferably to 500°C or more and 900°C or less, and even more preferably to 600°C or more and 800°C or less. The temperature of the quartz glass tube 61 is adjusted to below the transition temperature by the air heated in the air heating section 76 inside the furnace wall 4, which is below the transition temperature.

[0032] Thus, in the heating device 1, even when heating is performed by each infrared heater 60 that generates heat using electricity, the infrared heater section 6 surrounded by the furnace wall 4 makes it possible to efficiently and sufficiently heat the target to a temperature of, for example, 400°C to 600°C. Moreover, such heating can be performed while suppressing the occurrence of malfunctions in each infrared heater 60, in particular the whitening and deformation of the quartz glass tube 61 in environments above 1000°C. The airflow agitates the air inside the furnace wall 4, acting as a cooling airflow for each infrared heater 60 to help prevent malfunctions, and acting as a hot airflow for the object being heated to help prevent a decrease in heating efficiency or improve heating efficiency. Furthermore, even when the infrared heater 60 is at least one of a sheathed heater and a cartridge heater, from the viewpoint of suppressing damage to the metal tube and suppressing a decrease in the heating efficiency of the object to be heated, it is preferable that the air from the air heating unit 76 be heated to 400°C or more and less than 1000°C, more preferably to 500°C or more and less than 900°C, and even more preferably to 600°C or more and less than 800°C.

[0033] The heating device 1 described above provides the following effects. Specifically, the heating device 1 comprises a furnace wall 4, an infrared heater unit 6 located inside the furnace wall 4 that generates infrared rays using electricity, and a blower unit 8 that forms airflow inside the furnace wall 4. Therefore, a heating device 1 is provided in which at least one of the heating temperature and heating efficiency is improved while the occurrence of malfunctions is suppressed.

[0034] Furthermore, the infrared heater section 6 has one or more (four) infrared heaters 60. Each infrared heater 60 has a quartz glass tube 61, which is a tube made of quartz glass. The air blower section 8 sends air heated to a temperature below the transition temperature of quartz glass (for example, 400°C or more and less than 1000°C) into the furnace wall 4. Therefore, the infrared heater 60 has a quartz glass tube 61 that sufficiently transmits infrared rays and protects the carbonaceous heating element 65, which is the infrared source. Even when placed inside the enclosed space of the furnace wall 4, the air at a temperature below the transition temperature of the quartz glass suppresses the occurrence of whitening, deformation, etc., in the quartz glass tube 61. In addition, the heated air suppresses the temperature drop inside the furnace wall 4 and improves heating efficiency by stirring the air inside the furnace wall 4.

[0035] Furthermore, the air blowing unit 8 includes an air heating unit 76 that heats the air and an air blowing pipe 72 that sends the heated air into the furnace wall 4. Therefore, it is easier to create air inside the furnace wall 4 to improve heating efficiency and suppress malfunctions of the infrared heater unit 6. Furthermore, the air blower 8 directs air downwards within the furnace wall 4. As a result, higher temperature heat, which tends to accumulate at the top of the still furnace wall 4, moves downwards. Consequently, heating efficiency is further improved. Also, if the object to be heated is located at the bottom of the furnace wall 4, it will be heated more efficiently.

[0036] In addition, the infrared heater unit 6 has one or more (four) infrared heaters 60. Each infrared heater 60 has a quartz glass tube 61, which is a tube made of quartz glass. Each infrared heater 60 is capable of generating heat such that it reaches a temperature above the transition temperature of quartz glass within the furnace wall 4 when the air blower unit 8 is not blowing air. The air blower unit 8 can adjust the temperature of the quartz glass tube 61 to be below the transition temperature of quartz glass by blowing air into the furnace wall 4. Therefore, a heating device 1 is provided that can heat the inside of the furnace wall 4 to a higher temperature and suppress the occurrence of malfunctions in the infrared heater section 6.

[0037] Furthermore, the air blowing unit 8 has one or more (two) air blowing ducts 70. Each air blowing duct 70 has an air heating unit 76 that generates heat using electricity to heat the air, a lead wire 78 for supplying power to the air heating unit 76, an air blowing pipe 72 that sends the heated air into the furnace wall 4, and an air blowing hose 74 that sends the air generated by the blower to the air blowing pipe 72. The air heating unit 76 and a portion of the lead wire 78 are located inside the portion of the air blowing pipe 72 that is positioned inside the furnace wall 4. Therefore, the heating efficiency of the air is improved by the air heating unit 76 located inside the furnace wall 4. Moreover, even though the lead wires 78 are located inside the furnace wall 4, they are protected from malfunctions by the mitigation of the heat effects inside the furnace wall 4 due to the airflow.

[0038] Furthermore, the furnace wall 4 reflects the infrared rays generated by the infrared heater unit 6. As a result, leakage of infrared rays for heating is suppressed, and heating efficiency is improved. Furthermore, the infrared heater unit 6 has one or more (four) infrared heaters 60. Each infrared heater 60 has at least one of the following: a carbonaceous heating element 65, tungsten, iron-chromium, molybdenum disilicide, and silicon carbide. Therefore, stronger infrared rays are emitted more efficiently. In addition, the infrared heater unit 6 generates mid-infrared rays. Therefore, industrial products or their components made of commonly used materials such as metals and heat-resistant synthetic resins are heated more efficiently. [Explanation of symbols]

[0039] 1...Heating device 4. Furnace wall 6. Infrared heater section 8. Air blower 60-inch infrared heater 61. Quartz glass tube 65. Carbonaceous heating element 70. Air duct 72··Air pipe 74. Air blower hose 76...Wind heating section 78. Lead wire

Claims

1. The hearth wall and, An infrared heater unit, which is located within the furnace wall and generates infrared rays using electricity, A blower that forms air inside the furnace wall It is equipped with A heating device characterized by the following features.

2. The infrared heater section has one or more infrared heaters, The infrared heater has either a quartz glass tube or a metal tube. The blowing unit sends air heated to a temperature below the transition temperature of the quartz glass or to a temperature that does not cause damage to the metal tube into the furnace wall. The heating apparatus according to feature 1.

3. The infrared heater section has one or more infrared heaters, The infrared heater has a quartz glass tube, which is a tube made of quartz glass. The blowing unit sends air heated to less than 1000°C into the furnace wall. The heating apparatus according to feature 1.

4. The blowing unit includes a wind heating unit that heats the air and a blowing pipe that sends the heated air into the furnace wall. The heating apparatus according to feature 1.

5. The blowing unit blows air downwards within the furnace wall. The heating apparatus according to feature 1.

6. The infrared heater section has one or more infrared heaters, The infrared heater has a quartz glass tube, which is a tube made of quartz glass, and when the air blower does not blow air, it is capable of generating heat within the furnace wall to a temperature above the transition temperature of the quartz glass. The blowing unit can adjust the temperature of the quartz glass tube to be below the transition temperature of the quartz glass by sending air into the furnace wall. The heating apparatus according to feature 1.

7. The aforementioned air blower heats the air to a temperature of 400°C or higher but less than 1000°C. The heating apparatus according to feature 1.

8. The aforementioned air blowing unit has one or more air ducts, The aforementioned air duct comprises an air heating unit that generates heat using electricity to heat the air, lead wires for supplying power to the air heating unit, an air pipe for sending the heated air into the furnace wall, and an air hose for sending the air generated by the blower to the air pipe. The air heating section and a portion of the lead wire are located inside the portion of the air supply pipe that is positioned within the furnace wall. The heating apparatus according to feature 1.

9. The furnace wall reflects the infrared rays generated by the infrared heater. The heating apparatus according to feature 1.

10. The infrared heater section has one or more infrared heaters, The infrared heater comprises at least one of the following: a carbonaceous heating element, tungsten, iron-chromium, molybdenum disilicide, and silicon carbide. The heating apparatus according to feature 1.

11. The infrared heater unit generates mid-infrared rays. The heating apparatus according to feature 1.

Images