JP4594263B2 - Double-sided heater and connected double-sided heater - Google Patents

Description

  The present invention relates to a heater used as heating means for a firing furnace.

  Conventionally, as a heater used as a heating means of a firing furnace, a heating wire in which a wire made of a Ni-Cr alloy or a Fe-Cr-Al alloy is spirally wound inside a fiber block made of ceramic fibers in a block shape. Panel-shaped heaters that are included are known. Normally, a panel heater has a heat generating surface in which a heating wire is embedded in the vicinity of the surface, and a back surface (non-heating surface) that is a surface opposite to the heat generating surface from which a lead wire for energizing the heating wire is derived. The lead wire led out from the back surface is drawn out of the furnace through a through hole provided in the furnace wall at the upper part (ceiling side) or the lower part (floor side) of the furnace, and is wired to a control device or the like.

  Recently, in the field of manufacturing plasma display panels (hereinafter referred to as “PDP”), a plurality of transport paths are provided in the vertical direction for the purpose of improving productivity and space saving. A multi-stage firing furnace has been developed that can simultaneously fire the object to be fired (see, for example, Patent Document 1). In such a baking furnace, when PDP is baked, the PDP that is a body to be baked usually needs to be heated from both the upper surface and the lower surface, and therefore, a partition wall (heat insulating wall) that partitions each conveyance path A heater (floor heater) for heating the lower surface of the PDP passing through the conveyance path above the partition is installed on the upper surface side of the PDP, and the upper surface of the PDP passing through the conveyance path below the partition is disposed on the lower surface side of the partition. It is necessary to install a heater (ceiling heater) for heating (see FIGS. 3 and 4 of Patent Document 1).

  Thus, since the partition which partitions between conveyance paths exists in the upper direction and the lower part, when it is going to pull out the lead wire of the heater installed in the partition from the ceiling side or the floor side to the outside of the furnace as mentioned above Therefore, in order to avoid such interference, the lead wire is led out in the lateral direction (furnace width direction) and the firing furnace It is necessary to draw out of the furnace through a through hole provided in the side wall.

  However, when trying to lead out the lead wire in the horizontal direction with a conventional heater, the lead wire 3 connected to the heating element 2 is connected to the heat insulating fiber block 13 as shown in FIGS. 6 (a) and 6 (b). Since it leads out through the inside, the thickness of the fiber block 13 needs to be at least about 100 mm. When this heater is installed on the upper side and lower side of the partition wall as described above, the combined thickness of the two heaters and the partition wall exceeds 200 mm, but is used for firing PDP or the like. If the furnace temperature is 600 ° C. or less, it is sufficient that the thickness is about 120 to 150 mm, and the excessive thickness is reduced in the height direction in the multi-stage firing furnace as described above. It becomes a factor that hinders space.

  In addition, the lead wire expands and contracts due to changes in furnace temperature during furnace operation and shutdown, but if the lead wire is constrained by a fiber block, free lead expansion and contraction of the lead wire is hindered. As a result, the lead wire may break.

Furthermore, in the field of PDP production, etc., the furnace width of the firing furnace tends to increase due to its upsizing, and accordingly, the length of the heater installed in the furnace width direction needs to be increased. In this heater, as the length becomes longer, the mass of the fiber block constituting the heater becomes larger and the assembly work becomes difficult.
JP 2005-156016 A

  The present invention has been made in view of the problems of the prior art as described above, and its object is to fire a multi-stage structure having a plurality of transport paths in the vertical direction for transporting a body to be fired. In the furnace, when installed between the conveyance paths, the object to be fired conveyed in the upper and lower conveyance paths can be heated at the same time, and also functions as a thin partition wall that divides the conveyance path, making assembly easy. An object of the present invention is to provide a panel-like heater that is less likely to break lead wires.

  In order to achieve the above object, according to the present invention, the following double-sided heater and connected double-sided heater are provided.

[1] A panel-shaped heater, in which both surfaces of the heater are heat generating surfaces in which heat generating wires are embedded in the vicinity of the surfaces, and both the surfaces can be independently temperature controlled. Double-sided heater configured as follows.

[2] Two single-sided heaters having a heat generating surface in which a heat generating wire is embedded in the vicinity of the surface and a back surface that is a surface opposite to the heat generating surface from which a lead wire for energizing the heat generating wire is derived. The double-sided heater according to [1], wherein the double-sided heater is configured by using and joining the back surfaces of the two single-sided heaters.

[3] The double-sided heater according to [2] is a connected double-sided heater in which three or more straight lines are connected so that the directions of the heat generating surfaces coincide with each other. For double-sided heaters that are not located at both ends of the double-sided heater, the lead wire is led out from the end of the connected double-sided heater through a groove formed on the back surface of the double-sided heater adjacent to the double-sided heater. Connected double-sided heater.

[4] The connected double-sided heater according to [3], wherein the groove is formed only on the back side of one of the single-sided heaters, out of the backsides of the two single-sided heaters joined to form the double-sided heater. .

  The double-sided heater and the connected double-sided heater according to the present invention are panel-shaped and both surfaces are heat generating surfaces, and both surfaces can be independently controlled in temperature, so that the object to be fired is conveyed. In a firing furnace having a multistage structure having a plurality of transport paths in the vertical direction, when being installed between the transport paths, the objects to be fired conveyed in the upper and lower transport paths can be heated simultaneously. In addition, when the double-sided heater and the connected double-sided heater are installed between the conveyance paths as described above, the double-sided heater and the coupled double-sided heater function as a partition wall that partitions the conveyance path, and the thicknesses of the upper surface side and the lower surface of the partition wall as in the prior art. Since it can be made thinner compared to the case where the heaters are installed on the sides, the height of the firing furnace can be lowered by that amount, and the space-saving property in the height direction is improved.

  Furthermore, since the double-sided heater of the present invention is configured by connecting the double-sided heaters of the present invention, even when many are connected and lengthened for installation in a wide furnace, the individual heaters at the time of assembly The weight of these components is lighter than that of a monolithic heater and is easy to assemble. Of the double-sided heaters constituting this connected double-sided heater, for the double-sided heaters that are not located at both ends of the connected double-sided heater, the lead wire is the back of the double-sided heater adjacent to the double-sided heater (the bonding surface between the single-sided heaters) ) Is formed through the groove formed in the outer side of the connected double-sided heater, so if the width and depth of the groove are larger than the outer diameter (thickness) of the lead wire, The lead wire can be freely thermally expanded and contracted without being constrained in the groove, and is difficult to break.

  Hereinafter, typical embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and the ordinary knowledge of those skilled in the art can be obtained without departing from the spirit of the present invention. It should be understood that design changes, improvements, and the like can be added as appropriate.

  The double-sided heater of the present invention is a panel-shaped heater, and both surfaces of the heater are heat generating surfaces in which heating lines are embedded in the vicinity of the surface, and both the surfaces are independent of each other. Thus, the temperature can be controlled. This double-sided heater is a single-sided heater having a heat generating surface in which a heating wire is embedded in the vicinity of the surface, and a back surface that is a surface opposite to the heat generating surface from which a lead wire for energizing the heating wire is derived. It is preferable that two are used and the back surfaces of the two single-sided heaters are joined to each other.

  FIG. 1 is an assembly explanatory view showing a structural example of the single-sided heater. This single-sided heater 6 sandwiches a heating wire 2 in which a wire made of Ni—Cr alloy or Fe—Cr—Al alloy is spirally wound between a heating surface side panel 7 and a back side panel 8 made of ceramic fibers. Consists of. The heat generating surface side panel 7 constitutes the heat generating surface 4 of the single-sided heater 6 and has a fixing groove 9 for facilitating fixing and heat exchange of the heat generating wire 2. The back surface side panel 8 constitutes a back surface (non-heat generating surface) 5 opposite to the heat generating surface 4. A lead wire 3 for energization is connected to the heating wire 2, and the lead wire 3 is bent toward the back surface 5 near the end of the single-sided heater 6 and led out to the back surface 5 side. The lead wire 3 is usually made of the same material as the heating wire 2, and has a cross-sectional area larger than that of the heating wire 2 to reduce the resistance value, or a twisted wire that combines multiple wires. Used.

  FIG. 2 is an assembly explanatory view showing a structural example of the double-sided heater 1 configured by using two such single-sided heaters 6. As shown in this figure, the double-sided heater 1 is constructed by joining the backsides 5 of the single-sided heater 6 together. As a result of joining the back surfaces 5 of the single-sided heaters 6 in this way, the resulting double-sided heater 1 has both surfaces serving as heating surfaces 4. Further, since the heating wires 2 embedded in the vicinity of each heating surface 4 are independent from each other and are energized by separate lead wires 3, both the heating surfaces 4 should be controlled in temperature independently. Can do. The lead wire 3 is preferably asymmetrically derived from the center line of the single-sided heater 6 so as not to overlap when the backsides 5 of the single-sided heater 6 are joined together.

  In a multi-stage firing furnace having a plurality of transport paths for transporting an object to be fired in the vertical direction, if such a double-sided heater is installed between the transport paths, each of the objects to be transported in the transport path above and below the transport path. The fired bodies can be simultaneously heated at appropriate temperatures. In addition, this double-sided heater also functions as a partition wall that divides the transport path when installed between the transport paths as described above, but the thickness is the upper surface side and lower surface side of the partition wall as in the prior art described above. In addition, since it can be made thinner than the case where each heater is installed (specifically, it can be about 100 mm thick), the height of the firing furnace can be lowered accordingly. Become.

  As shown in the side view of FIG. 3, the double-sided heater 11 of the present invention is formed by linearly connecting three or more double-sided heaters 1 so that the directions of the heat generating surfaces coincide with each other. In a firing furnace having a long furnace width, such as a firing furnace for a large PDP panel, a heater that is as long as the furnace width is required. However, the connected double-sided heater of the present invention is obtained by connecting a plurality of double-sided heaters 1. A heater having a required length can be obtained. With such a connection structure, the weight of the individual components at the time of assembly can be reduced as compared with a monolithic heater having an equivalent length, so that the assembly operation is facilitated. The length of each double-sided heater 1 constituting the coupled double-sided heater 11 is not particularly limited, but is preferably about 500 to 800 mm in consideration of workability during assembly. The upper limit number of the double-sided heaters 1 to be connected is not particularly limited, and may be appropriately determined according to the required heater length and the like.

  By the way, when it is set as such a connection structure, about the double-sided heater 1b located in the both ends of the connection double-sided heater 11 among the double-sided heaters 1 which comprise the connection double-sided heater 11, the lead wire 3 is used as an end part as it is. The double-sided heaters 1a that are not located at both ends of the coupled double-sided heater 11 can be drawn out from the adjacent double-sided heaters 1b in order to avoid interference with the equipment and the body to be fired in the upper and lower conveying paths. It must be led out to the end of the connected double-sided heater 11 through the inside.

  Therefore, in the coupled double-sided heater of the present invention, for the double-sided heater not positioned at both ends of the coupled double-sided heater, the lead wire is bonded to the back surface of the double-sided heater adjacent to the double-sided heater. In addition, it is drawn out from the end portion of the connected double-sided heater through a groove formed on the backside (joint surface) of the single-sided heater. Here, the “double-sided heater adjacent to the double-sided heater” means the double-sided heater when the double-sided heater located next to the double-sided heater is located at the end of the connected double-sided heater, Otherwise, it means all double-sided heaters from the double-sided heater located next to the double-sided heater to the double-sided heater located at the end of the connected double-sided heater.

  FIG. 4 is an explanatory view showing a state in which the double-sided heater constituting the coupled double-sided heater of the present invention is divided between the back surfaces (joint surfaces) of the single-sided heater, and FIG. FIG. 4B is a plan view of the other divided body viewed from the back surface side. FIG. 5A is an end view of the coupled double-sided heater, and FIG. 5B is a partially enlarged view thereof. In the figure, 3b ′ is a lead wire for energizing a heating element embedded in the vicinity of one heating surface of the double-sided heater 1b located at the end of the connected double-sided heater 11, and 3b ″ is the end of the connected double-sided heater 11 in the same manner. 3a 'is a lead wire for energizing a heating element embedded in the vicinity of the other heating surface of the double-sided heater 1b located in the section of the double-sided heater 1b. The lead wire 3a "for energizing the heating element embedded in the vicinity of the heating surface of the double-sided heater 11a is also located in the vicinity of the other heating surface of the double-sided heater 1a that is not located at the end of the connected double-sided heater 11. It is a lead wire for energizing.

  As described above, in the coupled double-sided heater 11 of the present invention, for the double-sided heater 1b located at both ends, the lead wires 3b ′ and 3b ″ are pulled out from the end in the lateral direction (furnace width direction) For the double-sided heater 1a that is not located at both ends, the lead wires 3a ', 3a' 'are connected to the backside of the double-sided heater 1b adjacent to the double-sided heater 1a It has a structure in which it is pulled out from the end of the connected double-sided heater 11 through the groove 12 formed in the bonding surface)) 5. Therefore, if the width W or depth D of the groove 12 is set to a large dimension having a sufficient margin with respect to the outer diameter (thickness) of the lead wire 3, the lead wire 3 is freely thermally expanded in the groove 12. -It can shrink, and it is possible to prevent breakage caused by restraining thermal expansion / contraction of the lead wire 3. The specific dimensions of the groove 12 are preferably about 3 to 4 times the width W and about 1.5 to 2 times the depth D with respect to the outer diameter of the lead wire 3.

  In addition, it is preferable that the said groove | channel is formed only in the back surface of one single-sided heater among the back surfaces of two single-sided heaters joined in comprising a double-sided heater. In this case, place the single-sided heater with the groove on the back side down, place the back side up, place the lead wires in the groove formed on the back side, If the double-sided heater is assembled according to the procedure of covering the other single-sided heater on which no is formed, it is easy to assemble the lead wire without departing from the groove.

  The double-sided heater and the connected double-sided heater of the present invention can be suitably used as heating means in a multi-stage firing furnace having a plurality of transport paths for transporting the object to be fired in the vertical direction.

It is assembly explanatory drawing which shows the structural example of a single-sided heater. It is assembly explanatory drawing which shows the structural example of the double-sided heater of this invention. It is a side view of the connection double-sided heater of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the state which divided | segmented the double-sided heater which comprises the connection double-sided heater of this invention between the back surfaces (joining surface) of a single-sided heater, (a) sees one division body from the heat generating surface side. (B) is the top view which looked at the other division body from the back surface side. (A) is an end view of a connected double-sided heater, and (b) is a partially enlarged view thereof. In the heater of the conventional structure, it is explanatory drawing which shows the state which led out the lead wire to the horizontal direction, (a) is a perspective view, (b) is sectional drawing.

Explanation of symbols

1, 1a, 1b: Double-sided heater, 2: Heating element, 3, 3a ′, 3a ″, 3b ′, 3b ″: Lead wire, 4: Heat generating surface, 5: Back surface, 7: Heat generating surface side panel, 8: Back surface Side panel, 9: fixed groove, 11: coupled double-sided heater, 12: groove, 13: fiber block.

Claims (3)

Using two single-sided heaters having a heating surface in which a heating wire is embedded in the vicinity of the surface and a back surface that is a surface opposite to the heating surface from which a lead wire for energizing the heating wire is derived, A panel-like heater constructed by joining the back surfaces of two single-sided heaters, both surfaces of the heater being heat-generating surfaces in which heating lines are embedded in the vicinity of the surface, and A double-sided heater configured such that both surfaces can be independently controlled in temperature. 2. The double-sided heater according to claim 1 , wherein the double-sided heater is connected to three or more straight lines so that the directions of the heat generating surfaces coincide with each other. For a double-sided heater that is not located at a portion, the connected double-sided heater in which the lead wire is led out from the end of the connected double-sided heater through a groove formed on the back surface of the double-sided heater adjacent to the double-sided heater. The connected double-sided heater according to claim 2 , wherein the groove is formed only on the back surface of one of the single-sided heaters among the backsides of the two single-sided heaters that are joined to form the double-sided heater.

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