Heating device

Abstract

Provided is a heat-generating device in which a first electrode and a second electrode can be provided on a side surface of a honeycomb structure, and the honeycomb structure can be configured as a heat-generating body. A heat-generating device according to an embodiment of the present invention is provided with a honeycomb structure, a first electrode, and a second electrode. The honeycomb structure has an outer wall and partition walls. The partition wall is disposed on the inner side of the outer wall and defines a plurality of cells extending from the first end surface to the second end surface. The first electrode is disposed on a side surface of the honeycomb structure. The second electrode is provided on a side surface of the honeycomb structure and is located at a position separated from the first electrode. A side surface of the honeycomb structure includes a first portion located between the first electrode and the second electrode, and a second portion located on a side opposite to the first portion with respect to a center of a cross-section of the honeycomb structure in a direction orthogonal to a direction in which the cells extend. The honeycomb structure has a first slit. The first slit extends from the first portion toward the second portion.

Description

Technical Field

[0001] The invention relates to a heating device. Background Art

[0002] Since the fluid can flow inside the honeycomb structure having a plurality of cells, research is being conducted on its application to filters used in various industrial products, such as filters for exhaust gas purification and filters for acid gas adsorption. In these applications, for example, for the activation of catalysts and the desorption of acid gases, it is sometimes required to heat the honeycomb structure. Therefore, it is desirable to construct the honeycomb structure itself as a heating element. For example, a ceramic heating element is proposed, which comprises a honeycomb structure composed of silicon nitride, a conductive material, an oxide or a nitrogen oxide, and electrodes disposed on both end faces of the honeycomb structure in the direction in which the cells extend (see patent document 1). However, in the ceramic heating element described in patent document 1, the electrodes disposed on the end faces of the honeycomb structure become an obstacle, and its application in various industrial products is sometimes restricted.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-128637 Summary of the invention

[0006] Problems to be solved by the invention

[0007] A main object of the present invention is to provide a heat generating device in which a first electrode and a second electrode can be disposed on the side surfaces of a honeycomb structure, and the honeycomb structure can be configured as a heat generating body.

[0008] Methods for solving problems

[0009] [1] The heat generating device of an embodiment of the present invention comprises a honeycomb structure, a first electrode and a second electrode. The honeycomb structure has an outer wall and a partition wall. The partition wall is arranged on the inner side of the outer wall and defines a plurality of cells extending from the first end face to the second end face. The first electrode is arranged on the side of the honeycomb structure. The second electrode is arranged on the side of the honeycomb structure and is located at a position separated from the first electrode. The side of the honeycomb structure includes a first portion and a second portion, the first portion is located between the first electrode and the second electrode, and the second portion is located on the opposite side of the first portion relative to the center of a cross section of the honeycomb structure in a direction orthogonal to the direction in which the cells extend. The honeycomb structure has a first slit. The first slit extends from the first portion toward the second portion.

[0010] [2] In the heat generating device described in [1] above, the honeycomb structure may have a substantially quadrilateral shape in a cross section in a direction perpendicular to the direction in which the cells extend. The honeycomb structure has: a first side surface and a second side surface that are spaced apart from each other in a first direction perpendicular to the direction in which the cells extend, and a third side surface and a fourth side surface that are spaced apart from each other in a second direction perpendicular to the direction in which the cells extend and the first direction. The first side surface may also be provided with the first electrode and the second electrode and include the first portion. The second side surface may also include the second portion.

[0011] [3] In the heat generating device described in [1] or [2] above, the first slit may have a substantially wedge-shaped shape in a cross section in a direction perpendicular to the direction in which the cells extend, the width of the first slit becoming narrower as it moves away from the first portion.

[0012] [4] In the heat generating device described in any one of [1] to [3] above, the interior of the first slit may be hollow.

[0013] [5] In the heat generating device described in any one of [1] to [3] above, the first slit may be filled with a filling material.

[0014] [6] In the heat generating device described in any one of [1] to [5] above, the first slit may be provided in plurality. The honeycomb structure may further include a second slit. The second slit extends from the second portion toward the first portion. The second slit is located between the plurality of first slits adjacent to each other.

[0015] [7] In the heating device described in [6] above, the sum of the number of the first slits and the number of the second slits between the first electrode and the second electrode may be an odd number.

[0016] [8] In the heat generating device described in [6] or [7] above, the second slit may have a substantially wedge-shaped shape in a cross section in a direction perpendicular to the direction in which the cells extend, the width of the second slit becoming narrower as it moves away from the second portion.

[0017] [9] In the heat generating device described in any one of [6] to [8] above, the interior of the second slit may be hollow.

[0018]

[10] In the heat generating device described in any one of [6] to [8] above, the interior of the second slit may be filled with a filling material.

[0019]

[11] In the heat generating device described in any one of [1] to

[10] above, the honeycomb structure may be made of a conductive ceramic material.

[0020] Effects of the Invention

[0021] According to the embodiment of the present invention, the first electrode and the second electrode can be provided on the side surfaces of the honeycomb structure, and a heat generating device capable of configuring the honeycomb structure as a heat generating body can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic plan view of a heat generating device according to one embodiment of the present invention.

[0023] Figure 2 yes Figure 1 II-II′ cross-sectional view of the heating device.

[0024] Figure 3 It is a schematic plan view of a heat generating device according to another embodiment of the present invention.

[0025] Figure 4 yes Figure 3 A magnified view of the first slit.

[0026] Figure 5 It is an enlarged view of a modified example of the first slit.

[0027] Figure 6 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention.

[0028] Figure 7 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention.

[0029] Figure 8 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention.

[0030] Fig. 9 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention.

[0031] Fig.10 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention.

[0032] Fig.11 It is a schematic plan view of a heat generating device according to still another embodiment of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to these embodiments. In addition, in order to make the description clearer, the accompanying drawings sometimes schematically show the width, thickness, shape, etc. of each part compared with the embodiments, but this is only an example and does not limit the interpretation of the present invention.

[0034] A. Overview of heating device

[0035] Figure 1 is a schematic top view of a heating device according to an embodiment of the present invention. Figure 2 yes Figure 1 II-II′ cross-sectional view of the heating device.

[0036] The heat generating device 100 shown in the figure comprises a honeycomb structure 1, a first electrode 2 and a second electrode 3. The honeycomb structure 1 has an outer wall 10 and a partition wall 12. The partition wall 12 is disposed inside the outer wall 10 and defines a plurality of cells 13. The plurality of cells 13 extend from a first end face E1 to a second end face E2 of the honeycomb structure 1 (see Figure 2 ). Typically, a fluid corresponding to the purpose of the heat generating device can flow through the cells 13. The side surface 11 of the honeycomb structure 1 is typically located between the first end surface E1 and the second end surface E2, and extends parallel to the direction in which the cells 13 extend. The side surface 11 of the honeycomb structure 1 is the outer surface of the outer wall 10. It should be noted that in this specification, unless otherwise specified, the side surface 11 of the honeycomb structure 1 refers to the entire surface located between the first end surface E1 and the second end surface E2 and extending parallel to the cells 13. The first electrode 2 is provided on the side surface 11 of the honeycomb structure 1. The second electrode 3 is provided on the side surface 11 of the honeycomb structure 1 and is located at a position separated from the first electrode 2. The side surface 11 of the honeycomb structure 1 includes a first portion P1 located between the first electrode 2 and the second electrode 3 and a second portion P2 located on the opposite side of the first portion P1 relative to the center of the cross section of the honeycomb structure 1 in a direction orthogonal to the direction in which the cells 13 extend. The first portion P1 and the second portion P2 are in a 180° rotationally symmetrical relationship with respect to the central axis of the honeycomb structure 1. The honeycomb structure 1 has the first slits 17. The first slits 17 extend from the first portion P1 toward the second portion P2 of the side surface 11. The first slits 17 function as an electrical insulating portion.

[0037] According to such a structure, the first slit extends from the first portion of the side of the honeycomb structure between the first electrode and the second electrode, so even if the first electrode and the second electrode are arranged on the side of the honeycomb structure, the short circuit between the first electrode and the second electrode can be suppressed. Therefore, by applying a voltage to the honeycomb structure via the first electrode and the second electrode, the honeycomb structure can be stably heated. That is, the first electrode and the second electrode can be arranged on the side of the honeycomb structure, and the honeycomb structure can be configured as a heating element. As a result, for industrial products that are difficult to apply to heating devices in which electrodes are arranged on the end faces of the honeycomb structure, a heating device according to an embodiment of the present invention can be applied. Therefore, it is possible to improve the possibility of application to various industrial products.

[0038] The honeycomb structure 1 can have any appropriate shape in the cross section in the direction perpendicular to the direction in which the cells 13 extend. Examples of the cross-sectional shape of the honeycomb structure include a triangle, a quadrilateral, a pentagon, a polygon with a hexagon or more, a circle, and an ellipse. The size of the honeycomb structure can be appropriately set according to the purpose.

[0039] In one embodiment, the honeycomb structure 1 has a substantially quadrilateral shape in a cross section in a direction perpendicular to the extending direction of the cells 13. In the example shown in the figure, the honeycomb structure 1 has a prism shape with a quadrilateral bottom surface.

[0040] The honeycomb structure 1 has a first side surface 11a and a second side surface 11b which are arranged at intervals from each other in a first direction perpendicular to the direction in which the cells 13 extend, and a third side surface 11c and a fourth side surface 11d which are arranged at intervals from each other in a second direction perpendicular to the direction in which the cells 13 extend and the first direction. In other words, the side surface 11 of the honeycomb structure 1 includes the first side surface 11a, the second side surface 11b, the third side surface 11c, and the fourth side surface 11d.

[0041] In one embodiment, the first electrode 2 and the second electrode 3 are disposed on the first side 11a of the honeycomb structure 1. The first side 11a includes a first portion P1 located between the first electrode 2 and the second electrode 3 in the second direction. The second side 11b on the side opposite to the first side 11a includes a second portion P2. The first slit 17 extends from the first portion P1 of the first side 11a toward the second portion P2 of the second side 11b. According to such a structure, even if the first electrode and the second electrode are disposed on the same side among the four sides of the honeycomb structure having a prismatic shape, the first slit can stably suppress the short circuit between the first electrode and the second electrode.

[0042] In the example shown in the figure, the first slit 17 extends in the first direction. The base end of the first slit 17 is located at the first portion P1 in the first side surface 11a of the honeycomb structure 1, and the front end of the first slit 17 does not reach the second portion P2, but is located between the first portion P1 and the second portion P2. That is, the front end of the first slit 17 is located at a position separated from the second portion P2 in the second side surface 11b.

[0043] The length of the first slit 17 (the dimension in the first direction in the example shown) can adopt any appropriate value according to the size of the honeycomb structure. The length of the first slit 17 is, for example, more than 1 times, preferably more than 5 times, for example less than 25 times, preferably less than 15 times, relative to the interval between the front end portion of the first slit and the second portion. If the length of the first slit is within the above range, the length of the wire 19 electrically connecting the first electrode to the second electrode can be fully ensured. When the length of the slit is less than the above lower limit, the heat generation sometimes becomes uneven (even the four corners do not heat up), and when the length of the slit exceeds the above upper limit, the strength is sometimes impaired.

[0044] The number of the first slits 17 is not particularly limited, and is, for example, 1 or more, preferably 2 or more, more preferably 3 or more, and, for example, 20 or less. If the number of slits is too large, the intervals between the slits may be too narrow, thereby impairing the strength.

[0045] In one embodiment, a plurality of first slits 17 are provided. Typically, the plurality of first slits 17 are arranged at intervals from each other in a direction perpendicular to the extending direction of the first slits. In the illustrated example, three first slits 17 are arranged at intervals from each other in the second direction.

[0046] The honeycomb structure 1 also has a second slit 18. The second slit 18 functions as an electrical insulating portion in the same manner as the first slit 17. The second slit 18 is located between the first slits 17 adjacent to each other among the plurality of first slits 17. The second slit 18 extends from the second portion P2 in the side 11 of the honeycomb structure 1 toward the first portion P1. The honeycomb structure 1 is configured as a wire 19 that electrically connects the first electrode 2 to the second electrode 3 through the first slit 17 and the second slit 18. When viewed from the axial direction of the honeycomb structure 1, the wire 19 is formed into a zigzag shape. Therefore, a voltage can be uniformly applied to the entire honeycomb structure via the first electrode and the second electrode, and the entire honeycomb structure can be uniformly heated.

[0047] Typically, one second slit 18 is disposed between each of the adjacent first slits 17. In the illustrated example, the second slit 18 extends in the first direction from the second portion P2 of the second side surface 11b toward the first portion P1 of the first side surface 11a. The base end of the second slit 18 is located at the second portion P2 of the second side surface 11b of the honeycomb structure 1, and the front end of the second slit 18 does not reach the first portion P1, but is located between the second portion P2 and the first portion P1. That is, the front end of the second slit 18 is located at a position separated from the first portion P1 of the first side surface 11a.

[0048] The length of the second slit 18 (the dimension in the first direction in the example shown) can be any appropriate value according to the size of the honeycomb structure. The length of the second slit 18 is, for example, 1 or more times, preferably 5 or more times, for example, 25 or less times, preferably 15 or less times, relative to the distance between the front end of the second slit and the first portion. If the length of the second slit is within the above range, the wire electrically connecting the first electrode and the second electrode can be stably formed into a meandering shape.

[0049] The number of the second slits 18 is, for example, 1 or more, preferably the number of the first slits minus 1. The sum of the number of the first slits 17 and the number of the second slits 18 between the first electrode 2 and the second electrode 3 is preferably an odd number. In the example shown in the figure, the sum of the number of the first slits 17 and the number of the second slits 18 between the first electrode 2 and the second electrode 3 is 5. If the total number of the first slits and the second slits between the first electrode and the second electrode is an odd number, the wire electrically connecting the first electrode and the second electrode can be stably formed into a meandering shape.

[0050] The first slit 17 and the second slit 18 may adopt any appropriate structure as long as they each function as an electrical insulating portion.

[0051] The first slit 17 and the second slit 18 each have any appropriate shape in a cross section in a direction perpendicular to the axial direction of the honeycomb structure 1. As the cross-sectional shape of each of the first slit 17 and the second slit 18, for example, a substantially rectangular shape (see Figure 1 ), roughly wedge-shaped (refer to Figure 3 ).

[0052] like Figure 1 As shown, when the cross-sectional shape of the slit (the first slit or the second slit) is substantially rectangular, the width of the slit (the dimension in the second direction in the example shown) is substantially constant over the entire slit.

[0053] The dimension of the width direction of the roughly rectangular slit (the first slit or the second slit) can adopt any appropriate value according to the voltage applied to the first electrode and the second electrode. The width of the roughly rectangular slit (the first slit or the second slit) is, for example, more than 0.05 cm, preferably more than 0.1 cm. If the width of the roughly rectangular slit is above the above lower limit, the short circuit of the wire electrically connecting the first electrode to the second electrode can be stably suppressed. Representatively, the width of the roughly rectangular slit is less than 1.0 cm. When the slit width exceeds the above upper limit, the area blocked by the filler is sometimes increased, and the pressure loss becomes larger. In addition, if the slit width is less than the above lower limit, it is sometimes impossible to obtain a sufficient insulation distance.

[0054] like Figure 3As shown, when the cross-sectional shape of the first slit 17 is roughly wedge-shaped, the width of the first slit 17 becomes narrower as it separates from the first part P1. The range of the width of the base end of the first slit 17 (the dimension in the second direction in the example shown) is the same as the range of the width of the rectangular slit described above. According to such a structure, the width of the first slit can be appropriately adjusted according to the magnitude of the potential difference in the conductor. In the conductor that electrically connects the first electrode to the second electrode, the potential difference between the portion where the electrode (the first electrode or the second electrode) is directly connected and the return portion between the front end of the second slit and the first portion is relatively easy to become larger. In this regard, since the width of the base end of the first slit is above the above lower limit, the short circuit between the portions with relatively large potential differences can be stably suppressed. In addition, the width of the first slit between the portions with relatively small potential differences in the conductor can be made smaller than the base end. Therefore, compared with the case where the cross-sectional shape of the first slit is roughly rectangular, the area occupied by the first slit in the cross section of the honeycomb structure can be reduced, and the area occupied by the plurality of cells can be increased.

[0055] The taper angle of the front end of the first slit 17 having a substantially wedge shape is, for example, 0.5° or more, preferably 1.0° or more, for example, 12.0° or less, preferably 3.0° or less. When the taper angle is less than the lower limit, the slit width becomes too thin, and thus a sufficient insulation distance may not be obtained. When the taper angle is greater than the upper limit, the slit width at the root of the slit becomes larger, and thus, the pressure loss may increase and the surface area may decrease.

[0056] In the case where the cross-sectional shape of the second slit 18 is roughly wedge-shaped, the width of the second slit 18 becomes narrower as it separates from the second part P2. The range of the width of the base end of the second slit 18 (the dimension of the second direction in the example shown) is the same as the range of the width of the rectangular slit described above. According to such a structure, the width of the second slit can be appropriately adjusted according to the magnitude of the potential difference in the conductor. In the conductor that electrically connects the first electrode to the second electrode, the potential difference between the return portion between the front end of the first slit and the second portion is relatively easy to increase. In this regard, since the width of the base end of the second slit is above the above lower limit, it is possible to stably suppress the short circuit between the portions with relatively large potential differences. In addition, the width of the second slit between the portions with relatively small potential differences in the conductor can be made smaller than the base end. Therefore, compared with the case where the cross-sectional shape of the second slit is roughly rectangular, the area occupied by the second slit in the cross section of the honeycomb structure can be reduced, and the area occupied by the plurality of cells can be increased.

[0057] The range of the taper angle of the front end portion of the second slit 18 having a substantially wedge shape is the same as the range of the taper angle of the front end portion of the first slit 17 described above.

[0058] In one embodiment, the first slit 17 and the second slit 18 have opposite and congruent substantially wedge shapes in a cross section in a direction orthogonal to the axial direction of the honeycomb structure 1. If the first slit and the second slit have congruent substantially wedge shapes, the end faces of the first slits and the end faces of the second slits adjacent to each other can be arranged substantially parallel to each other, and the width of the wire formed therebetween can be made constant. Therefore, when a voltage is applied to the honeycomb structure via the first electrode and the second electrode, the honeycomb structure can be heated more uniformly.

[0059] The slit (first slit or second slit) having a substantially wedge shape can be formed by linearly cutting the partition wall 12 so that the width becomes narrower toward the front end (see Figure 4 ), it is also possible to form by removing the partition wall 12 in stages (refer to Figure 5 ).

[0060] Although not shown, the cross-sectional shape of one of the first slit 17 and the second slit 18 may be substantially rectangular, and the cross-sectional shape of the other of the first slit 17 and the second slit 18 may be substantially wedge-shaped.

[0061] like Figure 2 As shown, the first slits 17 are typically formed throughout the entire honeycomb structure 1 (i.e., from the first end face E1 to the second end face E2) in the direction in which the cells 13 extend. In addition, although not shown, the second slits 18 are typically formed throughout the entire honeycomb structure 1 in the direction in which the cells 13 extend.

[0062] In one embodiment, the first slit 17 and the second slit 18 each have a hollow space inside. In this embodiment, air exists inside each of the first slit and the second slit. Therefore, the first slit and the second slit can stably function as an electrical insulating portion.

[0063] In addition, if Figure 6 As shown, the first slit 17 and the second slit 18 may be filled with a filling material 5. If the first slit and the second slit are filled with a filling material, the strength of the honeycomb structure can be improved. In addition, if the first slit and the second slit are filled with a filling material, when the fluid corresponding to the purpose of the heating device is made to flow to the pores, the fluid can be suppressed from flowing into the slits. Therefore, the fluid can flow stably to the pores. It should be noted that, although not shown in the figure, the interior of the first slit may be hollow and the interior of the second slit may be filled with a filling material, or the interior of the second slit may be hollow and the interior of the first slit may be filled with a filling material.

[0064] The filling material 5 may be filled in the entire first slit 17 and / or the second slit 18, or may be filled in only a portion of the first slit 17 and / or the second slit 18. For example, if the end of the first end face side (inflow end face side) of the slit (first slit or second slit) is filled with a filling material, the flow of the fluid into the slit can be suppressed. In addition, if the filling material is filled in the entire slit, the strength of the honeycomb structure can be fully improved, and the flow of the fluid into the slit can be more stably suppressed.

[0065] The volume resistance value of the filler at 25°C is, for example, greater than 1.0×10 11 Ω·cm, preferably 1.0×10 13 Ω·cm or more. As the filler, representative examples include insulating ceramic materials. As the insulating ceramic material, for example, examples include aluminum nitride, aluminum oxide, silicon nitride, silicon carbide, zirconium oxide, cordierite, and mullite. The filler can be used alone or in combination.

[0066] B. Modification of the heating device

[0067] Figures 1 to 6 The honeycomb structure 1 shown in the figure has a plurality of second slits 18. As mentioned above, the number of the second slits 18 is not limited thereto. Figure 7 As shown, the second slit 18 can also be one. Figure 8 As shown, the honeycomb structure 1 may not include the second slits 18 but may include only the first slits 17 .

[0068] Figures 1 to 8 The heating device shown in FIG. 1 includes a first electrode and a second electrode. The number of electrodes is not limited thereto. Fig. 9 As shown, the heating device 100 may also include a plurality of first electrodes and / or second electrodes. In this case, the side 11 of the honeycomb structure 1 includes a plurality of first portions P1 and a plurality of second portions P2. In the example shown in the figure, a first electrode 2 and two second electrodes 3 are provided on the first side 11a of the honeycomb structure 1, and the first electrode 2 is disposed between the two second electrodes 3. The sum of the number of first slits 17 and the number of second slits 18 located between the first electrode 2 and each second electrode 3 is an odd number, specifically 3.

[0069] Figures 1 to 9 In the heat generating device shown in FIG. 1 , the first electrode and the second electrode are arranged on the same side of the four side surfaces of the honeycomb structure having a prism shape. The arrangement of the first electrode and the second electrode is not limited thereto. Fig.10As shown, the first electrode 2 and the second electrode 3 can be arranged on different sides of the four sides of the honeycomb structure having a prism shape. In the example shown in the figure, the first electrode 2 is arranged on the first side 11a of the honeycomb structure 1, and the second electrode 3 is arranged on the third side 11c of the honeycomb structure 1.

[0070] Figures 1 to 10 In the heat generating device 100 shown in FIG. 1 , the honeycomb structure 1 has a substantially quadrilateral shape in a cross section in a direction perpendicular to the direction in which the cells 13 extend. As described above, the cross-sectional shape of the honeycomb structure is not limited thereto. In one embodiment, as shown in FIG. Fig.11 As shown, the honeycomb structure 1 has a substantially circular shape in a cross section in a direction orthogonal to the direction in which the cells 13 extend. In the present embodiment, the honeycomb structure has a cylindrical shape with a circular bottom surface. In this case, the first electrode 2 and the second electrode 3 are arranged on the outer peripheral surface 11e which is the side surface of the honeycomb structure 1. The outer peripheral surface 11e of the honeycomb structure 1 includes a first portion P1 which is located between the first electrode 2 and the second electrode 3 in the circumferential direction of the honeycomb structure 1 and a second portion P2 which is located on the opposite side of the first portion P1 relative to the central axis of the honeycomb structure 1.

[0071] Hereinafter, the specific structures of the honeycomb structure, the first electrode, and the second electrode will be described.

[0072] C. Honeycomb structure

[0073] The honeycomb structure 1 is a flow-through type honeycomb structure having a plurality of cells 13 .

[0074] The cell 13 has any appropriate shape in the cross section in the direction perpendicular to the axial direction of the honeycomb structure 1. As the cross-sectional shape of the cell, for example, a triangle, a quadrilateral, a pentagon, a polygon higher than a hexagon, a circle, and an ellipse can be listed. The cross-sectional shape and size of the cell can be all the same, or at least a part can be different. In such a cross-sectional shape of the cell, a quadrilateral is preferably cited, and a square or a rectangle is more preferably cited.

[0075] In one embodiment, the internal space of the cells 13 is configured as a flow path for a fluid to flow according to the purpose of the heat generating device 100 .

[0076] The cell density (i.e., the number of cells 13 per unit area) in the cross section of the honeycomb structure in a direction perpendicular to the longitudinal direction can be appropriately set according to the purpose. For example, the cell density can be 4 cells / cm 2 ~320 cells / cm 2 When the cell density is within such a range, the strength and effective GSA (geometric surface area) of the honeycomb structure can be sufficiently ensured.

[0077] Typically, the honeycomb structure 1 is made of a conductive ceramic material. With such a structure, the honeycomb structure can be stably configured as a heat generating body.

[0078] The volume resistivity of the conductive ceramic material at 25°C is typically 10Ω·cm or less, preferably 1Ω·cm or less. Examples of the conductive ceramic material include conductive zirconia-based materials, aluminum oxide-titanium carbide-based composite materials, Si-SiC-based composite materials, and Si-SiC-based composite materials impregnated with Si metal, preferably Si-SiC-based composite materials. The conductive ceramic material can be used alone or in combination.

[0079] As described above, the honeycomb structure 1 includes an outer wall 10 and a partition wall 12. In the illustrated example, the outer wall 10 and the partition wall 12 are formed integrally. In the present embodiment, the conductive ceramic material constituting the outer wall 10 is the same as the conductive ceramic material constituting the partition wall 12. In addition, the outer wall 10 and the partition wall 12 may also be separate. In this case, the conductive ceramic material constituting the outer wall 10 and the conductive ceramic material constituting the partition wall 12 may be the same or different.

[0080] The outer wall 10 has a cylindrical shape corresponding to the shape of the honeycomb structure 1. Figures 1 to 10 In the embodiment, the outer wall 10 has a square tube shape. The thickness of the outer wall 10 may be, for example, 0.5 mm to 10 mm, or, for example, 1 mm to 8 mm.

[0081] The partition wall 12 defines a plurality of cells 13. More specifically, the partition wall 12 includes a first partition wall 12a and a second partition wall 12b that are orthogonal to each other, and the first partition wall 12a and the second partition wall 12b define a plurality of cells 13. It should be noted that the structure of the partition wall is not limited to the above-mentioned partition wall 12. The partition wall may also include a first partition wall extending in a radial direction and a second partition wall extending in a circumferential direction, which define a plurality of cells.

[0082] Although not shown, a functional layer corresponding to the purpose of the heat generating device 100 may be provided on the surface of the partition wall 12. When the functional layer is provided on the surface of the partition wall 12, the portion (representatively the central portion) in the cross section of the cell 13 where the functional layer is not formed constitutes a flow path. The functional layer may be formed on the entire inner surface of the partition wall 12 or on a portion of the surface of the partition wall 12.

[0083] The thickness of the partition wall 12 can be appropriately set according to the purpose of the honeycomb structure. Typically, the thickness of the partition wall 12 is thinner than the thickness of the outer wall 10. The thickness of the partition wall 12 can be, for example, 0.05 mm to 1.0 mm, and can be, for example, 0.08 mm to 0.6 mm. The thickness of the partition wall is measured, for example, by cross-sectional observation using a SEM (scanning electron microscope). If the thickness of the partition wall is within such a range, the mechanical strength of the honeycomb structure can be improved, and the opening area (the total area of ​​the cells in the cross section) can be improved.

[0084] The partition walls 12 are basically dense bodies, and the porosity of the partition walls 12 is, for example, 10% or less, or preferably 5% or less. The porosity can be measured, for example, by mercury intrusion porosimetry.

[0085] The density of the partition wall 12 is, for example, 0.4 g / cm 3 Above, preferably 0.5 g / cm 3 Above, for example 6g / cm 3 Below, preferably 5g / cm 3 The density can be measured, for example, by mercury intrusion porosimetry.

[0086] D. First electrode and second electrode

[0087] The first electrode 2 and the second electrode 3 are typically provided directly on the side surface 11 of the honeycomb structure 1. Any appropriate metal can be used as the material of the electrode (the first electrode or the second electrode). Although not shown, the first electrode 2 and the second electrode 3 can be electrically connected to a power source.

[0088] Possibility of industrial application

[0089] The heat generating device according to the embodiment of the present invention can be used in various industrial products, and can be particularly suitably used as a filter.

[0090] Description of Reference Numerals

[0091] 1: honeycomb structure, 10: outer wall, 12: partition wall, 13: cell, 17: first slit, 18: second slit, 2: first electrode, 3: second electrode, 100: heat generating device.

Claims

1. A heating device, comprising: A honeycomb structure having an outer wall and partition walls disposed inside the outer wall and defining a plurality of cells extending from a first end face to a second end face, a first electrode disposed on a side of the honeycomb structure, and A second electrode is disposed on a side of the honeycomb structure and is located at a position separated from the first electrode; The side surface of the honeycomb structure comprises: a first portion located between the first electrode and the second electrode, and a second portion located on the opposite side of the first portion with respect to the center of a cross section of the honeycomb structure in a direction perpendicular to the direction in which the cells extend; The honeycomb structure has a first slit extending from the first portion toward the second portion.

2. The heating device according to claim 1, wherein: The honeycomb structure has a substantially quadrilateral shape in a cross section in a direction perpendicular to a direction in which the cells extend; The honeycomb structure has: a first side surface and a second side surface which are arranged at a distance from each other in a first direction orthogonal to a direction in which the cells extend; and A third side surface and a fourth side surface are arranged at intervals from each other in a second direction perpendicular to the direction in which the cells extend and the first direction; The first side surface is provided with the first electrode and the second electrode and includes the first portion, The second side includes the second portion.

3. The heating device according to claim 1 or 2, wherein: The first slit has a substantially wedge-shaped shape in a cross section in a direction perpendicular to a direction in which the cells extend, the width of the first slit becoming narrower as it moves away from the first portion.

4. The heating device according to claim 1 or 2, wherein: The interior of the first slit is hollow.

5. The heating device according to claim 1 or 2, wherein: The first slit is filled with a filling material.

6. The heating device according to claim 1 or 2, wherein: The first slits are provided with a plurality of slits. The honeycomb structure further includes a second slit extending from the second portion toward the first portion and located between the first slits adjacent to each other among the plurality of the first slits.

7. The heating device according to claim 6, wherein: The sum of the number of the first slits and the number of the second slits between the first electrode and the second electrode is an odd number.

8. The heating device according to claim 6, wherein: The second slit has a substantially wedge-shaped shape in a cross section in a direction perpendicular to the direction in which the cells extend, the width of the second slit becoming narrower as it moves away from the second portion.

9. The heating device according to claim 6, wherein: The interior of the second slit is hollow.

10. The heating device according to claim 6, wherein: The second slit is filled with a filling material.

11. The heating device according to claim 1 or 2, wherein: The honeycomb structure is made of a conductive ceramic material.

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