Three-phase honeycomb heater

Abstract

To provide a three-phase type honeycomb heater which improves heat efficiency and heat exchange efficiency.SOLUTION: A three-phase type honeycomb heater comprises: a honeycomb structure 1 including an outer peripheral wall and a partition wall 102 disposed inside of the outer peripheral wall and defining and forming a plurality of cells 101 forming a passage extending from one end face to the other end face; a first electrode which is connectable to a first phase output terminal (R) of a three-phase AC power supply circuit; a second electrode which is connectable to a second phase output terminal (S) of the three-phase AC power supply circuit; and a third electrode which is connectable to a third phase output terminal (T) of the three-phase AC power supply circuit. The honeycomb structure includes: slits 103 disposed so as to specify an electrification path for star-connecting a first electrode 201, a second electrode 202, and a third electrode 203 on the outer peripheral wall and / or the partition wall; and a connection section 104 which mutually connects the first electrode 201, the second electrode 202, and the third electrode 203.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a three-phase honeycomb heater.

Background Art

[0002] As a conventional three-phase heating element, a heating element made of silicon carbide material is known. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-257056) discloses a structure in which a cylindrical reaction-sintered silicon carbide having a relative density of 90% or more has three grooves arranged at 120° intervals in the heating portion cut in a spiral shape, a structure in which three grooves arranged at 120° intervals at the end portion are cut straight, and an electrode portion has an insulating refractory inserted on the inner diameter side and is fixed with a metal electrode plate from the outer shape side. A three-phase silicon carbide heating element is described.

[0003] Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 08-250263) discloses a three-phase silicon carbide heating element including a heating portion formed by casting a slurry containing silicon carbide and having a central heating portion and two end heating portions, and a tip portion for connecting the central heating portion and the two end heating portions. A three-phase silicon carbide heating element is described, characterized in that the tip portion is formed in a W shape and the central heating portion and the two end heating portions are arranged in a single plane.

[0004] As an advantage of a three-phase heating element, for example, Patent Document 1 discloses that "since it can be directly used with a three-phase power supply, compared with a normal single-phase heater, a device for converting to a single-phase power supply can be omitted, so the power supply device is low-cost, and the balance of each phase is also easy to maintain, leading to power saving. Further, since it is a single-terminal type, a setting method such as hanging from the ceiling or side wall of a heating furnace becomes easy, and the wiring capacity can also be reduced."

[0005] On the other hand, it has been proposed to generate heat by passing an electric current through a honeycomb structure used as a catalyst support or the like. For example, Patent Document 3 (Japanese Patent Publication No. 07-085952) describes a three-phase honeycomb heater in which a heater body is formed mainly from conductive ceramics and heater through holes are provided in the heater body, characterized in that the heater body is provided with notches that change the effective length and effective width of the heater body and thereby change the resistance value. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2001-257056 [Patent Document 2] Japanese Patent Application Publication No. 08-250263 [Patent Document 3] Japanese Patent Application Publication No. 07-085952 [Overview of the project] [Problems that the invention aims to solve]

[0007] Although the three-phase heating elements disclosed in Patent Documents 1 and 2 have high heating efficiency, they lack a cell flow path structure and therefore have limited heat exchange efficiency. For this reason, there is a need for a three-phase heating element with a structure different from conventional ones.

[0008] This invention was completed in view of the above-mentioned problems, and in one embodiment, aims to provide a three-phase honeycomb heater with high heat generation efficiency and heat exchange efficiency. [Means for solving the problem]

[0009] As a result of diligent research by the inventors, it has been found that the above problem can be solved by providing multiple electrodes in a three-phase honeycomb heater equipped with a honeycomb structure, and by arranging slits to define a current flow path for connecting a three-phase AC power supply circuit. The present invention was completed based on the above findings and is illustrated below.

[0010] Item 1. A honeycomb structure comprising an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which divide and form a plurality of cells that form a flow path extending from one end face to the other end face, A first electrode connected to the outer wall and connectable to the first phase output terminal (R) of the three-phase AC power supply circuit, A second electrode is connected to the outer wall, away from the first electrode, and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit. The outer periphery wall includes a third electrode connected at a distance from the first and second electrodes, and capable of being connected to the third-phase output terminal (T) of a three-phase AC power supply circuit, The honeycomb structure A slit is provided in the outer wall and / or partition wall to define a current passage for connecting the first electrode, the second electrode, and the third electrode in a star configuration, A connection portion that connects the first electrode, the second electrode, and the third electrode to each other, A three-phase honeycomb heater equipped with [features / equipment].

[0011] Item 2. A three-phase honeycomb heater as described in Item 1, wherein the electrical resistance of the three current-carrying paths from the connection point to the outer wall to which the first electrode, second electrode, and third electrode are connected is equal.

[0012] Item 3. A three-phase honeycomb heater as described in Item 2, wherein the lengths of the three current-carrying paths from the connection point to the outer wall to which the first electrode, second electrode, and third electrode are connected are equal.

[0013] Item 4. A three-phase honeycomb heater according to any one of items 1 to 3, wherein the honeycomb structure has a first side surface and a second side surface facing the first side surface on its outer periphery, and the slits are provided with a plurality of slits that extend from the first side surface as the base end toward the second side surface and in a direction parallel to the direction in which the cells extend, and the connecting portion is disposed on the second side surface, and the first electrode, second electrode and third electrode are disposed on the first side surface.

[0014] Item 5. The honeycomb structure has a first side and a second side facing the first side on its outer perimeter wall. A three-phase honeycomb heater according to any one of items 1 to 3, wherein, in a cross section perpendicular to the direction in which the cells extend, the directions that are mutually orthogonal are defined as the first and second directions, the slits extend in the first and second directions, and the slits extend parallel to the direction in which the cells extend, and the connecting portion is disposed inside the honeycomb structure.

[0015] Item 6. A honeycomb structure comprising an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which demarcate and form a plurality of cells that form a flow path extending from one end face to the other end face, A first electrode connected to the outer wall of the honeycomb structure and connectable to the first phase output terminal (R) of the three-phase AC power supply circuit, A second electrode is connected to the outer wall of the honeycomb structure, away from the first electrode, and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit. A third electrode is connected to the outer wall of the honeycomb structure, separated from the first and second electrodes, and is connectable to the third phase output terminal (T) of the three-phase AC power supply circuit. The honeycomb structure includes a fourth electrode connected to the outer periphery wall of the honeycomb structure, separated from the first, second, and third electrodes, and connected to the first phase output terminal (R) of a three-phase AC power supply circuit, The honeycomb structure A three-phase honeycomb heater, comprising slits arranged in the outer wall and partition wall to define energizing paths, each having a first energizing path, a second energizing path, and a third energizing path for connecting the first, second, third, and fourth electrodes in a delta-type connection.

[0016] Item 7. A three-phase honeycomb heater according to Item 6, comprising a first energizing path between the first electrode and the second electrode, a second energizing path between the second electrode and the third electrode, and a third energizing path between the third electrode and the fourth electrode, wherein the electrical resistances of the first energizing path, the second energizing path, and the third energizing path are equal.

[0017] Item 8. The energization path includes a first energization path between the first electrode and the second electrode, a second energization path between the second electrode and the third electrode, and a third energization path between the third electrode and the fourth electrode, and the lengths of the first energization path, the second energization path, and the third energization path are equal. The three-phase honeycomb heater according to Item 7.

[0018] Item 9. The honeycomb structure includes a first side surface on the outer peripheral wall and a second side surface facing the first side surface. The slit is When the directions orthogonal to each other in a cross-section perpendicular to the extending direction of the cells are defined as the first direction and the second direction, a first slit that extends along the first direction with the first side surface as the base end and has a tip on the second side surface side, A second slit that is separated from the first slit in the second direction, extends along the first direction with the second side surface as the base end, and has a tip on the first side surface side. And includes The first slit and the second slit are alternately arranged in the second direction in a cross-section perpendicular to the extending direction of the cells, whereby the current can flow in the first direction and the second direction along the outer peripheral wall and / or the partition wall in sequence repeatedly. The three-phase honeycomb heater according to any one of Items 6 to 8.

[0019] Item 10. The honeycomb structure includes a first side surface on the outer peripheral wall and a second side surface facing the first side surface. The slit is When the directions orthogonal to each other in a cross-section parallel to the extending direction of the cells are defined as the first direction and the second direction, a first slit that extends along the first direction with the first side surface as the base end and has a tip on the second side surface side, A second slit that is separated from the first slit in the second direction in a cross-section parallel to the extending direction of the cells, extends along the first direction with the second side surface as the base end, and has a tip on the first side surface side. And includes A three-phase honeycomb heater according to any one of items 6 to 8, wherein the first and second slits are alternately arranged in a second direction in a cross section parallel to the direction in which the cell extends, thereby enabling the current to flow sequentially in the first and second directions along the outer wall and / or partition wall.

[0020] Item 11. A three-phase honeycomb heater as described in Item 9, wherein the first electrode, second electrode, third electrode, and fourth electrode are connected to the first side surface.

[0021] Item 12. A three-phase honeycomb heater as described in Item 10, wherein the first electrode, second electrode, third electrode, and fourth electrode are connected to the first side surface.

[0022] Item 13. A three-phase honeycomb heater according to Item 9, wherein, in a cross section perpendicular to the direction in which the cell extends, the current flows in a first direction along the outer wall and / or partition wall, then in a second direction, and then in the first direction, and one or more first current-carrying paths, the first electrode, second electrode, third electrode, and fourth electrode are arranged on the first side surface or second side surface such that there are one or more first current-carrying paths, a second current-carrying path, and a third current-carrying path.

[0023] Item 14. A three-phase honeycomb heater according to Item 10, wherein, in a cross section parallel to the direction in which the cell extends, when the current flows in a first direction along the outer wall and / or partition wall, then in a second direction, and then in the first direction, one current path is defined as one current path, and there are at least one first current path, a second current path, and a third current path, each of which is provided, the first electrode, second electrode, third electrode, and fourth electrode are arranged apart on the first side or second side, respectively. [Effects of the Invention]

[0024] According to one embodiment of the present invention, a three-phase honeycomb heater with high heat generation efficiency and heat exchange efficiency can be provided. [Brief explanation of the drawing]

[0025] [Figure 1A]This is a perspective view showing a honeycomb structure 1 according to one embodiment of the present invention. [Figure 1B] This is a cross-sectional view of the honeycomb structure 1 in Figure 1A, observed perpendicular to the direction in which the cells extend. [Figure 2A] This is a perspective view showing a honeycomb structure 1 according to one embodiment of the present invention. [Figure 2B] Figure 2A is a cross-sectional view of the honeycomb structure 1, observed perpendicular to the direction in which the cells extend. [Figure 3] This is a schematic diagram showing the structure of a three-phase honeycomb heater 20 according to one embodiment of the present invention. Figure 3(A) is a cross-sectional view of the three-phase honeycomb heater 20 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 3(B) is a side view of the three-phase honeycomb heater 20 in a direction parallel to the direction in which the cells extend. [Figure 4] Figure 4 is a schematic diagram showing the structure of a three-phase honeycomb heater 30 according to another embodiment of the present invention. Figure 4(A) is a cross-sectional view of the three-phase honeycomb heater 30 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 4(B) is a side view of the three-phase honeycomb heater 30 in a direction parallel to the direction in which the cells extend. [Figure 5] This is a schematic diagram showing the three energization paths in the three-phase honeycomb heater 30 in the embodiment shown in Figure 4. [Figure 6] This is a schematic diagram showing the structure of a three-phase honeycomb heater 40 according to another embodiment of the present invention. Figure 6(A) is a cross-sectional view of the three-phase honeycomb heater 40 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 6(B) is a side view of the three-phase honeycomb heater 40 in a direction parallel to the direction in which the cells extend. [Figure 7] Figure 6 is a schematic diagram showing the three energization paths in the three-phase honeycomb heater 40 in the embodiment shown. [Figure 8] This is a schematic diagram showing the structure of a three-phase honeycomb heater 50 according to one embodiment of the present invention. Figure 8(A) is a cross-sectional view of the three-phase honeycomb heater 50 when observed in a cross section perpendicular to the direction in which the cell 102 extends, and Figure 8(B) is a side view of the three-phase honeycomb heater 50 in a direction parallel to the direction in which the cell 102 extends. [Figure 9] This is a schematic diagram showing the structure of a three-phase honeycomb heater 60 according to another embodiment of the present invention. Figure 9(A) is a cross-sectional view of the three-phase honeycomb heater 60 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 9(B) is a side view of the three-phase honeycomb heater 60 in a direction parallel to the direction in which the cells extend. [Figure 10] This is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 10(A) is a cross-sectional view of the three-phase honeycomb heater 70 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 10(B) is a side view of the three-phase honeycomb heater 70 in a direction parallel to the direction in which the cells extend. [Figure 11] This is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 11(A) is a cross-sectional view of the three-phase honeycomb heater 80 when observed in a cross section perpendicular to the direction in which the cell 102 extends, and Figure 11(B) is a side view of the three-phase honeycomb heater 80 in a direction parallel to the direction in which the cell 102 extends. [Figure 12] This is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 12(A) is a cross-sectional view of the three-phase honeycomb heater 90 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 12(B) is a side view of the three-phase honeycomb heater 90 in a direction parallel to the direction in which the cells extend. [Figure 13] This is a schematic diagram showing the structure of a three-phase honeycomb heater 21 according to yet another embodiment of the present invention. Figure 13(A) is a cross-sectional view of the three-phase honeycomb heater 21 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 12(B) is a side view of the three-phase honeycomb heater 21 in a direction parallel to the direction in which the cells extend. [Modes for carrying out the invention]

[0026] Next, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that appropriate design changes, improvements, etc., can be made based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention.

[0027] (1. Honeycomb structure) Figure 1A is a perspective view showing a honeycomb structure 1 that may be used in one embodiment of the present invention. Figure 1B is a cross-sectional view of the honeycomb structure 1 of Figure 1A, observed in a cross section perpendicular to the direction in which the cells extend. Figure 2A is a perspective view showing a honeycomb structure 1 that may be used in another embodiment of the present invention. Figure 2B is a cross-sectional view of the honeycomb structure 1 of Figure 2A, observed in a cross section perpendicular to the direction in which the cells extend.

[0028] The honeycomb structure 1 comprises an outer perimeter wall 100, partition walls 101 disposed inside the outer perimeter wall 100 and forming partitions for a plurality of cells 102 that form a flow path extending from one end face to the other, and a plurality of slits 103 arranged apart from each other in a cross section perpendicular to the direction in which the cells 102 extend, so as to restrict the current flow path between the outer perimeter wall 100 and between each other. Furthermore, from the viewpoint of maintaining the strength of the honeycomb structure 1, it is preferable that the thickness of the outer perimeter wall 100 is greater than the thickness of the partition walls 101.

[0029] In the embodiments shown in Figures 1A and 1B, the honeycomb structure 1 has a cross section perpendicular to the direction in which the cells 102 extend, with mutually orthogonal directions designated as a first direction (FD, vertical direction in the drawings) and a second direction (SD, horizontal direction in the drawings). The honeycomb structure 1 includes a first slit 103a, with one end in the first direction FD as the base and the other end as the tip, and a second slit 103b, which is separated from the first slit 103a in the second direction SD, with the other end of the first direction FD as the base and the one end as the tip. In the illustrated embodiments, there are three first slits 103a and two second slits 103b.

[0030] In the embodiments shown in Figures 2A and 2B, the honeycomb structure 1 has a cross section parallel to the direction in which the cells 102 extend, with mutually orthogonal directions designated as a first direction (FD, vertical direction in the drawings) and a second direction (SD, horizontal direction in the drawings). The honeycomb structure 1 includes a first slit 103a, with one end in the first direction FD as the base and the other end as the tip, and a second slit 103b, which is separated from the first slit 103a in the second direction SD, with the other end of the first direction FD as the base and the one end as the tip. In the illustrated embodiments, there are three first slits 103a and two second slits 103b.

[0031] The ratio of the length of the first direction FD of each slit 103 to the length of the first direction FD from the tip of each slit 103 to the outer surface of the outer peripheral wall 100 on the other end of the honeycomb structure 1 is preferably 3:1 or more, more preferably 6:1 or more, and even more preferably 9:1 or more, from the viewpoint of improving uniform heat generation. Furthermore, from the viewpoint of ensuring the mechanical strength of the honeycomb structure 1, the ratio is preferably 18:1 or less, more preferably 15:1 or less, and even more preferably 12:1 or less. Accordingly, the ratio is preferably, for example, 3 to 18:1, more preferably 6 to 15:1, and even more preferably 9 to 12:1.

[0032] Furthermore, the honeycomb structure 1 is restricted by the first slit 103a and the second slit 103b, so that when the honeycomb structure 1 is energized, an energizing path is formed for connection with a predetermined wiring. Details of the energizing path will be described later.

[0033] Furthermore, in the embodiments shown in Figures 1A and 1B, and Figures 2A and 2B, the first slit 103a and the second slit 103b are arranged parallel to each other with equal spacing in the second direction SD. Also, the first slit 103a and the second slit 103b are arranged alternately in the second direction SD. Also, the first slit 103a and the second slit 103b are the same length in the first direction FD. However, in other embodiments of the present invention, the location, direction, and length of the slit 103 may be changed. These will be described in more detail below.

[0034] The shape of the cells 102 of the honeycomb structure 1 is not particularly limited, but in a cross-section perpendicular to the direction in which the cells 102 extend, they can be polygonal (square, pentagonal, hexagonal, heptagonal, octagonal, etc.), circular, or oval. These shapes may be single or a combination of two or more. Among these shapes, square or hexagonal is preferred. By providing cells 102 of such shapes, the pressure loss when air flows can be reduced. Figures 1 and 2 show an example of a honeycomb structure 1 in which the outer shape of the cross-section and the shape of the cells 102 are square in a cross-section perpendicular to the direction in which the cells 102 extend.

[0035] The thickness of the partition wall 101 that divides the cell 102 is not particularly limited, but is for example 70 μm to 500 μm. The number of cells 102 in a cross section perpendicular to the direction in which the cell 102 extends is not particularly limited, but is for example 15 cells / cm 2 ~150 cells / cm 2 The thickness of the partition wall 101 is defined as the length of the line segment that crosses the partition wall 101 when the centroids of adjacent cells 102 are connected by a line segment perpendicular to the direction in which the cells 102 extend. The thickness of the partition wall 101 and the number of cells 102 can be measured, for example, by a digital microscope.

[0036] The aperture ratio of the honeycomb structure 1 is not particularly limited, but is for example 65-90%. Here, the aperture ratio of the honeycomb structure 1 refers to the ratio of the aperture area per unit area in a cross section perpendicular to the direction in which the cells 102 of the honeycomb structure 1 extend. Specifically, the aperture ratio of the honeycomb structure 1 is the ratio of the total aperture area of ​​the cells 102 to the total area of ​​the cross section perpendicular to the direction in which the cells 102 of the honeycomb structure 1 extend (including the partition walls 101, the openings of the cells 102, the slits 103, and the outer peripheral walls 100; if electrodes or electrode layers described later are provided, these are not considered). The aperture ratio of the honeycomb structure 1 can be measured, for example, by a digital microscope.

[0037] The hydraulic diameter of cell 102 in honeycomb structure 1 is, for example, 0.7 mm to 1.8 mm. Here, the hydraulic diameter of cell 102 in honeycomb structure 1 is determined by the circumference (unit: mm) surrounded by partition wall 101 and the cross-sectional area (unit: mm) of cell 102. 2 Based on this, it is calculated by the formula: 4 × (cross-sectional area) / (perimeter). The perimeter surrounded by the partition wall 101 and the cross-sectional area of ​​cell 102 can be measured, for example, by a digital microscope.

[0038] In the embodiments shown in Figures 1 and 2A and 2B, the shape of the outer perimeter wall 100 in a cross-section perpendicular to the direction in which the cell 102 extends is rectangular, but it may be other polygons or other shapes such as circles. The thickness of the outer perimeter wall 100 is, for example, 0.5 mm to 5 mm. In addition, a heating element can be constructed by electrically connecting multiple honeycomb structures 1 having different shapes and sizes. Here, the thickness of the outer perimeter wall 100 is defined as the thickness in the direction normal to the tangent of the outer perimeter wall 100 at the measurement point when the location of the outer perimeter wall 100 to be measured is observed in a cross-section perpendicular to the direction in which the cell 102 extends. The thickness of the outer perimeter wall 100 can be measured, for example, by a digital microscope.

[0039] The difference between the average thickness of the outer wall 100 and the average thickness of the partition wall 101 can be, for example, 100 to 1200 μm, and typically 200 to 800 μm. The average thickness of the outer wall 100 refers to the average value obtained when the thickness of the outer wall 100 is measured at 10 locations without bias. The average thickness of the partition wall 101 refers to the average value obtained when the thickness of the partition wall 101 is measured at 10 locations without bias.

[0040] The volume resistivity of the honeycomb structure 1 is, for example, 0.001 Ω·cm or more, preferably 0.01 Ω·cm or more, and more preferably 0.1 Ω·cm or more. With such a volume resistivity, problems such as excessive current flow depending on the applied voltage can be suppressed. On the other hand, the volume resistivity of the honeycomb structure 1 is, for example, 200 Ω·cm or less, preferably 100 Ω·cm or less. With such a volume resistivity, sufficient heat can be generated when current is applied. The volume resistivity is the value measured at 25°C by the four-terminal method.

[0041] The honeycomb structure 1 may be mainly composed of ceramics. Preferably, the honeycomb structure 1 is mainly composed of conductive ceramics. When the honeycomb structure 1 is said to be mainly composed of ceramics, it means that the honeycomb structure 1 contains ceramics in a total of 80% by mass or more, preferably 90% by mass or more. The ceramics can be selected from the group consisting of oxide-based ceramics such as alumina, mullite, zirconia, and cordierite, and non-oxide-based ceramics such as silicon carbide (SiC), silicon nitride, and aluminum nitride, although this is not limited to these materials. Examples of conductive ceramics include metal compounds such as metal silicides such as silicon carbide, tantalum silicide (TaSi2), and chromium silicide (CrSi2).

[0042] In one embodiment, the honeycomb structure 1 is made of a material containing silicon carbide. Preferably, the honeycomb structure 1 is made of a material mainly composed of silicon carbide material or carbon-silicon carbide composite material. When we say that the honeycomb structure 1 is mainly composed of silicon carbide material or carbon-silicon carbide composite material, it means that the honeycomb structure 1 contains silicon carbide material or carbon-silicon carbide composite material in an amount of 80% by mass or more, preferably 90% by mass or more of the total.

[0043] The silicon carbide material described above may be a silicon-impregnated material (silicon-impregnated silicon carbide). The silicon-silicon carbide composite material may be a material in which multiple silicon carbide particles are bonded together by metallic silicon. In the silicon-silicon carbide composite material, the silicon carbide particles can function as aggregate, and silicon can function as a binder. By using such a material, the above volume resistivity can be achieved well. The volume resistivity of the honeycomb structure 1 can also be controlled by adjusting its porosity.

[0044] The honeycomb structure 1 can typically be obtained by molding a molding material containing ceramic raw materials, drying the resulting molded body, and firing it. When the honeycomb structure 1 is composed of the silicon-silicon carbide composite material, the molding material may contain silicon carbide (e.g., silicon carbide powder) and metallic silicon (e.g., metallic silicon powder). Other raw materials that may be included in the molding material include, for example, binders, dispersion media, and additives.

[0045] Typically, the honeycomb structure 1 can be used as a catalyst support, and a catalyst can be supported on its partition walls 101. For example, CO, NO in a fluid (e.g., gas) passing through cell 102. x Hydrocarbons and other substances can be rendered harmless through catalytic reactions. The catalyst may preferably contain noble metals (e.g., platinum, rhodium, palladium, ruthenium, indium, silver, gold), aluminum, nickel, zirconium, titanium, cerium, cobalt, manganese, zinc, copper, tin, iron, niobium, magnesium, lanthanum, samarium, bismuth, barium, and combinations thereof.

[0046] (2. Three-phase honeycomb heater: Star connection) Figure 3 is a schematic diagram showing the structure of a three-phase honeycomb heater 20 according to one embodiment of the present invention. Figure 3(A) is a cross-sectional view of the three-phase honeycomb heater 20 when observed in a cross section perpendicular to the direction in which the cell 102 extends, and Figure 3(B) is a side view of the three-phase honeycomb heater 20 in a direction parallel to the direction in which the cell 102 extends.

[0047] In the embodiment shown in Figure 3, the three-phase honeycomb heater 20 is A honeycomb structure 1 comprises an outer perimeter wall 100 and partition walls 101 disposed inside the outer perimeter wall 100, which divide and form a plurality of cells 102 that form a flow path extending from one end face to the other end face. A first electrode 201 is connected to the outer wall 100 and is connectable to the first phase output terminal (R) of a three-phase AC power supply circuit (not shown), A second electrode 202 is connected to the outer perimeter wall 100, away from the first electrode 201, and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit. The outer periphery wall 100 is provided with a third electrode 203 connected at a distance from the first electrode 201 and the second electrode 202, respectively, and connectable to the third phase output terminal (T) of the three-phase AC power supply circuit, The honeycomb structure 1 A slit 103 is provided in the outer wall 100 and / or partition wall 101 to define an energizing path (in the direction of the arrow in the drawing) for connecting the first electrode 201, the second electrode 202, and the third electrode 203 in a star configuration, The device includes a connecting portion 104 that connects the first electrode 201, the second electrode 202, and the third electrode 203 to each other.

[0048] The honeycomb structure 1 has a first side surface 105 and a second side surface 106 facing the first side surface 105 on its outer periphery wall 100. The slits 103 extend from the first side surface 105 toward the second side surface 106 and are provided with a plurality of slits 103 that extend in a direction parallel to the direction in which the cells 102 extend. A connecting portion 104 is provided on the second side surface 106 side. The first electrode 201, the second electrode 202, and the third electrode 203 are provided on the first side surface 105.

[0049] The configuration of the three-phase AC power supply circuit is not particularly limited, and any general three-phase AC power supply circuit can be used. By connecting the first electrode 201, the second electrode 202, and the third electrode 203, which are spaced apart from each other, on the outer perimeter wall 100, a so-called star-type current supply path is formed, and a connection section 104 is formed in which these are electrically connected to each other. Because power is transmitted using a three-phase AC power supply circuit, the amount of power that can be transmitted per unit time increases compared to when using a conventional single-phase AC power supply circuit (ideally it becomes √3 times), so the heat generation efficiency is significantly improved. Furthermore, since the honeycomb structure 1 is configured as a heating element, the heat exchange area is significantly increased compared to conventional silicon carbide heating elements, resulting in high heat exchange efficiency. Therefore, when configured as a heater, it also has the advantage of being able to be made smaller than conventional heaters.

[0050] The current flow paths indicated by the arrows in the drawings are for illustrative purposes only, and in reality, current will flow through all outer walls 100 and partition walls 101. Furthermore, the connection portion 104 is naturally formed by energizing the honeycomb structure 1 and does not need to be made of a different material or structure than other parts. Also, the first electrode 201, the second electrode 202, and the third electrode 203 can be connected to the first phase output terminal (R), second phase output terminal (S), and third phase output terminal (T) of the three-phase AC power supply circuit in any combination and are not necessarily limited to the illustrated combinations. These explanations also apply to other embodiments of the present invention.

[0051] Furthermore, from the viewpoint of ensuring more uniform heat generation during energization, it is preferable that the electrical resistance of the three energizing paths from the connection part 104 to the outer peripheral wall 100 to which the first electrode 201, the second electrode 202, and the third electrode 203 are connected are equal. The electrical resistance of the energizing paths can be adjusted by changing the length of each energizing path, the cross-sectional area of ​​the surface perpendicular to the direction of energization, and the material.

[0052] Similarly, from the viewpoint of achieving more uniform heat generation during energization, it is preferable that the lengths of the three energizing paths from the connection portion 104 to the outer peripheral wall 100 to which the first electrode 201, the second electrode 202, and the third electrode 203 are connected are equal. If the honeycomb structure 1 has a homogeneous composition and the cross-sectional areas of the surfaces perpendicular to the direction of energization are equal, then having equal lengths for the three energizing paths also means that the electrical resistance of the energizing paths is equal, making it easier to achieve uniform heat generation.

[0053] In this specification, the length of the current-carrying path refers to the length of the centerlines of each current-carrying path from the first electrode 201, the second electrode 202, and the third electrode 203 to the connection portion 104. If the geometric shapes of the parts of the honeycomb structure 1 constituting each current-carrying path are the same or symmetrical, the lengths of the current-carrying paths may be considered equal. Furthermore, "equal" lengths of the current-carrying paths mean that the length of each current-carrying region is within ±10% of the average value of the lengths of all current-carrying paths. The electrical resistance of each current-carrying path shall be the value measured at 25°C using the four-terminal method.

[0054] In the embodiments shown in Figures 3(A) and 3(B), the current path from the connection point 104 to the outer peripheral wall 100 to which the second electrode 202 is connected is considered to be slightly shorter than the other two current paths. Other embodiments of the star connection will be described below as examples.

[0055] The first electrode 201, the second electrode 202, and the third electrode 203 may each be composed of electrode terminals. When the honeycomb structure 1 is viewed from the direction in which the cell 102 extends, the first electrode 201, the second electrode 202, and the third electrode 203 are positioned at the center of the honeycomb structure 1. However, the first electrode 201, the second electrode 202, and the third electrode 203 may be arbitrarily positioned on one or both sides of the center of the honeycomb structure 1. In order to equalize the electrical resistance of each current-carrying path and improve heat dissipation uniformity, it is preferable that the first electrode 201, the second electrode 202, and the third electrode 203 are connected to the ends of their respective current-carrying paths. In the example of Figure 3, it is preferable that the first electrode 201, the second electrode 202, and the third electrode 203 are connected to the first side surface 105 so as close as possible to the base ends of the three current-carrying paths separated by the two slits 103.

[0056] In the illustrated example, cylindrical electrode terminals are provided as the first electrode 201, second electrode 202, and third electrode 203, but the shape and size of the electrode terminals are not particularly limited. For example, the shape of the electrode terminals can be prismatic or comb-shaped. Although not shown in the illustration, the first electrode 201, second electrode 202, and third electrode 203 may also be constructed by forming an electrode layer on the outer peripheral wall 100 of the honeycomb structure 1 and providing the electrode terminals through this electrode layer. The thickness of the electrode layer is, for example, 100 μm to 5 mm.

[0057] The volume resistivity of the first electrode 201, the second electrode 202, and the third electrode 203 varies depending on their composition and materials, but a lower volume resistivity is preferable, and is typically 0.01 Ω·cm or less. The volume resistivity is the value measured at 25°C using the four-terminal method.

[0058] The first electrode 201, the second electrode 202, and the third electrode 203 can be composed of any suitable material. Examples of constituent materials for the first electrode 201, the second electrode 202, and the third electrode 203 include metals, conductive ceramics, or composite materials (cermets) of metals and conductive ceramics. Examples of metals include Cr, Fe, Co, Ni, Si, and Ti. These can be used individually or in combination of two or more. When using a combination of two or more, alloys of two or more metals may be used. Examples of conductive ceramics include metal compounds such as silicon carbide, tantalum silicide (TaSi2), and chromium silicide (CrSi2). Specific examples of composite materials (cermets) of metals and conductive ceramics include composite materials of metallic silicon and silicon carbide, and composite materials of the above-mentioned metallic silicides, metallic silicon, and silicon carbide. Furthermore, as a specific example of a composite material (cermet) of metal and conductive ceramics, from the viewpoint of reducing thermal expansion, a composite material can be mentioned in which one or more insulating ceramics such as alumina, mullite, zirconia, cordierite, silicon nitride, and aluminum nitride are added to one or more of the above-mentioned metals.

[0059] When the constituent material of the electrode terminals constituting the first electrode 201, the second electrode 202, and the third electrode 203 is metal, the shape of the electrode terminals is preferably comb-shaped. When the constituent material of the electrode terminals is conductive ceramics or a composite material of metal and conductive ceramics (cermet), the shape of the electrode terminals is preferably cylindrical or prismatic. When the constituent material of the electrode terminals is conductive ceramics or a composite material of metal and conductive ceramics (cermet), metal parts may be joined to both ends thereof. The joining of the ceramic electrode terminals and the metal parts can be performed, for example, by crimping, welding, or using a conductive adhesive. Examples of materials for the metal parts include conductive metals such as iron alloys and nickel alloys.

[0060] Preferably, at least a portion of the first electrode 201, the second electrode 202, and the third electrode 203 are made of the same material as the honeycomb structure 1. With such a configuration, the difference in thermal expansion coefficients between the honeycomb structure 1 and the first electrode 201, the second electrode 202, and the third electrode 203 can be reduced, and the bonding strength between them can be increased. This can also contribute to improved productivity. The volume resistivity of the first electrode 201, the second electrode 202, and the third electrode 203 can also be controlled by adjusting their porosity.

[0061] The above description of electrodes and electrode layers may also be applied to other embodiments of the present invention.

[0062] Figure 4 is a schematic diagram showing the structure of a three-phase honeycomb heater 30 according to another embodiment of the present invention. Figure 4(A) is a cross-sectional view of the three-phase honeycomb heater 30 observed perpendicular to the direction in which the cells extend, and Figure 4(B) is a side view of the three-phase honeycomb heater 30 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partition walls and cells are omitted.

[0063] The honeycomb structure 1 has a first side surface 105 and a second side surface 106 facing the first side surface 105 on its outer perimeter wall 100. When the directions perpendicular to each other in a cross section perpendicular to the direction in which the cells extend are defined as the first direction FD and the second direction SD, the slits 103 extend in the first direction FD and the second direction SD, and also extend parallel to the direction in which the cells extend. The connecting portion 104 is disposed inside the honeycomb structure 1. That is, each of the multiple slits 103 has both a portion extending in the first direction FD and a portion extending in the second direction SD, and the connecting portion 104 is located inside the honeycomb structure 1 and is separated from the outer perimeter wall 100.

[0064] In the three-phase honeycomb heater 30 shown in Figure 4, three slits 103 are arranged in a helical pattern, and a first electrode 301, a second electrode 302, and a third electrode 303 are positioned near the base end of each slit 103. As a result, the first electrode 301 and the second electrode 302 are positioned on the second side surface 106 of the honeycomb structure 1, and the third electrode 303 is positioned on the first side surface 105 of the honeycomb structure 1.

[0065] Figure 5 is a schematic diagram showing the three current paths in the three-phase honeycomb heater 30 in the embodiment shown in Figure 4. If the point where the three current paths formed by the three slits 103 intersect is defined as the connection point 104, then current paths are formed from the first electrode 301, the second electrode 302, and the third electrode 303 to the connection point 104 in the order of the circled numbers 1 to 8, respectively. For the sake of understanding, these current paths are connected by black lines in Figure 5, but as mentioned above, in reality, current flows through all the outer walls 100 and partition walls 101. Therefore, in the first embodiment, when referring to the length of the current path, this length of the current path refers to the length of the centerline of each current path from the contact point between each electrode and the honeycomb structure 1 to the connection point 104. Furthermore, if the geometric shapes of the parts of the honeycomb structure 1 constituting each current path are the same or symmetrical, the lengths of the current paths may be considered equal. Please note that the notation for each cell in Figure 5 is conceptual and does not actually represent the divisions that make up the honeycomb structure 1.

[0066] Figure 6 is a schematic diagram showing the structure of a three-phase honeycomb heater 40 according to yet another embodiment of the present invention. Figure 6(A) is a cross-sectional view of the three-phase honeycomb heater 40 observed in a cross-section perpendicular to the direction in which the cells extend, and Figure 6(B) is a side view of the three-phase honeycomb heater 40 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partitions and cells are omitted.

[0067] The honeycomb structure 1 has a first side surface 105 and a second side surface 106 facing the first side surface 105 on its outer perimeter wall 100. When the directions perpendicular to each other in a cross section perpendicular to the direction in which the cells extend are defined as the first direction FD and the second direction SD, the slits 103 extend in the first direction FD and the second direction SD, and also extend parallel to the direction in which the cells extend. The connecting portion 104 is disposed inside the honeycomb structure 1. That is, each of the multiple slits 103 has both a portion extending in the first direction FD and a portion extending in the second direction SD, and the connecting portion 104 is located inside the honeycomb structure 1 and is separated from the outer perimeter wall 100.

[0068] In the three-phase honeycomb heater 40 shown in Figure 6, three slits 103 are arranged in a helical pattern, and a first electrode 401, a second electrode 402, and a third electrode 403 are positioned near the base end of each slit 103. As a result, the first electrode 401 and the second electrode 402 are positioned on the second side surface 106 of the honeycomb structure 1, and the third electrode 403 is positioned on the first side surface 105 of the honeycomb structure 1.

[0069] Figure 7 is a schematic diagram showing the three current paths in the three-phase honeycomb heater 40 in the embodiment shown in Figure 6. If the point where the three current paths formed by the three slits 103 intersect is designated as the connection point 104, then current paths are formed from the first electrode 401, the second electrode 402, and the third electrode 403 to the connection point 104 in the order of the circled numbers 1 to 16. These current paths are connected by black lines in Figure 7 for illustrative purposes, but as mentioned above, in reality, current flows through all the outer walls 100 and partition walls 101. Also, please note that the notation of each cell in Figure 7 is conceptual and does not mean that the honeycomb structure 1 is actually divided and constructed in that way.

[0070] (3. Three-phase honeycomb heater: Delta connection) Figure 8 is a schematic diagram showing the structure of a three-phase honeycomb heater 50 according to one embodiment of the present invention. Figure 8(A) is a cross-sectional view of the three-phase honeycomb heater 50 when observed in a cross section perpendicular to the direction in which the cell 102 extends, and Figure 8(B) is a side view of the three-phase honeycomb heater 50 in a direction parallel to the direction in which the cell 102 extends.

[0071] In the embodiment shown in Figure 8, the three-phase honeycomb heater 50 is A honeycomb structure 1 comprises an outer perimeter wall 100 and partition walls 101 disposed inside the outer perimeter wall 100, which divide and form a plurality of cells 102 that form a flow path extending from one end face to the other end face. A first electrode 501 is connected to the outer wall of the honeycomb structure 1 and is connectable to the first phase output terminal (R) of the three-phase AC power supply circuit, A second electrode 502 is connected to the outer periphery wall 100 of the honeycomb structure 1, away from the first electrode 501, and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit. A third electrode 503 is connected to the outer periphery wall 100 of the honeycomb structure 1, separated from the first electrode 501 and the second electrode 502, and is connectable to the third phase output terminal (T) of the three-phase AC power supply circuit. The honeycomb structure 1 is connected to the outer periphery wall 100, separated from the first electrode 501, the second electrode 502, and the third electrode 503, and includes a fourth electrode 504 that can be connected to the first phase output terminal (R) of a three-phase AC power supply circuit. The honeycomb structure 1 The device includes a slit 103 provided in the outer perimeter wall 100 and partition wall 101, which defines energizing paths having a first energizing path 5012, a second energizing path 5023, and a third energizing path 5034 for connecting the first electrode 501, the second electrode 502, the third electrode 503, and the fourth electrode 504 in a delta-type connection.

[0072] The honeycomb structure 1 has a first side surface 105 and a second side surface 106 facing the first side surface 105 on the outer peripheral wall 100. The slit 103 has a first slit 103a that extends along the first direction FD with the first side surface 105 as its base end and has its tip on the second side surface side, and a second slit 103b that is separated from the first slit 103a in the second direction SD, with the second side surface 106 as its base end and has its tip on the first side surface 105 side. The first slit 103a and the second slit 103b are alternately arranged in the second direction SD in a cross section perpendicular to the direction in which the cell 102 extends, thereby allowing current to flow sequentially along the outer peripheral wall 100 and / or partition wall 101 in the first direction FD and the second direction SD.

[0073] In the embodiment shown in Figure 8, the first slit 103a and the second slit 103b are arranged parallel to each other with equal spacing in the second direction SD. Furthermore, the first slit 103a and the second slit 103b are arranged alternately in the second direction SD. Also, the first slit 103a and the second slit 103b are the same length in the first direction FD. In the embodiment shown in Figure 8, there are three first slits 103a and two second slits 103b.

[0074] In the embodiment shown in Figure 8, the first electrode 501, the second electrode 502, the third electrode 503, and the fourth electrode 504 are connected on the first side surface 105. In other embodiments of the present invention, the first electrode 501, the second electrode 502, the third electrode 503, and the fourth electrode 504 may be connected on the second side surface 106.

[0075] The configuration of the three-phase AC power supply circuit is not particularly limited, and any known three-phase AC power supply circuit can be used. By connecting the first electrode 501, second electrode 502, third electrode 503, and fourth electrode 504, which are spaced apart from each other, on the outer perimeter wall 100, a so-called delta-type current path is formed. Because power is transmitted using the three-phase AC power supply circuit, the amount of power that can be transmitted per unit time increases compared to when using a conventional single-phase AC power supply circuit (ideally it becomes √3 times), so the heat generation efficiency is significantly improved. Furthermore, since the honeycomb structure 1 is configured as a heating element, the heat exchange area is significantly increased compared to conventional silicon carbide heating elements, resulting in high heat exchange efficiency. Therefore, when configured as a heater, it also has the advantage of being able to be made smaller than conventional heaters.

[0076] In the first embodiment of the present invention, the star connection, when one of the three phases fails and power cannot be supplied, effectively becomes a single-phase AC power supply circuit (i.e., the output drops to half). However, the delta connection provided in the second embodiment of the present invention can maintain two-thirds of the original output even when one of the three phases fails and power cannot be supplied. Therefore, the second embodiment of the present invention is more preferable in that it can generate heat at a relatively high output even when a part of the three-phase AC power supply circuit fails.

[0077] The first current path 5012, the second current path 5023, and the third current path 5034, indicated by the arrows in the drawing, are for illustrative purposes only and represent the general flow of current; in reality, current will flow through all outer walls 100 and partition walls 101. Furthermore, the first electrode 501, the second electrode 502, and the third electrode 503 can be connected to the first phase output terminal (R), the second phase output terminal (S), and the third phase output terminal (T) of the three-phase AC power supply circuit in any combination, and the first electrode 501 and the fourth electrode 504 are not necessarily limited to the illustrated combinations, as long as they are connected to the same output terminals. These explanations also apply to other embodiments of the present invention.

[0078] Furthermore, from the viewpoint of ensuring more uniform heat generation during energization, if the energization paths are defined as a first energization path 5012 between the first electrode 501 and the second electrode 502, a second energization path 5023 between the second electrode 502 and the third electrode 503, and a third energization path 5034 between the third electrode 503 and the fourth electrode 504, it is preferable that the electrical resistances of the first energization path 5012, the second energization path 5023, and the third energization path 5034 are equal. The electrical resistance of the energization paths can be adjusted by changing the length of each energization path, the cross-sectional area of ​​the surface perpendicular to the direction of energization, and the material.

[0079] Similarly, from the viewpoint of achieving more uniform heat generation during energization, if the energization paths are defined as a first energization path 5012 between the first electrode 501 and the second electrode 502, a second energization path 5023 between the second electrode 502 and the third electrode 503, and a third energization path 5034 between the third electrode 503 and the fourth electrode 504, it is preferable that the lengths of the first energization path 5012, the second energization path 5023, and the third energization path 5034 are equal. If the honeycomb structure 1 has a homogeneous composition and the cross-sectional areas of the surfaces perpendicular to the direction of energization are equal, then having three energization paths of equal length also means that the electrical resistance of the energization paths is equal, making it easier to achieve uniform heat generation. These energization paths are shown by arrows in Figure 8 for illustrative purposes, but as mentioned above, in reality, current flows through all the outer walls 100 and partition walls 101. Therefore, in the second embodiment, when referring to the length of the current-carrying path, the length of the current-carrying path refers to the length of the centerline of each current-carrying path, and may include the fact that the length of each current-carrying path is within ±10% of the average value of the lengths of all current-carrying paths. Furthermore, if the geometric shapes of the parts of the honeycomb structure 1 constituting each current-carrying path are the same or symmetrical, the lengths of the current-carrying paths may be considered equal. Also, "equal" lengths of the current-carrying paths mean that the lengths of each current-carrying path are within ±10%. The electrical resistance of each current-carrying path shall be the value measured at 25°C using the four-terminal method.

[0080] In the embodiment shown in Figure 8, when the current flows in a first direction FD along the outer peripheral wall 100 and / or partition wall 101, then in a second direction SD, and then back to the first direction FD, one current path is considered, it is preferable that the number of paths for the first current path 5012, the second current path 5023, and the third current path 5034 is one or more. In a preferred embodiment of the present invention, the first electrode 501, the second electrode 502, the third electrode 503, and the fourth electrode 504 can be arranged on the first side surface 105 or the second side surface 106 of the honeycomb structure 1 so that the first current path 5012, the second current path 5023, and the third current path 5034 have even more paths. In the embodiment shown in Figure 8, it is possible to increase the number of paths for the first current-carrying path 5012, the second current-carrying path 5023, and the third current-carrying path 5034 by increasing the number of first slits 103a and second slits 103b while maintaining the positional relationship of the first electrode 501, the second electrode 502, the third electrode 503, and the fourth electrode 504.

[0081] Figure 9 is a schematic diagram showing the structure of a three-phase honeycomb heater 60 according to another embodiment of the present invention. Figure 9(A) is a cross-sectional view of the three-phase honeycomb heater 60 when observed in a cross-section perpendicular to the direction in which the cells extend, and Figure 9(B) is a side view of the three-phase honeycomb heater 60 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partition walls and cells are omitted. Descriptions of components common to the embodiment in Figure 8 are also omitted.

[0082] In the embodiment shown in Figure 9, if the first current-carrying path 6012 is between the first electrode 601 and the second electrode 602, the second current-carrying path 6023 is between the second electrode 602 and the third electrode 603, and the third current-carrying path 6034 is between the third electrode 603 and the fourth electrode 604, then the first current-carrying path 6012 is the longest, the second current-carrying path 6023 is the next longest, and the third current-carrying path 6034 is the shortest. Counting the number of paths, the first current-carrying path 6012 has 5 paths, the second current-carrying path 6023 has 3 paths, and the third current-carrying path 6034 has 1 path. However, since these current-carrying paths form a delta-type connection, the advantages of the present invention can be obtained. Furthermore, by changing the material of the honeycomb structure 1 included in the first current-carrying path 6012, the second current-carrying path 6023, and the third current-carrying path 6034, it is possible to make the electrical resistance of these current-carrying paths equal.

[0083] Figure 10 is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 10(A) is a cross-sectional view of the three-phase honeycomb heater 70 observed in a cross section perpendicular to the direction in which the cells extend, and Figure 10(B) is a side view of the three-phase honeycomb heater 70 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partitions and cells are omitted.

[0084] In the three-phase honeycomb heater 70 shown in Figure 10, the first electrode 701 and the third electrode 703 are connected to the first side surface 105, and the second electrode 702 and the fourth electrode 704 are connected to the second side surface 106. In addition, four first slits 103a and four second slits 103b are provided. As a result, a first current path 7012, a second current path 7023, and a third current path 7034 with equal lengths are formed.

[0085] The other components of the three-phase honeycomb heater 70 shown in Figure 10 are similar to those of the three-phase honeycomb heater 50 shown in Figure 8, so further detailed explanations are omitted.

[0086] Figure 11 is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 11(A) is a cross-sectional view of the three-phase honeycomb heater 80 when observed in a cross section perpendicular to the direction in which the cell 102 extends, and Figure 11(B) is a side view of the three-phase honeycomb heater 80 in a direction parallel to the direction in which the cell 102 extends.

[0087] In the three-phase honeycomb heater 80 shown in Figure 11, the honeycomb structure 1 has a first side surface 105 and a second side surface 106 facing the first side surface 105 on the outer peripheral wall 100, and the slit 103 has a first slit 103a that extends along the first direction FD with the first side surface 105 as its base end and has its tip on the second side surface 106 side, when the directions that are perpendicular to each other in a cross section parallel to the direction in which the cell 102 extends are defined as the first direction FD and the second direction SD, and the first slit in a cross section parallel to the direction in which the cell 102 extends The first slit 103a and the second slit 103b are separated from 103a in the second direction SD, and the second slit 103b extends along the first direction FD with the second side surface 106 as its base end and has its tip on the first side surface 105 side. The first slit 103a and the second slit 103b are alternately arranged in the second direction SD in a cross section parallel to the direction in which the cell 102 extends, thereby enabling the current to flow sequentially along the outer peripheral wall 100 and / or partition wall 101 in the first direction FD and the second direction SD.

[0088] In other words, in the three-phase honeycomb heater 80 of the embodiment shown in Figure 11, the direction in which the first slit 103a and the second slit 103b are arranged differs from the direction of the first slit 103a and the second slit 103b in the three-phase honeycomb heater 50 of the embodiment shown in Figure 8. However, even with this configuration of the first slit 103a and the second slit 103b, it is still possible to define energizing paths in the outer periphery wall 100 and partition wall 101, having a first energizing path 8012, a second energizing path 8023, and a third energizing path 8034 for connecting the first electrode 801, the second electrode 802, the third electrode 803, and the fourth electrode 804 in a delta connection.

[0089] In the embodiment shown in Figure 11, when the current flows in a first direction FD along the outer peripheral wall 100 and / or partition wall 101, then in a second direction SD, and then back to the first direction FD, one current path is defined as one path, the number of paths for the first current path 8012, the second current path 8023, and the third current path 8034 is one each. In a preferred embodiment of the present invention, the first electrode, the second electrode, the third electrode, and the fourth electrode can be arranged on the first or second side surface of the honeycomb structure 1 such that the first current path, the second current path, and the third current path have a further number of paths. With respect to the embodiment shown in Figure 11, by increasing the number of first slits 103a and second slits 103b while maintaining the positional relationship of the first electrode 801, second electrode 802, third electrode 803, and fourth electrode 804, it is possible to increase the number of paths, such as the first current-carrying path 8012, the second current-carrying path 8023, and the third current-carrying path 8034, when there is one current-carrying path.

[0090] The other components of the three-phase honeycomb heater 70 shown in Figure 11 are similar to those of the three-phase honeycomb heater 50 shown in Figure 8, so further detailed explanations are omitted.

[0091] Figure 12 is a schematic diagram showing the structure of a three-phase honeycomb heater 70 according to yet another embodiment of the present invention. Figure 12(A) is a cross-sectional view of the three-phase honeycomb heater 90 when observed in a cross section perpendicular to the direction in which the cells extend, and Figure 12(B) is a side view of the three-phase honeycomb heater 90 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partitions and cells are omitted.

[0092] In the three-phase honeycomb heater 90 shown in Figure 12, the first electrode 901 and the third electrode 903 are connected to the first side surface 105, and the second electrode 902 and the fourth electrode 904 are connected to the second side surface 106. In addition, four first slits 103a and four second slits 103b are provided. As a result, a first current path 9012, a second current path 9023, and a third current path 9034 with equal lengths are formed.

[0093] The other components of the three-phase honeycomb heater 90 shown in Figure 12 are similar to those of the three-phase honeycomb heater 50 shown in Figure 8, so further detailed explanations are omitted.

[0094] Figure 13 is a schematic diagram showing the structure of a three-phase honeycomb heater 21 according to yet another embodiment of the present invention. Figure 13(A) is a cross-sectional view of the three-phase honeycomb heater 21 observed in a cross section perpendicular to the direction in which the cells extend, and Figure 13(B) is a side view of the three-phase honeycomb heater 21 in a direction parallel to the direction in which the cells extend. Note that enlarged views of the partitions and cells are omitted.

[0095] The embodiment shown in Figure 13 differs from the embodiment shown in Figure 8 in that the three-phase honeycomb heater 21 structure comprises two honeycomb structures 11 and 12. Specifically, two honeycomb structures 11 and 12, having a structure similar to the honeycomb structure 1 of the embodiment shown in Figure 8, are joined via a conductive joint 107. The first electrode 211, second electrode 212, third electrode 213, and fourth electrode 214 are connected to the first side surface 105 of the honeycomb structure 12. As a result, a first current path 2112, a second current path 2123, and a third current path 2134 are formed. In this case, since the thickness of the conductive joint 107 occupies a very small proportion of the second current path 2123, the lengths of the first current path 2112, the second current path 2123, and the third current path 2134 can be considered substantially equal. Furthermore, since the influence of the electrical resistance of the conductive junction 107 is small, the electrical resistances of the first current path 2112, the second current path 2123, and the third current path 2134 can be considered to be substantially equal.

[0096] Various materials can be used for the conductive joint 107. For example, the conductive joint 107 can be made of the same material as the first electrode 211, second electrode 212, third electrode 213, and fourth electrode 214, such as metal, conductive ceramics, or a composite material of metal and conductive ceramics (cermet). Examples of metals include Cr, Fe, Co, Ni, Si, and Ti. The conductive joint 107 only needs to be provided in at least a part of the region where the honeycomb structure 11 and the honeycomb structure 12 face each other. Preferably, the volume resistivity of the conductive joint 107 is the same as or less than the volume resistivity of the honeycomb structures 11 and 12. Furthermore, it is preferable that the conductive joint 107, the honeycomb structures 11 and 12, the first electrode 211, the second electrode 212, the third electrode 213, and the fourth electrode 214 are made of the same material. This configuration reduces the difference in thermal expansion coefficients between the conductive joint 107, the honeycomb structures 11 and 12, the first electrode 211, the second electrode 212, the third electrode 213, and the fourth electrode 214, thereby increasing the bonding strength between them. It can also contribute to improved productivity.

[0097] In a cross-section perpendicular to the direction of cell extension, the thickness of the conductive joint 107 is not particularly limited, but can be, for example, 500 μm to 5 mm. The thickness of the conductive joint 107 may correspond to the distance between the honeycomb structure 11 and the honeycomb structure 12. [Industrial applicability]

[0098] The honeycomb structure and the three-phase honeycomb heater according to embodiments of the present invention can be used, for example, as a catalyst support on which a catalyst is supported. [Explanation of Symbols]

[0099] 1. Honeycomb structure 100 Peripheral wall 101 Bulkhead 102 cells 103 Slit 103a First Slit 103b Second Slit 104 Connection part 105 First aspect 106 Second aspect 20 Three-phase honeycomb heater 201 1st electrode 202 2nd electrode 203 3rd electrode 30 Three-phase honeycomb heater 301 1st electrode 302 2nd electrode 303 3rd electrode 40 Three-phase honeycomb heater 401 1st electrode 402 2nd electrode 403 3rd electrode 501 1st electrode 502 2nd electrode 503 3rd electrode 504 4th electrode 5012 First power supply route 5023 Second power supply route 5034 Third power supply route 60 Three-phase honeycomb heater 601 1st electrode 602 2nd electrode 603 3rd electrode 604 4th electrode 6012 First power supply path 6023 Second power supply route 6034 Third power supply route 70 Three-phase honeycomb heater 701 1st electrode 702 2nd electrode 703 3rd electrode 704 4th electrode 7012 First power supply route 7023 Second power supply route 7034 Third power supply route 80 Three-phase honeycomb heater 801 1st electrode 802 2nd electrode 803 3rd electrode 804 4th electrode 8012 First power supply route 8023 Second power supply route 8034 Third power supply route 90 Three-phase honeycomb heater 901 1st electrode 902 2nd electrode 903 3rd electrode 904 4th electrode 9012 First power supply route 9023 Second power supply route 9034 Third power supply route 21 Three-phase honeycomb heater 11 Honeycomb structure 12 Honeycomb Structure 107 Conductive joint 211 1st electrode 212 2nd electrode 213 3rd electrode 214 4th electrode 2112 First power supply path 2123 Second power supply route 2134 Third power supply route

Claims

1. A honeycomb structure comprising an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which divide and form a plurality of cells that form a flow path extending from one end face to the other end face, A first electrode connected to the outer peripheral wall and connectable to the first phase output terminal (R) of the three-phase AC power supply circuit, A second electrode is connected to the outer peripheral wall at a distance from the first electrode and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit, The outer peripheral wall includes a third electrode connected at a distance from the first electrode and the second electrode, and connected to the third phase output terminal (T) of the three-phase AC power supply circuit, The aforementioned honeycomb structure, A slit is provided in the outer wall and / or partition wall so as to define a current-carrying path for connecting the first electrode, the second electrode, and the third electrode in a star configuration, A connecting portion that connects the first electrode, the second electrode, and the third electrode to each other, A three-phase honeycomb heater equipped with [features / equipment].

2. The three-phase honeycomb heater according to claim 1, wherein the electrical resistance of the three current-carrying paths from the connection portion to the outer peripheral wall to which the first electrode, the second electrode, and the third electrode are connected is equal.

3. The three-phase honeycomb heater according to claim 2, wherein the lengths of the three current-carrying paths from the connection portion to the outer peripheral wall to which the first electrode, the second electrode, and the third electrode are connected are equal.

4. The honeycomb structure comprises a first side surface and a second side surface facing the first side surface on the outer peripheral wall, the slits comprising a plurality of slits extending toward the second side surface with the first side surface as the base end and in a direction parallel to the direction in which the cell extends, the connecting portion being disposed on the second side surface, and the first electrode, the second electrode and the third electrode being disposed on the first side surface, the three-phase honeycomb heater according to any one of claims 1 to 3.

5. The honeycomb structure has a first side surface and a second side surface facing the first side surface on its outer peripheral wall. A three-phase honeycomb heater according to any one of claims 1 to 3, wherein, in a cross section perpendicular to the direction in which the cell extends, the directions that are mutually orthogonal to each other are defined as the first direction and the second direction, the slits include a plurality of slits that extend in the first direction and the second direction and that extend parallel to the direction in which the cell extends, and the connecting portion is disposed inside the honeycomb structure.

6. A honeycomb structure comprising an outer perimeter wall and partition walls disposed inside the outer perimeter wall, which divide and form a plurality of cells that form a flow path extending from one end face to the other end face, A first electrode connected to the outer wall of the honeycomb structure and connectable to the first phase output terminal (R) of the three-phase AC power supply circuit, A second electrode is connected to the outer periphery wall of the honeycomb structure, away from the first electrode, and is connectable to the second phase output terminal (S) of the three-phase AC power supply circuit. A third electrode is connected to the outer periphery wall of the honeycomb structure, separated from the first and second electrodes, and is connectable to the third phase output terminal (T) of the three-phase AC power supply circuit. The honeycomb structure comprises a fourth electrode connected to the outer periphery wall of the honeycomb structure, separated from the first, second, and third electrodes, and connected to the first phase output terminal (R) of the three-phase AC power supply circuit, The aforementioned honeycomb structure, A three-phase honeycomb heater, comprising slits arranged in the outer periphery wall and partition wall, which define energizing paths having a first energizing path, a second energizing path, and a third energizing path for connecting the first electrode, the second electrode, the third electrode, and the fourth electrode in a delta-type connection.

7. The three-phase honeycomb heater according to claim 6, wherein the current supply path comprises a first current supply path between the first electrode and the second electrode, a second current supply path between the second electrode and the third electrode, and a third current supply path between the third electrode and the fourth electrode, and the electrical resistance of the first current supply path, the second current supply path, and the third current supply path is equal.

8. The three-phase honeycomb heater according to claim 7, wherein the current supply path comprises a first current supply path between the first electrode and the second electrode, a second current supply path between the second electrode and the third electrode, and a third current supply path between the third electrode and the fourth electrode, and the lengths of the first current supply path, the second current supply path, and the third current supply path are equal.

9. The honeycomb structure has a first side surface and a second side surface facing the first side surface on its outer peripheral wall. The aforementioned slit is When the directions perpendicular to each other in a cross-section perpendicular to the direction in which the cell extends are defined as the first direction and the second direction, a first slit extends along the first direction with the first side surface as its base end and has its tip on the second side surface side, A second slit that is separated from the first slit in the second direction, the second slit extending along the first direction with the second side surface as its base end, and having its tip on the first side surface side. Equipped with, The three-phase honeycomb heater according to any one of claims 6 to 8, wherein the first slit and the second slit are alternately arranged in the second direction in a cross section perpendicular to the direction in which the cell extends, thereby enabling the current to flow sequentially in the first direction and the second direction along the outer peripheral wall and / or the partition wall.

10. The honeycomb structure has a first side surface and a second side surface facing the first side surface on its outer peripheral wall. The aforementioned slit is When the directions perpendicular to each other in a cross-section parallel to the direction in which the cell extends are defined as the first direction and the second direction, a first slit extends along the first direction with the first side surface as its base end and having its tip on the second side surface side, A second slit in a cross-section parallel to the direction in which the cell extends, which is separated from the first slit in the second direction, and which extends along the first direction with the second side surface as its base end and has its tip on the first side surface side. Equipped with, The three-phase honeycomb heater according to any one of claims 6 to 8, wherein the first slit and the second slit are alternately arranged in the second direction in a cross section parallel to the direction in which the cell extends, thereby enabling the current to flow sequentially in the first direction and the second direction along the outer peripheral wall and / or the partition wall.

11. The three-phase honeycomb heater according to claim 9, wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are connected to the first side surface.

12. The three-phase honeycomb heater according to claim 10, wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are connected on the first side surface.

13. The three-phase honeycomb heater according to claim 9, wherein, in a cross section perpendicular to the direction in which the cell extends, when the current flows in a first direction along the outer peripheral wall and / or the partition wall, then in a second direction, and then in the first direction, one current path is defined as one current path, the first electrode, the second electrode, and the third current path are each provided as one or more paths.

14. The three-phase honeycomb heater according to claim 10, wherein, in a cross section parallel to the direction in which the cell extends, when the current flows in a first direction along the outer peripheral wall and / or the partition wall, then in a second direction, and then in the first direction, one current path is defined as one current path, the first electrode, the second electrode, and the third electrode are arranged apart on the first side or the second side, respectively, so that one or more first current path, second current path, and third current path are provided.

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