Regenerative burner device, heat storage body, and method for manufacturing heat storage body

Abstract

To provide a single type regeneration burner device reducing a possibility of mixing combustion air and exhaust gas due to the damage of a partition wall, even if a honeycomb structure made of ceramic is used as a heat accumulation element.SOLUTION: In a structure of a heat accumulation body 50, a plurality of honeycomb segments 30 made of ceramic and having a honeycomb structure equipped with a plurality of cells 32 divided by partition walls 31 extended and arranged in a single direction are collected. Without opening the cell on a side peripheral surface of the honeycomb segment, the side peripheral surface is formed by a wall surface of the partition wall, and heat resisting cloth 42 is sandwiched between the adjacent honeycomb segments. Therefore, at a boundary portion 40 between the adjacent honeycomb segments, the partition walls 31 are duplicated with the heat resisting cloth 42 sandwiched. Gas circulating in each honeycomb segment is switched between combustion air and exhaust gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a single-type regenerative burner device, a heat storage body used therein, and a method for manufacturing the heat storage body. [Background technology]

[0002] Regenerative burners, used in industrial furnaces such as forging furnaces, heat treatment furnaces, melting furnaces, baking furnaces, and rolling furnaces, are burners that switch the gas flow direction so that the exhaust gas heated to a high temperature by the burner combustion and the air supplied for the burner combustion (combustion air) flow alternately through a heat storage body. The heat of the exhaust gas is recovered in the heat storage body and used to preheat the newly supplied combustion air. Such regenerative burners are broadly divided into burner systems equipped with a pair of burners (twin regenerative burners) and single-type regenerative burners (self-regenerative burners) that switch the gas flow direction using a single burner.

[0003] In a burner system with a pair of burners, one burner is supplied with fresh combustion air for combustion, while the other burner discharges high-temperature exhaust gas and recovers the exhaust heat in a regenerator. This operation is repeated alternately every few tens of seconds. When the burner that recovered the exhaust heat in the regenerator next burns, the combustion air is heated by the regenerator, which has reached a high temperature. Because the main burner must be extinguished and reignited every time the pair of burners is switched, lost time is unavoidable, making it difficult to shorten the time interval for switching the gas flow direction.

[0004] On the other hand, the single-type regenerative burner has the advantage of requiring less space for installation because only one burner device incorporating the burner and regenerative heat storage is required. In addition, there is no need to extinguish and reignite the main burner, and it is possible to shorten the time interval for switching the flow of combustion air and exhaust gas in the regenerative heat storage, which has the advantage of improving thermal efficiency.

[0005] As such a single-type regenerative burner, one that uses a rotating member to switch the flow of combustion air and exhaust gas in the regenerator has been proposed (see, for example, Patent Documents 1 and 2). In the burner device of Patent Document 1, a regenerator is filled into a case divided into multiple compartments, and a branch pipe consisting of multiple flow passages is provided to match the compartments of the regenerator. A rotating partition plate with holes that communicate with one of the multiple flow passages by rotation is used to switch the flow of combustion air and exhaust gas to each flow passage. However, the burner device of Patent Document 1 uses alumina balls as the regenerator. When the regenerator is ball-shaped, gas flows through the gaps between the balls, which has the disadvantage of large pressure loss. Furthermore, ball-shaped regenerators have low thermal efficiency because the center does not contribute to heat exchange.

[0006] On the other hand, the burner device of Patent Document 2 uses a ceramic honeycomb structure as a heat storage body. A honeycomb structure has cells separated by a large number of partition walls, and the cells extend in a single direction, which has the advantage of low pressure loss due to gas flow. In addition, the honeycomb structure has a very large specific surface area, which means that the area in contact with the flowing gas is very large, resulting in high thermal efficiency. Another advantage is that the partition walls of the honeycomb structure are thin, which means that the entire volume of the heat storage body can easily contribute to heat exchange.

[0007] In the burner device of Patent Document 2, a cylindrical body is connected to a honeycomb-structured heat storage body, and the interior of the cylinder is divided into equal parts by partition walls, forming multiple small passages in the circumferential direction. Meanwhile, an air nozzle is provided at the tip of an air duct for supplying combustion air to the heat storage body, and this air nozzle has openings formed in positions corresponding to every other small passage in the cylinder. In other words, combustion air is supplied from the air duct to the heat storage body through small passages that communicate with the openings of the air nozzle, and in areas without openings, exhaust gas flows from the heat storage body to the exhaust duct through the small passages. Therefore, by intermittently rotating the air duct, it is possible to switch between the small passages that supply combustion air to the heat storage body and the small passages that carry exhaust gas discharged from the heat storage body.

[0008] In the burner device of Patent Document 2, it is desirable to apply partition plates, which are located at positions corresponding to the partition walls that divide the cylinder into a plurality of small passages, to the end faces of the honeycomb-structured heat storage body. The reason for this is explained to be that by applying the partition plates to the heat storage body, the heat storage body is mechanically reinforced and a gas passage from the air nozzle to the heat storage body is reliably formed via the small passages in the cylinder.

[0009] However, in the burner device of Patent Document 2, even if a partition plate is attached to the end face of the heat storage body, "the honeycomb-structured heat storage body itself is a single unit." Therefore, in the honeycomb-structured heat storage body, if damage such as cracks occurs in the partition wall between a cell communicating with a small passage through which combustion air flows and an adjacent cell communicating with a small passage through which exhaust gas flows, there is a problem of mixing of the combustion air and the exhaust gas. As described above, the partition walls separating the cells in the honeycomb structure are very thin, and ceramics are a brittle material, so it is not realistic to eliminate the risk of cracks or other damage. Therefore, there has been a demand for a single-type regenerative burner that reduces the risk of mixing of the combustion air and the exhaust gas even when a ceramic honeycomb structure is used as the heat storage body. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Utility Model Application Publication No. 62-908 [Patent Document 2] Japanese Patent Application Publication No. 8-233251 Summary of the Invention [Problem to be solved by the invention]

[0011] In view of the above-mentioned circumstances, the present invention aims to provide a single-type regenerative burner device that reduces the risk of mixing of combustion air and exhaust gas due to damage to the partition walls of a honeycomb structure, even when a ceramic honeycomb structure is used as a heat storage body, a heat storage body to be used therein, and a method for manufacturing the heat storage body. [Means for solving the problem]

[0012] In order to solve the above problems, the single-type regenerative burner device according to the present invention comprises: "A burner that penetrates the outer shell of the main body, an air intake port for supplying combustion air for combustion of fuel gas by the burner to the inside of the main body outer shell; an exhaust port for discharging exhaust gas heated by combustion of the fuel gas from the outer casing of the main body; a heat storage body made of ceramics, in which a plurality of honeycomb segments having a honeycomb structure with a plurality of cells separated by partition walls arranged in a row and extending in a single direction are assembled so that the axial directions of the respective cells coincide, the heat storage body being housed in the outer shell of the main body with the burner inserted therethrough; a rotary switching disk that rotates around an axis parallel to the axial direction of the cells relative to the heat storage body, thereby switching the gas to be circulated through each of the honeycomb segments between the combustion air and the exhaust gas, The cells are not open on the side peripheral surface of each of the honeycomb segments, and the side peripheral surface is formed by the wall surfaces of the partition walls, A heat-resistant fabric, which is a nonwoven or woven fabric made of heat-resistant fibers, is sandwiched between the adjacent honeycomb segments, At the boundary between the adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween. And, A silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment on the side peripheral surface of the honeycomb segment. "It is something like that.

[0013] The material of the "ceramics" constituting the honeycomb segments is not particularly limited, and can be, for example, silicon carbide ceramics, alumina ceramics, cordierite ceramics, mullite ceramics, or aluminum titanate ceramics. The "heat-resistant fibers" forming the "heat-resistant fabric" can be ceramic fibers or carbon-based fibers. Examples of ceramic fibers that can be used include amorphous alumina-silica fibers (RCF) and crystalline fibers made of alumina and mullite (AF). RCFs are primarily composed of alumina and silica, with other raw materials including zirconia, chromium oxide, and natural minerals. The weight ratio of alumina to silica in AF is 72:28 to 97:3.

[0014] In this configuration, the gas flowing through each of the honeycomb segments constituting one regenerator is switched between exhaust gas and combustion air by rotating the rotary switch disk. Therefore, in each honeycomb segment, the heat recovered from the high-temperature exhaust gas when the exhaust gas is passed through can be used to preheat the combustion air to be passed next.

[0015] In this configuration, the heat storage body is made up of multiple honeycomb segments, and at the boundary between adjacent honeycomb segments, the partition walls are doubled with a layer of heat-resistant fabric sandwiched in between. Therefore, the honeycomb segment through which combustion air flows and the honeycomb segment through which exhaust gas flows are adjacent to each other, and even if damage occurs to the partition wall constituting the boundary surface in one honeycomb segment, the partition wall constituting the boundary surface in the other honeycomb segment remains, effectively preventing the combustion air and the exhaust gas from mixing.

[0016] Furthermore, if the honeycomb segments are formed by dividing an extrusion-molded honeycomb structure into multiple segments, the cells are open on the side peripheral surface of each honeycomb segment. Therefore, if the layer interposed between adjacent honeycomb segments is permeable, the combustion air and exhaust gas will mix between the adjacent honeycomb segments through that portion. In contrast, in the single-type regenerative burner device of this configuration, even if the layer interposed between adjacent honeycomb segments is permeable, the adjacent honeycomb segments each have partition walls on their outer peripheries, which effectively prevents the combustion air and exhaust gas from mixing.

[0017] In this configuration, the layer interposed between adjacent honeycomb segments is a layer of heat-resistant fabric, which is a nonwoven or woven fabric made of heat-resistant fibers. Heat-resistant fabric, which is a nonwoven or woven fabric, is a highly elastic material, in other words, a layer with high cushioning properties. Therefore, the thermal stress that inevitably occurs in the honeycomb segments due to repeated heat dissipation and absorption is absorbed by the heat-resistant fabric layer interposed between adjacent honeycomb segments. This increases the thermal shock resistance of the honeycomb segments, making it less likely that damage such as cracks will occur in the partition walls on the outer periphery of each honeycomb segment. Therefore, even if a honeycomb segment through which combustion air flows and a honeycomb segment through which exhaust gas flows are adjacent to each other, mixing of the absorbed combustion air and the exhaust gas can be effectively suppressed.

[0018] The heat storage body according to the present invention comprises: "A heat storage body made of ceramics, in which a plurality of honeycomb segments having a honeycomb structure with a plurality of cells separated by partition walls arranged in a row extending in a single direction are assembled so that the axial directions of the respective cells are aligned, The heat storage body has a burner through hole at the center that is larger than the cell and penetrates the cell in the axial direction, The cells are not open on the side peripheral surface of each of the honeycomb segments, and the side peripheral surface is formed by the wall surfaces of the partition walls, A heat-resistant fabric, which is a nonwoven or woven fabric made of heat-resistant fibers, is sandwiched between the adjacent honeycomb segments, At the boundary between the adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween. And, A silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment on the side peripheral surface of the honeycomb segment. "It is something like that.

[0019] This is the configuration of the regenerator used in the single-type regenerative burner device described above.

[0020] In addition to the above configuration, the heat storage body according to the present invention has the following features: " The honeycomb segments are made of silicon carbide ceramics. " It can be said that

[0021] In this configuration, at least the partition walls that form the boundary between adjacent honeycomb segments on the side peripheral surface of the honeycomb segment are coated with silicate glass. Therefore, when a honeycomb segment through which combustion air flows and a honeycomb segment through which exhaust gas flows are adjacent to each other, even if damage occurs to both of the partition walls that form the boundary between the adjacent honeycomb segments, the two silicate glass layers and the heat-resistant fabric layer present between the partition walls effectively prevent the combustion air and the exhaust gas from mixing. In particular, because the silicate glass layer is a dense and highly airtight layer, even if damage occurs to the partition walls of each honeycomb segment, the silicate glass layer prevents gas from leaking through the damage, thereby preventing the combustion air and the exhaust gas from mixing.

[0022] Furthermore, silicate-based glass has the property of softening and plastically deforming at high temperatures. Therefore, even if damage occurs to the partition walls, the expansion is suppressed, and the brittle fracture of the ceramic honeycomb segments is suppressed. Therefore, the silicate-based glass layer can further improve the thermal shock resistance of the honeycomb segments that constitute the heat storage body, which repeatedly absorbs and releases heat. Furthermore, because silicate-based glass softens and becomes adhesive at high temperatures, once a heat-resistant fabric is laminated on a silicate-based glass layer and heated, the heat-resistant fabric adheres to the silicate-based glass layer. This stabilizes the state in which the heat-resistant fabric is sandwiched between adjacent honeycomb segments.

[0023] Here, the silicate glass is coated on at least the partition walls that form the boundary surface with adjacent honeycomb segments on the side peripheral surface of the honeycomb segment, but it can also be coated over the entire side peripheral surface. This prevents gas circulating within the cells of the honeycomb segment from leaking even if damage occurs to any part of the partition walls that form the side peripheral surface of the honeycomb segment. Furthermore, because a dense, airtight silicate glass layer is laminated on the entire side peripheral surface, oxidation of the ceramic that forms the honeycomb segment is effectively prevented even if it is a non-oxide ceramic such as silicon carbide.

[0024] The method for manufacturing a heat storage body according to the present invention comprises the steps of: "A honeycomb segment is formed by extrusion molding, which is made of ceramics and has a honeycomb structure including a plurality of cells separated by partition walls arranged in a row extending in a single direction, and the cells do not open to the side peripheral surfaces, and the side peripheral surfaces are formed by the wall surfaces of the partition walls, After firing a plurality of the honeycomb segments, the honeycomb segments are assembled so that the axial directions of the cells are aligned, thereby manufacturing a heat storage body having a burner through-hole at the center that is larger than the cell and penetrates the cell in the axial direction, When the honeycomb segments are assembled, a heat-resistant fabric, which is a nonwoven fabric or a woven fabric made of heat-resistant fibers, is sandwiched between adjacent honeycomb segments, At the boundary between adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween. And, A silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment on the side peripheral surface of the honeycomb segment. "Manufacture of heat storage bodies."

[0025] This is a manufacturing method of a regenerator used in the single-type regenerative burner device. A plurality of honeycomb segments are extruded using an extrusion die, respectively, to form honeycomb segments in which the cells do not open on the side peripheral surfaces and the entire side peripheral surfaces are formed by the wall surfaces of the partition walls.

[0026] In addition to the above configuration, the heat storage body manufacturing method according to the present invention includes: The heat-resistant fabric may be impregnated with a slurry containing ceramic powder or a slurry that becomes silicate glass when heated.

[0027] A heat-resistant fabric is impregnated with a slurry containing ceramic powder or a slurry that turns into silicate glass upon heating, and then the slurry is solidified by heating. As a result, the heat-resistant fabric layer is configured so that the ceramic component or silicate glass is supported between the ceramic fibers. This makes it possible to reduce the air permeability of the heat-resistant fabric while maintaining a certain degree of elasticity of the heat-resistant fabric. As a result of the reduced air permeability of the heat-resistant fabric, even if damage occurs to the partition walls that form the boundaries between adjacent honeycomb segments, the heat-resistant fabric layer prevents gas from leaking from each honeycomb segment through this damage, reducing the risk of mixing of combustion air and exhaust gas. [Effects of the Invention]

[0028] As described above, according to the present invention, it is possible to provide a single-type regenerative burner device in which the risk of mixing of combustion air and exhaust gas due to damage to the partition walls of the honeycomb structure is reduced even when a ceramic honeycomb structure is used as the heat storage body, a heat storage body used therein, and a method for manufacturing the heat storage body. [Brief explanation of the drawings]

[0029] [Figure 1] Figure 1(a) is a perspective view of a honeycomb segment, Figure 1(b) is a perspective view of a heat storage body, Figure 1(c) is a cross-sectional view of the heat storage body cut in a direction perpendicular to the axial direction of the cells, and Figure 1(d) is an enlarged cross-sectional view between AA and BB. [Figure 2] Figure 2(a) is an enlarged cross-sectional view showing the area corresponding to Figure 1(d) for a modified heat storage body, and Figure 2(b) is an enlarged cross-sectional view showing the area corresponding to Figure 1(d) for another modified heat storage body. [Figure 3] 3(a) and (b) are explanatory diagrams of a method for manufacturing the heat storage body shown in FIG. 2(a). [Figure 4] 4(a) and (b) are explanatory diagrams of a method for manufacturing the heat storage body shown in FIG. 2(b). [Figure 5] FIG. 5(a) is a perspective view of a single-type regenerative burner device according to one embodiment of the present invention, as viewed from the inner end side, and FIG. 5(b) is a perspective view of the single-type regenerative burner device as viewed from the outer end side. [Figure 6] Figure 6(a) is a cross-sectional view of the single-type regenerative burner device of Figure 5 cut along a plane including the central axis of the main body outer casing, and Figure 6(b) is a cross-sectional view cut along the same plane as Figure 6(a) with the rotary switch panel rotated. [Figure 7] FIG. 7 is a diagram for explaining switching of gases to be circulated through a plurality of honeycomb segments. [Figure 8] FIG. 8 is an explanatory diagram of a method for manufacturing a heat storage body using honeycomb segments with different shapes. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, a single-type regenerative burner device 1 (hereinafter referred to as "burner device 1") according to an embodiment of the present invention and a regenerator 50 used therein will be specifically described with reference to the drawings.

[0031] The burner device 1 mainly comprises a main body outer casing 10, a burner 20, an air inlet 11, an exhaust port 12, a heat storage body 50, a rotary switch panel 60, a rotation mechanism, and a burner tile 80. This burner device 1 is attached so as to penetrate the furnace wall in order to heat the atmosphere inside the industrial furnace. Here, the burner device 1 and its configuration will be described by referring to the end facing the inside of the industrial furnace as the inner end E1 and the end facing the outside as the outer end E2.

[0032] First, the heat storage body 50 will be described. The heat storage body 50 is formed from a plurality of honeycomb segments 30 of the same configuration. Each honeycomb segment 30 is made of ceramics and has a honeycomb structure. The honeycomb structure is a structure comprising a plurality of cells 32 separated by partition walls 31 arranged in a row extending in a single direction. In this embodiment, the ceramic that constitutes the honeycomb segments 30 is silicon carbide ceramics.

[0033] Each honeycomb segment 30 has a columnar fan-shaped outer shape in a cross section perpendicular to the axial direction of the cells 32 (hereinafter referred to as the "cross section"), and by assembling and integrating a plurality of honeycomb segments 30, a cylindrical heat storage body 50 having a burner through-hole 55 in the center and in which a plurality of honeycomb segments 30 are radially assembled is manufactured, as shown in Figures 1(b) and 1(c), i.e., a heat storage body 50 having a circular outer shape in cross section. The burner through-hole 55 has a larger opening than the cells 32 and is a circular hole.

[0034] Therefore, the side surface of each honeycomb segment 30 is composed of a plane 35 (plane 35 facing the adjacent honeycomb segment 30) that serves as the boundary surface between adjacent honeycomb segments 30, a curved surface 36 that forms the inner surface of the burner through hole 55 in the heat storage body 50, and a curved surface 37 that forms the outer surface of the heat storage body 50.

[0035] In each honeycomb segment 30, the cells 32 do not open on any of the surfaces (flat surface 35, curved surface 36, curved surface 37) that make up the side peripheral surface, and the side peripheral surface is formed by the wall surfaces of the partition walls 31. That is, in the cross section of the cell 32, the outer periphery is surrounded by sector-shaped partition walls 31, and the cells 32 are defined by the partition walls 31 that intersect inside. In this embodiment, the central angle of the sector is 60 degrees. The shape of the cells 32 in the cross section is square, but since the outer shape of the cross section of the honeycomb segment 30 is sector-shaped, the shape of the cells 32 along the outer periphery is trapezoidal or triangular. Here, a case where the cell density is 100 cells / square inch is illustrated as an example. Note that the shape and cell density of the cells are not limited to those exemplified here.

[0036] Such a honeycomb segment 30 is formed by extruding and firing a mixture obtained by adding water and a binder to a ceramic material. In the extrusion molding, an extrusion die corresponding to the cross-sectional shape of the honeycomb segment 30 as described above is used. In other words, the honeycomb segments 30 are not formed by dividing an extruded molded body into honeycomb segments 30, but are formed individually by extrusion molding. The molded bodies of the honeycomb segments 30 are then fired to form sintered bodies of the honeycomb segments 30.

[0037] A plurality of sintered honeycomb segments 30 are assembled so that the axial directions of the cells 32 of each honeycomb segment 30 are aligned, with a heat-resistant fabric 42 sandwiched between adjacent honeycomb segments 30. At this time, the heat-resistant fabric 42 is sandwiched so that it overlaps at least the flat surface 35 of the side peripheral surface consisting of the flat surface 35, the curved surface 36, and the curved surface 37 of each of the adjacent honeycomb segments 30. The number of honeycomb segments 30 to be assembled is set so that the external shape of the cross section of the heat storage body 50 is circular, and is six in this example.

[0038] Here, a nonwoven fabric in which ceramic fibers are entangled can be suitably used as the heat-resistant fabric 42. Methods for entangling ceramic fibers include a needle punch method in which fibers are entangled by repeatedly piercing them with needles, and a hydroentangling method in which fibers are entangled by spraying a high-pressure water stream onto them.

[0039] In a heat storage body 50 manufactured by assembling sintered bodies of a plurality of honeycomb segments 30 while sandwiching a heat-resistant fabric 42, at the boundary 40 between adjacent honeycomb segments 30, the partition walls 31 are doubled with a layer of heat-resistant fabric 42 sandwiched between them, as shown in the enlarged cross-sectional view of FIG. 1(d). In other words, the boundary 40 has a three-layer structure of partition wall 31 - layer of heat-resistant fabric 42 - partition wall 31. Here, a case where the layer of heat-resistant fabric 42 is single-layered is exemplified, but the heat-resistant fabric 42 can also be multi-layered by folding and overlapping it or by stacking multiple sheets.

[0040] 3(a) and 3(b), a heat-resistant fabric 42 may be wrapped around the entire peripheral side surfaces (flat surfaces 35, curved surfaces 36, and curved surfaces 37) of each of a plurality of honeycomb segments 30, and then the honeycomb segments 30 may be assembled to form a heat storage body 50b. In this case, the boundary 40 between adjacent honeycomb segments 30 has a laminated structure of partition wall 31-two layers of heat-resistant fabric 42-partition wall 31, as shown in the enlarged cross-sectional view of FIG.

[0041] As another modification, a heat storage body can be formed by laminating a silicate glass layer 41 on at least the flat surface 35 of each of the side peripheral surfaces of a plurality of honeycomb segments 30, and then sandwiching a heat-resistant fabric 42 between adjacent honeycomb segments 30. The silicate glass layer 41 is formed using a coating agent containing silicon dioxide.

[0042] Coating agents are made by mixing a silicon dioxide source with a liquid medium such as water and a binder. The silicon dioxide source can be silica powder, glass powder (glass frit), or clay, either alone or in combination. In addition to the above ingredients, the coating agent raw materials can also contain other ingredients. The addition of boron oxide (B2O3) can adjust the viscosity (fluidity) and durability of the glass. Alkali metal oxides (such as Na2O, K2O, and Li2O) lower the viscosity and glass transition temperature of glass. Alkaline earth metal oxides (such as CaO, MgO, BaO, and SrO) increase the chemical durability of glass and affect its amorphization and crystallization. Aluminum oxide enhances the chemical durability of glass.

[0043] After coating at least the flat surface 35 of the side peripheral surface of the sintered honeycomb segment 30 by applying or spraying a coating agent, the honeycomb segment 30 is heated at a predetermined temperature of 1000°C to 1200°C for a predetermined time to melt the silicon dioxide, and then cooled to a temperature below the glass transition point, thereby forming a dense and airtight silicate glass layer 41.

[0044] 4(a) and 4(b), in each honeycomb segment 30, a silicate glass layer 41 is laminated over the entire side peripheral surface consisting of the flat surfaces 35, curved surfaces 36, and curved surfaces 37, and then the entire side peripheral surface of each honeycomb segment 30 is wrapped with a heat-resistant fabric 42, and in this state, a plurality of honeycomb segments 30 can be assembled to form a heat storage body 50c. In this case, the boundary 40 between adjacent honeycomb segments 30 has a laminated structure of partition wall 31-silicic acid glass layer 41-two heat-resistant fabric 42 layers-silicic acid glass layer 41-partition wall 31, as shown in the enlarged cross-sectional view of FIG. 2(b).

[0045] In the above-mentioned heat storage bodies 50, 50b, and 50c, the heat-resistant fabric 42 may be impregnated with a slurry containing ceramic powder or a slurry that becomes silicate glass when heated. The ceramic powder slurry may be a slurry in which a binder such as colloidal silica is added to ceramic powder and mixed with water. The silicate glass slurry may be a slurry containing the same components as the above-mentioned coating agent but with lower viscosity than the coating agent.

[0046] When a slurry containing ceramic powder is heated, the slurry solidifies to form a heat-resistant fabric 42 having a ceramic component supported between ceramic fibers. Alternatively, when a heat-resistant fabric 42 impregnated with a slurry that turns into silicate glass when heated is heated to melt the silicon dioxide, and then cooled to a temperature below the glass transition point, the slurry solidifies to form a heat-resistant fabric 42 having a silicate glass supported between ceramic fibers. By solidifying the slurry in this manner, the breathability of the heat-resistant fabric 42 can be reduced while maintaining some of the elasticity of the heat-resistant fabric 42.

[0047] Here, heating to solidify the slurry containing ceramic powder or the slurry that becomes silicate glass when heated can be carried out after assembling a plurality of honeycomb segments 30. In the case of the heat storage bodies 50b, 50c in which honeycomb segments 30 whose entire peripheral surfaces are wrapped in heat-resistant fabric 42 are assembled, heating can be carried out on a honeycomb segment 30 basis before assembling the plurality of honeycomb segments 30.

[0048] In addition, Figures 3 and 4 show only the configuration of two boundary sections 40 when three honeycomb segments 30 are aggregated, and the others are omitted, but when six segments 30 are aggregated, all five boundary sections 40 have the same configuration.

[0049] Next, the configuration of the burner device 1 other than the heat storage body 50 will be described. The main body outer casing 10 is substantially cylindrical, with a flange portion 13 projecting outward at a midpoint. This flange portion 13 is used when fixing the burner device 1 to the furnace wall in a state where the burner device 1 is inserted into a hole formed in the furnace wall of an industrial furnace. The main body outer casing 10 accommodates the heat storage body 50 and the burner 20 in a state where the burner 20 is inserted into the burner through-hole 55 of the heat storage body 50. If the axis of the substantially cylindrical main body outer casing 10 is referred to as the "central axis X," the heat storage body 50 is accommodated in the main body outer casing 10 with the axial direction of the cells 32 parallel to the central axis X.

[0050] A double-cylindrical burner tile 80 is fitted into the main body outer casing 10 on the inner end E1 side of the flange portion 13, and the inner end E1 side of the burner tile 80 is exposed from the main body outer casing 10. The inner end E1 of the burner tile 80 is closed except for a central hole 85 and multiple vent holes 83. The central hole 85 penetrates the burner tile 80 and the main body outer casing 10 on an extension of the central axis X, and the end of the burner 20 on the inner end E1 side faces the opening of this central hole 85 on the inner end E1 side. The multiple vent holes 83 are provided at equal angular intervals around the central axis X, and this angle is 360 degrees divided by the number of honeycomb segments 30 (60 degrees in this embodiment). The positions of these vent holes 83 are set so as to be on an extended line passing through the centers of each of the multiple honeycomb segments 30 that make up the heat storage body 50.

[0051] Two exhaust ports 12 are provided on the outer end E2 side of the flange portion 13, branching off from the main body outer casing 10 in a direction perpendicular to the central axis X. The two exhaust ports 12 are provided symmetrically with respect to the central axis X. The outer end E2 of the main body outer casing 10 is closed except for a hole 15 for inserting the burner 20, an air inlet 11, and holes required for the rotation mechanism described below. The outer end E2 of the burner 20 is exposed outward from the hole 15, and a fuel inlet 25 for introducing fuel gas opens in this portion. The air inlet 11 is provided on a line parallel to the central axis X.

[0052] The rotary switch disk 60 is disposed between the outer end E2 of the main body outer casing 10 and the heat storage body 50, and the end of the rotary switch disk 60 on the inner end E1 side faces the end of the heat storage body 50 on the outer end E2 side. The rotary switch disk 60 has partition walls 61 corresponding to each of the multiple honeycomb segments 30 that make up the heat storage body 50. The partition walls 61 are inclined and bent walls so that two exhaust ports 12 and one air intake port 11 communicate with the intra-cell space of one of the multiple honeycomb segments 30 as the rotary switch disk 60 rotates in one direction around the central axis X.

[0053] The rotation mechanism is a mechanism that drives the rotation of the rotary switch panel 60, and is mainly composed of a shaft 72 to which the rotation of the output shaft 71p of the motor 71 is transmitted, a gear 73 that rotates integrally with the shaft 72, and a gear 74 that rotates following the gear 73, and the rotation shaft of the gear 74 rotates integrally with the rotary switch panel 60. The rotary switch panel 60 is supported by the main body casing 10 via a bearing 79 near the central hole 85.

[0054] Next, we will explain the operation of the burner device 1 configured as described above. When the burner device 1 is attached to the furnace wall of an industrial furnace and fuel gas is introduced through the fuel inlet 25, the fuel gas burns using oxygen contained in the combustion air supplied from the air inlet 11 as a supporting gas, and a flame is emitted from the inner end E1 of the burner 20. This combustion of the fuel gas heats up the atmosphere inside the furnace.

[0055] When the rotary switch disk 60 is continuously rotated in one direction around the central axis X, either one of the two exhaust ports 12 and one air inlet port 11 communicates with the intracellular space of one of the multiple honeycomb segments 30. FIG. 6( a) shows a case where one of the exhaust ports 12 communicates with one of the honeycomb segments 30 and the air inlet port 11 is closed. In this state, exhaust gas heated to a high temperature in the furnace flows through the intracellular space of this honeycomb segment 30 and is discharged from the exhaust port 12. At that time, exhaust gas is taken in from the atmosphere in the furnace through the vent port 83 located on an extension of the center of the honeycomb segment 30. Then, during the process of the exhaust gas flowing through the intracellular space of the honeycomb segment, this honeycomb segment 30 recovers heat from the high-temperature exhaust gas and becomes hot.

[0056] 6(b) shows a state in which the rotation of the rotary switch 60 causes the air intake port 11 to communicate with the intra-cellular space of one of the multiple honeycomb segments 30, and the exhaust port 12 to be closed. In this state, combustion air newly supplied through the air intake port 11 flows through the intra-cellular space of this honeycomb segment 30. The combustion air that has flowed through the honeycomb segment 30 is supplied to the furnace atmosphere from the vent port 83 located on an extension of the center of this honeycomb segment 30, and supports the combustion of fuel gas in the burner 20. This honeycomb segment 30 has already recovered exhaust heat from the previous flow of exhaust gas, and is therefore at a high temperature, so the combustion air is preheated when it is passed through.

[0057] By rotating the rotary switch 60 in this way, the gas flowing through each of the multiple honeycomb segments 30 constituting one regenerator 50 is switched between exhaust gas and combustion air, and the combustion air is preheated with the heat recovered from the exhaust gas. Specifically, when the temperature of the exhaust gas heated in the furnace is 1000°C, by giving the exhaust heat to the honeycomb segment 30, the temperature of the exhaust gas discharged from the exhaust port 12 becomes 250°C, and the combustion air is preheated by that amount.

[0058] In the burner device 1 of this embodiment, the rotary switching panel 60 rotates once every 12 seconds. Therefore, the time interval for switching the gas flowing through the regenerative heat storage body 50 between exhaust gas and combustion air is extremely short compared to conventional regenerative burner systems that use a pair of burners. Therefore, the heat recovered from the exhaust gas can be immediately provided to the combustion air.

[0059] In this embodiment, the regenerator 50 is composed of six honeycomb segments 30. The gas flow can be switched by rotating the rotary switch disk 60 as follows. Specifically, if the state in which combustion air flows is represented by "In," the state in which exhaust gas flows is represented by "Out," and the state in which neither combustion air nor exhaust gas flows is represented by "N," the shape of the partition walls 61 on the rotary switch disk 60 can be set so that the six honeycomb segments 30 can be switched in the order In-In-Out-Out-Out-N, as shown in FIG. 7 . This switching results in a ratio of 2:3 between the volume of combustion air supplied through the regenerator 50 and the volume of exhaust gas discharged through the regenerator 50 per rotation of the rotary switch disk 60. Because gas pressure is inversely proportional to volume, the pressure decrease due to the discharge of exhaust gas in the furnace atmosphere is greater than the pressure increase due to the supply of combustion air, which at first glance appears unbalanced. However, the pressure of the gas inside the furnace also increases due to the supply of fuel gas to the burner 20. Therefore, by making the volume of the exhaust gas larger than the volume of the combustion air circulated through the regenerator 50, it is possible to balance the pressure of the gas supplied into the furnace and the gas exhausted from the furnace.

[0060] Furthermore, even if a state in which neither combustion air nor exhaust gas is circulated is established as described above, combustion air and exhaust gas are alternately circulated through each honeycomb segment 30, and therefore the rotary switching disk 60 of this embodiment satisfies the requirement of the present invention of "switching the gas circulating through each honeycomb segment between combustion air and exhaust gas."

[0061] As described above, in the burner device 1 of this embodiment, the regenerators 50, 50b, 50c are formed by a plurality of honeycomb segments 30, and at the boundary 40 between adjacent honeycomb segments 30, the partition walls 31 are doubled with a layer of heat-resistant fabric 42 sandwiched between them. Therefore, the honeycomb segment 30 through which combustion air flows and the honeycomb segment 30 through which exhaust gas flows are adjacent to each other, and even if damage occurs to the partition wall 31 that forms the boundary surface (plane 35) in one of the honeycomb segments 30, the partition wall 31 that forms the boundary surface (plane 35) in the other honeycomb segment 30 remains, so that mixing of the combustion air and the exhaust gas is effectively prevented.

[0062] Conventionally, when manufacturing a cylindrical honeycomb structure, a circular extrusion die is used for extrusion molding into a cylindrical shape. Therefore, those skilled in the art would not have thought of molding honeycomb segments using a fan-shaped extrusion die and then assembling a plurality of such honeycomb segments to manufacture a cylindrical honeycomb structure. In this respect, the manufacturing method of this embodiment, in which individual honeycomb segments 30 are molded using a fan-shaped extrusion die, is very novel.

[0063] Furthermore, if the honeycomb segments are formed by dividing one extrusion-molded honeycomb structure into a plurality of segments, the cells are open on the side peripheral surface of each honeycomb segment. Therefore, if the layer interposed between adjacent honeycomb segments is permeable, the combustion air and exhaust gas will mix between the adjacent honeycomb segments through that portion. In contrast, in the burner device 1 of this embodiment, even if the layer interposed between adjacent honeycomb segments 30 is permeable, the adjacent honeycomb segments 30 each have partition walls 31 on their outer peripheries, so that the combustion air and exhaust gas are effectively prevented from mixing.

[0064] The layer interposed between adjacent honeycomb segments 30 is a layer of heat-resistant fabric 42 made of ceramic fiber. The heat-resistant fabric 42 is made of a highly elastic material, in other words, a layer with high cushioning properties. Therefore, the layer of heat-resistant fabric 42 absorbs the thermal stress that inevitably occurs in the honeycomb segments 30 due to repeated heat radiation and heat absorption. This increases the thermal shock resistance of the honeycomb segments 30, making it less likely that damage such as cracks will occur in the partition walls 31 on the outer periphery of each honeycomb segment 30. Therefore, even if a honeycomb segment 30 through which combustion air flows and a honeycomb segment 30 through which exhaust gas flows are adjacent to each other, mixing of the absorbing combustion air and the exhaust gas can be effectively suppressed.

[0065] In this embodiment, the ceramics constituting the honeycomb segments 30 are silicon carbide ceramics. Silicon carbide has a high thermal conductivity, which has the advantage of allowing rapid heat exchange with the circulating gas. That is, heat can be quickly recovered from the exhaust gas and quickly transferred to newly supplied combustion air. In particular, in the burner device 1 of this embodiment, the switching of the circulating gas by the rotation of the rotary switching disk 60 is performed at extremely short intervals, so the merits of high thermal conductivity are significant. In addition, silicon carbide has a low thermal expansion coefficient, which has the advantage of being highly resistant to the thermal shock that inevitably acts on a heat storage material that repeatedly absorbs and releases heat.

[0066] In this embodiment, the cross-sectional shape of the honeycomb segment 30 is sectorial, and the cross-sectional shape of the heat storage bodies 50, 50b, and 50c, which are formed by radially assembling a plurality of honeycomb segments, is circular. That is, the heat storage bodies 50, 50b, and 50c are cylindrical with a circular burner through-hole 55 at their centers. This allows the burner 20, which has a circular cross-sectional shape in the same direction as the cross-section of the honeycomb segment 30, to be easily accommodated in the cylindrical main body outer shell 10 while passing through the burner through-hole 55. The cylindrical shape of the main body outer shell 10 not only simplifies manufacturing, but also makes it easier to maintain a constant gap between the cylindrical heat storage bodies 50, 50b, and 50c, making it easier to fill the gap with insulating material or the like. Another advantage of the cylindrical heat storage bodies 50, 50b, and 50c is that temperature distribution is less likely to occur. In addition, in the case of heat storage bodies 50b, 50c whose entire lateral surfaces are wrapped in heat-resistant fabric 42, the heat-resistant fabric 42 can also serve as the insulating material filled between the main body outer casing 10 and the heat storage bodies 50b, 50c.

[0067] Furthermore, in a heat storage body in which a silicate glass layer 41 is laminated on the partition walls 31 that form at least the boundary surface (plane 35) between adjacent honeycomb segments on the side peripheral surface of the honeycomb segment 30, when a honeycomb segment 30 through which combustion air flows and a honeycomb segment 30 through which exhaust gas flows are adjacent to each other, even if damage occurs to both of the partition walls 31 that form the boundary surface in each of the adjacent honeycomb segments 30, mixing of the combustion air and the exhaust gas is effectively prevented because there are two silicate glass layers 41 and one or more layers of the heat-resistant fabric 42 between the partition walls 31. In particular, because the silicate glass layer 41 is a dense and highly airtight layer, even if damage occurs to the partition wall 31 of each honeycomb segment 30, the silicate glass layer 41 prevents gas from leaking through the damage, and mixing of the combustion air and the exhaust gas is prevented.

[0068] Furthermore, silicate glass has the property of softening and plastically deforming at high temperatures. Therefore, even if damage occurs to the partition walls 31, the extension of the damage is suppressed, and the ceramic honeycomb segments 30 are also suppressed from brittle fracture. Therefore, the silicate glass layer 41 can further improve the thermal shock resistance of the honeycomb segments that constitute the heat storage body, which repeatedly absorbs and releases heat. Also, because silicate glass softens and becomes adhesive at high temperatures, once the heat-resistant fabric 42 is heated in a state where it is laminated on the silicate glass layer 41, the heat-resistant fabric 42 adheres to the silicate glass layer 41. This stabilizes the state in which the heat-resistant fabric 42 is sandwiched between adjacent honeycomb segments 30.

[0069] Furthermore, in the heat storage body 50c formed by assembling honeycomb segments 30 having silicate glass layers 41 laminated over the entire side peripheral surfaces, even if any part of the partition walls 31 constituting the side peripheral surfaces of the honeycomb segments 30 is damaged, the gas circulating within the cells of the honeycomb segments 30 is prevented from leaking into the inside of the outer shell body 10. Furthermore, while silicon carbide constituting the honeycomb segments 30 has the advantages described above, it has the problem of being oxidized when heated in an oxygen-containing atmosphere. However, in the heat storage body 50c, the dense and highly airtight silicate glass layers 41 are laminated over the entire side peripheral surfaces of the honeycomb segments 30, so oxidation of the silicon carbide is effectively prevented.

[0070] In addition, when the heat-resistant fabric 42 constituting the heat storage bodies 50, 50b, 50c is impregnated with a slurry containing ceramic powder or a slurry that becomes silicate glass when heated, and then the slurry is solidified by heating, the ceramic component or silicate glass is carried between the ceramic fibers, reducing the air permeability of the heat-resistant fabric 42. Therefore, even if damage occurs to the partition walls 31 that form the boundaries between adjacent honeycomb segments 30, the layer of the heat-resistant fabric 42 prevents gas from leaking from each of the honeycomb segments 30 through this damage, and therefore the risk of mixing of the combustion air and exhaust gas can be reduced.

[0071] The present invention has been described above by citing preferred embodiments, but the present invention is not limited to the above embodiments, and various improvements and design changes are possible as described below, without departing from the spirit of the present invention.

[0072] For example, in the above example, one heat storage body 50, 50b, 50c is formed by assembling six honeycomb segments 30, but the number of honeycomb segments constituting one heat storage body is not limited as long as it is plural (two or more). When one heat storage body is composed of an odd number of honeycomb segments, for the reasons mentioned above, the shape of the partition walls on the rotary switch disk is set so that the number of honeycomb segments through which exhaust gas flows is greater than the number of honeycomb segments through which combustion air flows per rotation of the rotary switch disk.

[0073] In the above example, the heat storage bodies 50, 50b, 50c having a circular cross section are formed by assembling honeycomb segments 30 having a sector-shaped cross section. The shapes of the heat storage body and honeycomb segments are not limited to this, and for example, as shown in Fig. 8, the cross section of the honeycomb segment 30b may be formed into an isosceles triangle with the apex angle cut out in an arc shape, and a heat-resistant fabric 42 may be sandwiched between the honeycomb segments and assembled to form a polygonal columnar heat storage body having a circular burner through-hole in the center. [Explanation of symbols]

[0074] 1. Burner device (single type regenerative burner device) 10 Main body casing 11 Air supply port 12 exhaust port 20 Burner 30,30b Honeycomb segment 31 Bulkhead 32 cells 35 Plane (boundary surface) 40 Boundary 41 Silicate glass layer 42 Heat-resistant fabric 50,50b,50c Heat storage body 55 Burner through hole 60 Rotating switchboard

Claims

1. a burner penetrating the outer shell of the main body; an air intake port for supplying combustion air for combustion of fuel gas by the burner to the inside of the main body outer shell; an exhaust port for discharging exhaust gas heated by combustion of the fuel gas from the outer casing of the main body; a heat storage body made of ceramics, in which a plurality of honeycomb segments having a honeycomb structure with a plurality of cells separated by partition walls arranged in a row and extending in a single direction are assembled so that the axial directions of the respective cells coincide, the heat storage body being housed in the outer shell of the main body with the burner inserted therethrough; a rotary switching disk that rotates around an axis parallel to the axial direction of the cells relative to the heat storage body, thereby switching the gas to be circulated through each of the honeycomb segments between the combustion air and the exhaust gas, The cells are not open on the side peripheral surface of each of the honeycomb segments, and the side peripheral surface is formed by the wall surfaces of the partition walls, A heat-resistant fabric, which is a nonwoven or woven fabric made of heat-resistant fibers, is sandwiched between the adjacent honeycomb segments, At the boundary between adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween, A silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment on the side peripheral surface of the honeycomb segment. A single-type regenerative burner device characterized by:

2. a heat storage body in which a plurality of honeycomb segments made of ceramics and having a honeycomb structure with a plurality of cells separated by partition walls arranged in a row and extending in a single direction are assembled together so that the axial directions of the respective cells are aligned, The heat storage body has a burner through hole at the center that is larger than the cell and penetrates the cell in the axial direction, The cells are not open on the side peripheral surface of each of the honeycomb segments, and the side peripheral surface is formed by the wall surfaces of the partition walls, A heat-resistant fabric, which is a nonwoven or woven fabric made of heat-resistant fibers, is sandwiched between the adjacent honeycomb segments, At the boundary between adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween, A silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment on the side peripheral surface of the honeycomb segment. A heat storage body characterized by:

3. The honeycomb segment is made of silicon carbide ceramics.

3. The heat storage body according to claim 2.

4. A honeycomb segment is formed by extrusion molding, the honeycomb segment being made of ceramics and having a honeycomb structure including a plurality of cells separated by partition walls arranged in a row and extending in a single direction, wherein the cells do not open to side peripheral surfaces and the side peripheral surfaces are formed by wall surfaces of the partition walls, After firing a plurality of the honeycomb segments, the honeycomb segments are assembled so that the axial directions of the cells are aligned, thereby manufacturing a heat storage body having a burner through-hole at the center that is larger than the cell and penetrates the cell in the axial direction, When the honeycomb segments are assembled, a heat-resistant fabric, which is a nonwoven fabric or a woven fabric made of heat-resistant fibers, is sandwiched between adjacent honeycomb segments, At the boundary between adjacent honeycomb segments, the partition walls are doubled with the heat-resistant fabric layer sandwiched therebetween, A heat storage body is manufactured in which a silicate glass layer is formed between the heat-resistant fabric layer and at least the boundary surface between the honeycomb segment and the adjacent honeycomb segment among the side peripheral surfaces of the honeycomb segment. A method for manufacturing a heat storage body, comprising:

5. The heat-resistant fabric is impregnated with a slurry containing ceramic powder or a slurry that becomes silicate glass when heated. The method for manufacturing a heat storage body according to claim 4 .

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