KR20240051147A - Exhaust gas purification device and method of manufacturing the exhaust gas purification device - Google Patents

Abstract

An exhaust gas purification device and a method of manufacturing the exhaust gas purification device are provided. The exhaust gas purification device includes a lightweight catalyst structure and a multi-layer body, and the multi-layer body is obtained in such a way that it is not deformed during the manufacturing process, so that the occurrence of any gaps between the catalyst structure and the housing case is suppressed. do. The exhaust gas purification device has a catalyst structure 2 configured to allow the exhaust gas to flow, supported by the catalyst structure 2, and reacting with the exhaust gas flowing through the catalyst structure 2 to purify the exhaust gas. It includes a housing case (4) that accommodates a purifiable metal catalyst (3) and the catalyst structure (2) and is attachable to an exhaust gas flow path through which the exhaust gas flows. The catalyst structure 2 is a multi-layer body (E) obtained by stacking a plurality of fibrous sheets composed of fibrous sheets E1 and E2, each having a curved wave shape, with one on top of the other. and the reinforcing members F1, F2 are provided on the outer periphery of the multi-layer body E in such a way as to extend along the inner periphery of the housing case 4.

Description

Exhaust gas purification device and method of manufacturing the exhaust gas purification device

The present invention relates to an exhaust gas purification device and a method of manufacturing the exhaust gas purification device. The exhaust gas purification device includes a catalyst structure configured to allow exhaust gas to flow, a metal catalyst supported on the catalyst structure and capable of purifying the exhaust gas by reacting with the exhaust gas flowing through the catalyst structure, and the catalyst structure. It includes a housing case that accommodates and is attachable to an exhaust gas flow path through which exhaust gas is distributed.

A woodstove (wood stove) is a heater intended to heat an indoor space by dissipating heat while firewood is burned within its metal sealed box-shaped body. Radiant heat and convection of indoor air synergistically fill the indoor space with mild warmth. Wood stoves typically include a chimney extending through the outdoors, and an exhaust gas purification device attached to an exhaust gas flow path extending between the chimney and the space for burning wood.

A known exhaust gas purification device is configured to purify exhaust gas generated by burning firewood, and includes a catalyst structure configured to allow the exhaust gas to circulate, supported by the catalyst structure, and CO resulting from incomplete combustion. A metal catalyst capable of reacting with PM (particulate matter (particulate matter) such as carbon monoxide) and ash particles and purifying them accordingly, and a catalyst structure that can be attached to the exhaust gas flow path through which the exhaust gas will circulate. Includes housing case. A typical configuration of a wood stove is disclosed in patent documents.

Japanese Patent Application Publication No. 2014-20573

In the above known exhaust gas purification device, the honeycomb structure (catalyst structure) supporting the metal catalyst is relatively heavy, which makes it difficult to reduce the weight of the device as a whole. Therefore, the applicant proposes the following methods: bending a plurality of fibrous sheets, for example obtained by a wet sheet-forming technique, into a wavy shape; stacking the bent fibrous sheets, one on top of the other, to form a multi-layered body; The possibility of obtaining a lightweight catalyst structure was being examined by drying and burning the multi-layer body.

A plurality of curved corrugated fibrous sheets are stacked one on top of another to form a multilayer body, for example another fibrous sheet is wrapped around the multilayer body to maintain its shape. It is supposed to be there. However, during this process, extra forces may be applied to the multi-layer body and may deform the multi-layer body. If this modified catalyst structure is accommodated in a housing case, gaps are created between the catalyst structure and the inner outer periphery of the housing case, which may adversely affect purification performance.

The present invention is taken into account in view of the above circumstances and provides an exhaust gas purification device comprising a lightweight catalyst structure and a multi-layer body, the multi-layer body being obtained in such a way that it is not deformed during the manufacturing process, so that The occurrence of any gaps between the catalyst structure and the housing case is suppressed. The present invention also provides a method of manufacturing an exhaust gas purification device.

According to the invention of claim 1, there is provided a catalyst structure configured to allow exhaust gas to flow, a metal catalyst supported by the catalyst structure and capable of purifying the exhaust gas by reacting with the exhaust gas flowing through the catalyst structure, and An exhaust gas purification device is provided that includes a housing case that accommodates a catalyst structure and is attachable to an exhaust gas flow path through which exhaust gases circulate. The catalyst structure includes a multi-layer body obtained by stacking a plurality of fibrous sheets each having a curved wave shape, one on top of another, and the reinforcing member is such that it extends along the inner periphery of the housing case. It is provided on the outer perimeter of the multi-layer body in a manner.

According to the invention of claim 2, in the exhaust gas purification device according to claim 1, the catalyst structure has a prismatic shape conforming to the shape defined by the inner periphery of the housing case, and the reinforcing member is an outer peripheral surface of the prismatic catalyst structure. It includes a plurality of sheet-like members extending along the edges.

According to the invention of claim 3, in the exhaust gas purification device according to claim 1 or 2, the reinforcing member is made of the same material as the fibrous sheets constituting the multi-layer body, and the individual fibers constituting the multi-layer body are It is a sheet-like member that is at least thicker than sheets.

According to the invention of claim 4, in the exhaust gas purification device according to any one of claims 1 to 3, the exhaust gas purification device is capable of dissipating heat with firewood burning inside, and heat generated by burning firewood is provided. It is designed to be attached to a wood stove that can discharge exhaust gases to the outside.

According to the invention of claim 5, there is provided a method of manufacturing an exhaust gas purification device, the device comprising a catalyst structure configured to allow exhaust gas to flow, supported by the catalyst structure, and flowing through the catalyst structure. It includes a metal catalyst capable of purifying exhaust gas by reacting with exhaust gas, and a housing case that accommodates the catalyst structure and is attachable to an exhaust gas flow path through which exhaust gas flows. The catalyst structure is formed by stacking a plurality of fibrous sheets each having a curved wave shape, one on top of the other, to form a multilayer body in this manner, such as extending along the inner periphery of the housing case. It is obtained by placing a reinforcing member on the outer circumference of .

According to the invention of claim 6, the method of manufacturing the exhaust gas purification device according to claim 5 includes: a fibrous-sheet-forming step of forming fibrous sheets by a sheet-forming technique; A multilayer forming a multilayer body in which some of the fibrous sheets obtained in the fibrous-sheet-forming step are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked one on top of the other - body-forming step; One of the fibrous sheets obtained in the fibrous-sheet-forming step is subjected to a reinforcing-member-forming step of forming a reinforcing member, on which a coating material is applied and burned; The reinforcing member obtained in the reinforcing-member-forming step is attached to the outer periphery of the multilayer body obtained in the multilayer-body-forming step, and the multilayer body is combusted with the reinforcing member attached to the catalyst structure. Forming catalyst-structure-forming step; and a supporting step of allowing the metal catalyst to be supported by the catalyst structure obtained in the catalyst-structure-forming step.

According to the invention of claim 7, in the method of manufacturing the exhaust gas purification device according to claim 6, in the catalyst-structure-forming step, the reinforcing member obtained in the reinforcing-member-forming step is obtained in the multilayer-body-forming step. Attached to the outer periphery of the resulting multilayer body, one of the fibrous sheets obtained in the fibrous-sheet-forming step is wrapped over and secured to the outer surface of the reinforcing member, and the multilayer body is formed with the reinforcing member and the reinforcing member. The fibrous sheet is burned while stationary.

According to the invention of claim 1 or claim 5, the catalyst structure includes a multi-layer body obtained by stacking a plurality of fibrous sheets each having a curved wave shape with one on top of another, and the reinforcing member is a housing case. It is provided on the outer circumference of the multi-layer body in such a way that it extends along the inner circumference of the. Accordingly, weight reduction of the catalyst structure is achieved, while deformation of the multi-layer body that may occur during the manufacturing process is prevented, and thus the occurrence of any gaps between the housing case and the catalyst structure is suppressed.

According to the invention of claim 2, the catalyst structure has a prismatic shape conforming to the shape defined by the inner periphery of the housing case, and the reinforcing member includes a plurality of sheet-like members extending along the outer peripheral surfaces of the prismatic catalyst structure. Includes. Accordingly, even if the housing case has a rectangular shape (such as an oblong rectangle) that conforms to the shape of the exhaust gas flow path, the catalyst structure is received within the housing case in such a way that it conforms to the inner periphery of the housing case.

According to the invention of claim 3, the reinforcing member is a sheet-like member made of the same material as the fibrous sheets that make up the multi-layer body and at least thicker than the individual fibrous sheets that make up the multi-layer body. Accordingly, fibrous sheets with different thicknesses are utilized to obtain both the multilayer body and the reinforcement member. Moreover, the use of reinforcing elements with greater thickness and higher rigidity reliably prevents deformation of the multilayer body that may occur during the manufacturing process.

According to the invention of claim 4, the exhaust gas purification device is attached to a woodstove, which is capable of dissipating heat while firewood is burning inside and exhaust gas generated by burning firewood can be discharged to the outside. Accordingly, the exhaust gas discharged from the wood stove is reliably purified.

According to the invention of claim 6, the method comprises: a fibrous-sheet-forming step of forming fibrous sheets by a sheet-forming technique; A multilayer forming a multilayer body in which some of the fibrous sheets obtained in the fibrous-sheet-forming step are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked one on top of the other - body-forming step; One of the fibrous sheets obtained in the fibrous-sheet-forming step is subjected to a reinforcing-member-forming step of forming a reinforcing member, on which a coating material is applied and burned; The reinforcing member obtained in the reinforcing-member-forming step is attached to the outer periphery of the multilayer body obtained in the multilayer-body-forming step, and the multilayer body is combusted with the reinforcing member attached to the catalyst structure. Forming catalyst-structure-forming step; and a supporting step of allowing the metal catalyst to be supported by the catalyst structure obtained in the catalyst-structure-forming step. Accordingly, deformation of the multi-layer body that may occur during the manufacturing process is reliably prevented, while smooth manufacturing of a lightweight exhaust gas purification device is achieved.

1 is a perspective view of a wood stove exhaust gas purification device according to an embodiment of the present invention, showing its appearance.
Figure 2 is a four-sided view of a wood stove exhaust gas purification device.
Figure 3 shows a cross section taken along line III-III given in Figure 2.
Figure 4 shows a cross section taken along line IV-IV given in Figure 2.
Figure 5 includes a perspective view of one of the fibrous sheets as components of a catalytic structure included in a woodstove exhaust gas purification device.
Figure 6 contains a perspective view of a multilayer body obtained by stacking fibrous sheets one on top of another.
Figure 7 is a perspective view of the catalyst structure, with reinforcing members attached to the outer peripheral surfaces of the multilayer body.
Figure 8 includes a top view and a side view of some of the reinforcing members (reinforcement members adapted to be attached to the respective stack-wise end faces).
Figure 9 includes a top view and a side view of another one of the remaining reinforcing members (a reinforcing member adapted to be attached to a peripheral surface different from the lamination-wise end face).
Figure 10 is a perspective view of the catalyst structure, where the fibrous sheet is wrapped over reinforcing members attached to the outer peripheral surfaces of the multilayer body.
Figure 11 is a perspective view of the catalyst structure, with the holding member attached thereto on its outer peripheral surfaces.
Figure 12 schematically shows the entire retaining member (which is not intended to be attached to the catalyst structure).
Figure 13 is a three-sided view of the housing case included in the wood stove exhaust gas purification device.
Figure 14 schematically shows a wood stove to be applied to this embodiment.
Figure 15 is a flow chart showing the process of manufacturing the wood stove exhaust gas purification device according to this embodiment.
Figure 16 includes a top view and a side view of some of the reinforcing members (reinforcement members connected to each other by connecting members) in a state during the process of manufacturing the wood stove exhaust gas purification device according to the present embodiment. do.
Figure 17 is an enlarged cross-sectional view at the connection between reinforcing members.
Figure 18 is a schematic cross-sectional view of fibrous sheets stacked in a space defined by reinforcing members (reinforcement members connected to each other) during the manufacturing process of the wood stove exhaust gas purification device according to the present embodiment.
Figure 19 is a schematic cross-sectional view of laminated fibrous sheets surrounded by reinforcing members.
FIG. 20 is a graph showing the technical advantages generated by the metal catalyst supported by the catalyst structure included in the wood stove exhaust gas purification device according to this embodiment.

Embodiments of the present invention will next be described in detail with reference to the drawings.

The exhaust gas purification device according to this embodiment is applied to a wood stove exhaust gas purification device that is attached to a wood stove. A wood stove can radiate heat while wood is burning inside it, and exhaust gases generated by burning wood can be discharged to the outside. Wood stove exhaust gas purification devices are intended to purify exhaust gases.

Referring to FIG. 14, the wood stove (W) applied to this embodiment includes a box-shaped metal body (W1) and a chimney (W3). The metal body W1 has a combustion chamber W2 in which the firewood M is burned for heat dissipation. The chimney W3 allows the exhaust gas generated by burning the firewood M to be discharged to the outside. The metal body W1 has a glass front door D that is open when firewood M is introduced into the combustion chamber W2 or closed when ash in the combustion chamber W2 is collected. It is provided on the front side.

Between the combustion chamber W2 and the chimney W3, two exhaust gas flow paths N1 and N2 are provided that allow the exhaust gas generated within the combustion chamber W2 to circulate. One of the exhaust gas flow paths, namely the exhaust gas flow path N1, is provided with the present exhaust gas purification device 1. The other exhaust gas flow path N2 is provided with a damper B, with which the flow path can be opened or closed. The damper (B) can be arbitrarily operated by the operator. That is, the exhaust gas flow path N2 can be opened or closed at any time.

When the exhaust gas generated by burning the firewood (M) has a low temperature, the damper (B) is opened, thereby allowing the exhaust gas (a) to circulate through another exhaust gas flow path (N2) and through the chimney (W3). is discharged to the outside through When the temperature of the exhaust gas rises, the damper B is closed, so that the exhaust gas B flows through one exhaust gas flow path N1. In the exhaust gas flow path N1, the exhaust gas b is purified by the exhaust gas purification device 1 and discharged to the outside through the chimney W3.

The exhaust gas purification device 1 can be attached to the exhaust gas flow path N1 of the wood stove W, and as shown in FIGS. 1 to 3, it includes a catalyst structure 2, a metal catalyst 3, It includes a housing case (4) and a holding member (5). The catalyst structure 2 is configured to allow exhaust gas to circulate. The metal catalyst 3 is supported by the catalyst structure 2, and can purify the exhaust gas by reacting with the exhaust gas flowing through the catalyst structure 2. The housing case 4 accommodates the catalyst structure 2 and is attachable to the exhaust gas flow path N1 through which exhaust gas flows. Since the holding member 5 is interposed between the catalyst structure 2 and the housing case 4, the catalyst structure 2 is held within the housing case 4.

5 and 6, the catalyst structure 2 according to this embodiment is a multi-layer body (E) obtained by stacking a plurality of layers each composed of a fibrous sheet (E1) and a fibrous sheet (E2). ) includes. The fibrous sheet E1 has a curved wave shape. The fibrous sheet E1 and the fibrous sheet E2 are, respectively, sheet-like members (flexible paper-like members) obtained by wet sheet-forming technology (papermaking technology) and made mainly of inorganic materials. As shown in Figure 5, the fibrous sheet E1 has a wavy shape obtained through bending. The fibrous sheet E2 has two curved ends.

The fibrous sheet E1 is placed on the fibrous sheet E2, thereby obtaining the fibrous-sheet pair shown in Figure 5. The multilayer body E shown in Figure 6 is obtained by stacking a plurality of such fiber-sheet pairs, one on top of the other. The combination of the fibrous sheets E1 each having a curved wave shape and the fibrous sheets E2 each having a flat sheet shape forms a so-called honeycomb shape through which exhaust gas is allowed to circulate.

Referring to FIGS. 7 to 9, the catalyst structure 2 according to this embodiment is provided with reinforcing members F1 and F2 attached to the outer periphery of the multilayer body E. The reinforcing members F1 and F2 are each sheet-like members extending along the inner periphery of the housing case 4. The reinforcing elements (F1, F2) are made of the same material as the fibrous sheets (E1, E2) constituting the multi-layer body (E), each at least an individual fibrous sheet constituting the multi-layer body (E). It is a thicker sheet-like member than E1, E2.

More specifically, the reinforcing members F1, F2 are respectively fibrous sheets thicker than the individual fibrous sheets E1, E2 constituting the multilayer body E, obtained by being impregnated with a coating material and then dried. and hardens through combustion. Accordingly, the reinforcing members F1 and F2 have high rigidity. The coating material is a liquid coating agent intended to be applied to the multilayer body (E) before combustion. The coating material is characterized in that it hardens when dried and burned.

Accordingly, the catalyst structure 2 according to this embodiment is composed of a multi-layer body E and reinforcing members F1 and F2, and has a shape defined by the inner periphery of the housing case 4 as a whole. It has a congruent prismatic shape (block shape with a rectangular cross section). The reinforcing members F1 and F2 are a plurality of sheet-like members extending along the outer peripheral surfaces of the prismatic catalyst structure 2. The front surfaces of the reinforcing members F1, F2 form the outer peripheral faces α, β of the prism.

Specifically, as shown in FIG. 7, the catalyst structure 2 according to this embodiment has a prismatic shape obtained by attaching a plurality of reinforcing members F1 and F2 to the outer periphery of the multilayer body E. It has a (block shape). The catalyst structure 2 has stacking direction end faces α (top and bottom faces in Fig. 7), and other end faces β (left and right faces in Fig. 7). The stacking direction end faces α are located at individual ends in the stacking direction G, on which the fibrous sheets (fibrous sheets E1, E2 constituting the multilayer body E) are stacked. there is. The prismatic catalyst structure 2 according to this embodiment has an oblong rectangular cross-section with long and short sides. The stacking direction end faces α extend along individual long sides of the rectangle, and the other end faces β extend along individual short sides of the rectangle.

As shown in FIG. 7, the catalyst structure 2 according to this embodiment has a cutout portion A provided on each of the end surfaces α in the stacking direction. The cutout portion A is provided at the center of each long side of the cross section (oblong rectangular shape) of the catalyst structure 2. In this embodiment, the cut portion A is a gap provided between adjacent reinforcing members F1. The size of the incision (A) varies depending on the shape and size of the catalyst structure (2). The incision (A) may be referred to as a slit.

Referring to Figure 10, the catalyst structure 2 is additionally provided with a fibrous sheet E3 wrapped over the outer surfaces of the reinforcement members F1 and F2. The fibrous sheet (E3) is made of the same material as the fibrous sheets (E1, E2) making up the multi-layer body (E), and the individual fibrous sheets (E1, E2) making up the multi-layer body (E). It is a thinner sheet-like member. The fibrous sheet E3 is wrapped over the reinforcing elements F1, F2, so that the reinforcing elements F1, F2 are fixed to the multilayer body E during the manufacturing process.

Referring to FIG. 11, the catalyst structure 2 having a fibrous sheet E3 wrapped around it as described above has a retaining member 5 provided on the outer surface of the fibrous sheet E3 added to its circumference. is wrapped with The holding member 5 is a sheet-like member made of alumina fibers. As shown in FIGS. 2 to 4, the holding member 5 is interposed between the catalyst structure 2 and the housing case 4, so the catalyst structure 2 is maintained within the housing case 4. there is.

More specifically, the holding member 5 is made of crystalline alumina fibers composed of Al ₂ O ₃ :SiO ₂ at a weight ratio of 72:28, which is a material that is difficult to experience thermal expansion. Referring to Figure 12, the holding member 5 according to this embodiment has two ends each having a crank-shaped outline, one of the two ends has end faces 5a, 5b, and the other has end faces 5a and 5b. The end has end faces 5c, 5d. When the holding member 5 is wrapped around the outer periphery of the catalyst structure 2, the end face 5a meets the end face 5c, while the end face 5b meets the end face 5d.

The housing case 4 is a pressed metal part adapted to accommodate the catalyst structure 2 and attachable to the exhaust gas flow path N1 (see Figure 14) provided in the woodstove W. Referring to FIG. 13, the housing case 4 has a housing space 4a to accommodate the catalyst structure 2, and folded portions 4b that reinforce the edges of the openings of the housing case 4. Specifically, the catalyst structure 2 has a prismatic shape that conforms to the shape defined by the inner periphery of the housing case 4. In this embodiment, the housing case 4 accommodates a plurality (two) of catalyst structures 2 arranged next to each other. The holding member 5 is wrapped over the outer periphery of each of the catalyst structures 2.

As described above, the housing case 4 according to the present embodiment has folds 4b that reinforce the edges of the openings of the housing case 4. The folds 4b prevent the holding member 5 from coming out. Specifically, as shown in FIG. 3, when the catalyst structure 2 is accommodated in the housing case 4, the holding member 5 has side walls of the holding member 5 facing each other and a folded portion ( In the state stopped by 4b), it is interposed between the catalyst structure 2 and the inner outer periphery of the housing case 4.

The metal catalyst 3 is in the form of metal particles (metal particles schematically shown and marked with reference numeral 3 in Figure 6) supported by the multilayer body E of the catalyst structure 2. there is. The metal catalyst 3 according to this embodiment contains silver (Ag) and palladium (Pd). On the other hand, the catalyst structure 2 (material for the fibrous sheets E1, E2) is composed of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ), and alumina (ZrO 2 ) for zirconia (ZrO ₂ ). The weight ratio of Al ₂ O ₃ ) is 60% to 90%.

The metal catalyst 3 according to this embodiment has a weight ratio of silver (Ag) to palladium (Pd) corresponding to 50% to 80%. The technical advantage of setting the weight ratio of silver (Ag) to palladium (Pd) (Ag ratio (%)) to 50% to 80% will be described below with reference to Table 1 and the graph shown in FIG. 20.

Catalyst structures 2 constitute two groups, namely: catalyst structures 2 composed of cerium (Ce) and zirconia (ZrO ₂ ) in different weight ratios of 5:5 and 8:2; and catalyst structures 2 composed of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) in different weight ratios of 5:5, 6:4, 7:3, 8:2 and 9:1; This is ready. Catalyst structures 2 composed of cerium (Ce) and zirconia (ZrO ₂ ) in weight ratios of 5:5 and 8:2 are 100% (silver only), 80%, 70%, 60%, 50%. It is made to support different types of metal catalysts (3) obtained by varying the weight ratio (Ag ratio) of silver (Ag) to palladium (Pd) among %, 20% and 0% (palladium only).

Likewise, the catalyst structures 2 composed of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ) at a weight ratio of 8:2 were 100% (silver only), 80%, 70%, 60%, 50%. It is made to support different types of metal catalysts 3 obtained by varying the weight ratio (Ag ratio) of silver (Ag) to palladium (Pd) among %, 20%, and 0% (palladium only). The catalyst structures 2 are individually heated, and the reaction-start temperatures (°C) (temperatures at which the individual metal catalysts 3 start to react to purify the exhaust gas) are measured. Table 1 summarizes the results.

Reaction-start temperature (℃) Ce:Zr Al:Zr Ag ratio (%) 5:5 8:2 5:5 6:4 7:3 8:2 9:1 100 370 405 360 338 340 367 320 80 354 406 382 345 343 331 323 70 328 368 335 341 328 320 60 325 365 333 332 318 321 50 336 398 334 20 374 421 345 0 402 430

The results, summarized in Table 1, are graphed as shown in Figure 20, with the horizontal axis showing the Ag ratio (%) and the vertical axis showing the reaction-start temperature (°C). am. The graph shows that those drawn in the area indicated by reference symbol (H) in FIG. 20 are marking a low reaction-onset temperature (°C) and a high level of purification performance. Specifically, the catalyst supports metal catalysts having weight ratios of silver (Ag) to palladium (Pd) of 50% to 80% and is composed of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ). The structure (2) displays high purification performance. In particular, the catalyst structure 2 with weight ratios of alumina (Al ₂ O ₃ ) to zirconia (ZrO ₂ ) corresponding to 60% to 90% displays particularly high purification performance and is therefore preferred.

Next, the method of manufacturing the wood stove exhaust gas purification device 1 according to this embodiment will be described with reference to the flow chart shown in FIG. 15.

The wood stove exhaust gas purification device 1 according to this embodiment includes the following steps, namely: a fibrous-sheet-forming step (S1), in which fibrous sheets are formed by a sheet-forming technique; Some of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) are each bent into a wavy shape and the bent wavy fibrous sheets are stacked with one on top of the other to form a multilayer body (E). a multilayer-body-forming step (S2); a reinforcing-member-forming step (S3), in which the remaining part of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) is coated with a coating material and burned to become reinforcing members (F1, F2); Reinforcement members (F1, F2) obtained in the reinforcement-member-forming step (S3) are attached to the outer periphery of the multilayer body (E) obtained in the multilayer-body-forming step (S2), and the multilayer Catalyst-structure-forming steps (S4 to S7) in which the body (E) is burned to become a catalyst structure (2) with the reinforcing members (F1, F2) attached thereto; and a supporting step (S8), in which the metal catalyst (3) is supported by the catalyst structure (2) obtained in the catalyst-structure-forming steps (S4 to S7).

The details are as follows. First, fibrous sheets are formed by a sheet-forming technique (fibrous-sheet-forming step (S1)). The sheet-forming technique applied in this example is a wet sheet-forming technique. For example, a predetermined amount of fibers containing alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ) and the like, and other related materials such as an inorganic binder, are introduced into a predetermined amount of water, thereby forming an aqueous solution. It is acquired. This solution is then made into a slurry in which the above-mentioned contents are evenly dispersed. The slurry is then made into flocs by adding a flocculant thereto. The flocks are then made into fibrous sheets (E1, E2) which are paper-like members.

In the fibrous-sheet forming step S1, in addition to the fibrous sheets E1, E2, the following are formed, namely: fibrous sheets thicker than the fibrous sheets E1, E2 (reinforcement members F1, F2)); and a fibrous sheet (E3) that is thinner than the fibrous sheets (E1, E2). The fibrous sheets E1 are bent and then combined with the fibrous sheets E2, thereby obtaining fibrous sheets each having a bent wave shape as shown in FIG. 5. Furthermore, the bent corrugated fibrous sheets are stacked one on top of the other to form the multilayer body E shown in Figure 6 (multilayer-body-forming step S2).

On the other hand, the fibrous sheets obtained in the fibrous-sheet forming step (S1) and thicker than the fibrous sheets (E1, E2) are impregnated with a coating material that is a liquid coating agent, and then form very rigid reinforcing members (F1, F2). It is dried to harden and fired (reinforcement-member-forming step (S3)). In the reinforcement-element forming step S3, negative pressure may for example be applied to the fibrous sheets while they are being impregnated with the coating material. Accordingly, the fibrous sheets, including their surfaces, are deeply impregnated with the coating material. The coating material is sticky and hardens when burned.

In this embodiment, referring to FIGS. 16 and 17, the reinforcing members (F1) obtained in the reinforcing-member-forming step (S3) are connected members (6) that are designed to disappear when burned in the burning step (S7). ) are connected in pairs. Since the connecting member 6 disappears when burned in the catalyst-structure-formation steps S4 to S7 (when burned in the combustion step S7), cut-outs A (see FIG. 7) are provided. there is. As shown in Figure 17, the connecting members 6 include a cut-out seal 6a adapted to be sandwiched between the end faces of the paired reinforcing members F1 which are positioned face to face; and a connecting seal 6b each adapted to be applied over the area comprising the cut-out seal 6a in the same way as connecting two adjacent reinforcing members F1 to each other. When going through the combustion step, the incision-forming seal 6a and the connection seal 6b disappear. Since the incision-forming seal 6a disappears, an incision A is provided.

Subsequently, as shown in Figure 7, reinforcing members F1, F2 are attached to the outer periphery of the multilayer body E. Furthermore, as shown in Figure 10, the fibrous sheet E3 is wrapped over the outer surface of the reinforcing members F1, F2 and is secured thereto. The entire resulting assembly is then dipped into the same coating material as used in S3, thereby impregnating the assembly with the coating material (assembly and full-coating step S4). Specifically, referring to FIG. 18, one of the pairs of reinforcing members F1 connected by the connecting member 6 is positioned as the bottom surface, and the reinforcing members F2 are positioned as two of the connected reinforcing members F1. A predetermined number of layers composed of fibrous sheets (E1, E2), each having a curved corrugated shape, arranged at the ends of each layer, form a multi-layer body in the space defined by the reinforcing members (F1, F2). They are stacked so that one is on top of the other.

After the multi-layer body E has been obtained as above, the remaining pair of reinforcing members F1, connected by connecting members 6, are attached to the top face of the multi-layer body E. Accordingly, a multi-layer body E is obtained with reinforcing members F1 and F2 attached thereto, as shown in Fig. 7. Thereafter, the fibrous sheet E3 is wrapped over the outer periphery of the multilayer body E and secured thereto. Furthermore, the resulting multilayer body E is dipped into the coating material so as to be impregnated with the coating material. Accordingly, the assembly and full-coating step (S4) is performed.

Afterwards, the multilayer body (E) impregnated with the coating material undergoes a drying step (S5) and a degreasing step (S6) (low-temperature heating step), and then the multilayer body (E) is formed into a cured catalyst structure (2). It is burned at a predetermined temperature (burned by high-temperature heating). The assembly and full-coating step (S4), the drying step (S5), the degreasing step (S6) and the combustion step (S7) are included in the catalyst-structure-forming step according to the invention.

Subsequently, silver (Ag) and palladium (Pd) used as the metal catalyst 3 are supported by the catalyst structure 2 obtained in the above combustion step (S7). Afterwards, the catalyst structure 2 is impregnated with the coating material again, and undergoes drying the same as the drying step S5, degreasing the same as the degreasing step S6, and combustion the same as the combustion step S7. Accordingly, the catalyst structure 2 supporting the metal catalyst 3 is obtained (supporting step S8). Thereafter, the holding member 5 is wrapped over and attached to the outer periphery of the catalyst structure 2 obtained as above (holding-member-attaching step (S9)). Furthermore, the catalyst structure 2 surrounded by the holding member 5 is placed into the housing case 4 to be assembled therewith. Accordingly, the wood stove exhaust gas purification device 1 is obtained (assembly step S10). In the assembly step (S10), the holding member 5 is interposed between the catalyst structure 2 and the housing case 4, so that the catalyst structure 2 is maintained within the housing case 4.

According to this embodiment, the metal catalyst 3 contains silver (Ag) and palladium (Pd). Inexpensive silver (Ag) replaces expensive precious metals such as platinum (Pt). The use of these metal catalysts containing inexpensive metals not only reduces manufacturing costs but also lowers the reaction-onset temperature of the metal catalyst (3).

According to this embodiment, the catalyst structure 2 is composed of alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ), and the metal catalyst 3 supported by the catalyst structure 2 is 50% to 80%. It has a weight ratio of silver (Ag) to palladium (Pd) corresponding to . Accordingly, the reaction-start temperature of the metal catalyst 3 is lowered, while improved purification performance is achieved. In particular, if the catalyst structure (2) has a weight ratio of alumina (Al ₂ O ₃ ) to zirconia (ZrO ₂ ) of 60% to 90%, the improvement in purification performance is achieved by further improving the metal catalyst (3). This is achieved with a lowered reaction-start temperature.

According to this embodiment, the catalyst structure 2 includes a multi-layer body E obtained by stacking a plurality of layers made of fibrous sheets E1 and E2, each having a curved wave shape. Accordingly, weight reduction of the catalyst structure 2 is achieved while the level of purification performance is maintained. According to this embodiment, the exhaust gas purification device 1 is attachable to the exhaust gas flow path N1 of the woodstove W in such a way as to conform to the exhaust gas flow path N1. Accordingly, occurrence of exhaust gas leakage is prevented. Accordingly, effective purification of exhaust gas is achieved.

This embodiment includes the following steps: a fibrous-sheet-forming step (S1) of forming fibrous sheets by a sheet-forming technique; A multilayer body (E), in which some of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked with one on top of the other. A multilayer-body-forming step (S2) of forming a; Catalyst-structure-forming steps (S4 to S7) of forming the catalyst structure (2), in which the multi-layer body (E) obtained in the multilayer-body-forming step (S2) is burned; and a support step (S8) in which silver (Ag) and palladium (Pd) used as the metal catalyst (3) are supported by the catalyst structure (2) obtained in the catalyst-structure-formation steps (S4 to S7). do. Accordingly, reduction of manufacturing costs and lowering of the reaction-start temperature of the metal catalyst 3 are achieved, while smooth manufacturing of a lightweight exhaust gas purification device is achieved.

According to this embodiment, the catalyst structure 2 is a multilayer structure obtained by stacking a plurality of layers made of fibrous sheets E1 and E2, each having a curved wave shape, with one on top of the other. It includes a layer body (E). Moreover, reinforcing members F1, F2 are provided on the outer periphery of the multi-layer body E in such a way that they extend along the inner periphery of the housing case 4. Accordingly, weight reduction of the catalyst structure 2 is achieved, while deformation of the multi-layer body E that may occur during the manufacturing process is prevented, so that any material between the catalyst structure 2 and the housing case 4 is prevented. The occurrence of gaps is suppressed.

The catalyst structure 2 has a prismatic shape that conforms to the shape defined by the inner periphery of the housing case 4, and the reinforcing members F1 and F2 extend along the outer peripheral surfaces of the prismatic catalyst structure 2. There are multiple sheet-like members. Accordingly, even if the housing case 4 has a rectangular shape (such as an oblong rectangle) that conforms to the shape of the exhaust gas flow path N1, the catalyst structure 2 conforms to the inner circumference of the housing case 4. It is accommodated in the housing case 4 in this way.

The reinforcing members (F1, F2) are made of the same material as the fibrous sheets (E1, E2) that make up the multi-layer body (E), and are each individual fibrous sheets that make up the multi-layer body (E). It is a sheet-like member at least thicker than (E1, E2). Accordingly, fibrous sheets with different thicknesses are utilized to obtain both the multilayer body E and the reinforcing elements F1, F2. Moreover, the use of reinforcing members F1, F2 with greater thickness and higher rigidity reliably prevents deformation of the multi-layer body E that may occur during the manufacturing process.

The exhaust gas purification device 1 is attached to a wood stove W, which is capable of dissipating heat while firewood is burning internally and exhaust gas generated by burning firewood can be discharged to the outside. Accordingly, the exhaust gas discharged from the wood stove (W) is reliably purified.

This embodiment includes the following steps: a fibrous-sheet-forming step (S1) of forming fibrous sheets by a sheet-forming technique; A multi-layered body (E) in which some of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked with one on top of the other. A multilayer-body-forming step (S2) of forming a; The remaining part of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) is subjected to a reinforcing-member-forming step (S3) where a coating material is applied and burned to form reinforcing members (F1, F2); The reinforcing members (F1, F2) obtained in the reinforcing-member-forming step (S3) are attached to the outer periphery of the multilayer body (E) obtained in the multilayer-body-forming step (S2) and the multilayer Catalyst-structure-forming steps (S4 to S7) of forming a catalyst structure 2, wherein the body E is burned with the reinforcing members F1 and F2 attached thereto; and a supporting step (S8) in which the metal catalyst (3) is supported by the catalyst structure (2) obtained in the catalyst-structure-forming steps (S4 to S7). Accordingly, deformation of the multi-layer body E that may occur during the manufacturing process is reliably prevented, while smooth manufacturing of the lightweight exhaust gas purification device 1 is achieved.

The catalyst structure 2 has a multi-layer body E obtained by stacking a plurality of layers made of fibrous sheets E1 and E2, each having a curved wave shape, with one on top of the other. Includes. Moreover, the catalyst structure 2 has a prismatic shape conforming to the shape defined by the inner circumference of the housing case 4, and, among the prismatic outer circumferential surfaces, the fibrous sheets E1 and E2 are stacked. It has at least an incision (A) in each of the stacking direction end faces (α) located at the respective ends in the direction (G). Accordingly, weight reduction of the catalyst structure 2 is achieved, while the occurrence of any cracks that may occur in the prismatic catalyst structure 2 is suppressed.

The catalyst structure 2 has an oblong rectangular cross-section with long and short sides. Moreover, the stacking direction end faces α extend along individual long sides of the rectangle. Accordingly, the number of layers made up of fibrous sheets E1, E2 in the multilayer body E is reduced. Accordingly, the ease of operation in the manufacturing process increases. Additionally, an incision A is provided at the center of each of the long sides. This configuration more effectively suppresses the occurrence of any cracks within the multi-layer body E, which has a rectangular cross-section with long and short sides.

The reinforcing members F1, F2 are provided on the outer circumference of the multi-layer body E in such a way that they extend along the inner circumference of the housing case 4, and the cut-outs are between the reinforcing members F1. is provided in. Accordingly, the reinforcing members (F1, F2) prevent deformation of the multi-layer body (E) that may occur during the manufacturing process, while the incisions (A) provided between the reinforcing members (F1) prevent cracking. suppress the occurrence.

In addition, the reinforcing members F1 and F2 are a plurality of sheet-like members extending along the outer peripheral surfaces of the prismatic catalyst structure 2, and the incisions A are located on the end faces α in the stacking direction. It is provided between the sheet-like members. Therefore, even if the housing case 4 has a rectangular shape (such as an oblong rectangle) that conforms to the shape of the exhaust gas flow path N1, the catalyst structure 2 has a shape conforming to the inner circumference of the housing case 4. It is accommodated in the housing case 4 in this way. Moreover, the cut portions A provided between the reinforcing members F1 suppress the occurrence of cracking.

This embodiment includes the following steps: a fibrous-sheet-forming step (S1) of forming fibrous sheets by a sheet-forming technique; A multi-layered body (E) in which some of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked with one on top of the other. A multilayer-body-forming step (S2) of forming a; The remaining part of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) is subjected to a reinforcing-member-forming step (S3) where a coating material is applied and burned to form reinforcing members (F1, F2); The reinforcing members (F1, F2) obtained in the reinforcing-member-forming step (S3) are attached to the outer periphery of the multilayer body (E) obtained in the multilayer-body-forming step (S2) and the multilayer Catalyst-structure-forming steps (S4 to S7) of forming a catalyst structure 2, wherein the body E is burned with the reinforcing members F1 and F2 attached thereto; and a supporting step (S8) in which the metal catalyst (3) is supported by the catalyst structure (2) obtained in the catalyst-structure-forming steps (S4 to S7). Accordingly, the occurrence of cracking is suppressed during the combustion step (S7). Moreover, deformation of the multi-layer body E is reliably prevented, while smooth manufacturing of the lightweight exhaust gas purification device 1 is achieved.

The reinforcing members F1 obtained in the reinforcing-member-forming step S3 are connected in pairs by connecting members 6 which are designed to disappear when burned. When the connecting member 6 is destroyed by combustion in the catalyst-structure-formation step (combustion step S7), incisions A are provided. Since the reinforcing members F1 are temporarily connected by the connecting members 6, the ease of operation in the manufacturing process is increased. Moreover, since the connecting members 6 disappear when burned, the provision of the incision A is easily and reliably achieved.

In the catalyst-structure generation steps (S4 to S7), the reinforcing members (F1, F2) obtained in the reinforcing member-forming step (S3) are combined with the multilayer body (E) obtained in the multilayer-body-forming step (S2). ), the fibrous sheet E3 obtained in the fibrous-sheet-forming step S1 is wrapped over and fixed to the outer surfaces of the reinforcing members F1, F2, and The multilayer body (E) is burned with the reinforcing members (F1, F2) and the fibrous sheet (E3) fixed. Accordingly, the ease of operation in the pre-combustion manufacturing process is further increased.

In this embodiment, the holding member is a sheet-like member made of alumina fibers and interposed between the catalyst structure 2 and the housing case 4 so that the catalyst structure 2 is held within the housing case 4. (5) is adopted. Moreover, the housing case 4 has bends 4b that reinforce the edges of the openings of the housing case 4. The folds 4b prevent the holding member 5 from coming out. This configuration prevents deformation of the folded portions 4b that may be caused by the retaining member 5 undergoing thermal expansion. Accordingly, the folded portions 4b are maintained so as to perform the function of reinforcing the housing case 4 and preventing the holding member 5 from coming out.

The catalyst structure 2 is one of a plurality of catalyst structures 2 (two in this embodiment) arranged right next to each other in the housing case 4. Each of the catalyst structures 2 is provided with a holding member 5 wrapped around its outer periphery. This configuration prevents deformation or damage to the catalyst structures 2, which are housed next to each other in the housing case 4, which may be caused by the holding members 5 experiencing thermal expansion while pushing against each other. .

This embodiment includes the following steps: a fibrous-sheet-forming step (S1) of forming fibrous sheets by a sheet-forming technique; A multi-layered body (E) in which some of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) are each bent into a corrugated shape and the bent corrugated fibrous sheets are stacked with one on top of the other. A multilayer-body-forming step (S2) of forming a; The remaining part of the fibrous sheets obtained in the fibrous-sheet-forming step (S1) is subjected to a reinforcing-member-forming step (S3) where a coating material is applied and burned to form reinforcing members (F1, F2); The reinforcing members (F1, F2) obtained in the reinforcing-member-forming step (S3) are attached to the outer periphery of the multilayer body (E) obtained in the multilayer-body-forming step (S2) and the multilayer Catalyst-structure-forming steps (S4 to S7) of forming a catalyst structure 2, wherein the body E is burned with the reinforcing members F1 and F2 attached thereto; a supporting step (S8) allowing the metal catalyst (3) to be supported by the catalyst structure (2) obtained in the catalyst-structure-forming steps (S4 to S7); and an assembly step (S10) of interposing the holding member 5 between the catalyst structure 2 and the housing case 4 so that the catalyst structure 2 is maintained within the housing case 4. Accordingly, the side walls of the holding member 5 are reliably made to face the folded portions 4b of the housing case 4. This configuration prevents deformation of the folded portions 4b that may be caused by the retaining member 5 undergoing thermal expansion. Moreover, smooth manufacturing of the lightweight exhaust gas purification device 1 is achieved.

Although this embodiment is described above, the invention is not limited thereto. For example, another metal catalyst could be supported, the incision A could be omitted, or the retaining member 5 could be made of another material. Moreover, the application of the present invention is not limited to the wood stove W, but may be any other device that emits exhaust gas. Moreover, the cross-sectional shape of the catalyst structure 2 is not limited to a rectangular prism shape, but may be a round cylinder shape or other shapes.

The present invention is applicable to any exhaust gas purification device having a different appearance, additional functions or the like, wherein the exhaust gas purification device is a multi-layer body obtained by laminating a plurality of fibrous sheets each having a curved wave shape. and so long as the reinforcing member is provided on the outer periphery of the multilayer body in such a way as to extend along the inner periphery of the housing case.

1 Exhaust gas purification device
2 Catalyst structure
3 metal catalyst
4 housing case
4a housing space
4b bend
5 absence of maintenance
6 connection member
6a Incision-Formation Seal
6b connection seal
W Wood Stove
W1 metal body
W2 combustion chamber
w3 chimney
N1 exhaust gas flow path
N2 exhaust gas flow path
B damper
M Harmony
D front door
E Multi-layer body
E1 fiber sheet
E2 fiber sheet
E3 fiber sheet
F1 reinforcement member
F2 reinforcement member
A incision
α stacking direction end face
β Other end faces
G stacking direction

Claims (7)

a catalyst structure configured to allow exhaust gases to circulate;
a metal catalyst supported by the catalyst structure and capable of purifying exhaust gas by reacting with the exhaust gas flowing through the catalyst structure; and
a housing case accommodating the catalyst structure and attachable to an exhaust gas flow path through which exhaust gas flows;
In the exhaust gas purification device comprising,
The catalyst structure includes a multi-layer body obtained by stacking a plurality of fibrous sheets each having a curved wave shape, one on top of another,
An exhaust gas purification device, characterized in that a reinforcing member is provided on the outer circumference of the multi-layer body in such a way that it extends along the inner circumference of the housing case. According to claim 1,
The catalyst structure has a prismatic shape that conforms to the shape defined by the inner periphery of the housing case,
The exhaust gas purification device, wherein the reinforcing member includes a plurality of sheet-like members extending along outer peripheral surfaces of the prismatic catalyst structure. The method of claim 1 or 2,
wherein the reinforcing member is a sheet-like member made of the same material as the fibrous sheets making up the multi-layer body and at least thicker than the individual fibrous sheets making up the multi-layer body. Gas purification device. The method according to any one of claims 1 to 3,
The exhaust gas purification device is attached to a wood stove, capable of dissipating heat while the firewood is burning internally and discharging the exhaust gas generated by burning the firewood to the outside. Device. A method of manufacturing an exhaust gas purification device, the device comprising:
a catalyst structure configured to allow exhaust gases to circulate;
a metal catalyst supported by the catalyst structure and capable of purifying exhaust gas by reacting with the exhaust gas flowing through the catalyst structure; and
a housing case accommodating the catalyst structure and attachable to an exhaust gas flow path through which exhaust gas flows;
Including,
The catalyst structure is formed by stacking a plurality of fibrous sheets, each having a curved wave shape, with one on top of the other to form a multi-layer body, and extending along the inner periphery of the housing case. A method of manufacturing an exhaust gas purification device, characterized in that obtained by placing a reinforcing member on the outer periphery of a multi-layer body. According to claim 5,
A fibrous-sheet-forming step of forming fibrous sheets using a sheet-forming technique;
wherein some of the fibrous sheets obtained in the fibrous-sheet-forming step are each bent into a wavy shape and the bent corrugated fibrous sheets are stacked with one on top of the other, forming the multi-layer body. multilayer-body-forming step;
A reinforcing-member-forming step of forming the reinforcing member, wherein one of the fibrous sheets obtained in the fibrous-sheet-forming step is coated with a coating material and burned;
The reinforcing member obtained in the reinforcing-member-forming step is attached to the outer periphery of the multilayer body obtained in the multilayer-body-forming step, and the multilayer body is in a state with the reinforcing member attached. A catalyst-structure-forming step of forming the catalyst structure, which is burned in; and
a supporting step of allowing the metal catalyst to be supported by the catalyst structure obtained in the catalyst-structure-forming step;
A method of manufacturing an exhaust gas purification device comprising: According to claim 6,
In the catalyst-structure-forming step, the reinforcing member obtained in the reinforcing-member-forming step is attached to the outer periphery of the multilayer body obtained in the multilayer-body-forming step, and the fibrous-sheet - one of the fibrous sheets obtained in the forming step is wrapped over the outer surface of the reinforcing member and fixed thereto, and the multi-layer body is burned while the reinforcing member and the fibrous sheet are fixed. Method for manufacturing an exhaust gas purification device characterized by: