JP7445464B2 - Filter manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a filter provided in a vehicle exhaust pipe.

Vehicles are equipped with a DPF (Diesel Particulate Filter) or a GPF (Gasoline Particulate Filter) in order to remove particulate matter such as soot and oil-derived ash contained in exhaust gas. A wall flow type filter having a plurality of cells partitioned by a filter wall is used as the DPF or GPF.

We also have a technology that removes hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) contained in exhaust gas by forming a three-way catalyst on the filter wall of a wall-flow type filter. has been developed (for example, Patent Document 1).

Japanese Patent Application Publication No. 2010-221155

However, in the technique of Patent Document 1, since the filter wall is coated with a layer of catalyst, there is a problem that the pores of the filter wall are blocked by the layer of catalyst, resulting in an increase in pressure loss.

Therefore, it is conceivable to support the catalyst inside a plurality of holes penetrating the filter wall. However, in this case, the exhaust gas purification efficiency is lower than that in a configuration in which a catalyst layer is formed on the filter wall.

In view of such problems, an object of the present invention is to provide a method for manufacturing a filter that can suppress an increase in pressure loss while maintaining exhaust gas purification efficiency.

In order to solve the above problems, the method for manufacturing a filter of the present invention is a method for manufacturing a filter used as a GPF or a DPF, which comprises at least one cell in a wall flow type carrier having a plurality of cells partitioned by filter walls. A step of adhering a catalyst slurry containing at least a catalyst metal and water to the surface of a filter wall constituting a cell, a step of adhering water-absorbing polymer particles to the surface of the catalyst slurry, and a step of adhering water-absorbing polymer particles to the surface of the catalyst slurry, a step of expanding the particles to a size where some of the particles come into contact with the surface of the filter wall ; a step of firing the carrier to which the catalyst slurry and the particles are attached;
including.

The carrier also includes a first sealing portion that seals an opening at one end of a cell classified into the first cell group among the plurality of cells, and a first sealing portion adjacent to a cell of the first cell group among the plurality of cells. and a second sealing part that seals the opening on the other end side of the cells classified into the second cell group, and the step of applying the catalyst slurry includes applying the catalyst slurry to the cells classified into the first cell group. It may also include a step of supplying.

Further, the step of applying the catalyst slurry may include a step of supplying the catalyst slurry to cells classified into the second cell group.

The carrier also includes a first sealing portion that seals an opening at one end of a cell classified into the first cell group among the plurality of cells, and a first sealing portion adjacent to a cell of the first cell group among the plurality of cells. and a second sealing part that seals the opening on the other end side of the cell classified into the second cell group, and the surface of the filter wall constituting the cell classified into the first cell group contains hydrocarbons. a step of attaching an adsorbent slurry containing at least an adsorbent and water; a step of adhering particles to the surface of the adsorbent slurry; The step of adhering the catalyst slurry is to supply the catalyst slurry to the cells classified into the second cell group, and the step of firing the catalyst slurry, the adsorbent slurry, and The carrier to which the particles are attached may be fired.

According to the present invention, it is possible to suppress an increase in pressure loss while maintaining exhaust gas purification efficiency.

FIG. 1 is a schematic diagram showing the configuration of an engine system according to a first embodiment. 3 is a flowchart showing the process flow of the filter manufacturing method according to the first embodiment. It is a figure explaining a carrier. It is a figure explaining the 1st catalyst slurry adhesion process and the 1st particle adhesion process concerning 1st Embodiment. FIG. 3 is a diagram illustrating the inside of a cell during a first catalyst slurry attachment step, a first particle attachment step, a second catalyst slurry attachment step, a second particle attachment step, an expansion step, and a firing step according to the first embodiment. 7 is a flowchart showing the process flow of the filter manufacturing method according to the second embodiment. It is a figure explaining the adsorbent slurry attachment process and the 3rd particle attachment process concerning 2nd Embodiment. It is a figure explaining the inside of a cell of an adsorbent slurry adhesion process, a 3rd particle adhesion process, a 2nd catalyst slurry adhesion process, a 2nd particle adhesion process, an expansion process, and a calcination process concerning a 2nd embodiment. It is a figure explaining the inside of a cell after performing the particle adhesion process concerning a modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

[First embodiment]
FIG. 1 is a schematic diagram showing the configuration of an engine system 100 according to the first embodiment. Engine system 100 is mounted on a vehicle. As shown in FIG. 1, engine system 100 includes an engine 110, an exhaust pipe 120, a catalyst 130, a filter 140, and a muffler 150.

Engine 110 is, for example, a gasoline engine. The engine 110 drives the vehicle using kinetic energy obtained by burning fuel. An exhaust pipe 120 is connected to an exhaust port of the engine 110 via an exhaust manifold. Exhaust gas exhausted from the exhaust port of engine 110 is guided to exhaust pipe 120.

A catalyst 130 is provided in the exhaust pipe 120. The catalyst 130 is a three-way catalyst (TWC). The catalyst 130 purifies (removes) hydrocarbons, carbon monoxide, and nitrogen oxides contained in the exhaust gas. Catalyst 130 includes a catalytic metal. The catalytic metal is one or more of platinum (Pt), palladium (Pd), and rhodium (Rh).

Filter 140 is provided downstream of catalyst 130 in exhaust pipe 120. In other words, the filter 140 is provided between the catalyst 130 and the muffler 150 in the exhaust pipe 120. Filter 140 is a GPF (Gasoline Particulate Filter). Filter 140 captures particulate matter (PM) contained in exhaust gas. The filter 140 has a catalyst supported on a wall flow type carrier.

The exhaust gas that has been purified by the catalyst 130 and has particulate matter removed by the filter 140 is exhausted to the outside through the muffler 150.

[Method for manufacturing filter 140]
Next, a method for manufacturing the filter 140 will be explained. FIG. 2 is a flowchart showing the process flow of the method for manufacturing the filter 140 according to the first embodiment. As shown in FIG. 2, the method for manufacturing the filter 140 according to the first embodiment includes a first catalyst slurry adhesion step S110, a first particle adhesion step S120, a second catalyst slurry adhesion step S130, and a second particle adhesion step S120. It includes an adhesion step S140, an expansion step S150, a drying step S160, and a firing step S170. Each step will be explained below.

[First catalyst slurry adhesion step S110]
The first catalyst slurry adhesion step S110 is a step of manufacturing a slurry adhesion carrier 250 by adhering catalyst slurry to a wall-flow type carrier. The catalyst slurry includes a catalyst metal, a binder, a base material, and water.

FIG. 3 is a diagram illustrating the carrier 160. FIG. 3(a) shows a perspective view of the carrier 160. FIG. 3(b) shows a front view of the carrier 160. FIG. 3(c) shows a YZ cross-sectional view of FIG. 3(a). Note that in FIG. 3(c), arrows indicate the flow of exhaust gas. Further, in FIG. 3 according to this embodiment, the X-axis, Y-axis, and Z-axis that intersect perpendicularly are defined as shown. In addition, in FIG. 3(c), the outer cylinder 162, the first sealing part 166, and the second sealing part 168 are shown filled in black for easy understanding.

As shown in FIG. 3(a), the carrier 160 is of a wall flow type. The carrier 160 includes an outer cylinder 162, a filter wall 164, a first sealing part 166, and a second sealing part 168. The outer cylinder 162 is a cylindrical member.

Filter wall 164 has a plurality of holes. As shown in FIG. 3(b), the filter wall 164 includes a first wall 164a and a second wall 164b. The first wall 164a is provided on the XY plane and extends in the Y-axis direction in FIGS. 3(a) to 3(c). The second wall 164b is provided on the YZ plane and extends in the Y-axis direction in FIGS. 3(a) to 3(c). As shown in FIG. 3(b), a space surrounded by two first walls 164a and two second walls 164b, or a space surrounded by first walls 164a, second walls 164b, and outer cylinder 162. is formed as a cell 170.

Therefore, the plurality of cells 170 extend in the axial direction (the Y-axis direction in FIG. 3) within the outer cylinder 162, and in the directions perpendicular to the axial direction (the X-axis direction and the Z-axis direction in FIG. 3). are formed in parallel. Note that the number of cells 170 is not limited.

As shown in FIG. 3C, the first sealing part 166 seals an opening at one end side 160a of a cell 170A classified into the first cell group among the plurality of cells 170. The second sealing portion 168 seals an opening on the other end side 160b of a cell 170B classified into the second cell group adjacent to the cell 170A of the first cell group. Cells 170A and cells 170B are arranged alternately.

When the filter 140 is installed in the exhaust pipe 120, the other end side 160b (the left side in FIG. 3(c)) of the carrier 160 is placed on the upstream side in the flow direction of exhaust gas, and the one end side 160a (the left side in FIG. 3(c)) is placed on the upstream side in the flow direction of exhaust gas. ) middle and right side) are arranged on the downstream side in the flow direction of exhaust gas. In other words, in the filter 140 (carrier 160), the second sealing part 168 is arranged on the upstream side in the flow direction of exhaust gas, and the first sealing part 166 is arranged on the downstream side in the flow direction of exhaust gas. . Therefore, the exhaust gas that has reached the filter 140 (carrier 160) is introduced into the cell 170A, passes through the filter wall 164 that partitions the cell 170A, and is introduced into the cell 170B. That is, the exhaust gas that has passed through the cell 170A is introduced into the cell 170B. Then, the exhaust gas introduced into the cell 170B is guided to the muffler 150 (see FIG. 1) through the opening at one end side 160a of the cell 170B.

FIG. 4 is a diagram illustrating the first catalyst slurry adhesion step S110 and the first particle adhesion step S120 according to the first embodiment. FIG. 4A is a diagram illustrating the first catalyst slurry deposition step S110. FIG. 4(b) is a diagram illustrating the first particle attachment step S120.

As shown in FIG. 4A, in the first catalyst slurry adhesion step S110, the catalyst slurry is applied to the surface of the filter wall 164 constituting the cell 170A of the carrier 160 using the supply device 210. The supply device 210 includes a guide cylinder 212, a slurry supply section 220, a suction section 230, and a particle supply section 240 (see FIG. 4(b)).

The guide tube 212 is a cylindrical member. The guide tube 212 is fitted into the end of the carrier 160. The inner diameter of the guide tube 212 is slightly larger than the outer diameter of the carrier 160 (outer tube 162). The guide tube 212 is formed in such a size that no gap is created between the guide tube 212 and the carrier 160 when the guide tube 212 is fitted onto the carrier 160 .

The slurry supply unit 220 supplies catalyst slurry to the carrier 160 (cell 170) via the guide cylinder 212. In this embodiment, the slurry supply section 220 includes a catalyst storage section 222, a slurry supply pipe 224, a slurry supply pump 226, and a slurry nozzle 228.

The catalyst storage section 222 stores catalyst slurry. Slurry supply pipe 224 connects catalyst storage section 222 and the suction side of slurry supply pump 226 . A suction side of the slurry supply pump 226 is connected to the catalyst storage section 222 via a slurry supply pipe 224 . The slurry supply pump 226 is connected to the slurry nozzle 228 at its discharge side. Slurry nozzle 228 is connected to guide tube 212. Slurry supply pump 226 sucks the catalyst slurry stored in catalyst storage section 222 and injects it toward carrier 160 from slurry nozzle 228 .

The suction unit 230 sucks the catalyst slurry from the end of the carrier 160. In this embodiment, the suction unit 230 includes a suction cylinder 232, a suction tube 234, and a suction pump 236.

The suction tube 232 is a cylindrical member. The suction tube 232 is open at one end and sealed at the other end. The opening of the suction tube 232 is fitted into the end of the carrier 160. The opening of the suction tube 232 is slightly larger than the outer diameter of the carrier 160. The suction cylinder 232 is formed in such a size that there is no gap between the suction cylinder 232 and the carrier 160 when the suction cylinder 232 is fitted onto the carrier 160 .

Suction pipe 234 connects suction cylinder 232 and suction pump 236. The suction side of the suction pump 236 is connected to the suction cylinder 232 via the suction pipe 234 . The suction pump 236 has a discharge side connected to the outside (for example, the catalyst storage section 222).

In the first catalyst slurry adhesion step S110, the guide cylinder 212 is fitted to the other end side 160b of the carrier 160, and the suction cylinder 232 is fitted to the one end side 160a. Furthermore, a slurry nozzle 228 is connected to the guide tube 212 . Then, the slurry supply pump 226 and the suction pump 236 are driven, and the carrier 160 is rotated by a rotating device (not shown) (indicated by a broken arrow in FIG. 4(a)). As a result, the catalyst slurry is evenly supplied to the cells 170A of the carrier 160. Note that the other end side 160b of the cell 170B of the carrier 160 is sealed by a second sealing part 168. Therefore, even if the first catalyst slurry adhesion step S110 is executed, the catalyst slurry is not supplied to the cells 170B.

FIG. 5 shows a first catalyst slurry attachment step S110, a first particle attachment step S120, a second catalyst slurry attachment step S130, a second particle attachment step S140, an expansion step S150, and a firing step S170 according to the first embodiment. FIG. 2 is a diagram illustrating the inside of cells 170A and 170B. FIG. 5A is a diagram illustrating the inside of the cells 170A and 170B after performing the first catalyst slurry deposition step S110. FIG. 5(b) is a diagram illustrating the inside of the cells 170A and 170B after performing the first particle attachment step S120. FIG. 5(c) is a diagram illustrating the inside of the cells 170A and 170B after performing the second catalyst slurry deposition step S130. FIG. 5D is a diagram illustrating the inside of the cells 170A and 170B after performing the second particle attachment step S140. FIG. 5E is a diagram illustrating the inside of the cells 170A and 170B after performing the expansion step S150. FIG. 5F is a diagram illustrating the inside of the cells 170A and 170B after performing the firing step S170.

By performing the first catalyst slurry adhesion step S110, the catalyst slurry is supplied to each cell 170A of the carrier 160, and as shown in FIG. A layer (catalyst slurry layer SL) is formed.

Then, when the thickness of the catalyst slurry layer SL (height from the surface of the filter wall 164 to the surface of the catalyst slurry layer SL) reaches a predetermined thickness, the slurry supply pump 226 and the suction pump 236 are stopped. In this way, the slurry adhesion carrier 250 is manufactured, in which the catalyst slurry layer SL is formed on the surface of the filter wall 164 constituting the cell 170A.

[First particle attachment step S120]
The first particle attachment step S120 is a step in which superabsorbent polymer particles (hereinafter referred to as "water-absorbing particles") are attached to the surface of the catalyst slurry layer SL of the slurry attachment carrier 250. Water-absorbing polymers are also called super-absorbent polymers, super-absorbent resins, and polymer absorbers. The water-absorbing polymer is, for example, sodium polyacrylate.

Returning to FIG. 4, as shown in FIG. 4(b), in this embodiment, in the first particle adhesion step S120, a plurality of water-absorbing particles are placed in the cells 170A of the slurry adhesion carrier 250 using the supply device 210. Supply (fill).

The particle supply unit 240 supplies water-absorbing particles to the slurry adhesion carrier 250 (carrier 160) via the guide tube 212. In this embodiment, the particle supply section 240 includes a water-absorbing particle storage section 242, a water-absorbing particle supply pipe 244, a feeder 246, and a water-absorbing particle nozzle 248.

The water-absorbing particle storage section 242 stores water-absorbing particles. The water-absorbing particle supply pipe 244 connects the water-absorbing particle storage section 242 and the inlet of the feeder 246. The feeder 246 has an inlet connected to the water-absorbing particle storage section 242 via the water-absorbing particle supply pipe 244 . The feeder 246 has an outlet connected to a water-absorbing particle nozzle 248 . The feeder 246 is, for example, a screw feeder. The water-absorbing particle nozzle 248 is connected to the guide tube 212. The feeder 246 supplies the water-absorbing particles stored in the water-absorbing particle storage section 242 to the slurry adhering carrier 250 through the water-absorbing particle nozzle 248.

In the first particle attachment step S120, first, the slurry nozzle 228 is removed from the guide tube 212. Subsequently, instead of the slurry nozzle 228, a water-absorbing particle nozzle 248 is connected to the guide tube 212.

Then, the feeder 246 is driven, and the slurry adhesion carrier 250 is rotated by a rotating device (not shown) (indicated by a broken line arrow in FIG. 4(b)). As a result, the cells 170A of the slurry adhesion carrier 250 are evenly filled with water-absorbing particles. Note that in the first particle adhesion step S120 of this embodiment, the suction pump 236 is stopped.

By performing the first particle attachment step S120, the cells 170A are filled with water-absorbing particles R, and as shown in FIG. 5(b), the water-absorbing particles R are attached to the surface of the catalyst slurry layer SL. In this way, a particle-attached carrier 252 in which water-absorbing particles R are attached to the surface of the catalyst slurry layer SL of the slurry-attached carrier 250 is manufactured.

[Second catalyst slurry adhesion step S130]
The second catalyst slurry adhesion step S130 is a step of manufacturing the slurry adhesion carrier 254 by adhering the catalyst slurry to the surface of the filter wall 164 constituting the cell 170B of the particle adhesion carrier 252 using the supply device 210.

In the second catalyst slurry adhesion step S130, the water-absorbing particle nozzle 248 is first removed from the guide tube 212. Subsequently, the guide tube 212 and the suction tube 232 are removed from the particle adhesion carrier 252. Then, the guide cylinder 212 is fitted to one end side 160a of the particle adhesion carrier 252, and the suction cylinder 232 is fitted to the other end side 160b. That is, the particle adhesion carrier 252 is moved upside down, and the guide tube 212 and the suction tube 232 are fitted together. Subsequently, the slurry nozzle 228 is connected to the guide cylinder 212, the slurry supply pump 226 and the suction pump 236 are driven, and the particle adhesion carrier 252 is rotated by a rotation device (not shown). As a result, the catalyst slurry is evenly supplied to the cells 170B of the particle-attached carrier 252. Note that one end side 160a of the cell 170A of the particle adhesion carrier 252 is sealed by a first sealing portion 166. Therefore, even if the second catalyst slurry adhesion step S130 is performed, the catalyst slurry is not supplied to the cell 170A.

By executing the second catalyst slurry adhesion step S130, the catalyst slurry is supplied to each cell 170B of the carrier 160, and as shown in FIG. A layer (catalyst slurry layer SL) is formed.

Then, when the thickness of the catalyst slurry layer SL (height from the surface of the filter wall 164 to the surface of the catalyst slurry layer SL) reaches a predetermined thickness, the slurry supply pump 226 and the suction pump 236 are stopped. In this way, the slurry adhesion carrier 254 is manufactured, in which the catalyst slurry layer SL is formed on the surface of the filter wall 164 constituting the cell 170B.

[Second particle attachment step S140]
The second particle adhesion step S140 is a step of adhering the water-absorbing particles R to the surface of the catalyst slurry layer SL in the cells 170B of the slurry adhesion carrier 254. In the second particle attachment step S140, a plurality of water-absorbing particles R are supplied (filled) into the cells 170B of the slurry attachment carrier 254 using the supply device 210.

In the second particle attachment step S140, first, the slurry nozzle 228 is removed from the guide tube 212. Subsequently, instead of the slurry nozzle 228, a water-absorbing particle nozzle 248 is connected to the guide tube 212.

Then, the feeder 246 is driven, and the slurry adhesion carrier 254 is rotated by a rotating device (not shown). As a result, the cells 170B of the slurry adhesion carrier 254 are evenly filled with water-absorbing particles. Note that in the second particle adhesion step S140 of this embodiment, the suction pump 236 is stopped.

By performing the second particle attachment step S140, the cells 170B are filled with water-absorbing particles R, and as shown in FIG. 5(d), the water-absorbing particles R are attached to the surface of the catalyst slurry layer SL. In this way, a particle-attached carrier 256 in which water-absorbing particles R are attached to the surface of the catalyst slurry layer SL of the slurry-attached carrier 254 is manufactured.

[Expansion step S150]
The expansion step S150 is a step of expanding the plurality of water-absorbing particles R to a predetermined size with water contained in the catalyst slurry layer SL (catalyst slurry). In the expansion step S150, the particle-attached carrier 256 is left for a predetermined period of time. In this embodiment, the predetermined size is a size at which the water-absorbing particles R come into contact with the filter wall 164.

By executing the expansion step S150, the water-absorbing particles R absorb water contained in the catalyst slurry layer SL and expand (swell). Then, as shown in FIG. 5(e), some of the expanded water-absorbing particles R come into contact with the surface of the filter wall 164. In this way, a particle-expanded carrier 258 in which a portion of the water-absorbing particles R penetrates through the catalyst slurry layer SL and contacts the filter wall 164 is manufactured.

[Drying step S160]
The drying step S160 is a step of drying the expanded particle carrier 258 for a predetermined period of time.

[Baking step S170]
The firing step S170 is a step of firing the expanded particle carrier 258 after performing the drying step S160. By executing the firing step S170, the water-absorbing particles R are burned and burned out. Then, as shown in FIG. 5(f), there is a region P where a catalyst layer (catalyst layer TL) is formed on the surface of the filter wall 164 in the cell 170 (cell 170A and cell 170B), and a region P where the catalyst layer (catalyst layer TL) is formed. A filter 140 having an unformed region Q is manufactured.

As described above, the method for manufacturing the filter 140 according to the present embodiment includes a first catalyst slurry attachment step S110, a first particle attachment step S120, a second catalyst slurry attachment step S130, a second particle attachment step S140, an expansion step S150, Filter 140 can be manufactured by performing drying step S160 and firing step S170.

[Setting the size of water-absorbing particles R]
Next, the setting of the size (initial size m) and filling rate n (bulk density) of the water-absorbing particles R to be filled in the first particle attachment step S120 and the second particle attachment step S140 will be explained.

First, the catalyst layer TL in the filter wall 164 is The size of the region Q that will not be formed is determined. For example, when increasing the target purification rate, the region Q where the catalyst layer TL is not formed is made smaller, and when the target pressure loss is decreased, the region Q where the catalyst layer TL is not formed is made larger. In other words, when increasing the target purification rate, the region P in which the catalyst layer TL is formed is increased, and when the target pressure loss is decreased, the region P in which the catalyst layer TL is formed is decreased. Then, based on the determined size of the region Q, the size M of the water-absorbing particles R after expansion (after execution of the expansion step S150) and the filling rate N of the water-absorbing particles R are derived.

The size M of the water-absorbing particles R after expansion is based on the water content (water content) of the catalyst slurry (catalyst slurry layer SL), and the initial (before water absorption) size m and water absorption amount of the water-absorbing particles R. derived. Therefore, the size m of the initial water-absorbing particles R filled in the first particle attachment step S120 and the second particle attachment step S140 is determined by the initial water absorption amount of the water-absorbing particles R, the water content of the catalyst slurry, and the derived It is set based on the size M of the water-absorbing particles R after expansion.

Further, the filling rate n of the water-absorbing particles R in the first particle attachment step S120 and the second particle attachment step S140 is set based on the derived filling rate N of the water-absorbing particles R after expansion.

As explained above, the method for manufacturing the filter 140 according to this embodiment includes a first particle attachment step S120, a second particle attachment step S140, and an expansion step S150. Thereby, water contained in the catalyst slurry layer SL can be absorbed by the water-absorbing particles R in the cell 170, and the water-absorbing particles R can be expanded until they come into contact with the filter wall 164. As a result, the method for manufacturing the filter 140 according to the present embodiment allows the expanded water-absorbing particles R to cause a depression in the catalyst slurry layer SL (a region where the water-absorbing particles R contact the filter wall 164 (a region where the catalyst slurry layer SL is not provided). )), a protrusion (region where the water-absorbing particles R do not contact the filter wall 164 (region where the catalyst slurry layer SL is provided)), and (irregularities) can be formed.

Then, by performing the firing step S170, the method for manufacturing the filter 140 according to the present embodiment can fire the catalyst slurry layer SL while maintaining the uneven shape. Further, since the water-absorbing particles R are formed of a water-absorbing polymer, the water-absorbing particles R can be burned out by executing the baking step S170. As a result, in the method for manufacturing the filter 140 according to the present embodiment, a cell 170 is formed which is composed of a filter wall 164 having a region P where the catalyst layer TL is formed and a region Q where the catalyst layer TL is not formed on the surface. It becomes possible to manufacture a filter 140 that is

When the filter 140 manufactured in this manner is installed in the exhaust pipe 120, exhaust gas is first introduced into the cell 170A, passes through the filter wall 164 from the cell 170A, and is guided to the cell 170B. As described above, the surface of the filter wall 164 is provided with a region P where the catalyst layer TL is formed and a region Q where the catalyst layer TL is not formed. In the region Q where the catalyst layer TL is not formed, the pores of the filter wall 164 are not blocked, so that the pressure loss is smaller than in the region P where the catalyst layer TL is formed. Therefore, the filter 140 can suppress an increase in pressure loss while maintaining exhaust gas purification efficiency, compared to the conventional technology in which the filter wall is entirely covered with a catalyst layer.

Further, unevenness is formed on the filter wall 164 by the region P where the catalyst layer TL is formed and the region Q where the catalyst layer TL is not formed. Therefore, when the exhaust gas is introduced into the cell 170, a turbulent flow of the exhaust gas is formed within the cell 170, unlike a cell in which the surface of the catalyst layer is flat. Therefore, the filter 140 can improve the diffusivity of exhaust gas within the cell 170. Therefore, the filter 140 can improve the purification efficiency of exhaust gas.

[Second embodiment]
In the first embodiment, the filter 140 includes the catalyst layer TL on the filter wall 164 that constitutes the cell 170A and the cell 170B. However, either cell 170A or cell 170B may be provided with another exhaust gas treatment layer.

FIG. 6 is a flowchart showing the process flow of the method for manufacturing the filter 340 according to the second embodiment. As shown in FIG. 6, the method for manufacturing a filter 340 according to the second embodiment includes an adsorbent slurry adhesion step S210, a third particle adhesion step S220, a second catalyst slurry adhesion step S130, and a second particle adhesion step S220. It includes a step S140, an expansion step S150, a drying step S160, and a firing step S170. Note that components that are substantially the same as those in the method for manufacturing the filter 140 described above are given the same reference numerals and explanations are omitted.

[Adsorbent slurry adhesion step S210]
The adsorbent slurry attachment step S210 is a step of attaching an adsorbent slurry to the surface of the filter wall 164 that constitutes the cell 170A of the carrier 160. The adsorbent slurry includes a hydrocarbon adsorbent, a binder, a matrix, and water. Hydrocarbon adsorbents adsorb hydrocarbons at a predetermined adsorption temperature. Hydrocarbon adsorbents desorb hydrocarbons at a predetermined desorption temperature. The adsorption temperature is, for example, room temperature (25°C) or higher and 200°C or lower. The desorption temperature is, for example, 300°C or more and 400°C or less. In this embodiment, the hydrocarbon adsorbent is zeolite.

FIG. 7 is a diagram illustrating the adsorbent slurry attachment step S210, the third particle attachment step S220, and the second catalyst slurry attachment step S130 according to the second embodiment. FIG. 7A is a diagram illustrating the adsorbent slurry adhesion step S210. FIG. 7(b) is a diagram illustrating the third particle attachment step S220. FIG. 7(c) is a diagram illustrating the second catalyst slurry deposition step S130.

As shown in FIG. 7A, in the adsorbent slurry adhesion step S210, the adsorbent slurry is applied to the surface of the filter wall 164 constituting the cell 170A of the carrier 160 using the supply device 410. The supply device 410 includes a guide tube 212, a slurry supply section 220, a slurry supply section 420, a suction section 230, and a particle supply section 240 (see FIG. 7(b)). Note that components that are substantially the same as those of the above-mentioned supply device 210 are given the same reference numerals and explanations are omitted.

The slurry supply unit 420 supplies adsorbent slurry to the cells 170A of the carrier 160 via the guide tube 212. In this embodiment, the slurry supply section 420 includes an adsorbent storage section 422, a slurry supply pipe 424, a slurry supply pump 426, and a slurry nozzle 428.

The adsorbent storage section 422 stores adsorbent slurry. Slurry supply pipe 424 connects adsorbent storage section 422 and the suction side of slurry supply pump 426. The suction side of the slurry supply pump 426 is connected to the adsorbent storage section 422 via a slurry supply pipe 424 . The slurry supply pump 426 is connected to the slurry nozzle 428 at its discharge side. Slurry nozzle 428 is connected to guide tube 212. Slurry supply pump 426 sucks the adsorbent slurry stored in adsorbent storage section 422 and injects it toward carrier 160 from slurry nozzle 428 .

In the adsorbent slurry application step S210, the guide cylinder 212 is fitted to the other end side 160b of the carrier 160, and the suction cylinder 232 is fitted to the one end side 160a. Further, a slurry nozzle 428 is connected to the guide tube 212. Then, the slurry supply pump 426 and the suction pump 236 are driven, and the carrier 160 is rotated by a rotating device (not shown) (indicated by a broken line arrow in FIG. 7(a)). As a result, the adsorbent slurry is evenly supplied to the cells 170A of the carrier 160. Note that the other end side 160b of the cell 170B of the carrier 160 is sealed by a second sealing part 168. Therefore, even if the adsorbent slurry attachment step S210 is executed, the adsorbent slurry is not supplied to the cell 170B.

FIG. 8 shows the adsorbent slurry attachment step S210, third particle attachment step S220, second catalyst slurry attachment step S130, second particle attachment step S140, expansion step S150, and firing step S170 according to the second embodiment. 3 is a diagram illustrating the inside of a cell 170. FIG. FIG. 8A is a diagram illustrating the inside of the cells 170A and 170B after performing the adsorbent slurry deposition step S210. FIG. 8(b) is a diagram illustrating the inside of the cells 170A and 170B after performing the third particle attachment step S220. FIG. 8(c) is a diagram illustrating the inside of the cells 170A and 170B after performing the second catalyst slurry deposition step S130. FIG. 8(d) is a diagram illustrating the inside of the cells 170A and 170B after performing the second particle attachment step S140. FIG. 8(e) is a diagram illustrating the inside of the cells 170A and 170B after performing the expansion step S150. FIG. 8(f) is a diagram illustrating the inside of the cells 170A and 170B after performing the firing step S170.

By executing the adsorbent slurry attachment step S210, the adsorbent slurry is supplied to each cell 170A of the carrier 160, and as shown in FIG. layer (adsorbent slurry layer KL) is formed.

Then, when the thickness of the adsorbent slurry layer KL (the height from the surface of the filter wall 164 to the surface of the adsorbent slurry layer KL) reaches a predetermined thickness, the slurry supply pump 426 and the suction pump 236 are stopped. In this way, the slurry adhesion carrier 450 is manufactured in which the adsorbent slurry layer KL is formed on the surface of the filter wall 164 constituting the cell 170A.

[Third particle attachment step S220]
The third particle adhesion step S220 is a step of adhering the water-absorbing particles R to the surface of the adsorbent slurry layer KL of the slurry adhesion carrier 450.

Returning to FIG. 7, in the third particle adhesion step S220, as shown in FIG. Supply (fill) R.

By performing the third particle attachment step S220, the cells 170A are filled with water-absorbing particles R, and as shown in FIG. 8(b), the water-absorbing particles R are attached to the surface of the adsorbent slurry layer KL. In this way, a particle-attached carrier 452 in which water-absorbing particles R are attached to the surface of the adsorbent slurry layer KL of the slurry-attached carrier 450 is manufactured.

Then, in the second catalyst slurry adhesion step S130, the water-absorbing particle nozzle 248 is removed from the guide tube 212. Subsequently, the guide tube 212 and the suction tube 232 are removed from the particle adhesion carrier 452. Then, as shown in FIG. 7C, the guide cylinder 212 is fitted to one end side 160a of the particle-attached carrier 452, and the suction cylinder 232 is fitted to the other end side 160b. That is, the particle adhesion carrier 452 is moved upside down, and the guide tube 212 and the suction tube 232 are fitted together. Subsequently, the slurry nozzle 228 is connected to the guide cylinder 212, the slurry supply pump 226 and the suction pump 236 are driven, and the particle adhesion carrier 452 is rotated by a rotating device (not shown). As a result, the catalyst slurry is evenly supplied to the cells 170B of the particle-attached carrier 452. In this way, by executing the second catalyst slurry adhesion step S130, as shown in FIG. 8(c), the slurry adhesion carrier 454 with the catalyst slurry layer SL formed on the surface of the filter wall 164 constituting the cell 170B is formed. Manufactured.

Moreover, by performing the second particle attachment step S140, the cells 170B are filled with water-absorbing particles R, and as shown in FIG. 8(d), the water-absorbing particles R are attached to the surface of the catalyst slurry layer SL. In this way, a particle-attached carrier 456 in which water-absorbing particles R are attached to the surface of the catalyst slurry layer SL of the slurry-attached carrier 454 is manufactured.

Subsequently, by executing the expansion step S150, the water-absorbing particles R in the cells 170A absorb water contained in the adsorbent slurry layer KL and expand, and the water-absorbing particles R in the cells 170B expand into the catalyst slurry layer SL. absorbs the water contained in it and expands. Then, as shown in FIG. 8(e), some of the expanded water-absorbing particles R come into contact with the surface of the filter wall 164. That is, in this embodiment, the predetermined size in the expansion step S150 is a size at which the water-absorbing particles R come into contact with the filter wall 164. In this way, a particle-expanded carrier 458 is manufactured in which a portion of the water-absorbing particles R penetrates through the adsorbent slurry layer KL and the catalyst slurry layer SL and contacts the filter wall 164.

Then, by performing the drying step S160 and the firing step S170, a layer of hydrocarbon adsorbent (adsorbent layer ZL) is formed on the surface of the filter wall 164 in the cell 170A, as shown in FIG. 8(f). The surface of the filter wall 164 in the cell 170B has a region S where the catalyst layer TL is formed and a region Q where the catalyst layer TL is not formed. A filter 340 having the following is manufactured.

As described above, the method for manufacturing the filter 340 according to the present embodiment includes an adsorbent slurry attachment step S210, a third particle attachment step S220, a second catalyst slurry attachment step S130, a second particle attachment step S140, an expansion step S150, and a drying step S150. Filter 340 can be manufactured by performing step S160 and firing step S170.

As explained above, the method for manufacturing the filter 340 according to the present embodiment can manufacture the filter 340 that includes the adsorbent layer ZL in the cell 170A and the catalyst layer TL in the cell 170B.

When the filter 340 manufactured in this manner is installed in the exhaust pipe 120, exhaust gas is first introduced into the cell 170A, passes through the filter wall 164 from the cell 170A, and is guided to the cell 170B. That is, the exhaust gas first passes through the adsorbent layer ZL, and then reaches the catalyst layer TL.

When starting the engine 110, the temperature of the exhaust gas is relatively low, so the ability of the three-way catalyst to remove hydrocarbons is lower than during normal operation. Therefore, by installing the filter 340 in the exhaust pipe 120 so that the adsorbent layer ZL is disposed on the upstream side in the flow direction of exhaust gas and the catalyst layer TL is disposed on the downstream side, the filter 340 is , hydrocarbons contained in the exhaust gas can be adsorbed onto the adsorbent layer ZL. Thereby, the filter 340 can improve the removal rate of hydrocarbons when the engine 110 is started. Moreover, at this time, carbon monoxide and nitrogen dioxide are converted into carbon dioxide and nitrogen in the catalyst layer TL, thereby warming up the catalyst layer TL.

Then, as the driving time of the engine 110 passes, when the temperature of the exhaust gas rises to the extent that hydrocarbons are desorbed from the adsorbent layer ZL, the catalyst layer TL has also risen to the activation temperature. Therefore, the catalyst layer TL located on the downstream side can purify the hydrocarbons desorbed from the adsorbent layer ZL.

Furthermore, the method for manufacturing the filter 340 according to this embodiment includes a third particle adhesion step S220 and an expansion step S150. Thereby, water contained in the adsorbent slurry layer KL can be absorbed by the water-absorbing particles R in the cell 170A, and the water-absorbing particles R can be expanded until they come into contact with the filter wall 164. As a result, in the manufacturing method of the filter 340 according to the present embodiment, the expanded water-absorbing particles R cause the adsorbent slurry layer KL to have a depressed portion (a region where the water-absorbing particles R contact the filter wall 164 (the area where the adsorbent slurry layer KL is provided). It is possible to form protrusions (regions where the water-absorbing particles R do not contact the filter wall 164 (regions where the adsorbent slurry layer KL is provided)), and (irregularities).

Then, by performing the firing step S170, the method for manufacturing the filter 340 according to the present embodiment can fire the adsorbent slurry layer KL while maintaining the uneven shape. Further, since the water-absorbing particles R are formed of a water-absorbing polymer, the water-absorbing particles R can be burned out by executing the baking step S170. As a result, the method for manufacturing the filter 340 according to the present embodiment is a cell 170A that is configured of a filter wall 164 having a region S where the adsorbent layer ZL is formed and a region T where the adsorbent layer ZL is not formed on the surface. It becomes possible to manufacture a filter 340 in which a cell 170B is formed, which is constituted by a filter wall 164 having a region P where the catalyst layer TL is formed and a region Q where the catalyst layer TL is not formed on the surface. .

When the filter 340 is installed in the exhaust pipe 120 as described above, the exhaust gas is first introduced into the cell 170A, passes through the filter wall 164 from the cell 170A, and is guided to the cell 170B. A region S where an adsorbent layer ZL is formed and a region T where an adsorbent layer ZL is not formed are provided on the surface of the filter wall 164 of the cell 170A, and a catalyst layer TL is provided on the surface of the filter wall 164 of the cell 170B. A region P where the catalyst layer TL is formed and a region Q where the catalyst layer TL is not formed are provided. In the region T where the adsorbent layer ZL is not formed and the region Q where the catalyst layer TL is not formed, the pores of the filter wall 164 are not blocked, so the region S where the adsorbent layer ZL is formed and the region Q where the catalyst layer TL is formed. The pressure loss is smaller than in the region P. Therefore, the filter 340 can suppress an increase in pressure loss while maintaining exhaust gas purification efficiency, compared to the conventional technology in which the entire filter wall is coated with a catalyst layer.

Moreover, in the cell 170A, unevenness is formed on the filter wall 164 in the region S where the adsorbent layer ZL is formed and the region T where the adsorbent layer ZL is not formed. Moreover, in the cell 170B, unevenness is formed on the filter wall 164 by the region P where the catalyst layer TL is formed and the region Q where the catalyst layer TL is not formed. Therefore, when the exhaust gas is introduced into the cells 170A and 170B, a turbulent flow of the exhaust gas is formed within the cells 170A and 170B, unlike cells in which the surface of the catalyst layer is flat. Therefore, the filter 340 can improve the diffusivity of exhaust gas within the cells 170A and 170B. Therefore, the filter 340 can improve the purification efficiency of exhaust gas.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these embodiments. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the claims, and it is understood that these naturally fall within the technical scope of the present invention. be done.

In addition, in the said 1st Embodiment, the case where the catalyst supported by the filter 140 is a three-way catalyst was mentioned as an example. However, the filter 140 may support other catalysts, such as a NOx storage reduction catalyst. Similarly, in the second embodiment, an example is given in which the catalyst supported on the filter 340 is a three-way catalyst. However, the filter 340 may support other catalysts, such as a NOx storage reduction catalyst.

In addition, in the first catalyst slurry adhesion step S110 of the first embodiment and the second catalyst slurry adhesion step S130 of the first embodiment and the second embodiment, all the cells 170A provided on the carrier 160 An example is given in which a catalyst slurry is applied to a substrate. However, in the first catalyst slurry adhesion step S110 and the second catalyst slurry adhesion step S130, the catalyst slurry may be applied to at least one cell 170A in the carrier 160.

In addition, in the adsorbent slurry adhesion step S210 of the second embodiment, a case where the adsorbent slurry is applied to all the cells 170A provided on the carrier 160 has been exemplified. However, in the adsorbent slurry attaching step S210, the adsorbent slurry may be attached to at least one cell 170A in the carrier 160.

Further, the first particle attachment step S120 of the first embodiment, the second particle attachment step S140 of the first embodiment and the second embodiment, and the third particle attachment step S220 of the second embodiment In this example, the cells 170A and 170B are filled with water-absorbing particles R arranged in a row without contacting each other. However, in the first particle attachment step S120, the second particle attachment step S140, and the third particle attachment step S220, the water-absorbing particles R may be in contact with each other, or the water-absorbing particles R may be arranged in multiple rows in the cells 170A and 170B. May be filled.

FIG. 9 is a diagram illustrating the inside after the particle adhesion step according to the modification is executed. For example, as shown in FIG. 9(a), the water-absorbing particles R may be filled in such a manner that the water-absorbing particles R are in contact with each other in one row. Furthermore, as shown in FIG. 9(b), the cells 170A and 170B may be filled with water-absorbing particles R in multiple rows. In this case, some of the filled water-absorbing particles R may not come into contact with the surface of the catalyst slurry layer SL or the adsorbent slurry layer KL, or all of the filled water-absorbing particles R may Alternatively, it may contact the surface of the adsorbent slurry layer KL.

Further, in the first particle attachment step S120 and the second particle attachment step S140 of the first embodiment, a case where the filling rate of the water-absorbing particles R is substantially equal was exemplified. However, the filling rate of the water-absorbing particles R may be made different between the first particle attachment step S120 and the second particle attachment step S140. Similarly, in the third particle attachment step S220 and the second particle attachment step S140 of the second embodiment, the case where the filling rate of the water-absorbing particles R is substantially equal is exemplified. However, the filling rate of the water-absorbing particles R may be made different between the third particle attachment step S220 and the second particle attachment step S140.

Further, in the first embodiment, the first catalyst slurry adhesion step S110, the first particle adhesion step S120, the second catalyst slurry adhesion step S130, the second particle adhesion step S140, the expansion step S150, the drying step S160, and the firing step The method for manufacturing the filter 140 in which S170 is performed in this order has been described. However, the expansion step S150 and the drying step S160 may be performed multiple times. For example, first catalyst slurry attachment step S110, first particle attachment step S120, expansion step S150, drying step S160, second catalyst slurry attachment step S130, second particle attachment step S140, expansion step S150, drying step S160, firing step S170 may be executed in this order.

Similarly, in the second embodiment, the adsorbent slurry attachment step S210, the third particle attachment step S220, the second catalyst slurry attachment step S130, the second particle attachment step S140, the expansion step S150, the drying step S160, and the firing step A method for manufacturing the filter 340 in which S170 is executed in this order has been described. However, the expansion step S150 and the drying step S160 may be performed multiple times. For example, adsorbent slurry attachment step S210, third particle attachment step S220, expansion step S150, drying step S160, second catalyst slurry attachment step S130, second particle attachment step S140, expansion step S150, drying step S160, firing step S170 may be executed in this order.

Furthermore, in the first embodiment described above, the case where the second catalyst slurry adhesion step S130 and the second particle adhesion step S140 are executed is taken as an example. However, the second catalyst slurry attachment step S130 and the second particle attachment step S140 may be omitted. That is, the catalyst slurry layer SL may be attached only to the surface of the filter wall 164 of the cell 170A. In other words, the catalyst slurry layer SL does not need to be attached to the surface of the filter wall 164 of the cell 170B. This makes it possible to reduce pressure loss compared to the filter 140.

Furthermore, in the expansion step S150 of the first embodiment and the second embodiment, the case where the water-absorbing particles R are expanded until they reach a size that contacts the filter wall 164 has been exemplified. However, in the expansion step S150, the size of the water-absorbing particles R after expansion is not limited as long as the water-absorbing particles R can be expanded. That is, in the expansion step S150, the water-absorbing particles R do not need to contact the filter wall 164. By performing the expansion step S150, even if the water-absorbing particles R do not contact the filter wall 164, the water-absorbing particles R can form a portion where the catalyst slurry layer SL becomes thin. This makes it possible to maintain exhaust gas purification efficiency and suppress an increase in pressure loss, compared to the conventional technology in which the entire filter wall is coated with a catalyst layer of uniform thickness.

Furthermore, in the first embodiment and the second embodiment described above, the case where the particle supply section 240 of the supply device 210, 410 includes the feeder 246 was exemplified. However, the particle supply unit 240 may not include the feeder 246. In this case, the slurry adhering carriers 250 and 254 are arranged so that the other end side 160b is above the end side 160a, and the water-absorbing particle storage section 242 is installed above the water-absorbing particle nozzle 248, so that the water-absorbing particle storage section 242 is The water-absorbing particles R may be allowed to fall onto the slurry adhering carriers 250 and 254 by their own weight.

Furthermore, in the first and second embodiments described above, an example is given in which the filters 140 and 340 are employed as GPFs. However, filters 140, 340 may also be employed as DPFs.

INDUSTRIAL APPLICATION This invention can be utilized for the manufacturing method of the filter provided in the exhaust pipe of a vehicle, and a catalyst.

R Water absorbing particles (particles)
SL Catalyst slurry layer (catalyst slurry)
KL Adsorbent slurry layer (Adsorbent slurry)
S110 First catalyst slurry attachment step S120 First particle attachment step S130 Second catalyst slurry attachment step S140 Second particle attachment step S150 Expansion step S170 Calcining step S210 Adsorbent slurry attachment step S220 Third particle attachment step 140, 340 Filter 160 Carrier 160a One end side 160b Other end side 164 Filter wall 166 First sealing part 168 Second sealing part 170 Cell 170A Cell 170B Cell

Claims (4)

A method for manufacturing a filter used as a GPF or DPF, the method comprising:
A step of attaching a catalyst slurry containing at least a catalyst metal and water to the surface of the filter wall constituting at least one cell in a wall flow type carrier having a plurality of cells partitioned by filter walls;
attaching water-absorbing polymer particles to the surface of the catalyst slurry;
expanding the particles with water contained in the catalyst slurry to a size where some of the particles contact the surface of the filter wall ;
a step of firing the carrier to which the catalyst slurry and the particles are attached;
A method of manufacturing a filter including: The carrier includes a first sealing portion that seals an opening on one end side of the cell classified into the first cell group among the plurality of cells, and a first sealing portion that seals an opening on one end side of the cell classified into the first cell group among the plurality of cells; a second sealing part that seals an opening on the other end side of the cell classified into a second cell group adjacent to the cell;
2. The method for manufacturing a filter according to claim 1, wherein the step of applying the catalyst slurry includes a step of supplying the catalyst slurry to the cells classified into the first cell group. 3. The method for manufacturing a filter according to claim 2, wherein the step of applying the catalyst slurry includes a step of supplying the catalyst slurry to the cells classified into the second cell group. The carrier includes a first sealing part that seals an opening on one end side of the cell classified into the first cell group among the plurality of cells, and a first sealing part that seals an opening on one end side of the cell classified into the first cell group among the plurality of cells. a second sealing part that seals an opening on the other end side of the cell classified into a second cell group adjacent to the cell;
attaching an adsorbent slurry containing at least a hydrocarbon adsorbent and water to the surface of the filter wall constituting the cells classified into the first cell group;
attaching the particles to the surface of the adsorbent slurry;
expanding the particles with water contained in the adsorbent slurry to a size where some of the particles contact the surface of the filter wall ;
including;
The step of attaching the catalyst slurry includes supplying the catalyst slurry to the cells classified into the second cell group,
2. The method for manufacturing a filter according to claim 1, wherein in the step of firing, the catalyst slurry, the adsorbent slurry, and the carrier to which the particles are attached are fired.

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