CA2313586C - Canning structure and catalyst carrying method thereof - Google Patents
Canning structure and catalyst carrying method thereof Download PDFInfo
- Publication number
- CA2313586C CA2313586C CA002313586A CA2313586A CA2313586C CA 2313586 C CA2313586 C CA 2313586C CA 002313586 A CA002313586 A CA 002313586A CA 2313586 A CA2313586 A CA 2313586A CA 2313586 C CA2313586 C CA 2313586C
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- Canada
- Prior art keywords
- ceramic honeycomb
- catalyst
- honeycomb structure
- holding material
- canning
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- 239000003054 catalyst Substances 0.000 title claims abstract description 93
- 238000009924 canning Methods 0.000 title claims abstract description 61
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000000919 ceramic Substances 0.000 claims abstract description 99
- 239000000463 material Substances 0.000 claims abstract description 53
- 239000002184 metal Substances 0.000 claims abstract description 20
- 239000002002 slurry Substances 0.000 claims abstract description 15
- 239000000835 fiber Substances 0.000 claims description 9
- 239000005871 repellent Substances 0.000 claims description 3
- 238000005336 cracking Methods 0.000 abstract description 9
- 230000003197 catalytic effect Effects 0.000 description 17
- 238000004519 manufacturing process Methods 0.000 description 13
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 238000005192 partition Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 4
- 238000007689 inspection Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/28—Construction of catalytic reactors
- F01N3/2839—Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration
- F01N3/2853—Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration using mats or gaskets between catalyst body and housing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
- B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2450/00—Methods or apparatus for fitting, inserting or repairing different elements
- F01N2450/02—Fitting monolithic blocks into the housing
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Exhaust Gas After Treatment (AREA)
- Catalysts (AREA)
Abstract
A canning structure comprises a ceramic honeycomb structure; said honeycomb structure having been not loaded with a catalyst, a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto. An impermeable film is provided between the ceramic honeycomb structure and the holding material . The canning structure has an impermeable film provided between the ceramic honeycomb structure and the holding material, and then a catalyst slurry is poured in only on the ceramic honeycomb structure side of the impermeable film, thereby preventing the holding material from carrying the catalyst , such that only the ceramic honeycomb structure carries the catalyst.
Thus, the holding material does not carry expensive catalyst at the time of carrying catalyst, and accordingly chipping and cracking of the ceramic honeycomb structure can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
Thus, the holding material does not carry expensive catalyst at the time of carrying catalyst, and accordingly chipping and cracking of the ceramic honeycomb structure can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
Description
CANNING STRUCTURE AND CATALYST CARRYING METHOD THEREOF
BACKGROUND OF THE INVENTION
Field of the invention The present invention relates to a canning structure for a catalytic converter which is a device for purifying harmful combustion gases exhausted from internal combustion engines and the like, and to a catalyst carrying method thereof.
Description of the Related Art Currently, ceramic honeycomb catalytic converters are widely used as automobile exhaust gas purifying devices.
Environmental issues in recent years along with even stricter exhaust gas restrictions are requiring that catalysts be able to function immediately following starting the engine when the exhaust gas is still cool, i.e., cold starts.
Accordingly, a step being taken is to reduce the thickness of the partitions of the catalyst carrier to 1/2 to 1/6 of the conventional thickness , so as to lower the thermal capacity of the catalyst carrier and speed up the temperature rising of the catalyst carrier, along with improving engine performance due to decrease of pressure loss.
Normally, a ceramic honeycomb catalytic converter is manufactured as shown in Fig. 3.
First , the carrier manufacturer packages a ceramic carrier 10 (ceramic honeycomb structure) which has passed inspection, and sends it to a catalyst manufacturer.
The catalyst manufacturer unpacks this, performs processes such as causing the ceramic carrier 10 (ceramic honeycomb structure ) to hold the catalyst ( i . a . , catalyst coating ) , thermal processing, inspection, etc., thereby forming a catalyst carrier 25 ( ceramic honeycomb catalyst carrier ) , which is then packaged and sent to a canning manufacturer.
The canning manufacturer unpacks this and attaches a holding material 13 to the catalyst carrier 25 so as to fix within a metal case 11 by compressed fixing (canning) , thus forming a canning catalyst carrier 30, following which joining parts such as a cone portion 17 and flange 18 and the like are welded to the canning catalyst carrier 30 as necessary, thus completing a catalytic converter 1 (ceramic honeycomb catalytic converter) (see Fig. 4).
Now, in the event that a ceramic honeycomb structure having the thickness of the partitions at around 1/2 to 1/6 of the conventional thickness is used as the above catalyst carrier, there has been the problem that the ceramic honeycomb structure easily cracks or chips during tranporting, the catalyst carrying process, the canning process, and handling in each of the processes (e.g. , packaging, unpacking, placing on or taking off of the mechanical facilities (conveyers, chucking, canning, etc.)).
In order to solve this problem, the present Inventors have proposed a new ceramic honeycomb catalytic converter manufacturing process using a canning structure (an article wherein a ceramic honeycomb structure before carrying the catalyst is fixed inside a metal case beforehand, using a holding material).
However, the above canningstructure hasbeen uneconomical, since at the time of carrying the catalyst (i.e., catalyst coating) , expensive catalyst is carried by not only the ceramic honeycomb structure but also the holding material which does not take part in the catalytic reaction with the exhaust gas.
SUMMARY OF THE INVENTION
The present invention has been made in light of the present situation, and accordingly, it is an object thereof to provide a canning structure and a catalyst carrying method thereof, capable of preventing chipping and cracking of the ceramic honeycomb structure at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes, without allowing the holding material to carry expensive catalyst at the time of carrying the catalyst.
According to the present invention, a canning structure is provided which comprises a ceramic honeycomb structure before carrying a catalyst fixed beforehand within a metal case by a holding material; wherein an impermeable film is provided between the ceramic honeycomb structure and the holding material.
BACKGROUND OF THE INVENTION
Field of the invention The present invention relates to a canning structure for a catalytic converter which is a device for purifying harmful combustion gases exhausted from internal combustion engines and the like, and to a catalyst carrying method thereof.
Description of the Related Art Currently, ceramic honeycomb catalytic converters are widely used as automobile exhaust gas purifying devices.
Environmental issues in recent years along with even stricter exhaust gas restrictions are requiring that catalysts be able to function immediately following starting the engine when the exhaust gas is still cool, i.e., cold starts.
Accordingly, a step being taken is to reduce the thickness of the partitions of the catalyst carrier to 1/2 to 1/6 of the conventional thickness , so as to lower the thermal capacity of the catalyst carrier and speed up the temperature rising of the catalyst carrier, along with improving engine performance due to decrease of pressure loss.
Normally, a ceramic honeycomb catalytic converter is manufactured as shown in Fig. 3.
First , the carrier manufacturer packages a ceramic carrier 10 (ceramic honeycomb structure) which has passed inspection, and sends it to a catalyst manufacturer.
The catalyst manufacturer unpacks this, performs processes such as causing the ceramic carrier 10 (ceramic honeycomb structure ) to hold the catalyst ( i . a . , catalyst coating ) , thermal processing, inspection, etc., thereby forming a catalyst carrier 25 ( ceramic honeycomb catalyst carrier ) , which is then packaged and sent to a canning manufacturer.
The canning manufacturer unpacks this and attaches a holding material 13 to the catalyst carrier 25 so as to fix within a metal case 11 by compressed fixing (canning) , thus forming a canning catalyst carrier 30, following which joining parts such as a cone portion 17 and flange 18 and the like are welded to the canning catalyst carrier 30 as necessary, thus completing a catalytic converter 1 (ceramic honeycomb catalytic converter) (see Fig. 4).
Now, in the event that a ceramic honeycomb structure having the thickness of the partitions at around 1/2 to 1/6 of the conventional thickness is used as the above catalyst carrier, there has been the problem that the ceramic honeycomb structure easily cracks or chips during tranporting, the catalyst carrying process, the canning process, and handling in each of the processes (e.g. , packaging, unpacking, placing on or taking off of the mechanical facilities (conveyers, chucking, canning, etc.)).
In order to solve this problem, the present Inventors have proposed a new ceramic honeycomb catalytic converter manufacturing process using a canning structure (an article wherein a ceramic honeycomb structure before carrying the catalyst is fixed inside a metal case beforehand, using a holding material).
However, the above canningstructure hasbeen uneconomical, since at the time of carrying the catalyst (i.e., catalyst coating) , expensive catalyst is carried by not only the ceramic honeycomb structure but also the holding material which does not take part in the catalytic reaction with the exhaust gas.
SUMMARY OF THE INVENTION
The present invention has been made in light of the present situation, and accordingly, it is an object thereof to provide a canning structure and a catalyst carrying method thereof, capable of preventing chipping and cracking of the ceramic honeycomb structure at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes, without allowing the holding material to carry expensive catalyst at the time of carrying the catalyst.
According to the present invention, a canning structure is provided which comprises a ceramic honeycomb structure before carrying a catalyst fixed beforehand within a metal case by a holding material; wherein an impermeable film is provided between the ceramic honeycomb structure and the holding material.
At this time, the impermeable film preferably circles at least the portion where the ceramic honeycomb structure and the holding material are in contact.
Also, according to the present invention, the impermeable film preferably has protrusions protruding from both edge planes of the ceramic honeycomb structure by 10 mm or more (preferably 20 mm or more, and more preferably 30 mm or more) , with the outer diameter of the protrusions of the impermeable film being greater than the outer diameter of the ceramic honeycomb structure.
Further, according to the present invention, the shape of the impermeable film is preferably cylindrical, and the thickness of the impermeable film is preferably 0.1 mm or less (preferably 0.05 mm or less, and more preferably 0.03 mm or less).
Here, the impermeable film is preferably combustible and also water-repellent.
Further, according to the present invention, the holding material is preferably a non-intumescent ceramic fiber mat.
Also, according to the present invention, a catalyst carrying method is provided for a canning structure comprises a ceramic honeycomb structure; said honeycomb structure having been not loaded with a catalyst, a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto;
wherein an impermeable film is provided between the ceramic honeycomb structure and the holding material, and then a catalyst slurry is poured in only on the ceramic honeycomb structure side of the impermeable film, thereby preventing the holding material from carrying the catalyst , such that only the ceramic honeycomb structure carries the catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. lA is a schematic perspective view illustrating an example of the canning structure according to the present invention;
1o Fig. 1B is a plan view of that shown in Fig. lA;
Fig. 1C is a longitudinal-sectional view of that shown in Fig. la;
Fig. 2 is a schematic diagram illustrating an example of the manufacturing process of the ceramic honeycomb catalytic i5 converter using the canning structure according to the present invention;
Fig. 3 is a schematic diagram illustrating an example of the manufacturing process of a conventional ceramic honeycomb catalytic converter; and 2o Fig. 4 is a schematic explanatory diagram illustrating an example of a ceramic honeycomb catalytic converter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The canning structure according to the present invention 25 is a canning structure comprises a ceramic honeycomb structure;
Also, according to the present invention, the impermeable film preferably has protrusions protruding from both edge planes of the ceramic honeycomb structure by 10 mm or more (preferably 20 mm or more, and more preferably 30 mm or more) , with the outer diameter of the protrusions of the impermeable film being greater than the outer diameter of the ceramic honeycomb structure.
Further, according to the present invention, the shape of the impermeable film is preferably cylindrical, and the thickness of the impermeable film is preferably 0.1 mm or less (preferably 0.05 mm or less, and more preferably 0.03 mm or less).
Here, the impermeable film is preferably combustible and also water-repellent.
Further, according to the present invention, the holding material is preferably a non-intumescent ceramic fiber mat.
Also, according to the present invention, a catalyst carrying method is provided for a canning structure comprises a ceramic honeycomb structure; said honeycomb structure having been not loaded with a catalyst, a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto;
wherein an impermeable film is provided between the ceramic honeycomb structure and the holding material, and then a catalyst slurry is poured in only on the ceramic honeycomb structure side of the impermeable film, thereby preventing the holding material from carrying the catalyst , such that only the ceramic honeycomb structure carries the catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. lA is a schematic perspective view illustrating an example of the canning structure according to the present invention;
1o Fig. 1B is a plan view of that shown in Fig. lA;
Fig. 1C is a longitudinal-sectional view of that shown in Fig. la;
Fig. 2 is a schematic diagram illustrating an example of the manufacturing process of the ceramic honeycomb catalytic i5 converter using the canning structure according to the present invention;
Fig. 3 is a schematic diagram illustrating an example of the manufacturing process of a conventional ceramic honeycomb catalytic converter; and 2o Fig. 4 is a schematic explanatory diagram illustrating an example of a ceramic honeycomb catalytic converter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The canning structure according to the present invention 25 is a canning structure comprises a ceramic honeycomb structure;
said honeycomb structure having been not loaded with a catalyst , a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto, wherein an impermeable film is provided between the ceramic honeycomb structure and the holding material .
Thus, chipping and cracking of the ceramic honeycomb structure can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes, without allowing the holding material to io carry expensive catalyst at the time of carrying the catalyst.
The present invention will be described in further detail with reference to the drawings.
Figs. lA through 1C illustrate an example of the canning structure according to the present invention, wherein Fig. lA
i5 is a schematic perspective view, Fig. 1B is a plan view, and Fig.
1C is a longitudinal-sectional view.
As shown in Figs. lA through 1C, the canning structure according to the present invention comprises a canning structure comprises a ceramic honeycomb structure 10; said honeycomb 2o structure having been not loaded with a catalyst, a metal case 11 and a holding material 13 , and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto, wherein an impermeable film 60 is provided between the ceramic honeycomb structure 10 and the holding 25 material 13.
_ 7 _ At this time, with the caning structure according to the present invention, the impermeable film 60 preferably circles at least the portion where the ceramic honeycomb structure 10 and the holding material 13 are in contact, as shown in Figs.
1A through 1C.
This is to prevent the catalyst slurry containing the catalyst component from flowing to the holding material in the event that the above canning structure is caused to hold the catalyst (i.e., subjected to catalyst coating).
1o Also, with the caning structure according to the present invention, the impermeable film preferably has protrusions 62 protruding from both edge planes of the ceramic honeycomb structure 10 by a length "a" which is 10 mm or more (preferably 20 mm or more, and more preferably 30 mm or more), as shown in Fig. 1C.
Also, the outer diameter L2 of the protrusions of the impermeable film are preferably greater than the outer diameter L1 of the ceramic honeycomb structure.
Thus, the catalyst slurry can be readily prevented from 2o flowing to the holding material in the catalyst carrying process, causing the canning structure to hold the catalyst (i.e., catalyst coating) can be performed in a sure manner, and the catalyst carrying process can be optimized.
Also, the shape of the impermeable film used in the present invention is preferably cylindrical.
_ g _ This is to allow the impermeable film to be easily provided so as to circle the ceramic honeycomb structure, so the canning process can be simplified, and also the perimeter of the ceramic honeycomb structure can be seamlessly circled, so catalyst slurry can be readily prevented from flowing out from the ceramic honeycomb structure in a sure manner.
Also, the impermeable film used in the present invention may be a sheet formed integrally with the ceramic fiber mat which serves as the holding material.
Thus, the impermeable film and the holding material can be wound onto the perimeter surface of the ceramic honeycomb structure at the same time, so the canning process can be simplified.
Further, the thickness of the impermeable film used with the present invention is preferably 0.1 mm or less (preferably 0.05 mm or less, and more preferably 0.03 mm or less).
This is due to the fact that the thickness of the impermeable film must be as thin as possible, in order to fix the ceramic honeycomb structure in the metal case in a secure manner with the holding material, in the event that the impermeable film is removed from the canning structure which has carried the catalyst (coated with the catalyst).
Here, the impermeable film used with the present invention is preferably combustible.
This is in order to easily remove the impermeable film which _ g _ has become no longer necessary, by a thermal process ( 500 to 700° C ) following carrying the catalyst (catalyst coating).
Also, the impermeable film used with the present invention is preferably water-repellent , in order to prevent the catalyst slurry from flowing to the holding material in a sure manner.
Now, while the material of the impermeable film used with the present invention is not particularly restricted as long as the above conditions are all met, polyethylene, nylon, etc. , are preferably used.
Further, in addition to the above advantages, the canning structure according to the present invention is capable of protecting the ceramic honeycomb structure from external shock and vibrations, and accordingly chipping and cracking of ceramic honeycomb structures (particularly of those with thin walls (thickness of partitions; 0.10 mm or thinner) ) can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
The canning structure according to the present invention is preferably of an arrangement wherein the metal case has a stuffing structure or a tourniquet structure.
This is because the plane pressure distribution at the time of canning is uniform, which allows prevention of engine exhaust gasses leaking, corrosion of the holding material due to the exhaust gasses, and rattling, damage, etc., of the ceramic honeycomb structure due to engine vibrations, thereby improving reliability.
Particularly, in the event that the metal case has a tourniquet structure, not only is the plane pressure distribution uniform, but canning can be performed at a constant plane pressure regardless of irregularities in the diameter of the ceramic honeycomb structure, which is particularly preferable for ceramic honeycomb structures with low mechanical strengths (particularly, those with thin walls).
Also, the holding material used with the present invention is preferably a non-intumescent ceramic fiber mat.
This allows the maximum plane pressure at the time of canning due to irregularities in the diameter of the ceramic honeycomb structure to be reduced, and further to prevent damage to ceramic honeycomb structures (particularly, those with thin walls ) , since an excessive pressure is not generated at the time of heating as with intumescent mats.
Now, the non-intumescent ceramic fiber mat used with the present invention is made up of at least one selected from the following group; alumina, mullite, silicon carbide, silicon nitride, and zirconia. This non-intumescent ceramic fiber mat is formed of ceramic fibers wherein the fiber diameter is 2 um or greater by less than 6 um, such that application of an initial plane pressure of 2 kgf /cm2 at room temperature and then raising the temperature to 1,000°C results in generation of a plane pressure of at least 1 kgf/cmz, and also has the compression properties in that there is little increase or decrease within the actual usage temperature range of the catalytic converter.
The partition thickness of the ceramic honeycomb structure used with the present invention is preferably 0.10 mm or thinner (more preferably, 0.08 mm or thinner).
This is in order to cause the catalyst to function at cold starts as well, by lowering the thermal capacity of the catalyst carrier and speeding up the temperature rising of the catalyst carrier, along with improving engine performance due to decreasing pressure loss.
Next, an example of a manufacturing processing for the ceramic honeycomb catalytic converter using the canning structure according to the present invention will be described with reference to Fig. 2.
First, the carrier manufacturer provides an impermeable film 60 to the perimeter of a ceramic carrier 10 ( ceramic honeycomb structure) which has passed inspection, further wraps the holding material 13 , and fixes the ceramic carrier 10 within a metal case 11 (i.e. , performs canning) , thereby forming a canning structure 22 (See Figs. lA through 1C), which is then packaged and sent to a catalyst manufacturer.
The catalyst manufacturer unpacks this, performs the processes such as causing the canning structure 22 to carry the catalyst (i.e., catalyst coating), thermal processing, inspection, etc., thereby forming a canning catalyst carrier, which is then packaged and sent to a canning manufacturer.
Incidentally, the catalyst carrying is performed by pouring a catalyst slurry in from the upper part of the canning structure 22 while suctioning the catalyst slurry out from the lower part of the canning structure 22, thereby causing the ceramic honeycomb structure to be dipped in catalyst slurry such that the canning structure 22 carries the catalyst.
At this time, the impermeable film provided to the perimeter of the ceramic honeycomb structure not only prevents the catalyst slurry from flowing out to the holding material, but also can be easily removed in the thermal process.
The canning manufacturer unpacks this and welds joining parts such as a cone portion 17 and flange 18 and the like to the canning catalyst carrier 30 as necessary, thereby completing the catalytic converter (ceramic honeycomb catalytic converter 1) (see Fig. 4).
As described above, method for manufacturing the ceramic honeycomb catalytic converter according to the present invention is capable of protecting the ceramic honeycomb structure from external shock and vibrations as compared with conventional manufacturing methods ( see Fig. 3 ) , and accordingly chipping and cracking of ceramic honeycomb structures can be markedly prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
r Next , the present invention will be described in further detail with reference to embodiments, but it should be noted that the present invention is by no means restricted to these embodiments.
A ceramic carrier (ceramic honeycomb structure) manufactured of cordierite, with a diameter of 106 mm, length of 114 mm, partition thickness of 0.03 mm, and 233 cells/cm2, was prepared. An impermeable film (material: polyethylene) 0.03 mm in thickness was wrapped on the perimiter thereof , following TM
which a non-intumescent ceramic fiber mat ("MAFTEC" (product name) , manufactured by MITSUBISHI CHEMICAL CORPORATION) of 1, 200 g per 1 m2 was further wrapped thereupon, as a holding material.
The ceramic honeycomb structure upon which the impermeable film and holding material have been wrapped was pressed into a stainless-steel can (metal case) with an inner diameter of 114 mm, length of 124 mm, and thickness of 1.5 mm, using a tapered jig for pressing, thereby manufacturing the canning structure 22 shown in Fig. 1.
Incidentally, the impermeable film 60 has protrusions 62 which protrude from both edge planes of the ceramic honeycomb structure 10 by a length "a" which is 10 mm.
Next, twenty of such canning structures 22 obtained with the embodiment were placed in the ceramic honeycomb catalytic converter manufacturing process shown in Fig. 2.
Consequently, the catalyst slurry was completely prevented from flowing out to the holding material in the catalyst carrying (catalyst coating) process, and loss of expensive catalyst slurry was prevented.
Also, absolutely no cracking or chipping of the ceramic honeycomb structures was observed at any point in the above manufacturing process.
A canning structure was manufactured under the same conditions asthe above embodiment, without using the impermeable film 60, and twenty of such were placed in the ceramic honeycomb catalytic converter manufacturing process shown in Fig. 2.
Consequently, the catalyst slurry flowed out to the holding material in the catalyst carrying process, such that 8~ of the catalyst slurry used was carried by the holding material and hence wasted.
Incidentally, absolutely no cracking or chipping of the ceramic honeycomb structures was observed at any point in the above manufacturing process.
Second Comparative Examp7~
Twenty ceramic carriers (ceramic honeycomb structures) manufactured of cordierite, with a diameter of 106 mm, length of 114 mm, partition thickness of 0.06 mm, and 140 cells/cm2, were prepared, and were placed in the ceramic honeycomb catalytic converter (pressing canning) manufacturing process shown in Fig.
3.
Consequently, the rate of cracking or chipping of the ceramic honeycomb structures throughout the above manufacturing process reached 25~.
Thus, according to the canning structure and catalyst carrying method thereof according to the present invention, the holding material does not carry expensive catalyst at the time of carrying catalyst, and accordingly chipping and cracking of ceramic honeycomb structures can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
Thus, chipping and cracking of the ceramic honeycomb structure can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes, without allowing the holding material to io carry expensive catalyst at the time of carrying the catalyst.
The present invention will be described in further detail with reference to the drawings.
Figs. lA through 1C illustrate an example of the canning structure according to the present invention, wherein Fig. lA
i5 is a schematic perspective view, Fig. 1B is a plan view, and Fig.
1C is a longitudinal-sectional view.
As shown in Figs. lA through 1C, the canning structure according to the present invention comprises a canning structure comprises a ceramic honeycomb structure 10; said honeycomb 2o structure having been not loaded with a catalyst, a metal case 11 and a holding material 13 , and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto, wherein an impermeable film 60 is provided between the ceramic honeycomb structure 10 and the holding 25 material 13.
_ 7 _ At this time, with the caning structure according to the present invention, the impermeable film 60 preferably circles at least the portion where the ceramic honeycomb structure 10 and the holding material 13 are in contact, as shown in Figs.
1A through 1C.
This is to prevent the catalyst slurry containing the catalyst component from flowing to the holding material in the event that the above canning structure is caused to hold the catalyst (i.e., subjected to catalyst coating).
1o Also, with the caning structure according to the present invention, the impermeable film preferably has protrusions 62 protruding from both edge planes of the ceramic honeycomb structure 10 by a length "a" which is 10 mm or more (preferably 20 mm or more, and more preferably 30 mm or more), as shown in Fig. 1C.
Also, the outer diameter L2 of the protrusions of the impermeable film are preferably greater than the outer diameter L1 of the ceramic honeycomb structure.
Thus, the catalyst slurry can be readily prevented from 2o flowing to the holding material in the catalyst carrying process, causing the canning structure to hold the catalyst (i.e., catalyst coating) can be performed in a sure manner, and the catalyst carrying process can be optimized.
Also, the shape of the impermeable film used in the present invention is preferably cylindrical.
_ g _ This is to allow the impermeable film to be easily provided so as to circle the ceramic honeycomb structure, so the canning process can be simplified, and also the perimeter of the ceramic honeycomb structure can be seamlessly circled, so catalyst slurry can be readily prevented from flowing out from the ceramic honeycomb structure in a sure manner.
Also, the impermeable film used in the present invention may be a sheet formed integrally with the ceramic fiber mat which serves as the holding material.
Thus, the impermeable film and the holding material can be wound onto the perimeter surface of the ceramic honeycomb structure at the same time, so the canning process can be simplified.
Further, the thickness of the impermeable film used with the present invention is preferably 0.1 mm or less (preferably 0.05 mm or less, and more preferably 0.03 mm or less).
This is due to the fact that the thickness of the impermeable film must be as thin as possible, in order to fix the ceramic honeycomb structure in the metal case in a secure manner with the holding material, in the event that the impermeable film is removed from the canning structure which has carried the catalyst (coated with the catalyst).
Here, the impermeable film used with the present invention is preferably combustible.
This is in order to easily remove the impermeable film which _ g _ has become no longer necessary, by a thermal process ( 500 to 700° C ) following carrying the catalyst (catalyst coating).
Also, the impermeable film used with the present invention is preferably water-repellent , in order to prevent the catalyst slurry from flowing to the holding material in a sure manner.
Now, while the material of the impermeable film used with the present invention is not particularly restricted as long as the above conditions are all met, polyethylene, nylon, etc. , are preferably used.
Further, in addition to the above advantages, the canning structure according to the present invention is capable of protecting the ceramic honeycomb structure from external shock and vibrations, and accordingly chipping and cracking of ceramic honeycomb structures (particularly of those with thin walls (thickness of partitions; 0.10 mm or thinner) ) can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
The canning structure according to the present invention is preferably of an arrangement wherein the metal case has a stuffing structure or a tourniquet structure.
This is because the plane pressure distribution at the time of canning is uniform, which allows prevention of engine exhaust gasses leaking, corrosion of the holding material due to the exhaust gasses, and rattling, damage, etc., of the ceramic honeycomb structure due to engine vibrations, thereby improving reliability.
Particularly, in the event that the metal case has a tourniquet structure, not only is the plane pressure distribution uniform, but canning can be performed at a constant plane pressure regardless of irregularities in the diameter of the ceramic honeycomb structure, which is particularly preferable for ceramic honeycomb structures with low mechanical strengths (particularly, those with thin walls).
Also, the holding material used with the present invention is preferably a non-intumescent ceramic fiber mat.
This allows the maximum plane pressure at the time of canning due to irregularities in the diameter of the ceramic honeycomb structure to be reduced, and further to prevent damage to ceramic honeycomb structures (particularly, those with thin walls ) , since an excessive pressure is not generated at the time of heating as with intumescent mats.
Now, the non-intumescent ceramic fiber mat used with the present invention is made up of at least one selected from the following group; alumina, mullite, silicon carbide, silicon nitride, and zirconia. This non-intumescent ceramic fiber mat is formed of ceramic fibers wherein the fiber diameter is 2 um or greater by less than 6 um, such that application of an initial plane pressure of 2 kgf /cm2 at room temperature and then raising the temperature to 1,000°C results in generation of a plane pressure of at least 1 kgf/cmz, and also has the compression properties in that there is little increase or decrease within the actual usage temperature range of the catalytic converter.
The partition thickness of the ceramic honeycomb structure used with the present invention is preferably 0.10 mm or thinner (more preferably, 0.08 mm or thinner).
This is in order to cause the catalyst to function at cold starts as well, by lowering the thermal capacity of the catalyst carrier and speeding up the temperature rising of the catalyst carrier, along with improving engine performance due to decreasing pressure loss.
Next, an example of a manufacturing processing for the ceramic honeycomb catalytic converter using the canning structure according to the present invention will be described with reference to Fig. 2.
First, the carrier manufacturer provides an impermeable film 60 to the perimeter of a ceramic carrier 10 ( ceramic honeycomb structure) which has passed inspection, further wraps the holding material 13 , and fixes the ceramic carrier 10 within a metal case 11 (i.e. , performs canning) , thereby forming a canning structure 22 (See Figs. lA through 1C), which is then packaged and sent to a catalyst manufacturer.
The catalyst manufacturer unpacks this, performs the processes such as causing the canning structure 22 to carry the catalyst (i.e., catalyst coating), thermal processing, inspection, etc., thereby forming a canning catalyst carrier, which is then packaged and sent to a canning manufacturer.
Incidentally, the catalyst carrying is performed by pouring a catalyst slurry in from the upper part of the canning structure 22 while suctioning the catalyst slurry out from the lower part of the canning structure 22, thereby causing the ceramic honeycomb structure to be dipped in catalyst slurry such that the canning structure 22 carries the catalyst.
At this time, the impermeable film provided to the perimeter of the ceramic honeycomb structure not only prevents the catalyst slurry from flowing out to the holding material, but also can be easily removed in the thermal process.
The canning manufacturer unpacks this and welds joining parts such as a cone portion 17 and flange 18 and the like to the canning catalyst carrier 30 as necessary, thereby completing the catalytic converter (ceramic honeycomb catalytic converter 1) (see Fig. 4).
As described above, method for manufacturing the ceramic honeycomb catalytic converter according to the present invention is capable of protecting the ceramic honeycomb structure from external shock and vibrations as compared with conventional manufacturing methods ( see Fig. 3 ) , and accordingly chipping and cracking of ceramic honeycomb structures can be markedly prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
r Next , the present invention will be described in further detail with reference to embodiments, but it should be noted that the present invention is by no means restricted to these embodiments.
A ceramic carrier (ceramic honeycomb structure) manufactured of cordierite, with a diameter of 106 mm, length of 114 mm, partition thickness of 0.03 mm, and 233 cells/cm2, was prepared. An impermeable film (material: polyethylene) 0.03 mm in thickness was wrapped on the perimiter thereof , following TM
which a non-intumescent ceramic fiber mat ("MAFTEC" (product name) , manufactured by MITSUBISHI CHEMICAL CORPORATION) of 1, 200 g per 1 m2 was further wrapped thereupon, as a holding material.
The ceramic honeycomb structure upon which the impermeable film and holding material have been wrapped was pressed into a stainless-steel can (metal case) with an inner diameter of 114 mm, length of 124 mm, and thickness of 1.5 mm, using a tapered jig for pressing, thereby manufacturing the canning structure 22 shown in Fig. 1.
Incidentally, the impermeable film 60 has protrusions 62 which protrude from both edge planes of the ceramic honeycomb structure 10 by a length "a" which is 10 mm.
Next, twenty of such canning structures 22 obtained with the embodiment were placed in the ceramic honeycomb catalytic converter manufacturing process shown in Fig. 2.
Consequently, the catalyst slurry was completely prevented from flowing out to the holding material in the catalyst carrying (catalyst coating) process, and loss of expensive catalyst slurry was prevented.
Also, absolutely no cracking or chipping of the ceramic honeycomb structures was observed at any point in the above manufacturing process.
A canning structure was manufactured under the same conditions asthe above embodiment, without using the impermeable film 60, and twenty of such were placed in the ceramic honeycomb catalytic converter manufacturing process shown in Fig. 2.
Consequently, the catalyst slurry flowed out to the holding material in the catalyst carrying process, such that 8~ of the catalyst slurry used was carried by the holding material and hence wasted.
Incidentally, absolutely no cracking or chipping of the ceramic honeycomb structures was observed at any point in the above manufacturing process.
Second Comparative Examp7~
Twenty ceramic carriers (ceramic honeycomb structures) manufactured of cordierite, with a diameter of 106 mm, length of 114 mm, partition thickness of 0.06 mm, and 140 cells/cm2, were prepared, and were placed in the ceramic honeycomb catalytic converter (pressing canning) manufacturing process shown in Fig.
3.
Consequently, the rate of cracking or chipping of the ceramic honeycomb structures throughout the above manufacturing process reached 25~.
Thus, according to the canning structure and catalyst carrying method thereof according to the present invention, the holding material does not carry expensive catalyst at the time of carrying catalyst, and accordingly chipping and cracking of ceramic honeycomb structures can be prevented at the time of transporting, the catalyst carrying process, the canning process, and handling in each of the processes.
Claims (7)
1. A canning structure comprising:
a ceramic honeycomb structure, said honeycomb structure being free of catalyst, a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto;
wherein an impermeable film is provided between said ceramic honeycomb structure and said holding material, said impermeable film being combustible and water-repellent and having a thickness of 0.1 mm or less.
a ceramic honeycomb structure, said honeycomb structure being free of catalyst, a metal case and a holding material, and said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto;
wherein an impermeable film is provided between said ceramic honeycomb structure and said holding material, said impermeable film being combustible and water-repellent and having a thickness of 0.1 mm or less.
2. A canning structure according to claim 1, wherein said impermeable film circles at least the portion where said ceramic honeycomb structure and said holding material are in contact.
3. A canning structure according to either claim 1 or 2, wherein said impermeable film has protrusions protruding from both edge planes of said ceramic honeycomb structure by 10 mm or more.
4. A canning structure according to claim 3, wherein the outer diameter of said protrusions of said impermeable film is greater than the outer diameter of said ceramic honeycomb structure.
5. A canning structure according to any one of claims 1 to 4 wherein the shape of said impermeable film is cylindrical.
6. A canning structure according to any one of claims 1 to 5, wherein said holding material is a non-expanding ceramic fiber mat.
7. A catalyst carrying method for use with a ceramic honeycomb structure, a metal case and a holding material, said ceramic honeycomb structure being canned in said metal case and being held by said holding material thereto, said honeycomb structure being free of catalyst, the method comprising the steps of:
providing an impermeable film between said ceramic honeycomb structure and said holding material, said impermeable film being combustible and water-repellant and having a thickness of 0.1 mm or less; and then pouring in a catalyst slurry only on the ceramic honeycomb structure side of said impermeable film, thereby preventing said holding material from carrying the catalyst, such that only said ceramic honeycomb structure carries the catalyst.
providing an impermeable film between said ceramic honeycomb structure and said holding material, said impermeable film being combustible and water-repellant and having a thickness of 0.1 mm or less; and then pouring in a catalyst slurry only on the ceramic honeycomb structure side of said impermeable film, thereby preventing said holding material from carrying the catalyst, such that only said ceramic honeycomb structure carries the catalyst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11-194125 | 1999-07-08 | ||
| JP19412599A JP4076677B2 (en) | 1999-07-08 | 1999-07-08 | CANNING STRUCTURE AND ITS CATALYST SUPPORT METHOD |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2313586A1 CA2313586A1 (en) | 2001-01-08 |
| CA2313586C true CA2313586C (en) | 2005-02-15 |
Family
ID=16319335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002313586A Expired - Fee Related CA2313586C (en) | 1999-07-08 | 2000-07-05 | Canning structure and catalyst carrying method thereof |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1067278B1 (en) |
| JP (1) | JP4076677B2 (en) |
| CA (1) | CA2313586C (en) |
| DE (1) | DE60014782T2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009037271A1 (en) * | 2009-08-12 | 2011-02-17 | Volkswagen Ag | catalyst device |
| CN107355286A (en) * | 2017-08-29 | 2017-11-17 | 浙江银轮机械股份有限公司 | The encapsulating structure of engine aftertreatment system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3959865A (en) * | 1972-12-08 | 1976-06-01 | Minnesota Mining And Manufacturing Company | Method of containing a resiliently supported rigid ceramic catalyst support |
| US4142864A (en) * | 1977-05-31 | 1979-03-06 | Engelhard Minerals & Chemicals Corporation | Catalytic apparatus |
| US4340505A (en) * | 1981-04-28 | 1982-07-20 | Johnson Matthey, Inc. | Reducing precious metal use in catalyst substrates |
| DE3827863A1 (en) * | 1988-08-17 | 1990-02-22 | Leistritz Ag | Catalytic exhaust gas purification apparatus |
| US5866079A (en) * | 1993-09-03 | 1999-02-02 | Ngk Insulators, Ltd. | Ceramic honeycomb catalytic converter |
-
1999
- 1999-07-08 JP JP19412599A patent/JP4076677B2/en not_active Expired - Lifetime
-
2000
- 2000-07-05 CA CA002313586A patent/CA2313586C/en not_active Expired - Fee Related
- 2000-07-07 DE DE60014782T patent/DE60014782T2/en not_active Expired - Lifetime
- 2000-07-07 EP EP00305759A patent/EP1067278B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP4076677B2 (en) | 2008-04-16 |
| EP1067278A2 (en) | 2001-01-10 |
| CA2313586A1 (en) | 2001-01-08 |
| EP1067278A3 (en) | 2002-08-14 |
| DE60014782D1 (en) | 2004-11-18 |
| EP1067278B1 (en) | 2004-10-13 |
| DE60014782T2 (en) | 2006-02-09 |
| JP2001017865A (en) | 2001-01-23 |
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| EEER | Examination request | ||
| MKLA | Lapsed |
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