CA1304298C - Catalytic converter for automotive exhaust system - Google Patents
Catalytic converter for automotive exhaust systemInfo
- Publication number
- CA1304298C CA1304298C CA000574736A CA574736A CA1304298C CA 1304298 C CA1304298 C CA 1304298C CA 000574736 A CA000574736 A CA 000574736A CA 574736 A CA574736 A CA 574736A CA 1304298 C CA1304298 C CA 1304298C
- Authority
- CA
- Canada
- Prior art keywords
- catalytic converter
- catalytic
- mat
- resilient
- thin
- 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
Links
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
-
- 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
- F01N3/2857—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 the mats or gaskets being at least partially made of intumescent material, e.g. unexpanded vermiculite
-
- 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
- F01N3/2864—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 the mats or gaskets comprising two or more insulation layers
-
- 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
- F01N2350/00—Arrangements for fitting catalyst support or particle filter element in the housing
- F01N2350/02—Fitting ceramic monoliths in a metallic housing
- F01N2350/04—Fitting ceramic monoliths in a metallic housing with means compensating thermal expansion
-
- 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
- F01N2350/00—Arrangements for fitting catalyst support or particle filter element in the housing
- F01N2350/02—Fitting ceramic monoliths in a metallic housing
- F01N2350/06—Fitting ceramic monoliths in a metallic housing with means preventing gas flow by-pass or leakage
-
- 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
-
- 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
- F01N2470/00—Structure or shape of gas passages, pipes or tubes
- F01N2470/10—Tubes having non-circular cross section
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49345—Catalytic device making
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
- Y10T29/49879—Spaced wall tube or receptacle
Abstract
Abstract of the Disclosure Catalytic converters for automotive exhaust systems wherein thin, resilient, flexible, intumescent sheet materials are utilized as mounting mats for catalytic monoliths are disclosed. Multiple wraps of such sheet materials have been found particularly useful and cost effective for positioning and supporting ceramic catalytic monoliths which have a large cross-sectional dimensional tolerance within the metallic casing of the converter.
Description
`` ~L3~g~
F.N. 42581 USA 4A
CATALYTIC CONYERTEP~ FOR ~UTOMOTIV~: E~3AU~;T SYSTEM
S 13A(~ GROIJND OF T~E INVENTION
__ The present invention rlelates to a catalytic converter utilizing an intumescent mountlng mat for mounting a ceramic monolith within a metallic ca~ing to produce a catalytic converter.
Catalytic converters ar~ univer6ally employed for oxidation of carbon mono~ide and hydrocarbons and reduction of the oxides of nitrogen in automobile exhaust gases in order to control atmospheric pollution. Due to the relatively high temperatures encountered in these catalytic processes, ceramics ha~e been the natural choice for cataly~t supports. Particularly useful supports are provided by ceramic honeycomb structures as described, for example, in U.S. Patent Re 27,747. These ceramic bodies tend to be frangible and have coefficients of thermal expansion differing markedly from the metal, usually stainles~ steel, casings of the converters. Thus, the mounting means for the ceramic body in the container must p~ovide resi~tance to mechanical shock due to impact and vibration. Intumescent sheet materials useful a~ mounting ~; 25 materials Por this purpose are described in U.S. Patents 3,916,057, 4,305,992 and 4,617,176 and in U.~ Patent 1,513,808.
Catalytic converters employing intumescent sheet mounting materials generally use a single rectangularly shaped sheet or mat usually having a slot on one end and a complementarily configured tab on the other. The sheet or mat is wrapped around the lateral (outer) peripheral surface of the ceramic monolith with tab and slot engaged.
The catalytic converter of U.S. Patent 9,617,176 uses a generally rectangularly shaped mat with sinusoidal l~ngthwise edye~ to minimize axial stresses in the ceramic monolith but still employs the tab and slot geometry. A
. . , ~o~2~a 2 disadvantage of such systems is that the tab must fit exactly into the slot to ensure a tight gas seal about the periphery of the ceramic monolith. Un~ortunately, this is difficult to do in an automated process and hand operations are expensive and time consuming.
In addition, ~ince the ceramic monolith has a very large dimensional tolerance (typically ~ 2 mm diameter), the circumference or perimeter of the monolith can vary more than ~ 6 mm. This means that for a given mat 1~ length, the mat will tend to be either too long or too short as the individual ceramic monolith size varies within its tolerance range, fittlng exactly only a monollth wlth an exactly nominal perimeter. Since mat overlap can cause improper shell closure with th~ attendant risk o~ mounting failure or crushing of the ceramic monolith, overlap is usually avoided by designing the mat length for a monolith of the maximum perimeter. This ensures that mat overlap will never occur, but also means that the mat will be too short in many cases, leaving a space where the two ends of 2Q the mat should come together. This space i~ undesirable because it provides additional mat edge area for the exhaust gas to impinge upon. Under severe driving conditions this can provide a site for mat erosion to begin. This space also allows more heat to be conducted to the metal shell since hot exhaust gases are in direct ; contact with the metal shell.
The large tolerance of the ceramic monolith also afects the mount or packing density of the intumescent material. With presently available materials, a minimum mount density of about 0.64 g/cm3 is required to hold the ceramic monolith in place under normal conditions and 0.75 g/cm3 under extreme conditions. ~he mount density must be kept below about 1.36 g/cm3 for a typical 62 cell/cm2 monolith or monolith hreakage can occur either during assembly or in operation. In order to achieve and maintain this mount density range under severe operating conditions, a single mat as thick as 9.8 mm has been used.
` ~3~9~ -3-SUMM~RY Or T~ IllVrNTION
The present invention relates to catalytic converters wherein a thin, resilient, flexible, intumescent mat is utilizQd to securely mount a ceramic monolith within a metallic casing to produce said c~nverters. It has been found that by using multiple layerwise wraps of a very thin (0.5 to 2.0 mm thick) mat, the tab and slot configuration of prior art catalytic converter mounting mats can be eliminated. The space that usually occurs between adjoining edges of the mounting mat and its a~sociated problems are eliminated. Perhaps even more importantly, the number of layers o~ wrap used can be tailored to the ~nd$vidual monolith perimeter, thus compensating for the large dimensional tolerance of the ceramic monoliths.
Thus, if the monolith is on the small end of the tolerance range, it receives more layers of wrap than a similar monolith on the large end of the tolerance range. Since the cost of producing ceramic monoliths is to a large 2~ d~gree ~ function of dimensional tolerance re~uired, it is po~sible to realize a cost savings by relaxing mcnolith tolerances and compensate for these larger tolerances by varying the number of layers of wrap of thin mat of the present invention when assembling the converter. Sincs the mat i~ very thin, the placement of the beginning and ending points of the mat are of little concern.
BllIEF DESCE~IPTION O~ THE DRAWINGS
FIG. 1 is a perspective view of a catalytic converter of the present invention shown in disassembled relation; and FIG. 2 is a plan view of the bottcm shell of the catalytic converter of FIG. 1 fihowing the layerwise wrapping of the mounting mat about the periphery of the ceramic monolith.
~3~ 8 DETAIIIED D~SCRIPTION OF THE I~VE~TION
Referring now to the drawings, catalytic converter 10 comprises metallic casing ll with generally frustoconical inlet and outlet ends 12 and 13, respectively. Di6posed within casing 11 is a ~onolithic catalytic element 20 formed of a refractory material such as ceramic and having a plurality of gas flow channels (not shown) therethrough. Surrounding catalytic el~ment 20 is mounting mat 30 comprising at least two layers of a thin, re~ilient, flexible, intume~cent mounting mat layerwise wrapped about its perimeter which serves to tightly but resiliently support catalytic element 20 within the casing 11 by expansion in situ. The expanded ~at then holds the catalytic slement 20 in place in the casing and seals the peripheral edges of the catalytic element to thus prevent exhaust gases from by-passing the catalytlc element. The mat 30 is layerwise wrapped about the periphery of catalytic element 20 by simply laying down the first end 31 of mat 30, which is ln strip form, on catalytic element 20 and layerwise wrapping mat 30 upon itself until the second end 32 of mat 30 rests upon the underlying layers of mat 30 on the surface o catalytic element 20.
The mounting mat for the catalytic converter of thi~ invention comprises a thin, resilient, flexible, intumescent sheet comprising from about 20% to 65% by weight of unexpanded vermiculite flakes, such flakes being either untreated or treated by being ion exchanged with an ammonium compound such as ammonium dihydrogen phosphate, ammonium carbonate, ammonium chloride or other suitable ammonium compound; from about 10% to 50% by weight of inorganic fibrous material including aluminosilicate fibers (available commercially under the tradenames Fiberfrax, Cerafiber, and Kaowool), asbestos fibers, glass fibers, zirconia-silica fibers and crystalline alum~na whiskers;
F.N. 42581 USA 4A
CATALYTIC CONYERTEP~ FOR ~UTOMOTIV~: E~3AU~;T SYSTEM
S 13A(~ GROIJND OF T~E INVENTION
__ The present invention rlelates to a catalytic converter utilizing an intumescent mountlng mat for mounting a ceramic monolith within a metallic ca~ing to produce a catalytic converter.
Catalytic converters ar~ univer6ally employed for oxidation of carbon mono~ide and hydrocarbons and reduction of the oxides of nitrogen in automobile exhaust gases in order to control atmospheric pollution. Due to the relatively high temperatures encountered in these catalytic processes, ceramics ha~e been the natural choice for cataly~t supports. Particularly useful supports are provided by ceramic honeycomb structures as described, for example, in U.S. Patent Re 27,747. These ceramic bodies tend to be frangible and have coefficients of thermal expansion differing markedly from the metal, usually stainles~ steel, casings of the converters. Thus, the mounting means for the ceramic body in the container must p~ovide resi~tance to mechanical shock due to impact and vibration. Intumescent sheet materials useful a~ mounting ~; 25 materials Por this purpose are described in U.S. Patents 3,916,057, 4,305,992 and 4,617,176 and in U.~ Patent 1,513,808.
Catalytic converters employing intumescent sheet mounting materials generally use a single rectangularly shaped sheet or mat usually having a slot on one end and a complementarily configured tab on the other. The sheet or mat is wrapped around the lateral (outer) peripheral surface of the ceramic monolith with tab and slot engaged.
The catalytic converter of U.S. Patent 9,617,176 uses a generally rectangularly shaped mat with sinusoidal l~ngthwise edye~ to minimize axial stresses in the ceramic monolith but still employs the tab and slot geometry. A
. . , ~o~2~a 2 disadvantage of such systems is that the tab must fit exactly into the slot to ensure a tight gas seal about the periphery of the ceramic monolith. Un~ortunately, this is difficult to do in an automated process and hand operations are expensive and time consuming.
In addition, ~ince the ceramic monolith has a very large dimensional tolerance (typically ~ 2 mm diameter), the circumference or perimeter of the monolith can vary more than ~ 6 mm. This means that for a given mat 1~ length, the mat will tend to be either too long or too short as the individual ceramic monolith size varies within its tolerance range, fittlng exactly only a monollth wlth an exactly nominal perimeter. Since mat overlap can cause improper shell closure with th~ attendant risk o~ mounting failure or crushing of the ceramic monolith, overlap is usually avoided by designing the mat length for a monolith of the maximum perimeter. This ensures that mat overlap will never occur, but also means that the mat will be too short in many cases, leaving a space where the two ends of 2Q the mat should come together. This space i~ undesirable because it provides additional mat edge area for the exhaust gas to impinge upon. Under severe driving conditions this can provide a site for mat erosion to begin. This space also allows more heat to be conducted to the metal shell since hot exhaust gases are in direct ; contact with the metal shell.
The large tolerance of the ceramic monolith also afects the mount or packing density of the intumescent material. With presently available materials, a minimum mount density of about 0.64 g/cm3 is required to hold the ceramic monolith in place under normal conditions and 0.75 g/cm3 under extreme conditions. ~he mount density must be kept below about 1.36 g/cm3 for a typical 62 cell/cm2 monolith or monolith hreakage can occur either during assembly or in operation. In order to achieve and maintain this mount density range under severe operating conditions, a single mat as thick as 9.8 mm has been used.
` ~3~9~ -3-SUMM~RY Or T~ IllVrNTION
The present invention relates to catalytic converters wherein a thin, resilient, flexible, intumescent mat is utilizQd to securely mount a ceramic monolith within a metallic casing to produce said c~nverters. It has been found that by using multiple layerwise wraps of a very thin (0.5 to 2.0 mm thick) mat, the tab and slot configuration of prior art catalytic converter mounting mats can be eliminated. The space that usually occurs between adjoining edges of the mounting mat and its a~sociated problems are eliminated. Perhaps even more importantly, the number of layers o~ wrap used can be tailored to the ~nd$vidual monolith perimeter, thus compensating for the large dimensional tolerance of the ceramic monoliths.
Thus, if the monolith is on the small end of the tolerance range, it receives more layers of wrap than a similar monolith on the large end of the tolerance range. Since the cost of producing ceramic monoliths is to a large 2~ d~gree ~ function of dimensional tolerance re~uired, it is po~sible to realize a cost savings by relaxing mcnolith tolerances and compensate for these larger tolerances by varying the number of layers of wrap of thin mat of the present invention when assembling the converter. Sincs the mat i~ very thin, the placement of the beginning and ending points of the mat are of little concern.
BllIEF DESCE~IPTION O~ THE DRAWINGS
FIG. 1 is a perspective view of a catalytic converter of the present invention shown in disassembled relation; and FIG. 2 is a plan view of the bottcm shell of the catalytic converter of FIG. 1 fihowing the layerwise wrapping of the mounting mat about the periphery of the ceramic monolith.
~3~ 8 DETAIIIED D~SCRIPTION OF THE I~VE~TION
Referring now to the drawings, catalytic converter 10 comprises metallic casing ll with generally frustoconical inlet and outlet ends 12 and 13, respectively. Di6posed within casing 11 is a ~onolithic catalytic element 20 formed of a refractory material such as ceramic and having a plurality of gas flow channels (not shown) therethrough. Surrounding catalytic el~ment 20 is mounting mat 30 comprising at least two layers of a thin, re~ilient, flexible, intume~cent mounting mat layerwise wrapped about its perimeter which serves to tightly but resiliently support catalytic element 20 within the casing 11 by expansion in situ. The expanded ~at then holds the catalytic slement 20 in place in the casing and seals the peripheral edges of the catalytic element to thus prevent exhaust gases from by-passing the catalytlc element. The mat 30 is layerwise wrapped about the periphery of catalytic element 20 by simply laying down the first end 31 of mat 30, which is ln strip form, on catalytic element 20 and layerwise wrapping mat 30 upon itself until the second end 32 of mat 30 rests upon the underlying layers of mat 30 on the surface o catalytic element 20.
The mounting mat for the catalytic converter of thi~ invention comprises a thin, resilient, flexible, intumescent sheet comprising from about 20% to 65% by weight of unexpanded vermiculite flakes, such flakes being either untreated or treated by being ion exchanged with an ammonium compound such as ammonium dihydrogen phosphate, ammonium carbonate, ammonium chloride or other suitable ammonium compound; from about 10% to 50% by weight of inorganic fibrous material including aluminosilicate fibers (available commercially under the tradenames Fiberfrax, Cerafiber, and Kaowool), asbestos fibers, glass fibers, zirconia-silica fibers and crystalline alum~na whiskers;
3~ from about 3% to 2~% by weight of binder including natural rubber latices, styrene-butadiene latices, butadiene acrylonitrile latices, latices of acrylate or methacrylate ~ 5-polymers and copolymers and the like; and up to about 40%
by weight of lnorganic flller includlng ~xpanded vermiculite, hollow glass microspheres and bentonite. The thin sheet material is made following basic papermaking processe6 ln a thickness of from 0 5 to 2.0 mm. The thus formed sheet material is then slit and wound upo~ itself into rolls having widths of from 50 mm to 400 mm. The mounting mat is layerwise wrapped upon itself continuously around a ceramio monolith from 2 to 20 times. The mat can be wrapped to meet a specific final external monolith dimension or the length of the mat material to be wrapped can be predetermined by the initial individual monolith dimension. In either case, the ordinarily large monolith tolerance~ ~ 2 mm diameter) can be readily compensated for by sslecting the proper number of layers of wrap or the length of mat needed. For example, a monolith on the small end of the tolerance range receives more layers of wrap than a monolith on the large end of the tolerance range resulting in mat wrapped monoliths having the same outside perimetrical dimensions. Consequently, very close control of mat mount density of the monolith inserted in the metal canister, is provided.
~ thlcknes~ of the intumescent sheet greater than 2 mm creates a significant "step" where the mat overlap begins and ends. This stepped area, depending on mat mount density, can be a source of exhaust gas leakage through the mat or a source of high stress concentratlon in the ceramic monolith. ~ikewise, a very thin mat, for example below 0.5 mm, is difficult to make and handle and the number of layers of wrap needed becomes excessive. Therefore, the preferred intumescent sheet thicknes~ is from 0.5 to 2.0 mm thick.
Catalytic converters assembled using the sheet material of this invention have the advantage of providing a much more uniform mount d~nsity from converter to converter re~ulting in more consistent performance. In addition, converters mounted utilizing this novel mat do ~3~2~ -6-not have a gap existing between mat end~ such as is found with tab and slot design mats which, under extreme conditions, can be a s~urce of mat erosion.
Exa~ples 1-4 Four catalytic converters consi~ting of an 11.84 cm diameter by 15.24 cm long monolith and a 12.34 cm I .D. ( in~ide diameter) metal container were mounted using multiple wrapped layers of 500 g/cm2 (0080 mm thick) intumescent sheet material described above. The mount density was determined ~y calculating the volume of the gap between the ceramic monolith and the container and then cutting the mat material to a length corresponding to the proper mass to mount converters at 0.64, 0.80, 0.96, and 1.12 g/cm . The monoliths were then subjected to a push-out test at various temperatures on the ~TS tensile tester ~MTS Systems Corp.) to measure the force needed to move the monolith. Thi~ is a measure of how tightly the monolith is held by the mat. Results are listed below.
Push Out Force Mount Room Return to Densi~y Temperature 600~C Room Temperature Example (g/cm ) tNewtons) (Newtons) (Newton~) 1 0.6~ 197 6,~67 2,787 2 0.~0 631 14,520 5,053 3 0.961,323 >25,000 ~,705 4 1.122,317 >25,000 13,~30 When the monolith did finally move, slippage occurred between the rnat and metal can rather than between succes6ive mat layeræ. These examples indicate that catalytic converters produced with the mounting mats according to this invention g~nerate significant holding force at a wide range o temperatures and mount densities.
2g~
Exa~lpl~ 5 A catalytlc converter was mountecl as in Examples 1-4 using multiple layers of 500 g/m2 mat (4 layers, 0~80 mm thick) to produce a mount density of 0.64 g/cm3.
The converter was then subjected to a hot shake test consisting of a natural gas burner and an Unholtz~Dickie vibration table. Inlet gas temperature was lOOO`C, acceleration was 30 Gs in the axial direction at frequency of 100 Hz. The test cont:Lnued for 20 hours. No monolith movement or damage such as "ring off" cracking was observed.
by weight of lnorganic flller includlng ~xpanded vermiculite, hollow glass microspheres and bentonite. The thin sheet material is made following basic papermaking processe6 ln a thickness of from 0 5 to 2.0 mm. The thus formed sheet material is then slit and wound upo~ itself into rolls having widths of from 50 mm to 400 mm. The mounting mat is layerwise wrapped upon itself continuously around a ceramio monolith from 2 to 20 times. The mat can be wrapped to meet a specific final external monolith dimension or the length of the mat material to be wrapped can be predetermined by the initial individual monolith dimension. In either case, the ordinarily large monolith tolerance~ ~ 2 mm diameter) can be readily compensated for by sslecting the proper number of layers of wrap or the length of mat needed. For example, a monolith on the small end of the tolerance range receives more layers of wrap than a monolith on the large end of the tolerance range resulting in mat wrapped monoliths having the same outside perimetrical dimensions. Consequently, very close control of mat mount density of the monolith inserted in the metal canister, is provided.
~ thlcknes~ of the intumescent sheet greater than 2 mm creates a significant "step" where the mat overlap begins and ends. This stepped area, depending on mat mount density, can be a source of exhaust gas leakage through the mat or a source of high stress concentratlon in the ceramic monolith. ~ikewise, a very thin mat, for example below 0.5 mm, is difficult to make and handle and the number of layers of wrap needed becomes excessive. Therefore, the preferred intumescent sheet thicknes~ is from 0.5 to 2.0 mm thick.
Catalytic converters assembled using the sheet material of this invention have the advantage of providing a much more uniform mount d~nsity from converter to converter re~ulting in more consistent performance. In addition, converters mounted utilizing this novel mat do ~3~2~ -6-not have a gap existing between mat end~ such as is found with tab and slot design mats which, under extreme conditions, can be a s~urce of mat erosion.
Exa~ples 1-4 Four catalytic converters consi~ting of an 11.84 cm diameter by 15.24 cm long monolith and a 12.34 cm I .D. ( in~ide diameter) metal container were mounted using multiple wrapped layers of 500 g/cm2 (0080 mm thick) intumescent sheet material described above. The mount density was determined ~y calculating the volume of the gap between the ceramic monolith and the container and then cutting the mat material to a length corresponding to the proper mass to mount converters at 0.64, 0.80, 0.96, and 1.12 g/cm . The monoliths were then subjected to a push-out test at various temperatures on the ~TS tensile tester ~MTS Systems Corp.) to measure the force needed to move the monolith. Thi~ is a measure of how tightly the monolith is held by the mat. Results are listed below.
Push Out Force Mount Room Return to Densi~y Temperature 600~C Room Temperature Example (g/cm ) tNewtons) (Newtons) (Newton~) 1 0.6~ 197 6,~67 2,787 2 0.~0 631 14,520 5,053 3 0.961,323 >25,000 ~,705 4 1.122,317 >25,000 13,~30 When the monolith did finally move, slippage occurred between the rnat and metal can rather than between succes6ive mat layeræ. These examples indicate that catalytic converters produced with the mounting mats according to this invention g~nerate significant holding force at a wide range o temperatures and mount densities.
2g~
Exa~lpl~ 5 A catalytlc converter was mountecl as in Examples 1-4 using multiple layers of 500 g/m2 mat (4 layers, 0~80 mm thick) to produce a mount density of 0.64 g/cm3.
The converter was then subjected to a hot shake test consisting of a natural gas burner and an Unholtz~Dickie vibration table. Inlet gas temperature was lOOO`C, acceleration was 30 Gs in the axial direction at frequency of 100 Hz. The test cont:Lnued for 20 hours. No monolith movement or damage such as "ring off" cracking was observed.
Claims (7)
1. In a catalytic converter having a metallic casing, a unitary, solid ceramic catalytic element disposed within said casing, and resilient means disposed between said catalytic element and said metallic casing for positioning said catalytic element and for absorbing mechanical and thermal shock, the improvement comprising:
said resilient means comprising at least two layers of a thin, resilient, flexible, intumescent sheet layerwise wrapped about the perimeter of the lateral surface of the solid ceramic catalytic element.
said resilient means comprising at least two layers of a thin, resilient, flexible, intumescent sheet layerwise wrapped about the perimeter of the lateral surface of the solid ceramic catalytic element.
2. The catalytic converter of claim 1 wherein the thickness of said thin, resilient, flexible, intumescent sheet is greater than 0.5 mm and less than 2.0 mm.
3. The catalytic converter of claim 1 wherein the thin, resilient, flexible, intumescent sheet comprises from about 20% to 65% by weight of unexpanded vermiculite flakes, from about 10% to 50% by weight of inorganic fibrous material, from about 3% to 20% by weight of binder and up to about 40% by weight of inorganic filler material.
4. The catalytic converter of claim 3 wherein the unexpanded vermiculite flakes have been ion-exchanged with an ammonium compound.
5. The catalytic converter of claim 3 wherein the inorganic fibrous material is selected from alimino-silicate fibers, asbestos fibers, glass fibers, zirconia-silica fibers or crystalline alumina whiskers.
6. The catalytic converter of claim 3 wherein the binder is selected from latices of natural rubber, styrene-butadiene copolymers, butadiene-acrylonitrile copolymers, acrylate polymers or methacrylate polymers.
7. The catalytic converter of claim 3 wherein the inorganic filler is selected from expanded vermiculite, hollow glass microspheres or bentonite.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/085,778 US4865818A (en) | 1987-08-17 | 1987-08-17 | Catalytic converter for automotive exhaust system |
US85,778 | 1987-08-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1304298C true CA1304298C (en) | 1992-06-30 |
Family
ID=22193872
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000574736A Expired - Fee Related CA1304298C (en) | 1987-08-17 | 1988-08-15 | Catalytic converter for automotive exhaust system |
Country Status (5)
Country | Link |
---|---|
US (1) | US4865818A (en) |
JP (1) | JPS6466412A (en) |
KR (1) | KR890004053A (en) |
AU (1) | AU608337B2 (en) |
CA (1) | CA1304298C (en) |
Families Citing this family (60)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69013974T2 (en) * | 1989-05-18 | 1995-04-13 | Nippon Pillar Packing | Heat-resistant expansion element. |
US5207989A (en) * | 1991-03-22 | 1993-05-04 | Acs Industries, Inc. | Seal for catalytic converter and method therefor |
US5413766A (en) * | 1991-10-04 | 1995-05-09 | Leistritz Ag & Co. Abgastechnik | Device for reducing exhaust gas contaminants, particularly for motor vehicles |
US5376341A (en) * | 1992-07-24 | 1994-12-27 | Corning Incorporated | Catalytic converter for motorcycles |
US5332609A (en) * | 1993-03-25 | 1994-07-26 | Minnesota Mining And Manufacturing Company | Intumescent mounting mat |
AU6710594A (en) * | 1993-04-22 | 1994-11-08 | Carborundum Company, The | Mounting mat for fragile structures such as catalytic converters |
JPH0842333A (en) * | 1994-06-06 | 1996-02-13 | Ford Motor Co | Preparation of catalyst exhaust treating device |
US5813222A (en) * | 1994-10-07 | 1998-09-29 | Appleby; Anthony John | Method and apparatus for heating a catalytic converter to reduce emissions |
US5686039A (en) * | 1995-06-30 | 1997-11-11 | Minnesota Mining And Manufacturing Company | Methods of making a catalytic converter or diesel particulate filter |
JPH11509510A (en) * | 1995-06-30 | 1999-08-24 | ミネソタ・マイニング・アンド・マニュファクチャリング・カンパニー | Expansion sheet material |
US5853675A (en) * | 1995-06-30 | 1998-12-29 | Minnesota Mining And Manufacturing Company | Composite mounting system |
US5736109A (en) * | 1995-06-30 | 1998-04-07 | Minnesota Mining And Manufacturing Company | Intumescent sheet material and paste with organic binder |
US5523059A (en) * | 1995-06-30 | 1996-06-04 | Minnesota Mining And Manufacturing Company | Intumescent sheet material with glass fibers |
DE29515081U1 (en) * | 1995-09-20 | 1997-01-23 | Leistritz Abgastech | Storage mat for an exhaust gas catalytic converter |
US5882608A (en) * | 1996-06-18 | 1999-03-16 | Minnesota Mining And Manufacturing Company | Hybrid mounting system for pollution control devices |
US6726884B1 (en) * | 1996-06-18 | 2004-04-27 | 3M Innovative Properties Company | Free-standing internally insulating liner |
US5845485A (en) * | 1996-07-16 | 1998-12-08 | Lynntech, Inc. | Method and apparatus for injecting hydrogen into a catalytic converter |
DE69833136T2 (en) | 1997-02-06 | 2006-08-31 | Minnesota Mining And Mfg. Co., St. Paul | Multi-layered inflatable mat |
US6051193A (en) | 1997-02-06 | 2000-04-18 | 3M Innovative Properties Company | Multilayer intumescent sheet |
US6923942B1 (en) | 1997-05-09 | 2005-08-02 | 3M Innovative Properties Company | Compressible preform insulating liner |
US6036827A (en) * | 1997-06-27 | 2000-03-14 | Lynntech, Inc. | Electrolyzer |
US5964089A (en) * | 1997-06-27 | 1999-10-12 | Lynntech, Inc | Diagnostics and control of an on board hydrogen generation and delivery system |
US6101714A (en) * | 1997-09-08 | 2000-08-15 | Corning Incorporated | Method of making a catalytic converter for use in an internal combustion engine |
US20010051116A1 (en) | 1997-11-17 | 2001-12-13 | Minnesota Mining And Manufacturing Company | Surface tension relieved mounting material |
US8404187B1 (en) | 1998-03-11 | 2013-03-26 | Unifrax I Llc | Support element for fragile structures such as catalytic converters |
US6158120A (en) * | 1998-12-14 | 2000-12-12 | General Motors Corporation | Method for making a catalytic converter containing a multiple layer mat |
US6468252B1 (en) | 2000-08-03 | 2002-10-22 | Sanfilippo, Ii Dominic J. | Clamp for vascular access device |
US6919052B2 (en) * | 2000-12-04 | 2005-07-19 | Delphi Technologies, Inc. | Catalytic converter |
US7524546B2 (en) * | 2000-12-28 | 2009-04-28 | 3M Innovative Properties Company | Thermal insulating material and pollution control device using the same |
US20030091479A1 (en) * | 2001-11-09 | 2003-05-15 | Zlatomir Kircanski | High temperature resistant material |
US20030129101A1 (en) * | 2002-01-10 | 2003-07-10 | Steven Zettel | Catalytic monolith support system with improved thermal resistance and mechanical properties |
US7323145B2 (en) * | 2002-03-26 | 2008-01-29 | Evolution Industries, Inc. | Automotive exhaust component and method of manufacture |
US7169365B2 (en) * | 2002-03-26 | 2007-01-30 | Evolution Industries, Inc. | Automotive exhaust component and method of manufacture |
BR0314957B1 (en) * | 2002-09-30 | 2011-11-01 | exhaust gas treatment device and method of manufacture thereof. | |
JP4805808B2 (en) | 2003-01-22 | 2011-11-02 | スリーエム イノベイティブ プロパティズ カンパニー | Molded three-dimensional insulator |
US7685714B2 (en) | 2003-03-18 | 2010-03-30 | Tursky John M | Automotive exhaust component and process of manufacture |
JP2004353561A (en) | 2003-05-29 | 2004-12-16 | Petroliam Nasional Bhd | Oil scrubber in engine |
JP4982363B2 (en) * | 2004-06-29 | 2012-07-25 | ユニフラックス ワン リミテッド ライアビリティ カンパニー | Exhaust gas treatment apparatus and method for manufacturing the same |
US20060045824A1 (en) * | 2004-08-25 | 2006-03-02 | Foster Michael R | Gas treatment device and system, and method for making the same |
BRPI0807933A2 (en) * | 2007-02-19 | 2014-07-08 | 3M Innovative Properties Co | FLEXIBLE FIBER MATERIAL, POLLUTION CONTROL DEVICE, AND METHODS FOR PRODUCTION |
MX2011002132A (en) * | 2008-08-29 | 2011-04-05 | Unifrax I Llc | Mounting mat with flexible edge protection and exhaust gas treatment device incorporating the mounting mat. |
JP5608665B2 (en) * | 2008-11-11 | 2014-10-15 | テネコ オートモティブ オペレーティング カンパニー インコーポレイテッド | Method for manufacturing catalyst unit for treating exhaust gas |
PL2358359T3 (en) | 2008-12-15 | 2019-10-31 | Unifrax I Llc | Ceramic honeycomb structure skin coating |
MX2011006953A (en) * | 2009-01-05 | 2011-08-03 | Unifrax I Llc | High strength biosoluble inorganic fiber insulation mat. |
CN102459834B (en) * | 2009-04-17 | 2017-02-08 | 尤尼弗瑞克斯 I 有限责任公司 | exhaust gas treatment device |
CN102713191B (en) | 2009-08-10 | 2016-06-22 | 尤尼弗瑞克斯I有限责任公司 | Variable basic weight pad or preform and emission-control equipment |
CN102686843B (en) * | 2009-08-14 | 2015-04-01 | 尤尼弗瑞克斯I有限责任公司 | Multiple layer substrate support and exhaust gas treatment device |
EP2464836A2 (en) | 2009-08-14 | 2012-06-20 | Unifrax I LLC | Mounting mat for exhaust gas treatment device |
US8071040B2 (en) | 2009-09-23 | 2011-12-06 | Unifax I LLC | Low shear mounting mat for pollution control devices |
JP5963053B2 (en) * | 2009-09-24 | 2016-08-03 | ユニフラックス ワン リミテッド ライアビリティ カンパニー | Multilayer mat and exhaust gas treatment device |
CN102753795B (en) | 2009-12-17 | 2016-02-17 | 尤尼弗瑞克斯I有限责任公司 | The purposes of microsphere in emission-control equipment mounting mat |
EP2513444B1 (en) | 2009-12-17 | 2017-05-03 | Unifrax I LLC | Multilayer mounting mat for pollution control devices |
CN102844536B (en) | 2009-12-17 | 2017-03-22 | 尤尼弗瑞克斯 I 有限责任公司 | Mounting mat for exhaust gas treatment device |
US8765069B2 (en) | 2010-08-12 | 2014-07-01 | Unifrax I Llc | Exhaust gas treatment device |
EP2603676B1 (en) | 2010-08-13 | 2016-03-23 | Unifrax I LLC | Mounting mat with flexible edge protection and exhaust gas treatment device incorporating the mounting mat |
WO2012065052A2 (en) | 2010-11-11 | 2012-05-18 | Unifrax I Llc | Mounting mat and exhaust gas treatment device |
US9163549B2 (en) | 2011-10-07 | 2015-10-20 | Tenneco Automotive Operating Company Inc. | Exhaust treatment device with integral mount |
US8721977B2 (en) | 2011-10-07 | 2014-05-13 | Tenneco Automotive Operating Company Inc. | Exhaust treatment device with integral mount |
GB2497843B (en) * | 2011-11-30 | 2018-05-09 | Bosch Gmbh Robert | Fuel cell system |
US9452719B2 (en) | 2015-02-24 | 2016-09-27 | Unifrax I Llc | High temperature resistant insulation mat |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS554717A (en) * | 1978-06-22 | 1980-01-14 | R & D Off Makoto:Kk | Pickup device |
US4239733A (en) * | 1979-04-16 | 1980-12-16 | General Motors Corporation | Catalytic converter having a monolith with support and seal means therefor |
US4269807A (en) * | 1979-10-22 | 1981-05-26 | Uop Inc. | Catalytic converter mounting arrangement for reducing bypass leakage |
US4343074A (en) * | 1979-10-22 | 1982-08-10 | Uop Inc. | Method of making a catalytic converter |
US4385135A (en) * | 1982-05-26 | 1983-05-24 | Minnesota Mining And Manufacturing Company | Intumescent sheet material containing low density fillers |
US4617176A (en) * | 1984-09-13 | 1986-10-14 | Minnesota Mining And Manufacturing Company | Catalytic converter for automotive exhaust system |
AU596966B2 (en) * | 1985-04-16 | 1990-05-24 | Unifrax Corporation | Monolithic catalytic convertor mounting arrangement |
US4782661A (en) * | 1987-02-13 | 1988-11-08 | General Motors Corporation | Mat support/substrate subassembly and method of making a catalytic converter therewith |
US4750251A (en) * | 1987-02-13 | 1988-06-14 | General Motors Corporation | Mat support/substrate subassembly and method of making a catalytic converter therewith |
-
1987
- 1987-08-17 US US07/085,778 patent/US4865818A/en not_active Expired - Lifetime
-
1988
- 1988-07-12 AU AU18959/88A patent/AU608337B2/en not_active Ceased
- 1988-08-15 CA CA000574736A patent/CA1304298C/en not_active Expired - Fee Related
- 1988-08-16 KR KR1019880010403A patent/KR890004053A/en not_active Application Discontinuation
- 1988-08-16 JP JP63203677A patent/JPS6466412A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
JPS6466412A (en) | 1989-03-13 |
KR890004053A (en) | 1989-04-19 |
AU1895988A (en) | 1989-02-23 |
US4865818A (en) | 1989-09-12 |
AU608337B2 (en) | 1991-03-28 |
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