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
• • 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
  • F01N2310/00—Selection of sound absorbing or insulating material
  • F01N2310/02—Mineral wool, e.g. glass wool, rock wool, asbestos or the like
• • 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
  • F01N2310/00—Selection of sound absorbing or insulating material
  • F01N2310/04—Metallic wool, e.g. steel wool, copper wool or the like

Definitions

• the present invention relates to a catalytic converter or diesel particulate trap used to clean the exhaust gas of an internal combustion engine where the catalytic converter system is mounted in close proximity to the engine exhaust gas manifold and subjected to higher exhaust gas temperatures in the region of 800°C to 1000°C than those experienced by the conventional catalytic system mounted beneath the car body and subjected to exhaust gas temperature not exceeding 700°C.
• the PRE CAT CONVERTER system Situated in such close proximity to the engine exhaust gas manifold the PRE CAT CONVERTER system will be subjected to exhaust gas temperatures in the region of 800°C - 1000°C, severe pressure pulsations and very high exhaust gas velocities.
• the ceramic monolithic blocks containing the catalytic reagents present an appreciable resistance to the flow of the hot engine exhaust gases and that unless the monolith is correctly supported and sealed within the metal enclosure system the hot gases will preferentially flow around the monolithic block.
• the effectiveness of the catalytic reaction on the hot exhaust gases is consequently greatly dependent upon the effectiveness of the support and sealing system.
• the present invention relates to a form of sealing ring which also acts as a form of support at the end of the monolithic block which combines heat resistant ceramic fibres enclosed within a heat resistant knitted wire mesh in such a configuration that the fibres fill the interstices between the strands of knitted wire and so prevent the passage of the hot exhaust gases through the combined structure forcing them to pass through the ceramic monolith and hence to react as desired with the catalytic agents within the monolith.
• the heat resistant ceramic fibres may consist of any material capable of withstanding the exhaust gas temperatures in the region of 800°C - 1000°C, as for example fibres of expanded alumina, titania or silica fibres or combinations of these substances, although silica is generally preferred.
• the heat resistant metals used as the knitted wire containment may be of any alloy composition which will withstand oxidation and degredation at temperatures in the region of 1000°C, but generally those alloy combinations containing nickel and chromium and known variously as stainless steels are preferred.
• Various methods may be used to obtain the appropriate admixture of ceramic fibres and knitted wire mesh including the surrounding of a knitted wire sleeve of an appropriate length with a thin layer of randomly laid ceramic fibres in the form of a blanket such that when the knitted wire sleeve is rolled back on itself there is produced a tubular ring comprised of alternate layers of knitted wire mesh and ceramic fibres.
• a second method which may be used with this present invention is to wind a strand composed of ceramic fibres in a spiral form around the said knitted wire sleeve at a sufficient pitch such that when the knitted wire mesh sleeve is rolled back on itself there is again produced a tubular ring comprised of alternate circular layers of knitted wire and ceramic fibres.
• the ceramic fibre may be combined with the wire mesh in the knitting operation whereby the fibre then forms an intimate component of the knitted mesh such that when an appropriate length of the knitted sleeve is rolled back on itself there is produced a tubular ring comprised of ceramic fibres intimately admixed with the knitted mesh.
• the ratio by weight of the knitted wire mesh to the ceramic fibre material may be varied by any of the above methods to be within the range of equality to 25:1 but a ratio of 7:1 is generally preferred.
• tubular ring produced by rolling the combination of knitted wire mesh and ceramic fibres may be compressed or formed into any required cross sectional configuration by use of the appropriate formed tools.
• the cross sectional configurations so produced may include such forms as square, rectangular, part circular, triangular or any combination of such shapes, with or without edges, lips or recesses.

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)
• Exhaust Gas After Treatment (AREA)
• Exhaust Silencers (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=10816973

Family Applications (1)

Country Status (2)

Citations (1)

Family Cites Families (3)

• 1997
  • 1997-08-05 GB GBGB9716493.3A patent/GB9716493D0/en active Pending
  • 1997-08-15 EP EP97306236A patent/EP0896137A3/fr not_active Withdrawn

Patent Citations (1)

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