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
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features
  • F01N13/14—Exhaust or silencing apparatus characterised by constructional features having thermal insulation
• • 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
  • F01N3/2882—Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices

Definitions

• the invention relates to a catalyst exhaust with thermal insulation.
• Exhausts equipped with a catalytic converter must therefore be equipped with thermal insulation to ensure that the outside temperature of the exhaust does not rise significantly above that of conventional exhausts.
• the thermal insulation according to the invention meets the requirements.
• the invention relates to a catalytic converter-equipped exhaust with thermal insulation, which is characterized in that the thermal insulation consists of a molded body made of compressed, microporous thermal insulation material of the composition 30 - 88.9% by weight of finely divided metal oxide 10 - 50 wt .-% opacifying material and 1 - 20 wt .-% fiber material exists, which is laminated at least on one side to stabilize the shape or is provided with 0.1 - 5 wt.
• exhaust pipe equipped with a catalytic converter is to be understood as meaning all exhaust systems or those parts of an exhaust system which are equipped with a catalytic converter suitable for exhaust gas purification, in particular appropriately equipped exhaust pots.
• the thermal insulation according to the invention envelops the exhaust, or the exhaust part, in close contact and is protected with a casing against mechanical destruction.
• the sheathing is constructed in such a way that the sheathed space is practically completely filled by the thermal insulation according to the invention.
• the thermal insulation according to the invention is designed as a shaped body.
• all moldings which are suitable for closely fitting the exhaust pipe to be insulated or the part of the exhaust pipe to be insulated are suitable as molded articles. These are, in particular, plate-shaped or mat-shaped bodies, which can be flat or already more or less accurately depict the outer shape of the exhaust to be insulated.
• the moldings are preferably produced by pressing the thermal insulation material at final pressures of 10-50 N / cm2 poses. It is often expedient to pre-seal the thermal insulation material, which is initially in the form of loose bulk material, if necessary with evacuation, for example at pressures of about 0.1-0.5 N / cm 2 and only in a second stage under the end pressures mentioned.
• the pressing temperatures are usually in the range of the ambient temperature, that is 15 ° to 30 ° C. Lower or higher temperatures can also be used. However, temperatures are always chosen at which the hardening of the thermal insulation material does not take place when hardener is used. Since temperatures above 500 ° C are required for curing, this parameter is of no importance in practice. Hardening takes place during operation of the catalytic converter exhaust.
• thermal insulation molded articles of the type according to the invention can be used as lamination with which thermal insulation molded articles of the type according to the invention have previously been laminated.
• These are in particular nonwovens or fabrics made of aluminum silicate, glass fiber, rock wool, cellulose, metal foil, in particular aluminum foil, cardboard, paper and others.
• the lamination gives the uncured molded body sufficient mechanical stabilization for transport and assembly.
• connection between lamination material and thermal insulation material can be adhesive or non-adhesive.
• materials such as glass fiber and the like
• Inorganic adhesives such as silica sol or water glass or known organic glue.
• lamination material that is already coated with adhesive can also be used.
• the thermal insulation material to be used according to the invention consists of 30 - 88.9% by weight of finely divided metal oxide 10 - 50% by weight opacifier 1 - 20 wt .-% fiber material and optionally 0.1 - 5% by weight hardener.
• finely divided metal oxide examples include pyrogenically produced silicas, including arcing silicas, low-alkali precipitated silicas, aluminum oxide, titanium dioxide and zirconium dioxide produced analogously. Pyrogenic metal oxides, including pyrogenic mixed oxides, are preferably used.
• the finely divided metal oxides have specific surfaces of 50 to 700 m2 / g, preferably 70 to 400 m2 / g.
• Suitable opacifiers are ilmenite, titanium dioxide, silicon carbide, iron-II-iron-III mixed oxide, chromium dioxide, zirconium oxide, zirconium silicate, manganese dioxide and iron oxide.
• the opacifiers advantageously have an adsorption maximum in the infrared range between 1.5 and 10 ⁇ m.
• fiber material examples include glass wool, rock wool, slag wool, ceramic fibers such as those obtained from melts of aluminum oxide and / or silicon oxide, asbestos fibers and others.
• thermal insulation mixtures mentioned are obtained by simply mixing the components in the desired composition.
• so-called agglomerated mixtures, in particular based on pyrogenic silica can also be used.
• the procedure is such that the opacifier is added continuously in the desired mixing ratio already during the production process of the silica, in which the silica is still in the form of the primary particles.
• the thermal insulation molded articles according to the invention have a layered ceiling of 2-10 mm, preferably 4-6 mm.
• a conventional catalytic exhaust was completely enclosed with a molded body, including one-sided lamination, 4.5 mm thick, and provided with a steel sheet sheathing, so that the sheathed space was practically completely filled by the molded body.
• the molded body had a 0.5 mm thick lamination of perforated cellulose paper.
• the molded body was produced by pressing a thermal insulation mixture of the following composition: 63.3% by weight of fumed silica 31.7% by weight of ilmenite 5.0% by weight aluminum silicate fiber with the lamination material under a final pressure of 28 N / cm2 at ambient temperature.
• the shaped body was in the form of a flat plate which was so flexible that the muffler could be encased without mechanical destruction of the shaped body.
• the thickness of the shaped body was chosen so that the shaped body was firmly embedded under pressure between the outer shells and the catalyst.
• the interior of the catalytic converter was brought to 850 ° C with a Bunsen burner.
• the temperature measuring point was on the inner wall of the catalyst pot at a distance of 20 cm from the exhaust opening.
• a second measuring point was located on the outside of the casing exactly opposite the first measuring point. At the second measuring point, the temperature was 200 ° C. The measurement was carried out without cooling the jacket.
• a pre-compressed insulation mat without lining was placed in the outer shells of a conventional exhaust converter.
• a suitable press die the shape of which was adapted to the insulation shell, the insulation material was brought into shape so that the insulation thickness was approx. 4 mm everywhere in the inner shell.
• the thermal insulation mixture was composed as follows: 62.5% by weight of fumed silica 31.7% by weight of ilmenite 5.0% by weight aluminum silicate fiber 0.8 wt% boron carbide
• the rapid heating is due to the exothermic curing reaction of the thermal insulation.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Exhaust Silencers (AREA)
• Exhaust Gas After Treatment (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6314978

Family Applications (1)

Country Status (3)

Cited By (3)

Families Citing this family (5)

Family Cites Families (10)

• 1986
  • 1986-11-28 DE DE19863640653 patent/DE3640653A1/de not_active Withdrawn
• 1987
  • 1987-10-08 JP JP25260787A patent/JPS63138112A/ja active Pending
  • 1987-11-26 EP EP87117433A patent/EP0269101A3/fr not_active Ceased

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