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
  • F01N13/16—Selection of particular materials
• • 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

Definitions

• a silencer for internal combustion engines and a method for its manufacture is provided.
• the invention relates to a silencer for internal combustion engines with outer walls consisting at least partly of a fireproof and corrosion resistant material and a surrounding cover of a weatherproof and impact resistant material.
• silencers of this kind solve the corrosion problems they have in another respect proved less suitable in practice because a sintered ceramic material is very sensitive to the mechanical influences in the form of impacts or shocks to which a silencer is exposed under normal operation. As a result of such influences cracks or fractures often arise in the ceramic shield of the silencer.
• a silencer according to the invention excellent sound absorbing properties as well as a great resistance to impact influences and other dynamic loads are obtained in combination with a substantially improved resistance to weather influences by means of a simple and cheap construction which according to the invention is characterized in that said fireproof and corrosion resistant material comprises a form stable internal lining of a high-insulating, thermo-resistant fibre- based material.
• the lining consists mainly of aluminium silicate fibres.
• this material is shrinkproof even at temperatures above 1000oC and in spite thereof elastic, as a result of which an external cover produced by the above mentioned direct spraying will give no occasion to harmful tensions which might otherwise be caused by differences between the thermal coefficients of expansion of the materials.
• a preferred embodiment is further characterized in that the lining at its ends comprises conical wall parts directed towards the interior of the silencer.
• the external impact, proof cover consists of a fibre-reinforced concrete or cement.
• the impact proof cover may be formed directly on the lining by spraying and/or bandaging of glass, steel, plastics or coal fibre- reinforced concrete or cement.
• the invention relates to a method for manufacturing a silencer of the above mentioned preferred embodiment, said method being characterized according to the invention in that the cylindrical wall of the lining is manufactured by vacuum forming from a liquid slurry of said fibre-based material on a tubular core corresponding to the internal space of the silencer, the lining thus produced being connected after curing with the conical wall parts and the flat end walls, the external cover of said fibre-reinforced concrete or cement being applied to the cylinder wall between said edge portions of the. conical wall parts.
• FIGS. 1 and 2 are longitudinal sectional views of two embodiments of a silencer according to the invention.
• the silencer shown in Fig. 1 which may be of conventional form with a circular or oval cross section comprises in accordance with the invention a form stable internal lining of a fire proof and corrosion resistant fibre-based material and an externally surrounding weather proof and impact proof cover of fibre-reinforced cement or concrete.
• the lining consists of aluminium silicate fibres and comprises a cylindrical part 1 manufactured by a vacuum forming process from a liquid slurry on a perforated tubular core matching the internal cross section of the silencer.
• the lining comprises, in addition, inwardly protruding conical wall parts 3 and 4 at the ends of the silencer, said parts being manufactured as separate vacuum formed parts of the same fibre based material as the wall 1 and being designed with flange-forming edge portions 12 and 13, which after connection of the wall parts 3 and 4 with the cylindrical wall 1 will extend outside the external side of the latter to an extent corresponding to the desired thickness of the surrounding impact proof cover 2.
• the silencer is externally finished with flat end walls 5 and 6, which may be of a corrosion resistant metal such as stainless steel and may be welded on to the combustion gas inlet pipe 7 and outlet pipe 8 of the silencer.
• pipes 7 and 8 are formed as a single pipe which is blocked in the middle by a transverse partition 9 so that there is no direct communication throughout the pipe.
• the pipes are of a corrosion resistant metal such as stainless steel and have each a number of openings 9a through which combustion gases are communicated to and from the interior of the silencer.
• the blocking between the inlet and the outlet pipes is not a necessary condition.
• each of the conical wall parts 3 and 4 of the lining is formed by a solid conical body 10 and 11, respectively, which are engaged on the external side by the flat end walls 5 and 6 and have towards the interior of the silencer a short tubular piece surrounding the inlet and outlet pipes 7 and 8, respectively.
• the external cover 2 may be provided by direct spraying and/or bandaging of glass, steel, plastics or coal fibre-reinforced cement or concrete on the external side of the cylindrical wall 1 of the lining.
• the thickness of the cylindrical part 1 of the lining may be 10 mms e.g. and of the external cover 2 about 4 mms, whereas the conical wall parts 3 and 4 may have an apical angle of e.g. 90°.
• a covering la of a vibration and flow resisting material may be applied to the internal side of the lining and on the wall parts 3 and 4.
• This covering may be applied with a relatively small thickness prior to the assembling of the cylindrical wall 1 of the lining with the conical bodies 10 and 11 and the end walls 5 and 6 from a liquid slurry of aluminium silicate compounds or by applicationof a fibre reinforced cement containing e.g. alumunium silicate fibres.
• the conical wall parts 16 and. 17 of the lining 15 are formed by double-conical solid bodies 18 and 19.
• the external cover 20 may be applied not only to the cylindrical part 15 of the. lining, but also on the external conical sides 21 and 22 of the bodies 18 and 19, so as to avoid the arrangement by welding of the relatively large flat end walls 5 and 6 of stainless steel shown in Fig. 1.
• the external conical sides 21 and 22 may be formed in the same way as the internal conical wall parts 16 and 17 with short tubular pieces, an excellent securing on the inlet and outlet pipes 23 and 24 may be obtained by means of caps 25 and 26 of stainless steel secured on to the tubular pieces by clips 27.
• the considerable axial length of the double-conical bodies 18 and 19 provides in itself an excellent sealing.
• a covering corresponding to the covering la of flow resistant material in Fig. 1 is designated with 15a.
• a layer of a ceramic adhesive between the external cover 20 and the bodies 18 and 19 as well as between the latter and the inlet and outlet pipes 23 and 24 is indicated by a thick line at 14 in Fig. 2.
• the invention is not limited to the embodiments illustrated in the drawings, since the manufacture of the lining by vacuum forming implies a considerable degree of freedom with respect to the geometrical shape of the silencer.
• the internal lining may also be utilized in connection with a conventional metallic external wall.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust Silencers (AREA)

Applications Claiming Priority (6)

Publications (1)

Family

ID=27221758

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (5)

• 1983
  • 1983-11-29 DK DK546483A patent/DK546483A/da not_active Application Discontinuation
• 1984
  • 1984-07-13 WO PCT/DK1984/000068 patent/WO1985000409A1/en not_active Ceased
  • 1984-07-13 EP EP19840902794 patent/EP0149660A1/en not_active Withdrawn

Non-Patent Citations (1)

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