Abstract:
The invention pertains to a diesel particulate exhaust filter having at least one inorganic filter body mounted in a housing through which flows exhaust gas from the diesel engine and having a device (electrically operated heating element) for combustion (oxidation) of the filtered exhaust particles, characterized in that the filter body is made of a low temperature age hardening material produced from a flowable organic molding material consisting of an oxide mixture including amorphous SiO2 and Al2O3 and/or electrostatic filter ash from high-temperature coal-fired power stations and/or calcined ground bauxite and an alkali silicate solution.
Abstract:
Metal honeycomb structure (1), especially a catalyst support for motor vehicles with internal combustion engines, with walls which form a plurality of channels (9) through which a fluid can pass. The honeycomb (1) has a length (l) and is arranged and secured in at least one inner (2a, 2b, 2c) and an outer casing pipe (3). In addition, the inner casing pipe (2a, 2b, 2c) is divided into at least three partial sections, i.e. a first (2a) partial section lying substantially only along a part of the length (l) of the honeycomb on the outside, a second (2b) flared partial region and a third (2c) lying on the inside of the outer casing pipe (3). The bent shape of the inner casing pipe means that the honeycomb (1) and the outer casing pipe (3) can be thermally and mechanically separated, thus ensuring that the securing system has a long service life even in extreme operating conditions.
Abstract:
The invention concerns a catalytic converter consisting of a tubular shealth (1) containing at least two separate honeycomb elements (2, 3) made of structured layers of sheet metal (4, 5). In order to make it possible to produce the catalytic converter inexpensively on a large scale, honeycomb elements (2, 3) are used which are flexible in their construction and are inserted in the tubular shealth with a prestress. This prestress is produced by compressing the flexible honeycomb elements by 2 to 10 % of the theoretical uncompressed diameter of the element (2, 3), this being carried out by compressing the honeycomb elements before inserting them in the tubular shealth (1) and/or by shrinking the tubular shealth (1) on to the honeycomb elements (2, 3) after they have been inserted. Owing to the prestress, elements (2, 3) of this kind are stable to the mechanical stresses involved in high-speed manufacturing operations and are suitable for welding in the upright position and subsequent coating with ceramic material. The mainapplication of such catalytic converters is in vehicles, particularly mass-produced vehicles.
Abstract:
Metal catalysts which are welded by means of laser or electron beams to a surrounding shell are known. A disadvantage of these is that the connection between metal catalyst and surrounding shell is of inadequate strength. It is proposed for a metal support (1) to comprise a plurality of layers of corrugated or corrugated and smooth sheets (3, 4) which are stacked one on top of the other and twisted and which have smooth, mutually overlapping end sections (5, 5'). The end sections (5, 5') form on the circumference of the metal support (1) an outer layer (8) which is connected, preferably welded, to the surround (2). Use for exhaust catalysts of internal-combustion engines.
Abstract:
A honeycomb body includes leading and trailing end surfaces being mutually spaced apart in a given flow direction. Subsections are disposed in succession in the given flow direction between the end surfaces. At least some sheet-metal layers have structures forming channels therebetween extending approximately in the given flow direction through which a fluid can flow. The channels have dimensions determined by the structures of the sheet-metal layers. Each of the subsections has a different number of channels per unit of cross-sectional area and the channels have cross-sectional areas differing in each of the subsections. The sheet-metal layers include some layers being smooth or slightly structured in proportion to the dimensions of the channels, having spacings therebetween and extending from the leading to the trailing end surfaces giving the honeycomb body a monolithic form, and the sheet-metal layers include different numbers of other sheet-metal layers filling the spacings in each of the subsections.
Abstract:
An exhaust system is described having a plurality of branches leading to different engine cylinders or groups of engine cylinders and a single catalytic converter (12) connected to the plurality branches in such a manner that gases from different branches of the manifold do not mix with one another prior to entering the converter nor during their passage through the converter.
Abstract:
A metallic catalyst support (1) of honeycomb structure, through which a fluid can flow, is surrounded by a tubular sheath (2) and inserted in an opening (5) in a separating wall (4) approximately perpendicular to the direction of flow. The manufacture of this relatively compact type of support (1), which is used to purify the exhaust gases of small motors, can be simplified and its service life prolonged by providing the tubular sheath (2) of the catalyst support (1) with at least one peripheral bead (3). The tubular sheath (2) can thus be pushed into an opening (5) in a separating wall (4) until it is stopped by the bead (3). The cavity (7) formed by the bead (3) prevents damage to the catalyst support (1) if the outer region of the bead (3) is subsequently welded to the separating wall (4). Although heavy demands cannot be imposed on the manufacturing tolerances, a stable arrangement is obtained in which there are virtually no leaks between the separating wall (4) and the tubular casing (2), even when only spot welded (6).
Abstract:
The invention concerns electrically conducting honeycomb elements consisting of structured metal sheets (31, 32), in particular catalyst substrates, which can be heated directly and/or whose temperature-dependent resistance can be used for operational control purposes. So that the honeycomb body has a suitable resistance, e.g. between 0.03 and 2 ohms, preferably between 0.1 and 1 ohm, it is divided electrically by electrically insulating intermediate layers (38) or surface coatings in such a way with respect to its cross-sectional plane that there is at least one electrical conduction path with the required resistance. Honeycomb bodies of this kind can be used as catalyst substrates in motor vehicles when they can be heated before and/or after the engine is started, thus reaching the operating temperature necessary for the catalystic reaction more rapidly and hence reducing the vehicle-exhaust output during the engine-start phase. The invention increases the resistance to axial loads by virtue of the fact that form-locking connections (33) are made between the metal sheets (31, 32), a ceramic intermediate layer being included in the form-locking connections (33) as electrical insulation.
Abstract:
The invention concerns a catalyzer housing (21) and a corresponding catalyzer support (26), in particular for a catalyzer located near the engine of a motor vehicle. The housing (21), which can preferably be a casting, has a larger cross-section than the catalyzer support and has an approximately rectangular opening through which the catalyzer support (26) can be inserted. The catalyzer suport (26) is fastened to a flat or convex holder plate (24) which closes the opening in the housing (21) like a lid. The catalyzer support (26) projects into the interior (28) of the housing (21). The arrangement permits cost-effective and independent manufacture of housing (21) and catalyzer support (26) and facilitates insertion and interchange of catalyzers. In particular, a catalyzer can be rotated at mid service life through 180 DEG and hence more profitably exploited.
Abstract:
A catalyst housing (1) which is part of a vehicle exhaust system, said catalyst housing (1) including an elliptical intermediate part (2) which encloses a monolithic catalyst body (4). An inlet part (7) connects the intermediate part (2) with a cylindrical inlet pipe (8), through which exhaust gases are intended to flow into the catalyst housing (1). With the object of simplifying the configuration of the inlet part (7), which has a supporting function in the catalyst housing (1), the pipe (8) is provided with an end portion (9) thrusting into the inlet part (7) and formed with two diametrically opposed impressions (10). These impressions converge towards each other towards the inner end (11) of the end portion (9) such that a symmetrical constriction of the end portion (9) is obtained. Two branch ducts (12) formed by the constriction enable distribution of the gas flow over the entire elliptical end wall surface (15) of the catalyst body (4).