DE8715289U1 - Carrier body for a catalytic reactor for exhaust gas purification - Google Patents

Description

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Description ;

Carrier body for a catalytic* reactor for exhaust gas purification

The innovation relates to a filter body for a catalytic reactor for exhaust gas purification, in particular for internal combustion engines, consisting of a honeycomb body wound or folded from corrugated or corrugated and smooth metal strips and provided with a plurality of flow channels, which is held in a casing tube.

Support bodies of this type are known (DE-OS 35 32 408). When producing such designs, the metal honeycomb body is pushed axially into the casing tube and soldered or welded to it for axial securing. A problem with this type of production, especially when there are no cylindrical honeycomb bodies and casing tubes, is the difficulty of bringing the honeycomb body with its outer circumference close to the casing tube in order to be able to subsequently carry out a good soldering.

It is therefore also known (DE-OS 28 56 030)/ instead of axially inserting it into a casing tube, to split the casing tube and press it onto the honeycomb body under radial pressure before the casing tube parts are firmly connected to one another. With this type of production, a certain amount of squeezing of the circumference of the honeycomb body occurs, which can ensure that the honeycomb body fits tightly against the casing tube, but a large part of the flow channels formed in the honeycomb body can be pressed shut, so that the corresponding surfaces cannot subsequently participate in the catalytic conversion.

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The innovation is therefore based on the task of designing a carrier body _in such a way that it can be easily manufactured without, however, impairing the fit of the honeycomb body in the casing tube.

Based on the idea that it is advantageous to embed the periphery of the honeycomb body in a protective layer, the innovation is that an elastically deformable, heat-resistant mat that envelops the honeycomb body is clamped between the periphery of the honeycomb body and the casing tube. This design allows the honeycomb body to be held in the casing tube under radial pressure, which does not cause any deformation of the honeycomb body. It has been shown that with such a carrier body, soldering can be dispensed with because the elastic forces and the friction and form fit between the casing tube and the honeycomb body caused by the elastic deformation of the mat are sufficient, with appropriate dimensions, to hold the honeycomb body in the casing tube without soldering.

According to the feature of claim 2, the mat is advantageously made from a material - known per se - that swells with increasing temperature. This measure ensures that the honeycomb body is held securely in the casing tube even at higher temperatures.

Subclaims 3 to 5 characterize an embodiment in which, in a manner known per se, the casing tube, which can be expanded radially by the division, is pressed radially from the outside onto the mat and onto the hub body and is then fixed in its final shape.

The features of claims 6 and 7 bring with them the advantage that the casing pipe can be made stable for this type of production. Another advantage is that the sound insulation is improved by the arrangement of the beads.

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Examples of the innovation are shown in the drawing and are explained below. They show:

Fig. 1 is a perspective schematic representation of a
first embodiment of the innovation with a
Final form cylindrical casing pipe,

Fig* 2 an enlarged detailed view of the seam
of the jacket pipe of Fig. 1,

Fig. 3 a variant of the seam of a jacket pipe,
similar to Fig. 1,

Fig. 4 another possibility for the formation of the seam of a jacket pipe, similar to Fig. 1,

Fig. 5 another possibility for the formation of the connection point on a jacket pipe, similar to Fig. 1
and

Fig* 6 is a perspective schematic representation of a
Embodiment of the innovation with a honeycomb body
with elliptical cross-section.

In Fig. 1, a cylindrical honeycomb body (1) is shown, constructed in a known manner by winding or folding a corrugated metal strip or a corrugated and a smooth metal strip, which is provided with a large number of flow channels (2), only indicated schematically here, which all run parallel to the axis (5) of the cylindrical honeycomb body (1). This honeycomb body (1) is held in a likewise cylindrical jacket tube (3) by a mat (4) made of an elastic but heat-resistant material being clamped between the jacket tube (3) and the outer circumference of the honeycomb body (1). The mat (4) is therefore elastically radially compressed in the position shown by the outer jacket tube (3).

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presses and presses: in turn on the hub body (J)/ without affecting its structure in the area of the outer circumference. The size of the annular gap t that remains between the honeycomb body (1) and the casing tube (3) in the final pitch is matched to the thickness of the mat (4) and its elastic properties in such a way that a sufficiently firm fit of the honeycomb body (1) in the casing tube (3) is ensured, but without having to fear damage to the honeycomb body (1).

In the embodiment shown, the casing tube (3) is placed radially from the outside on the honeycomb body (1) wrapped with the mat (4). For this purpose, the casing tube is slit along a casing line running parallel to the axis (5) and connected along this slit (8), which in the embodiment, as can be seen in particular from Fig. 2, is done by the edges (6 and 7) of the two casing parts to be joined overlapping in an overlapping area (9)* The outer edge (6) is then firmly connected to the casing part associated with the edge (7) by a weld seam (13) or the like*. This connection process is preceded by the radial compression of the casing, which is compressed by a suitable device from the position shown in dashed lines in Fig. 1, in which the edges (6' and 7') are not yet in contact with one another, to such an extent that the joining of the edges (6 and 7) becomes possible.

Instead of overlapping and welding the edges (6 and 7), it would also be possible to form a flange-like protruding edge (14) on one edge of the casing ( ³¹ ), which is overlapped by a flanged edge (15). It is also possible to provide both open ends of the casing ( ³¹ ), as shown in Fig. 4, with a protruding flange (14* or 16) in the area of the slot (8) and then to connect both flange edges to one another by means of a weld seam (13).

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A particularly suitable way of closing the
Shell (3 ¹ ), which is slit along a shell line, is

shown in Fig. 5. Here, in the area of the free edges (6 j

and 7) , which form the slot (8) between them, an arrangement '■'·

tion, which leads to the positive closing of the man- ·.

means (3 ¹ ). For this purpose, T-shaped protruding tabs (10) are provided on the edge (6), which engage in corresponding T-shaped recesses (11) on the edge (7) when the

casing (3') has reached the dimension during radial compression, |

which is used to fix the honeycomb body (1) under elastic compression [

forming of the mat (4) was determined sufficiently. In order to

This type of production prevents the elastic mat from getting jammed

(4) in the slot (8), one of the two jl

Shell parts, for example on the || associated with the edge (7).

A cover plate (17) must be provided on the casing part, which, when used,

closing the casing (3 ¹ ) a radial deflection of the mat |

(4) prevented. j

Fig. 6 shows a modification of the carrier body of Fig. 1 in that here the casing is constructed from two half-shells (3a and 3b) between which the honeycomb body (1) _is clamped with the mat (4) enveloping it. At the two overlapping points (9, 9a) a connection according to Fig. 2 or any of the other possibilities shown can be provided. In this embodiment it is advantageous if the two half-shells (3a and 3b) are provided with beads (12) which run _in planes which are perpendicular to the axis ( ⁵¹ ) of the honeycomb body. pers (I ¹ ) which in this case has an elliptical cross-section, which it can have from the beginning, or to which it is pressed starting from a cylindrical shape in which there are corresponding free spaces when the half-shells (3a and 3b) are placed. In this case too, an excellent hold of the honeycomb body (1·) in the casing is achieved, | without the need for soldering. In this way, the problems associated with the external sealing can also be avoided.

sufficiently secure soldering of metallic honeycomb bodies in a metallic jacket tube.

Claims (8)

PATENT ATTORNEYS - EUROPEAN PATENT ATTORNEYS D-7000 Stuttgart 1 Hospitalstraße 8 Tel.(0711) 291133/292857 Applicant; Süddeutsche Kühlerfabrik Stuttgart, 17.11.1987 Julius Fr. Behr GmbH & Co. KG G 8171 Mauserstraße 3 Dr.W/Ei 7000 Stuttgart 30 87-B-30 Protection claims 1. Support body for a catalytic reactor for exhaust gas purification, in particular for internal combustion engines, consisting of a honeycomb body (1) wound or folded from corrugated or corrugated and smooth metal strips, provided with a plurality of flow channels \2) , which is held in a casing tube (3), characterized in that an elastically deformable, heat-resistant mat (4) enveloping the honeycomb body (1) is clamped between the circumference of the honeycomb body (1) and the metal tube (3). 2. Support body according to claim 1, characterized in that the mat (4) consists of a material that swells with increasing temperature. 3. Support body according to claim 1, characterized in that the casing tube (3) is slotted at least along a casing line and is assembled with the edges (6, 7) of the casing parts along this slot (8) to form a tube. 4. Support body according to one of claims 1 to 3, characterized in that the in the region of the slot (8) · adjoining edges (6, 7) of the casing parts overlap each other and are connected at the overlap point (9). 5. Support body according to claim 3, characterized in that the edges (6, 7) of the casing parts are provided with form-fitting interlocking tabs (10) and recesses (11). 6. Support body according to one of claims 1 b:-Ä 5, characterized in that the casing tube (3) is provided with beads (12). 7. Support body according to claim 6, characterized in that the beads (12) are perpendicular to the axis of the casing tube ! (3) running planes. 8. Support body according to claims 1 to 3, characterized in that the jacket tube is composed of two halves (3a, 3b). Il lilt I · * &iacgr; § *· « · »« Il .11· < « « ₄ IJJ I 1 · « ·