DE8812805U1 - Component kit for a catalyst - Google Patents

Description

The invention relates to monoliths for catalysts for the exhaust gases of internal combustion engines.

Catalysts are known in a variety of designs (DE-OS 36 38 049 and EP-PS 176 722). The catalysts are manufactured in the form of two housing halves. The monoliths wrapped in the expansion mat, whose front sides are often ground flat, are then inserted into these. The inlet or outlet cone is guided close to the front side of the monolith using a guide plate to prevent the hot exhaust gas from directly hitting the expansion mat surrounding the monolith. To achieve this, the additional guide plate must be guided close to the front side of the monolith with little play. The two housing halves are then placed on top of one another and welded along their drawn edges.

The disadvantage of such known catalysts is the complex production and assembly of the monoliths in the housing, not to mention the fact that very often every monolith has to be ground flat on the front side, since the sealing rings do not allow any tolerances of the monolith, which is not only complex, but also carries the risk of damage. Finally, the welded edge protruding at the side is a hindrance, because a compact installation of the catalyst in confined spaces is not possible.

The invention is based on the object of creating a monolith

), 36

to be embedded in such a way that the catalyst can be manufactured more easily, less prone to failure, more reliably and more cheaply

is.
5

This object is achieved according to the invention by a modular system for a catalyst according to the main claim. According to the invention, an intermediate product is produced with the monolith for easy further processing, so that it can be worked on without any problems. Apart from the fact that production is possible without any problems and without any risk of damage to the monolith, the intermediate product is also very easy to process as a modular part and not only offers sufficient protection against damage in the form of this intermediate product, but also in the installed position, the protective ring reliably prevents the hot exhaust gas from flowing past or onto the swelling mat. In addition, the protective ring used, which is designed to be resilient, makes it easy to compensate for manufacturing tolerances in the monolith without the need for any further processing and without the risk of damaging it during assembly or operation. It is particularly advantageous that only the protective ring needs to be made of stainless steel.

To produce a shell-free catalyst, only the inlet and outlet cones need to be pushed over the monolith that protrudes axially at the front, butt-jointed with the sheet metal and then welded together along the joint edge. These parts can be manufactured individually in an extremely efficient manner and extruded without any problem, and can also be insulated according to thermal and acoustic requirements.

Since the monoliths can currently only be coated in a maximum axial length of six inches, they are usually manufactured and driven in two lengths, namely six inches and three inches. Depending on the design of an engine, it may be necessary to arrange several monoliths one behind the other. For this purpose, an intermediate ring must be provided between the monolith components.

^iKJ Both sides of the ring are designed to overlap the protruding part of the protective ring and to butt against the sheet metal. A weld seam can then be applied along the abutting edge, preferably by automatic machines. This intermediate ring is particularly advantageously made from sintered metal and has a grooved and/or corrugated surface for better heat dissipation.

Further expedient embodiments and developments of the invention are characterized in the subclaims.

A preferred embodiment is explained in more detail below with reference to the drawing.

In this shows: Fig. 1 a schematic cross section

by a monolith with a swelling mat;

Fig. 2 the monolith with swelling mat,

in view;

6 I

Fig.

the monolith according to Figure 1 with a sheet of metal placed around it, in schematic cross-section;

Fig.

Fig.

Fig.

the monolith with sheet metal according to Figure 3, in a schematic front view in a partially finished state;

the monolith according to Figure 3 with protective ring inserted;

a complete catalyst with an inserted monolith according to Figure 5 and an inlet and outlet cone without insulation as well as an intermediate ring, in schematic cross section;

Fig.

the monolith according to Figure 6 with additional thermal and/or acoustic insulation on the entrance cone and the exit cone;

Figures 8 to

Fig.

different shapes of entrance and exit cones;

the protective ring according to Fig. 5 in schematic cross-section.

·

1 Fig. 13 5 Fig. 14 Fig. 15 10

the detail XIII according to Fig. 12 in a partially broken-off representation and larger scale;

the intermediate ring according to Fig. 6, in schematic cross section and

the intermediate ring according to Fig. 14 in front view-

A swelling mat 21 is placed around the monolith 20, which is designed as a vertical cylinder with an oval front surface (Fig. 2), or its shell, leaving a distance to the two circumferential end edges 22 of the monolith, whereby the long side or the shell line of the monolith 20 is larger than that of the swelling mat.

21 is. 20

The swelling mat 21 is surrounded by a sheet metal 24 that protrudes on both sides to form an annular space, so that at least two ends of the sheet metal running along a surface line butt against each other and are welded together. Figure 4 shows the possibilities. It is either possible to use two mirror-symmetrical sheet metal halves, which are pressed against the swelling mat 21 on opposite sides (top and bottom in Figure 4) along a central plane 25 and welded in this position. However, it is also possible to use a single piece and to weld together the ends of the sheet metal that butt against each other along a surface line (plane 25).

35

However, before the connection of the along a generatrix

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If the butt-jointing parts of the sheet 24 are to be welded together, a protective ring 26 is inserted in the annular space 23 (Fig. 3) which encompasses the two end edges 22 of the monolith 20 and protrudes axially on both sides over the sheet 24. The sheet 24 is then welded, whereby the two protective rings 26 are sufficiently firmly attached to the sheet. However, it is also possible to fix the protective ring 26 separately with a circumferential weld seam. The protective ring ensures that the - sensitive - circumferential end edge 22 of the monolith 20 cannot be damaged and that during intermediate storage the monolith 20 comes to rest on the protruding protective ring 26 and not its front side 27, which greatly reduces the risk of damage. In addition, the protective ring 26, which is open towards the expansion mat 21, is resilient, so that manufacturing tolerances in the monolith can be easily compensated. Finally, its closed part, which protrudes forwards over the front side 27 of the monolith 20, prevents hot exhaust gases from reaching the expansion mat 21 and damaging it.

This intermediate part shown in Figure 5 as part of a modular system is used to produce a shell-free catalyst, as shown in Figure 6, using an inlet cone 28 with a pipe connection 29 and an outlet cone 30, also with a pipe connection 31. An intermediate ring 32 can be used to connect monolith components in series with monoliths of different lengths, for example. The individual parts are each pushed over the protruding part of the protective ring and butt-jointed with the sheet metal 24. A weld can be made at this butt-joint point.

without the risk of damaging the monolith during welding, because the weld seam is made in an area of the protective ring 26 that does not come into direct contact with the monolith. The respective blunt joints or welds are marked with the reference numeral 33. The component according to Fig. 5 is marked with 34 in the entire catalyst according to Fig. 6.

Figure 7 shows the same catalyst as in Fig. 6. Only

A separate thermal and/or acoustically necessary insulation 35 with an insulation shell 36 is attached to the input cone 20 and the output cone 30. The Ig intermediate ring 32 does not have to be a sintered ring, but can, as shown in the upper part of the cross section, also be a sheet metal ring 37 with an outer insulation 38 and an outer insulation shell 39.

2Q The inlet and outlet cones can be simple cones (in plan view as per Fig. 8 and in cross section as per Fig. 10) or double cones, as shown in plan view in Fig. 9. It is also possible to use an oval inlet pipe according to the embodiment in Fig. 11 instead of the double cone.

The protective ring 26 is shown in a schematic half-section in Fig. 12 and the detail in Fig. 13. From this it can be seen that in cross section an outer leg 40 for

QQ attachment to the sheet metal is provided. The outer leg 40 has an inwardly projecting rounded bend 41 for the purpose of attachment to the front side 27 of the monolith 20. The bend 41 is followed by a counter-

»g sets curved springy inner leg 42, which on

the long side of the monolith 20. The inner leg 42 and/or the bend 41 are shaped in such a way that the peripheral edge 22 of the monolith is surrounded at a distance - protected. The resilient design of the leg, which is open on one side, also ensures that manufacturing inaccuracies of the monolith 20 can be compensated for in a simple manner, namely by the legs and/or the bend of the

I^ protective ring 26 yields in a resilient manner. At the same time, when welding along the outer leg 40, it is ensured that the monolith not resting on this outer leg cannot be damaged. At the same time, however, reliable protection is ensured against the flow of hot exhaust gases against the swelling mat.

The intermediate ring 32 made of sintered metal is shown in cross-section in Fig. 14. For better heat dissipation, it has waves 45 on its surface. Its two sides are each designed to overlap the part of the protective ring 26 that protrudes beyond the front side 27 of the monolith 20 and to butt against the sheet metal 24, so that a simple circular weld seam parallel to the circumferential end edge 22 at the joint is preferably made by a welding machine.

*5 mats can be laid.

Claims (11)

Roth Technik GmbH S 13.635 P-DE/s/b COMPONENT KIT FOR A CATALYST CLAIMS 1. Cylindrical, preferably oval in cross-section and coated monolith made of ceramic as a modular system for a catalyst for the exhaust gas of internal combustion engines, which is provided with an inlet cone tapering from the cross-section of the monolith to the cross-section of the pipe carrying the exhaust gas, with a pipe connection and an outlet cone, also with a pipe connection, with a swelling mat being arranged between the jacket of the monolith and the sheet metal surrounding it, with the swelling mat (21) having a shorter surface line being laid around the jacket of the monolith (20) while leaving a distance to the two circumferential end edges (22) of the monolith (20), with the swelling mat being enclosed by a sheet metal (24) protruding on both sides over it to form an annular space (23) in such a way that at least both ends of the sheet metal are butt-jointed along a surface line (25). abut and are welded together, and wherein in each annular space (23) a protective ring (26) is inserted which encompasses the two end edges (22) and protrudes axially on both sides over the sheet (24) and the front side (27) of the monolith and is fixed to the sheet (24). 2. Monolith according to claim 1, characterized in that the protective ring (26) has a flat outer leg (40) in cross section for contact with the sheet metal (24). 3. Monolith according to claim 1 or ?., characterized in that the outer leg (40) has an inwardly rounded bend (41) for contact with the front side (27) of the monolith (20) having.
15 4. Monolith according to one of claims 1 to 3,
characterized in that the bend (41) is followed by an oppositely bent, resilient inner leg (42) which surrounds the peripheral edge (22) of the monolith (20) and rests on the martel or the long side of the monolith (20). ^i: 25 5, Monolith according to one of claims 1 to 4, characterized in that the inner leg (42) and/or the bend (41) are shaped such that the peripheral edge (22) of the monolith (20) is encompassed at a distance.
30 6. Monolith according to one of claims 1 to 5,
characterized in that the protective ring (26) is made of stainless steel. ' 36 •&igr; I • « ) Il 7. Monolith according to one of claims 1 to 6,
characterized in that the input cone (28) and/or the output cone (30) are designed to engage over the part of the protective ring (26) projecting beyond the front face (27) of the monolith (20) and to blunt Abutments are formed on the sheet (24).
10 8. Monolith according to one of claims 1 to 7,
characterized in that for arranging two or more monoliths (20) one behind the other, a I^ intermediate ring (32) is provided, both sides of which are designed to engage over the part of the protective ring (26) protruding beyond the front side (27) of the monolith (20) and to butt abut against the plate (24). 9. Monolith according to claim 8, characterized in that the Intermediate ring (32) is made of sintered metal. 10. Monolith according to claim 8, characterized in that the intermediate ring (32) consists of sheet metal with insulation. 11. Monolith according to one of claims 8 to 10,
characterized in that the surface of the intermediate ring is provided with waves running parallel to the surface lines or the jacket plate (24) (45).