FI76403C - FOERFARANDE FOER FRAMSTAELLNING AV ETT MANTELROER FOER EN KATALYSATOR. - Google Patents

Description

76403

METHOD OF MANUFACTURING A CATALYTIC OUTER SHELL

This invention relates to a longitudinally grooved shell structure of a catalyst for exhaust gas purification and to a method of making a longitudinal groove, comprising inserting at least one metallic catalyst cell into an outer shell tube, then securing the outer shell portions together to form a jacket around the cell and then grooving the catalyst.

The components of the catalytic exhaust purifiers currently in use are predominantly ceramic. Ceramic honeycombs are 2 7640 3 very fragile, so they need special precision and care to support. U.S. Patent No. 4,328,188 discloses a catalyst honeycomb support method in which the jacket forming the outer shell of the honeycomb consists of two steel shell halves welded together at their edges. Longitudinal movement of the catalyst cell is prevented by forming a protrusion on the shell halves to which the cell fits and by permanently fixing the cell using a separate fastening member which is welded to the shell. The separate fastening member may be a simple collar. In addition, a flexible material, such as a mat braided from steel wire or a high temperature resistant felt, must be placed between the jacket and the cell to prevent the cell from being knocked and broken during the propulsion phase or in use. The use of a damping layer also prevents possible disadvantages due to thermal expansion.

U.S. Patent No. 4,400,860 discloses a method of supporting a metal cell in which the cell is interposed between two shell halves. The shell halves are pressed together and welded to the seams. The honeycomb and the jacket are attached to each other by spot welding or soldering.

Prior art methods require the use of expensive press tools to make shell halves, and if the catalyst is to be resized, new tools are always required, which is costly. To keep costs reasonable, known methods require the production of long series in order to be profitable. Because ceramic honeycombs are very fragile, their encouragement requires special precision and care so that they do not break during the encouragement.

The object of the present invention is to provide a very rigid and temperature-resistant shell structure of a catalytic exhaust gas purifier, as well as a method for producing a longitudinal groove, which structure and method do not have the disadvantages of previously known methods. This is achieved according to the invention 3 76403 by preferably fitting metallic or metallic honeycombs inside a tube, preferably a steel tube, one end of which is optionally pre-formed into a cone, and then one or both ends of the tube being formed into a cone. Optionally, suitable end cones are then attached to the ends of the tube. The catalyst is then driven longitudinally through the groove shrinking device, whereby a compression joint is formed between the tube acting as the outer shell of the catalyst and the honeycomb and the movement of the honeycomb inside the shell is prevented.

According to the present invention, there is provided a catalyst shell structure which is very rigid. The method allows the use of a thinner shell material than usual, which reduces the weight of the catalyst and lowers the cost. The method also allows the pipe to be used as a shell material. The resulting structure retains its shape even under severe stress.

The metallic catalyst cells used in the process withstand the mechanical stresses occurring during the grooving-injection phase and in use without breaking. Thus, no ceramic material is required between the jacket and the honeycomb, like a ceramic honeycomb. On the contrary, a compression joint is formed between the outer jacket and the honeycomb. The resulting structure reduces the size of the catalyst and reduces both manufacturing and material costs.

The invention will now be described with reference to the accompanying figures, in which Figure 1 shows the shell structure of a longitudinal grooved exhaust gas purifier according to the invention in a side view.

Figure 2 shows an end view of a groove reduction method according to the invention.

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Figure 1 shows the shell structure of a 2-cell exhaust scrubber. The longitudinal grooves (2) are obtained by pushing the outer shell tube (1) through the shrinking device. The outer shell of the tube ends (6) is pressed into cones (7) and the end cones (7) are attached to the tube (1) to form a sheath around the honeycomb.

Figure 2 shows a preferred method of manufacturing a longitudinally grooved exhaust gas purifier. In it, the cleaner is pushed through the tool (3) according to Fig. 2. The shape of the longitudinal grooves (2) is determined by the circumferential shape of the rollers (5) on the circumference (4) of the tool (3). Figure 2 shows the groove shapes a and b, which enable a compression connection between the catalyst cell (6) and the outer shell tube (1).

Claims (2)

5 76403 A method of manufacturing an outer shell tube (1) of a catalyst having a long-grooved shell structure for cleaning exhaust gases, the method comprising placing at least one catalyst cell inside the outer shell tube (1), the ends (6) of which are pressed into a cone (7) and optionally the end cones ) is attached to the tube (1) to form a jacket around the honeycomb, characterized in that the outer shell tube (1) is driven longitudinally through the groove contraction device (3), thereby creating a compression connection between the catalyst assembly (6) and the outer shell tube (1). longitudinally grooved rigid exhaust gas cleaner shell structure (1). Process according to Claim 1, characterized in that the catalyst cell is preferably a metal cell