EP1061317B1 - Method and support for firing - Google Patents

Description

The subject of the present invention is a support intended to receive products to be baked in an oven or dried in a dryer.

This support is more particularly intended for the firing of ceramic products "honeycomb" type like catalyst supports.

These honeycomb elements generally consist of blocks parallelepipedic or cylindrical which are traversed right through by a multiplicity of square or triangular section channels which may be less than 1 millimeter with partitions from 1 mm to 3/100 of a millimeter thick.

Due to their small cross-section and their relatively long length (compared in section), these channels are very difficult for the hot gases from the furnace to pass through. cooking and their cooking is irregular which seriously affects their quality.

The use of perforated plates does not allow circulation homogeneous in all the channels from where the problems related to the differences of flow between open or closed channels.

The present invention relates to a method providing a solution to this problem.

The method according to the invention consists in placing the catalyst elements to be cooked or dry, their channels being vertical, on a parallelepipedic support constituted by a ceramic foam so that the catalyst element channels are in position vertical to the support which causes the hot gases to pass through the support from side to side and penetrate into said channels.

Ceramic foam is a known product which is mainly used as filter in foundry molds: molten metal is poured over these foam filters of ceramic, the molten metal passes through this filter and fills the mold.

Porous ceramic foam plates are already known and applied to the Lours estate (EP-A-307,319).

The plaintiff's work revealed that it was possible to do fill this material, ceramic foam, with a completely different function than the one for which it was designed.

It turns out, however, that the ceramic support must not be too thick, because the pressure drop which the flow of hot gases undergoes when passing through it would be such that this gas flow would not circulate, or at least would circulate poorly inside channels passing through the catalyst support block.

The support must therefore be a thin plate, that is to say of a thickness between 1 and 5 centimeters.

But then, as the ceramic foam has a very low resistance to punching and bending, means must be provided to stiffen it.

According to the invention, these means consist of bars carrying the plate in ceramic foam, these bars resting on the load-bearing elements of the oven.

Figure 1 : une vue schématique, en perspective, d'un premier exemple de mise en oeuvre de l'invention ;

Figure 2 : une vue schématique, en perspective, d'un deuxième exemple de mise en oeuvre de l'invention ;

Figure 3 : une vue schématique, en perspective, d'un troisième exemple de mise en oeuvre de l'invention ;

Figure 4 : une vue schématique, en perspective, d'un quatrième exemple de mise en oeuvre de l'invention ;

Figure 5 une vue schématique en bout d'un sixième exemple de mise en oeuvre de l'invention.

By way of nonlimiting example and to facilitate understanding of the invention, the accompanying drawings show:

Figure 1: a schematic perspective view of a first example of implementation of the invention;

Figure 2: a schematic perspective view of a second example of implementation of the invention;

Figure 3: a schematic perspective view of a third example of implementation of the invention;

Figure 4: a schematic perspective view of a fourth example of implementation of the invention;

Figure 5 a schematic end view of a sixth example of implementation of the invention.

Referring to FIG. 1, it can be seen that the device according to the invention is consisting of a plate 1, of small thickness, that is to say between 1.5 and 2.5 centimeters, which is ceramic foam.

This plate 1 is intended to serve as a support for one or more elements in catalytic ceramics that will be deposited on it so that the multiple channels that cross them right through are vertical or perpendicular to the surface upper 2 of plate 1.

The catalyst support elements, which are not part of the invention, are not not shown.

Plate 1 must be carried by the load-bearing elements 4 of the oven (also not shown).

But the plate 1, having only a very low resistance to punching, cannot not be deposited directly on the load-bearing elements 4. In addition, having only one very low mechanical resistance, it risks breaking between the load-bearing elements such as elements 4.

To eliminate this drawback, there are a plurality of bars 5 (two at the minimum), these bars 5 being parallel to each other and resting on the load-bearing elements 4.

But on contact between the underside 3 of the plate 1 and the bars 5, the material of which the plate 1 is made up will not resist the punching forces.

To eliminate this drawback, grooves are formed in the lower face 3 6 in which the bars 5 will come to fit.

In all the examples shown in FIGS. 1 to 6, the bars 5 are cylindrical and the grooves 6 are semi-cylindrical.

As a result, the bars 5 protrude beyond the surface of the underside 3 of plate 1 about half their diameter.

The bars 5 are placed on the load-bearing elements 4.

But as said bars 5 protrude beyond the underside 3 of the plate 1, the ceramic foam does not come into contact with the supporting elements 4.

Thus, there is no punching phenomenon on the underside 3 of the plate 1 and there is no phenomenon of bending of said plate 1.

Preferably, as shown, the carrier elements 4 include notches 7 corresponding to the grooves 6.

In Figure 2 the same elements have the same references.

The only difference with the example in figure 1 is that the distance separating the two carrying elements 4 is greater than the length of the plate 1.

Also in FIG. 3, the same elements have the same references.

In this figure, we see that in addition to the bars 5 which extend over the entire length of the plate 1, additional bars 15 have been placed, which are perpendicular to the bars 5.

While the bars 5 protrude beyond the surface of the underside 3 of the plate 1, the complementary bars 15 are arranged inside the mass of the plate 1 in bores made for this purpose.

In this figure 3 we also see that the plate 1 can be made up of two parts 1a and 1b placed side by side on the bars 5.

In FIG. 4, it can be seen that the complementary bars 15 can rest on complementary support elements 14.

In Figure 5 we see that bars 5 can, like additional bars 15, be arranged in the mass of the plate 1. But as it is necessary that the foam ceramic is not in contact with the supports 4, cleaning on the underside 3 of the plate 1 of the grooves 7 which make the bars 5 appear so that they come in contact with load-bearing elements 4.

The present invention has been described in its application to cooking elements catalytic but it is not limited to this particular application; she may be advantageously used for any product to be crossed vertically by a hot gas flow.

Claims (6)

1. A method for supporting in an oven products through which a flow of hot gases has to pass in a vertical direction, consisting of laying said products on a plate of porous ceramic foam (1), said plate being reinforced by bars (5, 15) passing through the mass of said plate and being borne by the carrying elements (4, 14) of the oven by means of said bars.
2. A device for implementing the process according to Claim 1, consisting of a thin plate (1) of ceramic foam, this plate being borne by the carrying elements (4) of the oven by means of the bars (5).
3. A device according to Claim 2, in which the bars (5) are embedded in grooves (6) formed in the lower face (3) of the plate (1) but project from this lower face (3) such that the material of the thin plate (1) does not come into contact with the carrying elements (4) of the oven.
4. A device according to Claim 3, in which complementary bars (15) which are perpendicular to the bars (5) pass through the mass of the plate (1).
5. A device according to Claim 4, in which the complementary bars (15) project from the plate (1) to come to bear on additional carrying elements (14) of the oven.
6. A device according to Claim 2, in which two perpendicular sets of bars (5 and 15) pass through from one side of the plate (1) to the other, the lower face (3) of the plate (1) being provided with grooves (7) which reveal the support bars (5) so that they come into contact with the carrying elements (4) of the oven.

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