DE9113928U1 - Honeycomb body with several discs supported against each other - Google Patents

Description

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Emitec Company for Emissions Technology mbH D-5204 Lohmar 1

Honeycomb body with several discs supported against each other

The invention relates to a honeycomb body through which a fluid can flow along an axis in that the fluid flows through a multiplicity of channels in the honeycomb body.

Such honeycomb bodies are used in a variety of ways as carrier bodies for catalysts, which are intended for the catalytic conversion of reactive components of fluids. An important area of application for honeycomb bodies with catalysts is the catalytic purification of exhaust gases from internal combustion engines, in particular from internal combustion engines in motor vehicles. For this purpose, catalytically coated honeycomb bodies are installed in the exhaust systems of the internal combustion engines and are flowed through by the exhaust gases generated during operation of the internal combustion engines.

The honeycomb bodies are made from ceramic masses or from metal sheets. To form a metallic honeycomb body, layers of at least partially corrugated, folded or similarly structured sheets are layered, stacked, spirally wound or intertwined in some other way. Possibilities for this are described in the patents EP 0 223 058 Bl, EP 0 245 736 Bl, EP 0 245 737 Bl, EP 0 245 738 Bl, US-PS 4,753,981 and US-PS 4,822,766, the publications WO 89/10470 Al, WO 89/10471 Al, WO 90/03220 Al, WO 90/12951 Al and DE 39 03 879 Al as well as in the German utility model DE 89 08 738 Ul.

Catalysts for the conversion of reactive components of a fluid flowing around them develop their catalytic effect usually only above certain temperatures that are specific to the respective

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Catalyst and the reaction to be catalyzed have specific limit temperatures, the so-called "light-off temperatures". For catalysts for converting pollutants in exhaust gases from conventional internal combustion engines, the light-off temperatures are generally several hundred degrees Celsius. Such a catalyst must therefore be heated up if it is to become active. In the exhaust system of a motor vehicle, this is usually done by the exhaust gas flowing through the honeycomb body coated with the catalyst, whereby the catalytic effect only begins with a certain delay after the internal combustion engine is started up. To eliminate or reduce this delay, electrical preheating of the catalyst or the honeycomb body supporting it is already known; corresponding information is available.

the documents WO 89/ Al, WO 90/ Al, DE 39 03 879 Al

and DE 89 08 738 Ul. The layers forming the metallic honeycomb body are electrically connected to one another in such a way that a path for conducting an electrical current through the honeycomb body is formed; furthermore, power leads are attached to the honeycomb body to which an electrical power source, for example a motor vehicle battery, can be connected via appropriate switching devices and lines. A honeycomb body of a conventional size and design for use in the exhaust system of a motor vehicle requires a heating output of several hundred watts to over four kilowatts in order to heat up in a sufficiently short time; accordingly, an on-board network with a voltage of 12 volts, as is usual in passenger vehicles, would have to supply currents of up to around 400 A to heat the honeycomb body. The electrical resistance of the honeycomb body must have a value that corresponds to the electrical voltage available and the heating output to be applied. Metallic honeycomb bodies of a conventional type, however, have electrical resistances of a maximum of a few thousandths of an ohm; From an electrical voltage source with a voltage of about 12 volts, such a honeycomb body would draw currents of up to 1000 A,

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;".,·;% &lgr;; »··. £1 G 67 1 9 OE 3 " ^: .,■'',■. ^; ' -J- ,. ^; .. I C"_; i, which would place a load on a conventional motor vehicle battery to a barely acceptable level. The cited documents on the state of the art already disclose measures to increase the electrical resistance of a honeycomb body with given geometric dimensions. For example, electrically heated Honeycomb bodies are divided by gaps and/or electrically insulating intermediate layers between the layers in such a way that a current path with an appropriate electrical resistance is created through the honeycomb body. It has also been suggested that instead of a single honeycomb body with a catalyst coating, two honeycomb bodies should be used, where an electrically heatable smaller honeycomb body is connected upstream of a larger honeycomb body that is not to be heated directly and both honeycomb bodies have essentially the same diameter, but the smaller honeycomb body is significantly shorter than the larger honeycomb body. Due to the dimensions alone, a significantly greater electrical resistance can be achieved on the smaller honeycomb body than can be realized on the larger honeycomb body; In particular, the smaller honeycomb body can be designed in such a way that it can be brought to a temperature above the light-off temperature of the catalyst on the honeycomb body sufficiently quickly with a limited load on the voltage source. The usually exothermic catalytic reaction that occurs in the exhaust gas flowing through the smaller honeycomb body leads to heating of the exhaust gas and thus supports the heating of the larger honeycomb body, which ultimately takes on the main burden of the catalytic conversion. According to DE 89 08 738 Ul, the sheets intended for the production of an electrically heated honeycomb body can be provided with holes, which increases their specific resistance and a honeycomb body with a relatively high electrical resistance can be realized. WO 90/12951 Al shows possibilities for mechanically resilient insulation in honeycomb bodies.

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The described arrangement with a smaller honeycomb body and a larger honeycomb body, with the smaller honeycomb body being arranged in the exhaust system in front of the larger honeycomb body, is also advantageous without the provision of a special heater. The smaller honeycomb body naturally has a lower heat capacity than the larger honeycomb body and therefore heats up relatively quickly when hot exhaust gas or the like flows through it. This means that a catalytic reaction is quickly set in motion in the smaller honeycomb body and the heat released supports the heating of the larger honeycomb body.

Both the considerations regarding the electrical heating of the smaller honeycomb body and the considerations regarding the dimensioning of its heat capacity lead to keeping the mass of the smaller honeycomb body as low as possible, of course under the secondary condition that the smaller honeycomb body provides sufficient heating of the fluid flowing through it after the activation of the catalyst on it and supports the heating of the larger honeycomb body. Even in view of this secondary condition, however, the considerations may possibly run counter to the requirements for the mechanical stability of the smaller honeycomb body; in particular in the exhaust system of a motor vehicle, strong pulsations occur in the exhaust gas streams and the honeycomb bodies are exposed to considerable mechanical stress, which is why high demands must be placed on their strength.

The present invention is based on the task of creating a honeycomb body in which the possibilities of arrangements with several honeycomb bodies can be exploited, but in particular the mentioned strength problems do not arise, and with which a significantly larger

^5 Freedom of design, especially with regard to optimizing the warm-up behavior with or without electrical heating,

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is offered.

The inventive solution to this problem is a honeycomb body that
a) a fluid can flow through it along an axis, the fluid flowing through a plurality of channels in the honeycomb body;

b) has at least two discs which are spaced apart from one another and arranged one behind the other with respect to the axis, and each of which has channels;

c) has at least one support arranged close to the axis, by which the discs are connected to one another.

According to the invention, the disks of the honeycomb body are supported against one another by at least one support arranged close to the axis, or an arrangement of several such supports; the connection of the disks to one another can significantly increase the mechanical load-bearing capacity of the honeycomb body, since the disks of the honeycomb body cooperate to absorb mechanical stresses.

The honeycomb body according to the invention is advantageously designed to be approximately axially symmetrical, in particular rotationally symmetrical, with respect to the axis, and each disc is advantageously delimited by two end faces aligned approximately perpendicular to the axis. These measures, both individually and in combination, facilitate the efficient production and further use of the honeycomb body.

It is particularly advantageous to provide a first disk and a second disk in the honeycomb body according to the invention, the first disk having a thickness parallel to the axis that is smaller, preferably significantly smaller, than the thickness of the second disk determined parallel to the axis. According to the invention, the first disk is supported by the second disk via the at least one support, so that the first

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The second pane can be designed largely solely with regard to low heat capacity and an electrical resistance of a given level; the overall required mechanical strength can essentially be ensured by the second pane, which supports the first pane via the at least one support.

Another advantageous embodiment of the honeycomb body according to the invention within the scope of any further development is the provision of an at least partially electrically conductive first disk in which a current path is formed for conducting an electric current for heating and which is supported against a second disk via at least one electrically insulating support. Within the scope of this embodiment, use is also made of the fact that according to the invention the mechanical strength of the honeycomb body can be determined by one of several disks and other disks can be designed for other tasks without special strength requirements. It is thus possible to largely adapt a first disk to the requirements for electrical heating and to ensure its strength, for example, by supporting it against a disk that determines the mechanical strength by means of insulating supports, for example ceramic or having ceramic components.

In another embodiment of the invention, the honeycomb body of any design has two disks, each of which is at least partially electrically conductive and which are supported against each other by at least one electrically conductive support, wherein at least one current path for conducting an electrical current for the purpose of heating is formed in the honeycomb body, in which current path both the disks and the support are included. In the context of this embodiment, the electrically conductive support is used to conduct the electrical current from a disk into

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another pane - this opens up the possibility of supplying electrical current to the honeycomb body on a surface bordering a first pane and of dissipating it again on a surface bordering a second pane. In this way, the invention makes an electrical connection in the area near the axis superfluous in the case of a honeycomb body that can be heated directly electrically; the invention also makes it possible to dispense with subdivisions of the surface that are electrically insulated from one another, the mechanically sufficiently robust design of which can be problematic. According to the invention, an electrically heatable honeycomb body can be provided with very simple means that has an electrical resistance of a size that is desirable and advantageous in motor vehicles.

An "at least partially" electrically conductive disc is understood to mean a disc that is electrically conductive to a substantial extent, but into which insulation and/or gaps can be inserted, for example for the purpose of adjusting the electrical resistance to a predetermined size.

A further advantageous embodiment of the honeycomb body according to the invention, which is preferably implemented together with a design described above, is characterized by different average cross-sectional areas of the channels in each segment from disc to disc. For example, in a first, thinner disc there are channels with larger cross-sectional areas than the cross-sectional areas of the channels in a second, thicker disc. Large cross-sectional areas of the channels mean low heat capacity, since less material is required to form the disc, and limited effectiveness of a catalyst located in the channels. A disc with channels of a relatively large cross-section is therefore particularly suitable for arrangement in front of another disc which is separated by channels

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smaller cross-section and sufficiently long length is designed for high effectiveness; the reduced effectiveness of the catalyst in the disk with large cross-sectional areas ensures reduced wear, which contributes significantly to extending the service life of the honeycomb body. Especially when a first, smaller disk is intended to support the heating of a second, larger disk, premature wear of the catalyst on the first disk is highly undesirable, since this wear immediately reduces the effect of the additional heating of the second disk. The design freedom opened up by the invention allows in particular the restriction of the catalytic effectiveness in a smaller disk that is arranged in front of a larger disk, so that no more than about a quarter of the convertible components contained in a fluid flowing through it are converted in the smaller disk. The long-term effectiveness of the catalyst can thus be ensured.

There are several possibilities for designing the support in the honeycomb body according to the invention. A single support can be provided, which is advantageously arranged so that it is penetrated by the axis of the honeycomb body; it can also be advantageous to provide several supports in the honeycomb body, arranged approximately symmetrically with respect to the axis.

A support in a honeycomb body according to the invention can in turn be a honeycomb body, ie in the support itself, as in other components of the honeycomb body, channels - ⁵ O can be located.

The multi-part structure of the honeycomb body according to the invention can be determined, for example, by a groove running around the axis, whereby the support is a part of the honeycomb body delimited by the groove and each disc is a part of the honeycomb body away from the groove. Such a groove can already be

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Production of a metallic honeycomb body by using sheets with corresponding slots. The groove can also be introduced into an originally one-piece honeycomb body by subsequent machining. Such subsequent machining can be, for example, a turning or milling process.

A honeycomb body according to the invention is advantageously made of metal within the scope of any design, with each disc having at least one spiral-wound stack with at least one sheet, in particular with at least two differently structured sheets, preferably with at least one smooth sheet and at least one corrugated sheet. In addition to the advantages of the metallic structure, which emerge from the cited prior art documents, a honeycomb body according to the invention made of sheets also allows the special designs already described to be easily implemented. In particular, the segments of the honeycomb body can be dimensioned differently, with channels with different cross-sectional areas being implemented in different segments, for example; a metallic honeycomb body according to the invention can also be obtained by simply reworking an originally one-piece metallic honeycomb body.

In a honeycomb body with metallic segments, the at least one support is advantageously also formed essentially from metal; the support can be a simple metal rod, a metal tube or a special honeycomb body wound from at least one, optionally structured, sheet metal.

Advantageously, the support is incorporated into the structure of each disc; in particular, each disc has at least one stack of at least one sheet folded and/or wound around the support. The stack can be

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10 '-.-'",S &Lgr;, ,u ,-■' can be wound in an S-shape around two supports spaced apart from one another in a known manner. In a honeycomb body with at least two supports spaced apart from one another, each support can also have a stack folded around it associated with it, all stacks being wound around the supports in the manner of a spiral.

As already mentioned, a metallic honeycomb body according to the invention is also particularly suitable for direct electrical heating if at least one current path for conducting an electrical current is formed in the honeycomb body.

In an electrically conductive honeycomb body according to the invention, at least one support is advantageously made electrically conductive, each disk is given an approximately axially aligned surface and a connection for feeding in and/or feeding out an electrical current is provided on each surface; this is done in such a way that each connection and the electrically conductive support are in the current path. Thus, a honeycomb body according to the invention with two disks has a connection on each surface; the electrical current flows in one of the disks from the connection in the surface to the support, through the support into the other disk and from there from the support to the surface, where it is fed out at the connection there. In this way, the invention allows the formation of an electrically heatable honeycomb body in which no connections are required inside, in particular near the axis. The invention thus enables a significant simplification of the power supply to an electrically heatable honeycomb body and allows the omission of power supplies that have to lead into areas of the honeycomb body close to the axis, which is potentially questionable.

In addition to an electrically conductive support, an electrically insulating

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Support can be provided; rods and the like made of ceramic masses are possible as such, and metal-ceramic composite materials can also be used. A ceramic-coated metal rod, for example, can be considered as a metal-ceramic composite material; if necessary, the ceramic layer can partially have a metal sleeve while retaining the insulation. Such a metal rod with a ceramic coating and a metal sleeve could also be used to form a complicated current path in a honeycomb body according to the invention with three or more disks, which can be advantageous in the context of special applications of the invention. An electrically insulating support can also be an insulating layer that extends from one disk of the honeycomb body to another, and which insulates two stacks from each other in each disk. In this way, a particularly robust honeycomb body is formed.

In a special development of the invention, at least one disc of an electrically conductive honeycomb body consists of at least two stacks that are electrically insulated from one another and each of which is folded and wound around an electrically conductive support lying in the current path. The two stacks can thus be electrically connected in series, which is useful for increasing the electrical resistance of the honeycomb body. The series connection of the two stacks is provided by the supports, which are electrically connected to one another via another disc of the honeycomb body, in or to which the supports are attached. In the simplest case, this is achieved by there being no insulating layers at all in the second disc; however, it is also possible to form the other disc, like the first, from stacks that are electrically insulated from one another and folded and wound around the electrically conductive supports and to provide electrical connections in the outer surface of the other disc, each of which connects two stacks to one another. In this way, all stacks, all electrically

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conductive supports and all electrical connections in the casing surfaces are electrically connected in series; this honeycomb body can be connected to an electrical voltage source at two corresponding connections.

A ceramic insulating layer, for example a mat made of ceramic fibers or the like, is particularly suitable as an insulating layer in a honeycomb body according to the invention. Ceramic spacers spaced apart from one another, which ensure air gaps between two stacks in a disk, are also conceivable.

The invention will be further explained using the embodiments shown in the drawing. The drawing is partially schematic and/or slightly distorted to illustrate the specific features of the invention. In detail:

Figure 1 shows a longitudinal section through a honeycomb body according to the invention;

Figure 2 shows a cross-section through a disc of the honeycomb body shown in Figure;

Figure 3 shows a special embodiment of a disk; Figure 4 shows a sketch relating to the formation of the disk shown in Figure 3;

Figure 5 shows a longitudinal section through another embodiment of the honeycomb body according to the invention; Figure 6 shows a sketch of the current path in a honeycomb body; Figure 7 shows a sketch of another embodiment of the current path;

Figure 8 shows the cross-section of a particular embodiment of a disc;

Figure 9 shows the longitudinal section of another embodiment of the

honeycomb body.
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Figure 1 shows a honeycomb body 1, formed from a first 01 12

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Disc 4 and a second disc 5 as well as two supports 6 that connect the first disc 4 and second disc 5 to one another. The honeycomb body 1 has an axis 2 and is largely rotationally symmetrical in this respect. Each disc 4, 5 is limited by an axially oriented shell surface 14 and two end faces 8 aligned perpendicular to the axis 2. Each disc 4, 5 is inserted into a casing tube 20. There is a connection 15 on each casing tube 20; an electrical current can be passed through the connections 15 through the honeycomb body 1, which is electrically conductive, ζ. β. metallic, to heat it. Electrical heating takes place mainly in the first disc 4, since this is thinner than the second disc 5 and accordingly has a significantly higher electrical resistance. In an exhaust system of an internal combustion engine, the honeycomb body 1 is advantageously arranged in such a way that exhaust gas coming from the internal combustion engine first flows through the first disc 4 and then the second disc 5. A catalytic converter in the first disc 4 can be activated very quickly by the electrical heating and thus contributes to the accelerated heating of this second disc 5 by heating the exhaust gas flowing to the second disc 5.

Figure 2 shows a cross section through the first disc 4 of the honeycomb body 1 shown in Figure 1. The first disc 4 consists of a stack 10 made of smooth sheets 11 and corrugated sheets 12, which is wrapped around the two supports 6 in the manner of an S. Channels 3 are formed between the smooth sheets 11 and corrugated sheets 12, through which exhaust gas or another fluid with catalytically convertible components can flow. Each smooth sheet 11 and each corrugated sheet 12 ends at the jacket surface 14 and is connected there to the jacket tube 20, in particular brazed.

The connection 15 serves to feed in or feed out an electric current; this current passes through the first disc

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4 to or from the supports 6; these supports 6 conduct the electrical current to another disc of the honeycomb body.

Figure 3 shows, in a highly schematic and simplified manner, a variant of the first disk 4 shown in Figure 2, formed from an S-shaped intertwined stack 10. According to Figure 3, an insulating layer 16 is provided in the disk 4, which prevents a radially directed current flow from the shell surface 14 to the supports 6 and thus increases the effective electrical resistance of the disk 4. The insulating layer 16 is inserted between superimposed turns of the stack 10, starting from one of the supports 6. Starting from the other support 6, the dividing line between superimposed turns of the stack 10 is shown; it is generally not absolutely necessary that insulating layers 16 are provided starting from both supports 6 - however, this possibility is not excluded.

Figure 4 demonstrates how a disk 4 shown in Figure 3 can be formed by S-shaped intertwining of a stack 10 of smooth sheets 11 and corrugated sheets 12; the stack 10 is held between two supports 6 and intertwined around these supports 6. An insulating layer 16 can be seen on the stack 10; this can be a ceramic coating of a sheet 11 of the stack 10, it can also be a ceramic fiber mat or the like placed on the stack 10.

Figure 5 shows a longitudinal section through a honeycomb body 1 according to a further embodiment of the invention. Two disks 4, 5 of the honeycomb body 1 are separated from each other by a groove 9, which is introduced into the honeycomb body 1 approximately perpendicular to the axis 2. The honeycomb body 1 is formed by intertwining a stack 10 with the insertion of an insulating layer 16, as shown in Figures 2 and

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3. The groove 9 can be subsequently introduced into the honeycomb body 1 and the casing tube 20 that surrounds the honeycomb body 1. The support 6 is defined as the area of the honeycomb body 1 that is bordered by the groove 9; the disks 1 and 5 are the areas of the honeycomb body 1 away from the groove 9.

Figures 6 and 7 show, in highly schematic form, the course of the current path 13 that an electric current takes through a honeycomb body according to the invention. Two disks 4 and 5 are indicated in each case. In each disk 4, 5, the current path 13 leads from a surface 14 to an electrically conductive support 6, through this support 6 into the other disk 4, 5, and from there via at least one stack 10 back to the surface 14. According to Figure 6, the electric current is fed in and out at connections 15, both of which are arranged on the first disk 4; the second disk 5 serves mainly to establish a connection between the two supports 6. In the example shown, this connection is made via the stacks 10 in the second disk 5 and via an electrical connection 17, which is to be imagined in the jacket surface 14 there - such a connection 17 can be a metallic jacket tube, which may need to be insulated from other components of the exhaust system in which the honeycomb body is located. According to Figure 6, heating of both the first disk 4 and the second disk 5 can be implemented. If heating of the second disk 5 is not desired, the connection there between the two supports 6 can be formed by the entire disk 5 if there are no insulating layers there; a special electrical connection 17 may be omitted in this case. According to Figure 7, the electrical current is fed to the first disk 4 at a connection 15, runs from the outer surface 14 through the stacks 10 and the support 6 to the second disk 5, passes through the stacks 10 there and is fed back to the outer surface 14 there at a connection 15.

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removed. Figure 7 thus shows the simplest possibility for forming a current path 13 in a honeycomb body according to the invention; this possibility is also implemented in Figure 1 (however, two supports 6 connected electrically in parallel are provided there).

Figure 8 shows a disk A of a honeycomb body with three stacks 101, 102, 103, each of which is folded around a support 61, 62 or 63, and which are wound around the three supports 61, 62, 63 in the manner of an involute. The three stacks 101, 102 and 103 are insulated from one another by insulating layers 16. The arrangement of the stacks 101, 102, 103 is located in a metallic casing tube 20, which is not complete, but into which two insulating pieces 18 are inserted in such a way that two stacks 102 and 103 are connected to one another via the casing tube 20, but are separated from the third stack 101. The part of the casing tube 20 connected to the stack 101 has a connection 15 through which, for example, an electric current can be supplied. The disk 4 is connected to a similar second disk (not shown). The electric current is conducted as follows: The current is fed into the connection 15 and flows into the stack 101 and from there through the support 61 into the second disk. In this disk, which must also be divided by insulating layers, the current is fed to the support 62, for example, passes through it and thus reaches the stack 102. From this stack it reaches the stack 103 via the connection provided by the casing tube 20 and from there into the support 63. It flows through this support 63 again to the second disk and is fed out there at another connection. In fact, the three stacks 101, 102 and 103 are electrically connected in series, which results in a relatively high electrical resistance. Such a high electrical resistance is known to be advantageous for heating purposes.

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Figure 9 shows a further embodiment of a honeycomb body 1 according to the invention. The honeycomb body 1 has two disks A and 5, which are arranged one behind the other with respect to the axis 2. Both disks A and 5 should be made of sheet metal or electrically conductive ceramic. An electrically conductive support 6 and two electrically insulating supports 7 are provided to connect the disks A and 5 to one another; all supports 6, 7 are connected to the disks A and 5, for example by brazing. Each disk A, 5 is enclosed in a jacket tube 20, and each jacket tube 20 has a connection for feeding in or feeding out an electrical current.

The invention relates to a honeycomb body through which a fluid can flow along an axis by the fluid flowing through a plurality of channels in the honeycomb body. The honeycomb body has at least two disks which are spaced apart from one another and arranged one behind the other with respect to the axis, and each of which has channels. According to the invention, at least one support is provided which is arranged close to the axis and by means of which the disks are connected to one another and supported against one another. The invention makes it possible to design a first disk with a view to rapid heating by exhaust gas flowing through it or by electrical current being passed through it and/or to ensure the mechanical strength of the honeycomb body essentially by appropriate design of the second disk and the support. The honeycomb body according to the invention is particularly suitable for use as a carrier for a catalyst in the exhaust system of an internal combustion engine, for example in a motor vehicle.

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Claims (23)

18 " Protection claims 1. Honeycomb body (1), the a) a fluid can flow through it along an axis (2) by the fluid flowing through a plurality of channels (3) in the honeycomb body (1); b) has at least two discs (A, 5) which are spaced apart from one another and arranged one behind the other with respect to the axis (2), and each of which has channels (3); c) has at least one support (6, 7, 61, 62, 63) arranged close to the axis (2), by means of which the discs (A, 5) are connected to one another. 2. Honeycomb body (1) according to claim 1, which is approximately axially symmetrical, in particular rotationally symmetrical, with respect to the axis (2). 3. Honeycomb body (1) according to claim 1 or 2, in which each disc (A, 5) is delimited by two end faces (8) aligned approximately perpendicular to the axis (2). A honeycomb body (1) according to one of the preceding claims, which comprises a first disc (A) and a second disc (5), each of which has a thickness parallel to the axis (2), the thickness of the second disc (5) being greater than the thickness of the first disc (A). 5. Honeycomb body (1) according to one of the preceding claims with an at least partially electrically conductive first disk (A), in which a current path (13) for conducting an electrical current for heating is formed, and which is supported against a second disk (5) via at least one electrically insulating support (7). 6. Honeycomb body (1) according to one of the preceding claims with two discs (A, 5) which are connected via at least one electrically 02 01 _r ; ,>■, -: 91 6 67 19 OE 19 ^::v ' ^: conductive supports (6) are supported against each other and each of which is at least partially electrically conductive, in which honeycomb body (1) at least one current path (13) is formed for conducting an electric current for heating, in which current path (13) the disks (4, 5) and the support (6) are included. 7. Honeycomb body (1) according to one of the preceding claims, in which a) each disc (4, 5) has an average cross-sectional area corresponding to the mean value of the cross-sectional areas of the channels (3) of the disc (4, 5) lying perpendicular to the axis (2);
b) the average cross-sectional area of a first disc (4) is larger than the average cross-sectional area of a second disc (5). 8. Honeycomb body (1) according to one of the preceding claims, in which the support (6, 7, 61, 62, 63) is itself a honeycomb body. 9. Honeycomb body (1) according to one of the preceding claims, in which the axis (2) penetrates the support (6, 7, 61, 62, 63). 10. Honeycomb body (1) according to one of the preceding claims with a plurality of supports (6, 7, 61, 62, 63) arranged approximately symmetrically with respect to the axis (2). ii. Honeycomb body (1) according to one of the preceding claims, which is provided with at least one groove (9) surrounding the axis (2), wherein the support (6, 7, 61, 62, 63) is a part of the honeycomb body (1) delimited by the groove (9) and each disc (4, 5) is a part of the honeycomb body (1) away from the groove (9). 12. Honeycomb body (1) according to one of the preceding claims, 02 02 Sl 6 6 7 1 9 EN 20 ■--- -■-""' in which each disc (A, 5) has at least one spiral-wound stack (10, 101, 102, 103) with at least one sheet (11, 12), in particular with at least two differently structured sheets (11, 12), preferably with at least one smooth sheet (11) and at least one corrugated sheet (12). 13. Honeycomb body (1) according to claim 12, wherein the support (6, 7, 61, 62, 63) consists essentially of metal. 14. Honeycomb body (1) according to claim 13, wherein the support (6, 7, 61, 62, 63) is wound from at least one sheet (11, 12). 15. Honeycomb body (1) according to one of claims 12 to 14, in which each disc (4, 5) has at least one support (6, 7, 61, 62, 63) folded and/or wound stacks (10, 101, 102, 103). 16. Honeycomb body (1) according to claim 15 with at least two supports (6, 7, 61, 62, 63) spaced apart from one another, in which each disc (4, 5) has an S-shaped support (6, 7, 61, 62, 63) wound stacks (10, 101, 102, 103). 17. Honeycomb body (1) according to claim 15 with at least two spaced-apart supports (6, 7, 61, 62, 63), in which in each disc (4, 5) each support (6, 7, 61, 62, 63) is assigned a stack (10, 101, 102, 103) folded around it and all stacks (10, 101, 102, 103) are wound in the manner of a spiral. 18. Honeycomb body (1) according to one of claims 12 to 17, in which at least one current path (13) is formed for conducting an electric current for heating the honeycomb body (1). 02 03 ⁹¹ 6 67 J 9 OE 21 '■- '' - ■■'' 19. Honeycomb body according to claim 18, in which a) each disc (4, 5) is delimited by an approximately axially aligned lateral surface (14); b) at least one support (6, 61, 62, 63) is electrically conductive; c) on each casing surface (14) there is a connection (15) for the input and/or output of an electric current; d) each terminal (15) and the electrically conductive support (6, 61, 62, 63) lie in the current path (13). 20. Honeycomb body (1) according to claim 18 or 19, which has at least one electrically conductive support (6, 61, 62, 63) and at least one electrically insulating support (7) between two disks (4, 5), wherein the electrically conductive support (6, 61, 62, 63) lies in the current path (13). 21. Honeycomb body according to one of claims 18 to 20, in which at least one disc (4) consists of at least two stacks (10, 101, 102, 103) which are electrically insulated from one another and each of which is folded and wound around an electrically conductive support (6, 61, 62, 63) located in the current path (13). 22. Honeycomb body (1) according to claim 21, in which the stacks (10, 102, 103) are insulated from one another by at least one insulating layer (16), in particular a ceramic insulating layer (16). 23. Honeycomb body (1) according to claim 21 or 22, in which a) each disc (4, 5) consists of at least two stacks (10, 101, 102, 103) which are electrically insulated from one another and each of which is folded and wound around an electrically conductive support (6, 61, 62, 63); b) each electrically conductive support (6, 61, 62, 63) connects a stack (10, 101, 102, 103) in a first disc (4) with a stack (10, 101, 102, 103) in a second disc (5) 02 04 ,-, < · ,*% JI 6 67 1 9OE connects; c) in the lateral surface (IA) of each disk (4, 5) at least one electrical connection (17) is arranged between two stacks (10, 101, 102, 103); d) all stacks (10, 101, 102, 103), all electrically conductive supports (6, 61, 62, 63) and all electrical connections (17) are electrically connected in series. 02