DE102015205498A1 - Cooking appliance with exhaust air catalytic converter - Google Patents

Abstract

The present invention relates to a cooking device with a cooking chamber (4) delimiting muffle (1), an electric heater (11) for heating the cooking chamber (4), a Wrasenauslass (2) for discharging vapors from the cooking chamber (4) and a Catalyst (15) for at least partial odor and / or fat removal in the vapor. The object of the present invention is to provide a cooking appliance, which is structurally easier to manufacture, is cheaper to manufacture and has improved odor and fat removal properties. For this purpose, a catalyst (15) is provided, which is provided at a distance from a muffle wall (3) between the electric heater (11) and the muffle wall (3) and aligned at least substantially parallel to the muffle wall (3).

Description

The present invention relates to a cooking appliance.

Background of the invention

A generic cooking appliance is for example from the EP 1 378 711 A2 known. In the previously known cooking appliance is an electric oven, in which in an opening of a muffle wall, an electric heater is used. In the center of this heating device, an outlet opening leading to a vapor outlet is provided in which a catalyst which molds the outlet opening is inserted. This catalyst decomposes fats contained in the vapor or compounds which cause "disturbing frying odor".

In this prior art oven there is the problem that it is often difficult to bring the catalyst to a predetermined operating temperature so that it has the maximum effectiveness, i. H. an efficient odor or fat removal, can afford in the vapors.

Another oven with a catalyst for odor and fat removal in the vapor is for example from the EP 0 209 887 A2 known. This oven is a so-called convection oven, which has a designed as a ring heater heater which surrounds a fan circulating the air in the oven. This annular heating element in turn surrounds a catalyst formed from a tube filled with a catalytically active material. This unit, which consists of a ventilator, annular heating element and catalyst, is provided between a muffle wall forming a rear wall of the furnace and a baffle wall. The circulating in the cooking chamber in circulation air flows through openings in the baffle in the fan and is guided by this radially outward on the ring heater and the catalyst.

Also from the EP 0 209 887 A2 Previously known oven is not ideal, since the structure is very complex and the scope is limited only to so-called Umluftbacköfen.

Object of the invention

Based on this, it is the object of the present invention to provide a cooking appliance, which is structurally easier to manufacture, is cheaper to manufacture and has improved odor and fat removal properties.

Brief description of the invention

To solve the problem, a cooking appliance with the features of claim 1 is proposed. This forms that out of the EP 1 378 711 A2 Previously known cooking appliance by the features in the characterizing part of claim 1 on.

The catalyst here is to be understood as meaning a one-part or multi-part structural unit which, at least in regions, has such catalytic properties that at least partial removal of odor or fat in the vapor is achieved.

The catalyst should not be part of the muffle wall, but spaced from it, be provided between the heater and the muffle wall. So at least one part, i. a region of the catalyst should extend between the heater and the muffle wall.

However, such an arrangement between the muffle wall and the heater does not exclude that the catalyst z. B. directly, so without gap, abuts the heater or is formed by a coating of the heater. Preferably, however, the catalyst is also not only spaced from the muffle wall but also spaced from the heater.

Detailed description of the invention

Preferably, the catalyst is thus designed as a structural unit, which may be one or more parts, which is at least partially provided between the muffle wall and the heater.

This subregion is furthermore preferably aligned substantially parallel to the muffle wall and preferably simultaneously also parallel to the heating device.

Insofar as the feature "substantially" is used, this does not exclude, however, that a wavy or structured configuration of this region or part of the catalyst is provided. Rather, here the view that an informal consideration of the user of the cooking appliance reveals that at least the region of the catalyst provided between the muffle wall and the heater particularly preferably aligns the entire catalyst-forming assembly as parallel to the muffle wall, and particularly preferably also simultaneously is seen as being aligned parallel to the heater.

Characterized in that at least a portion of the catalyst between the muffle wall and the heater are provided, it is achieved that the catalyst is substantially directly from the Heating device during operation of this is heated and flowing to the Wrasenauslass vapors can flow to the catalyst. Namely, such a vapor outlet usually starts from an outlet opening in a muffle wall of the muffle.

Particularly preferably, the electric heater is designed as a projecting into the oven grill, preferably a grill for the operation of top or bottom heat, as is well known in the art. In these known in the art grilling is z. B. around a meandering curved metal rod having at least one preferably two, three or more turns.

Preferably, this metal rod, i. the grill, two mutually parallel juxtaposed fastening-side ends over which a heating voltage is applied.

But such a grill can also be formed only by a straight-line extending rod-shaped element, which is energized via opposite ends, or by a substantially U-shaped element with mutually parallel bar legs whose fastening-side ends are provided for energizing side by side.

Anyway, this grill protrudes into the cooking chamber, d. H. Preferably, no baffle between the cooking chamber and the grill is provided. In particular, this embodiment distinguishes the grill from the well-known for so-called Umluftbacköfen annular heating elements.

At least parts of the catalyst are thus provided between the grill and the muffle wall, wherein in particular this part of the catalyst is also aligned parallel to the grill.

As far as parallel orientation with respect to the grill is concerned, the point of view is that the entire catalyst module or unit is considered with respect to the entire grill.

According to a preferred embodiment, the catalyst is formed by a tube, which consists of at least one heating element of the grill e.g. a portion of the meanderförigen metal rod is penetrated. Preferably, the tube surrounds the entire grill in a circumferential direction of the grill. At least, however, a part of the grill also penetrates part of the catalyst tube.

Accordingly, when the grill is heated, the tube surrounding the grill is heated substantially by heat radiation and optionally in addition to a small portion by convection.

So far as a part of the catalyst is to be provided between the muffle wall and the heater, this means in the case of the tube, e.g. a partial shell of the tube between the muffle wall and the heater is provided.

For ease of assembly, such a tube may be formed as a one-piece element and, for example, be longitudinally striped over the grill. Alternatively, such a tube may also be formed of a plurality of shell elements, in particular of two half shells. In this case, it is particularly preferable to provide a half shell between the muffle wall and the grill and to provide the other half shell on the side of the grill facing away from the muffle wall.

As far as the view of the tube engages, it is not important whether additional openings are provided in the tube, or that as far as the tube is formed in several parts, for. B. the half shells lie directly against each other, so that a closed tube is formed. Rather, here too, the view comes into focus, that as long as the envelope surface of the catalyst walls has a tubular configuration, the feature of the tube is met.

Accordingly, such a tube does not have to have a round cross-section, but merely to provide an envelope-like receiving space for the grill and preferably to be connected to the outlet opening leading to the vapor outlet. In particular, however, the tube is formed substantially cylindrical.

According to a preferred development, the tube communicates with the vapor outlet in such a way that the vapor passes into the vapor outlet merely by flowing through the tube.

That is, as far as it is a closed tube, the vapors enters only at its end openings in the cavity formed by the tube, in which the grill protrudes, and is through this cavity, for. passed via a outgoing from the pipe flow connection to the outlet opening.

As far as the tube is provided, for example, on the outer walls with further recesses, the vapor can also pass through these recesses in the cavity formed by the tube and be transferred from there into the Wrasenauslass. In any case, the vapor flows only through the pipe and preferably over the areas of the cavity in which the grill protrudes to Wrasenauslass.

According to a preferred embodiment of the invention, the tube extends perpendicular to the Wrasenauslass. This is especially the case when the Wrasenauslass is formed on the upper side of the cooking appliance. Thus, in particular, a further piece of pipe goes from the pipe, which leads to the outlet opening or is connected to it and thus connects the pipe with the vapor outlet. This pipe piece may be integrally provided on the pipe or attached as a separate element, for example by plug connection to the pipe.

At the same time, this further tube piece can serve as a fastening flange for the tube, i. to serve the catalyst. Preferably, therefore, the catalyst is formed by a T-shaped in its cross-section unit, wherein the tube into which the grill at least partially protrudes, the roof of the T's and the pipe section which leads to Wrasenauslass forms the base of the T's. As Wrasenauslass each fluid connection to the environment, which goes off from an opening, which opens into the cooking chamber, seen.

As an alternative or in addition to the above-mentioned fastening method via the pipe section, one end of the pipe is fastened to a holding flange for the grill and accordingly surrounds in particular a base region of the grill circumferentially. So far as it is in the grill to such, in which the two rod legs parallel to each other at a mounting end, so the tube surrounds at least these mutually parallel bar legs. The attachment-side end of the grill and the tube thus run substantially coaxially with each other.

The length of the tube may also be limited (in the following sub-tube) to essentially form a sleeve which only has the neck-shaped attachment-side end, i. surrounds the base area of the grill, and as soon as the grill widens again in the direction of the cooking space, the grill is free so that it does not protrude from the pipe into the cooking space. In this case, it is particularly preferred to provide an outlet opening to the vapor outlet in the muffle wall in the region of the holding flange for the grill, to which the tube is connected.

According to a further preferred embodiment of the invention, the grill is designed as a folding grill. Essentially, two alternative embodiments are offered here.

On the one hand, the pipe can be connected to the grill in such a way that the grill together with the pipe can be moved from a first position for the baking operation into a second position for a cleaning of the grill and / or pipe. Such folding mechanisms for the grill are well known. In the present case, however, attention must be paid in particular to an attachment of the pipe directly to the grill, for example by means of spacer arms between the pipe and the grill. This allows the grill to be folded together with the tube. Insofar as the tube or the partial tube is connected to the vapor outlet, it should therefore be ensured that a plug connection is provided between the vapor outlet and the catalyst-forming tube and / or the tube piece leading to the vapor outlet and the tube forming the catalyst.

On the other hand, the tube can be formed from at least two shell elements, wherein that shell element which is provided on the side facing away from the muffle wall side of the grill can be removed or folded down; the latter applies insofar as it is fastened to the other shell element via one or more hinges

In an alternative preferred embodiment of the catalyst, this is not formed as a tube but as a plate element, which is provided between the muffle wall and the grill and preferably of both spaced.

Such a plate element can have essentially any desired geometry, both in plan view and in cross-sectional view, as far as the casual view of a plate-like element results. Preferably, a circular or oval in plan geometry is provided, which projects beyond the outlet to the Wrasenauslass so far, so that at least one overlap area between muffle wall and plate element is formed.

Alternatively, such a plate segment may also mimic the geometry of the muffle wall to which the plate element is adjacent, but preferably be dimensioned (in plan view) smaller than this muffle wall so that a gap exists between the edge or edges of the plate element and the to the muffle wall opposite the plate member is adjacent, then form muffle walls.

As a result of this configuration, the plate element is heated directly by the heating device, in particular by the grill, and heated primarily by radiant heat and, secondly, the vapor can flow over the aforementioned gap and the gap between the plate element and the parrallel to it substantially Muffelwand are passed to the Wrasenauslass.

The Wrasenauslass or the outlet opening in the muffle wall is in the case that the catalyst is formed as a plate member, preferably provided on that muffle wall which is parallel to the plate member and adjacent thereto.

The plate element may be attached to the adjacent muffle wall via spacers, alternatively at its edges at the muffle walls adjacent to the edges and / or directly, i. be attached directly to the heater itself.

According to a preferred embodiment of the invention, a flow channel is formed to the Wrasenauslass between the plate member and this adjacent and parallel to this muffle wall. This means that substantially all of the vapor can only reach the vapor outlet via this flow channel.

According to a preferred embodiment of the invention, the plate member is formed perpendicular to the Wrasenauslass and projects beyond the leading to Wrasenauslass outlet. Because the plate element at least partially projects beyond the outlet opening, first a flow channel can be formed between the muffle wall and the plate element, since otherwise the vapor can pass directly into the vapor outlet without necessarily coming into contact with the plate element.

According to a preferred embodiment of the invention, the Wrasenauslass is provided at the top of the muffle. That is, in particular, therefore, the outlet opening is provided on an upper muffle wall, from which the Wrasenauslass goes off. This development has in particular so-called structural engineering equipment, especially building construction equipment in mind. That is, for example, in a kitchen such a cooking appliance is not installed below the worktop, but at least partially above the worktop in particular on chest or operating height of the operator. As far as it is in fact built-in devices that are installed below the countertop, it is often not possible, the Wrasenauslass as far as this is provided on an upper muffle wall to connect to an exhaust duct.

As a cooking appliance, the present invention next to long known ovens also called multifunction devices, in addition to the thermal heating of particular food by means of an electric heater and other functional elements such. B. microwave heating, and / or Dampfgareinrichtungen may contain.

Also, a cooking appliance is not limited to a single cooking chamber, but rather it can also be provided several cooking chambers within a housing.

According to a preferred development of the invention, the catalyst is provided adjacent to the heating device in such a way that the optimum operating temperature of the catalytic converter is achieved essentially only by the radiant heat of the heating device, in particular at a normal operating temperature thereof.

At the optimum operating temperature of the catalyst, i. H. That a significant odor or fat removal effect occurs, it is preferably a temperature between 200 ° and 800 ° C, more preferably 200 ° and 350 ° C or alternatively 350 ° to 700 ° C.

Typical operating temperatures of a cooking appliance are between 160 ° and 270 ° C. This means that the air in the cooking appliance is heated to this temperature. Any temperature in this range can be adjusted via a setting on the cooking appliance. It goes without saying that due to the air exchange, the temperature of the heater, such as the grill, must be several degrees above the operating temperature of the cooking appliance, in particular 10 ° to 80 ° C, preferably 20 ° to 40 ° C, in particular 30 ° C. above the operating temperature of the oven.

That is, due to the proximity of the heater to the catalyst, it is therefore preferably heated to temperatures above the air temperature in the cooking chamber, preferably the optimum operating temperature of the catalyst is about the same as the temperature of the heater or about 20 ° C lower Temperature than that of the heater. Alternatively, preferably, the optimum operating temperature of the catalyst is about 20 ° C higher than the operating temperature of the heater.

The catalyst is preferably a structural unit whose surface has a catalytic coating. Ie. at least a catalytically active coating should be applied at least in some areas on a surface of the assembly facing the heating device.

As far as, for example, is a catalyst designed as a tube, the inner wall of the tube should be coated at least in some areas, but preferably completely with a catalytically active material.

As far as the catalyst is a plate element, on the other hand, the surface facing the muffle wall should preferably also be used be provided a catalytic coating, ie the surface facing away from the heater.

Alternatively or additionally, the assembly of a material, such as in particular of a metallic material may be formed, which has catalytically active properties.

Alternatively or additionally, the catalyst, i. H. the structural unit, be filled with a porous body or porous bodies and / or a wire mesh, which in itself has catalytic properties or that is provided with a catalytically active coating.

So far as it is the design as a tube, the tube can be filled as such with the porous body, or the porous bodies, or the wire mesh or both in mixture or partially filled.

Alternatively, however, the tube can be designed as a double-walled, apertured housing, for. B. in particular in lattice form and within the housing, so between the pipe walls, the porous body, or the porous body, and / or the wire mesh to be introduced.

As far as the catalyst is a plate member, this plate member as such may have a plate-like apertured housing having a cavity in which the aforementioned catalytically active materials are filled. In particular, a grid-like housing may be provided. Alternatively or additionally preferably, the aforementioned catalytically active material may be introduced into the flow channel formed between the muffle wall and the plate element.

In any case, this catalytically active material should preferably be able to be heated by heat radiation from the heater to the predetermined optimum operating temperature.

Preferably, the catalytically active material contains noble metals, their mixtures or their compounds, such as in particular Pt, Pd, Au, Nb and alternatively or additionally oxides of Al, Cu, Ce, Ti, B and / or mixtures thereof and / or binary, tertiary , quaternary or other multinear compounds or mixtures of oxides and precious metals.

According to a further preferred embodiment of the invention, an air circulation device and a ring heater for recirculation mode is additionally provided. As far as the heating device of the cooking appliance is a grill for the top or bottom heat mode, therefore, a second heater should be provided for the recirculation mode. This ring heater may preferably be surrounded by a further catalyst, in the manner as in the EP 0 209 887 A2 is described, the disclosure of which is hereby incorporated in the present application in this regard.

By combining the catalyst surrounding the ring heater with the catalyst between muffle wall and heater, which preferably runs substantially parallel to the muffle wall, the efficiency of the odor and fat removal from the vapor can be further increased.

According to a further preferred development, in particular the surfaces of the muffle walls or as far as it is a convection oven, also provided in this baffle, behind which the ring heater is provided to be coated with a catalytically active material.

Further advantages and details of the present invention will become apparent from the following discussed embodiment in conjunction with the drawings.

Brief description of the invention

1A : a schematic embodiment of a high-installation oven,

1B a schematic representation of an upper part of a first embodiment of the invention, and

1C : A schematically illustrated upper part of a baking oven, according to a second embodiment of the invention.

An in 1A illustrated Hocheinbaubackofen has a muffle 1 and on the top side a Wrasenauslass 2 on, which has an outlet opening 2a from an upper muffle wall 3 going on. In the in 1A The front view encloses the muffle 1 by means of the upper muffle wall 3 a lower muffle wall 9 , two side muffle walls 5 , And a rear muffle wall, not shown, a cooking chamber 4 in which a food can be heated. Upper side and parallel to the upper muffle wall 3 arranged is a grill 11 ,

In 1B and 1C are two different embodiments, this upper area with the grill 11 and the upper muffle wall aligned parallel thereto 3 shown. Same elements are in these figures as well as in 1 denoted by the same reference numerals.

In 1B is a T-shaped catalyst module in its cross-sectional view 13 shown, which consists of a tube 14 and a vertically outgoing from this piece of pipe 15 is formed. The pipe piece 15 is in the outlet opening 2a plugged in and fastened there.

As schematically in 1B to see the grill passes through 11 the pipe 14 in the longitudinal direction. In the present case, the tube 14 formed of an upper shell member and a lower shell member, which can not be seen in the schematic drawing. The pipe 14 has at opposite sides in extension aligned openings 14a . 14b on, about which, like the arrows in 1B show the fumes through the pipe 14 over the part pipe 15 into the fume outlet 2 is directed. At its entire inner surface is both the tube 14 as well as the sub-pipe 15 provided with a catalytically active coating.

Due to the heating of the grill 11 The catalytic coating heats up by radiant heat of the grill and is thus brought to the appropriate temperature during operation of the oven.

In 1B is an upper part of the catalyst module 13 containing the upper half shell of the tube 14 between the upper muffle wall 3 and the grill 11 arranged.

In the in 1C illustrated embodiment is as a catalyst module 13 instead of in 1B illustrated tube 14 a plate element 16 between the grill 11 and the upper muffle wall 3 provided so that between the upper muffle wall 3 and the plate element 16 a flow channel 17 is formed, which of the vapors in the Wrasenauslass 2 flows.

The plate element 16 is essentially due to the radiant heat of the grill 11 brought to the operating temperatures necessary for catalysis.

The plate element 15 is on the to the upper muffle wall 3 executed side provided with a catalytically active coating. In the present case, the upper muffle wall is provided with just such a catalytically active coating.

LIST OF REFERENCE NUMBERS

1

 muffle

2

 Wrasenauslass

2a

 outlet

3

 Upper muffle wall

4

 oven

5, 7

 Side muffle walls

9

 Lower muffle wall

11

 grill

13

 catalyst module

14

 pipe

14a, 14b

 openings

15

 pipe section

16

 panel member

17

 flow channel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1378711 A2 [0002, 0007]
• EP 0209887 A2 [0004, 0005, 0062]

Claims (16)

Cooking appliance with a cooking chamber ( 4 ) narrowing muffle ( 1 ), an electric heater ( 11 ) for heating the cooking chamber ( 4 ), a Wrasenauslass ( 2 ) for discharging vapors from the cooking chamber ( 4 ) and a catalyst ( 15 ) for the at least partial odor and / or fat removal in the vapor, characterized in that at least part of the catalyst ( 15 ) spaced from a muffle wall ( 3 ) between the electric heater ( 11 ) and the muffle wall ( 3 ) is provided, and at least substantially parallel to the muffle wall ( 3 ) is aligned. Cooking appliance according to claim 1, characterized in that the electric heating device ( 11 ) from one to the cooking space ( 4 ) grilling ( 11 ), in particular for a top and / or bottom heat operation is formed. Cooking appliance according to claim 2, characterized in that the catalyst ( 15 ) through a pipe ( 14 ) formed by at least one of the grill ( 11 ) forming heating rod is penetrated. Cooking appliance according to claim 3, characterized in that the tube ( 14 ) with the Wrasenauslass ( 2 ) communicates and the vapors only through the pipe ( 14 ) to Wrasenauslass ( 2 ) can get. Cooking appliance according to claim 3 to 4, characterized in that pipe ( 14 ) perpendicular to the Wrasenauslass ( 2 ) runs. Cooking appliance according to claim 3 to 5, characterized in that pipe ( 14 ) on a support flange for the grill ( 11 ) is provided and surrounds the attachment-side end. Cooking appliance according to claim 3 to 6, characterized in that the grill ( 11 ) is designed as a folding grill, which separately from the pipe ( 14 ) or together with the tube ( 14 ) can be folded down. Cooking appliance according to claim 1 or 2, characterized in that the catalyst ( 15 ) by a between the muffle wall ( 3 ) and the heater ( 11 ) provided plate element ( 16 ) is formed. Cooking appliance according to claim 8, characterized in that the vapor is separated only by one between the plate element ( 16 ) and the muffle wall ( 3 ) formed flow channel ( 17 ) to Wrasenauslass ( 2 ) can get. Cooking appliance according to claim 8 or 9, characterized in that the plate element ( 16 ) perpendicular to the Wrasenauslass ( 2 ) is provided and a to Wrasenauslass ( 2 ) leading outlet opening ( 2a ) surmounted. Cooking appliance according to one of the preceding claims, characterized in that the Wrasenauslass ( 2 ) on an upper side of the muffle ( 1 ) is provided. Cooking appliance according to one of the preceding claims, characterized in that an operating temperature of the catalyst ( 15 ) is to be achieved substantially due to radiant heat produced by the heater. Cooking appliance according to one of the preceding claims, characterized in that the catalyst ( 15 ) has a catalytically active coating and / or a porous body and / or a wire mesh. Cooking appliance according to one of the preceding claims, characterized in that the catalyst ( 15 ) Pt, Pd, Au, Nb and / or mixtures thereof and / or their alloys, or that the catalyst ( 15 ) contains at least one oxide of Al, Cu, Ce, Ti, B and / or mixtures thereof and / or their multinary compounds. Cooking appliance according to one of the preceding claims, characterized in that an air circulation device and a ring heater are provided for recirculation mode, wherein the ring heater is surrounded by another catalyst. Cooking appliance according to one of the preceding claims, characterized in that at least one of the muffle walls ( 3 . 5 . 7 . 9 ) is provided with a catalytic coating.

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