WO2016150661A1 - Cooking device having an exhaust gas catalyst - Google Patents

Abstract

The present invention relates to a cooking device having a muffle (1) enclosing a cooking chamber (4), an electrical heating device (11) for heating the cooking chamber (4), a vapor outlet (2) for releasing vapors from the cooking chamber (4), and a catalyst (15) for at least partially eliminating odors and/or fat in the vapor. The object of the present invention is to provide a cooking device which is easier to produce in terms of construction, is more cost-effective to manufacture and has improved odor or fat eliminating properties. A catalyst (15) is provided for this purpose, which is provided at a distance from a muffle wall (3) between the electrical heating device (11) and the muffle wall (3), and is at least substantially oriented in parallel to the muffle wall (3).

Description

 Cooking appliance with exhaust air catalytic converter

The present invention relates to a cooking appliance. Background of the invention

A generic cooking appliance is known for example from EP 1 378 71 1 A2. 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 causing "offensive 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 efficiency, ie Another oven with a catalyst for odor or fat removal in the vapor is known, for example, from EP 0 209 887 A2 This annular heating element in turn surrounds a catalyst formed from a tube filled with a catalytically active material, this unit consisting of a fan, annular heating element and catalytic converter between a rear wall of the unit of ens forming muffle wall and a baffle wall provided. 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, the previously known from EP 0 209 887 A2 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 produce and has improved odor or fat removal properties.

BRIEF DESCRIPTION OF THE INVENTION To solve the problem, a cooking appliance having the features of claim 1 is proposed. This forms the previously known from EP 1 378 71 1 A2 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 has such catalytic properties at least in regions 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, on the heating device rests 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.

However, insofar as the feature "essentially" is used, this does not exclude that a wavy or structured configuration of this region or part of the catalyst is provided at least the region of the catalyst which is provided between the muffle wall and the heating device, in particular preferably the entire structural unit forming the catalyst, is oriented parallel to the muffle wall and is particularly preferably also simultaneously aligned as being parallel to the heating device.

Because at least part of the catalyst is provided between the muffle wall and the heating device, it is achieved that the catalyst is heated substantially immediately by the heating device during operation of the latter, and that for

 Wrasenauslass flowing fumes can flow to the catalyst. Such a

Wrasenauslass usually goes 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, ie the grill, two parallel aligned side by side provided fastener-side ends, via 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. In any case, this grill protrudes into the oven, ie preferably no baffle between the cooking chamber and the grill is provided. In particular, this embodiment distinguishes the grill from the known for so-called Umluftbacköfen Ringheizkör- pern.

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, also 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 can be designed as a one-piece element and, for example, be slotted along the grill along its length. 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 pipe 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 embodiment, the tube communicates with the so

Wrasenauslass that the vapors only in that he flows through the pipe, passes to the Wrasenauslass.

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 section can be integrated RAL be 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 Ts and the pipe section, which for

Wrasenauslass leads forming the base of Ts. The Wrasenauslass is in each case the fluidic connection to the environment, which emerges from an opening, which opens det in 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. However, in the present case, particular reference is made to one Attach the pipe directly to the grill, for example via spacer sleeves 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 may 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 substantially parallel thereto Muffelwand are passed to the Wrasenauslass. The vapor outlet or the outlet opening in the muffle wall is preferably provided on the muffle wall which runs parallel to the plate element and adjacent to it in the case where the catalyst is designed as a plate element.

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 operating staff. 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 it 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 catalyst is achieved essentially only by the radiant heat of the heating device, in particular at a normal operating temperature.

At the optimum operating temperature of the catalyst, i. H. that a significant odor 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. On the other hand, as far as the catalyst is a plate element, the surface facing the muffle wall should preferably be provided with a catalytic coating, i. H. 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 may be filled with a porous body or porous bodies and / or a wire mesh which in itself has catalytic properties or else which 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, e.g. 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 are. 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, 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 multinary compounds or mixtures of oxides and noble metals.

According to a further preferred embodiment of the invention, an air circulating 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 annular heating element may preferably be surrounded by a further catalyst, as described in EP 0 209 887 A2, the disclosure content of which is hereby included in the present application.

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

Figure 1A: a schematic embodiment of a high-installation oven, Figure 1 B: a schematic representation of an upper part of a first embodiment of the invention, and

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

A high-installation kiln shown in FIG. 1A has a muffle 1 and, on the upper side, a vapor outlet 2, which leaves from an upper muffle wall 3 via an outlet opening 2a. In the front view shown in FIG. 1A, the muffle 1 surrounds, by means of the upper muffle wall 3 of a lower muffle wall 9, two lateral muffle walls 5, and a rear muffle wall, not shown, a cooking space 4 in which a food can be heated. Arranged on the upper side and parallel to the upper muffle wall 3 is a grill 1 1.

FIGS. 1B and 1C show two different exemplary embodiments, this upper region with the grill 11 and the upper muffle wall 3 aligned parallel thereto. Identical elements are designated in these figures and in Figure 1 with the same reference numerals.

FIG. 1B shows a T-shaped catalyst module 13 in its cross-sectional view, which is formed from a tube 14 and a tube piece 15 extending vertically therefrom. The pipe section 15 is inserted into the outlet opening 2a and fixed there.

As can be seen schematically in Figure 1 B, the grill 1 1 extends through the tube 14 in its longitudinal direction. In the present case, the tube 14 is formed of an upper shell member and a lower shell member, which can not be seen in the schematic drawing. The tube 14 has at opposite sides in extension to each other aligned openings 14a, 14b, over which, as the arrows in Figure 1 B show the vapor through the tube 14 via the sub-tube 15 in the Wrasenauslass 2 is passed. At its entire inner surface, both the tube 14 and the sub-tube 15 is provided with a catalytically active coating.

Due to the heating of the grill 1 1, the catalytic coating is heated by radiant heat of the grill and is brought during operation of the oven to the appropriate temperature.

In Figure 1 B, 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 1 1 is arranged.

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

The plate element 16 is brought substantially by the radiant heat of the grill 1 1 to the necessary operating temperatures for catalysis.

The plate element 15 is provided on the executed to the upper muffle wall 3 side 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 vapor outlet

2a outlet opening

3 Upper muffle wall

4 cooking space

 5, 7 Side muffle walls

9 Lower muffle wall

1 1 barbecue

 13 catalyst module

14 pipe

 14a, 14b openings

 15 pipe section

 16 plate element

17 flow channel

Claims

Cooking appliance with a muffle (1) delimiting a cooking chamber (4), an electric heating device (11) for heating the cooking chamber (4), a vapor outlet (2) for discharging vapor from the cooking chamber (4) and a catalytic converter (15) for at least partial odor and / or fat removal in the vapor,  characterized in that  at least a part of the catalyst (15) spaced from a muffle wall (3) between the electric heater (1 1) 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 (1 1) by a in the cooking chamber (4) projecting grill (1 1), in particular for a top and / or bottom heat operation is formed. Cooking appliance according to claim 2, characterized in that the catalyst (15) by a tube (14) is formed, which is penetrated by at least one of the grill (1 1) forming the heating element. Cooking appliance according to claim 3, characterized in that the tube (14) communicates with the Wrasenauslass (2) and the vapors can pass only through the tube (14) to the Wrasenauslass (2). Cooking appliance according to claim 3 to 4, characterized in that the tube (14) perpendicular to the Wrasenauslass (2). 6. Cooking appliance according to claim 3 to 5, characterized in that pipe (14) is provided on a retaining flange for the grill (1 1) and surrounds the Befestigungsigungsseiti- ges end. 7. cooking appliance according to claim 3 to 6, characterized in that the grill (1 1) is designed as a folding grill, which separately from the tube (14) or together with the tube (14) is hinged. 8. Cooking appliance according to claim 1 or 2, characterized in that the catalyst (15) by a between the muffle wall (3) and the heating device (1 1) provided plate member (16) is formed. 9. Cooking appliance according to claim 8, characterized in that the vapor can only pass through a between the plate member (16) and the muffle wall (3) formed flow channel (17) to the Wrasenauslass (2). 10. Cooking appliance according to claim 8 or 9, characterized in that the plate element (16) is provided perpendicular to the Wrasenauslass (2) and extends to the Wrasenauslass (2) leading outlet opening (2a). 1 1. 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. 12. Cooking appliance according to one of the preceding claims, characterized in that an operating temperature of the catalyst (15) can be achieved substantially due to radiant heat produced by the heater. 13. 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. 14. Cooking appliance according to one of the preceding claims, characterized in that the catalyst (15) contains Pt, Pd, Au, Nb and / or mixtures thereof and / or their alloys, or that the catalyst (15) at least one oxide of Al, Cu, Ce, Ti, B and / or mixtures thereof and / or their multinary compounds. 15. 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. 16. 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 device.