EP3807576B1 - Cooking device - Google Patents

Description

The present invention relates to a cooking appliance.

Cooking appliances, such as ovens or steam cookers, have a cooking chamber for accommodating food to be cooked. A well-known requirement is to control the humidity in the cooking cavity.

The cause of moisture is water vapour. This occurs during cooking and escapes from the food. In addition, certain cooking appliances, such as steam cookers, also supply steam for the cooking process.

The requirement to be able to adjust the humidity in the cooking space is based on various reasons. First, humidity affects energy consumption. The wetter, i. H. the less fresh air that is fed into the cooking chamber, the lower the energy consumption. On the other hand, excessive humidity can have a negative effect on the service life of the cooking appliance.

Various approaches have therefore become known for adjusting the humidity in the cooking chamber. What these approaches have in common is that the escaping vapors containing the moisture are guided out of the cooking chamber in a controlled manner. For example, describes the WO 2011/080097 A2 a two-channel air shaft. A flow of cooling air generated by a fan can be controlled using a flap in such a way that it flows either through a first or through a second channel of the two-channel air duct. The vapor is fed exclusively to the second channel via an outlet line. If the humidity in the cooking chamber, which is detected by a temperature sensor, is below a threshold value, the flap is set in such a way that it does not allow any air flow through the second channel. Accordingly, the ambient pressure in which the vapor exits is approximately the same as in the second channel. The flow of cooling air flows exclusively through the first channel. If the humidity in the cooking chamber now exceeds the threshold value, the flap is set in such a way that the flow of cooling air only flows through the second channel and no longer through the first channel. The sweeping of the outlet with the cooling air flow in the second channel causes a negative pressure, which the vapor active pulls out of the cooking compartment and thus accelerates the release of moisture into the environment.

the WO 2011/080100 A2 takes a similar approach. This provides that the outlet leading the vapors out of the cooking space is led into a chamber that is at least partially decoupled from the ventilation system in terms of pressure. For this purpose, the chamber is only connected to the ventilation system via relatively small openings.

In addition, it follows from the DE 103 41 076 A1 a cooking appliance with a fan for sucking in cooling air to cool device components, the fan being arranged in a fan chamber which has at least one fan suction opening for sucking in the cooling air and a fan outlet opening, the fan chamber being fluidically connected with its fan suction opening to a vacuum chamber which has a number of cooling air intake openings.

In addition, it follows from DE 76 06 219 U1 an oven, in particular a built-in oven, with a vapor extraction arrangement in which the hot vapor from the muffle is mixed with a flow of cooling air in a wall area of the oven and exits into the environment via at least one filter unit together with the cooling air, characterized in that the heat-resistant filter unit is easily accessible and is arranged separately exchangeable in the fume extraction opening of the muffle.

Other such cooking devices result from the documents KR 200 349 536 Y1 , DE 23 05 025 A1 , EP 2 474 787 A2 and CH 709 723 A2 .

It is therefore an object of the present invention to provide an improved cooking appliance. Accordingly, a cooking appliance with a cooking chamber for accommodating food to be cooked, which is at least partially delimited by a cooking chamber wall, a fan for generating a cooling air flow for cooling an outside of the cooking chamber wall, with the result that a suction area in which there is a negative pressure compared to the environment , and a blow-out area is created in which there is an overpressure compared to the environment, a short-circuit device for generating a short-circuit air flow between the blow-out and the intake area and thereby creating a pressure-neutral area, and a vapor outlet provided in the cooking chamber wall for leading vapor out of the cooking chamber into the pressure-neutral area.

With the help of the short-circuit device, the pressure-neutral area can be created in a simple manner, in particular independently of additional actuators. At the same time, this approach creates the possibility of connecting the pressure-neutral drainage to the pressurized ventilation system and cooling down the vapors by mixing them with the general device cooling air and discharging them together. Furthermore, since the pressure-neutral area does not force any drainage, a large cross-section can be selected for the transition from the cooking chamber to the pressurized part of the ventilation system. This large cross-section allows large amounts of vapor to escape freely. In companies with little vapor, only the vapor is discharged without forcing fresh air to be conveyed.

According to one embodiment, the cooking appliance has a dividing wall structure which separates the pressure-neutral area from the exhaust and intake areas in terms of pressure.

The partition structure can have one or more partitions, for example. The partition structure or the one or more partitions can be made of sheet metal, for example. In particular, a two-channel ventilation system can be provided, with the first channel forming the suction area and the second area forming the exhaust area. The vapor outlet can in particular open into the first channel. The partition structure can in particular have a partition which separates the first channel from the second channel. Additionally or alternatively, the dividing wall structure can have a dividing wall which at least partially surrounds the vapor outlet on the outside of the cooking chamber wall. This dividing wall can be attached in a pressure-tight manner to the outside of the cooking chamber wall and/or in a pressure-tight manner to the dividing wall between the first and second channels.

According to a further embodiment, a volume enclosed by the partition structure is designed to be open towards the intake area.

The correspondingly provided opening allows the vapor to flow from the vapor outlet via the pressure-neutral area and the outside of the cooking chamber wall into the suction area. However, the intake area cannot expand into the pressure-neutral area by means of the opening. This can be achieved in particular in that the short-circuit air flow neutralizes the corresponding suction effect. The short-circuit air flow is preferably introduced between the pressure-neutral area and the intake area, in particular via an equalization opening in the partition structure.

According to a further embodiment, the short-circuit device has an equalizing opening, which is formed in the partition structure and is set up for the short-circuit current to flow through.

The compensating opening can in particular be designed as an opening or hole in the partition structure, in particular in a partition of the same. The short-circuit air flow flows from the exhaust area into the intake area through the equalization opening.

According to a further embodiment, the partition structure has a U-shape. In the present case, a “U shape” is to be understood as meaning any U shape, V shape, semicircular shape, trough shape or the like. The corresponding opening of the U is preferably directed in the direction of flow towards the fan. In addition, the compensation opening can be in the area of the opening. The U can be formed in particular by the partition wall described above, which extends around the vapor outlet. The U-shaped partition wall thus surrounds the pressure-neutral area on its inside at least in sections, while on its outside it is surrounded by the suction area.

According to a further embodiment, the short-circuit device is set up to set a volumetric flow of the short-circuit current.

In the present case, “adjusting the volume flow” means setting, ie changing, the volume flow with regard to its intensity (e.g. in liters/minute) and/or direction. This opens up the possibility of adjusting the pressure at the vapor outlet. In this case, the one provided in a first operating mode of the cooking appliance becomes pressure-neutral Area provided in a second operating mode of the cooking appliance with a negative pressure compared to the environment to let the vapors escape faster, especially in the case of high humidity in the cooking chamber. In the same way, an overpressure relative to the environment can be provided at the vapor outlet in this way, for example in the second operating mode or in a third operating mode of the cooking appliance. This is particularly the case when humidity in the cooking chamber is too low. The cooking appliance can have a humidity sensor, in particular in the cooking chamber, which detects the humidity in the cooking chamber or the humidity of the vapor. The short-circuit device can be set up to set the volumetric flow of the short-circuit current as a function of the moisture detected with the aid of the sensor.

According to a further embodiment, the short-circuit device has a blocking device for partially or completely blocking the equalizing opening.

The blocking device can be designed, for example, as a flap or slide. The flap can be pivotable, for example, in order to adjust the cross section of the equalization opening. The slider can be provided, for example, to be linearly displaceable in order to adjust the cross section of the equalization opening. According to a further embodiment, the short-circuit device has one or more air guiding elements for guiding the short-circuit air flow.

As a result, an effective pressure equalization can take place between the exhaust and the intake area, so that the pressure-neutral area can be reliably formed.

According to a further embodiment, a first air guiding element is provided, which is directed against an air flow in the blow-out area.

The first air guiding element thus guides the air flow in the blow-out area into the compensation opening.

According to a further embodiment, a second air guiding element is provided, which is set up to conduct the short-circuit current to the fan.

The second air guiding element thus effectively guides the air flow back to the fan after passing through the equalization opening. It should be noted that only the second air-guiding element and no first air-guiding element, and vice versa, can be provided. Correspondingly, the second air-guiding element can also be referred to as an “air-guiding element” or as a “first air-guiding element”. Likewise, the first air-guiding element can be referred to as "air-guiding element" or "second air-guiding element".

According to a further embodiment, the one or more air guiding elements are designed as tabs.

For example, the tabs can simply be made of metal. These can be produced in particular by partially punching out and bending out.

According to a further embodiment, the first and second air guiding element together with an edge structure delimiting the equalization opening form a Y-shape.

The Y-shape is particularly suitable for returning the air flow in the discharge area via the intake area to the fan.

According to a further embodiment, an orientation of the one or more air guiding elements can be adjusted with respect to a plane in which the equalizing opening is located.

Orientation can be adjusted automatically or manually. Correspondingly, the orientation can be based on, for example, the fan installed in each case or the current operating mode of the fan (in particular adapted to a negative pressure currently generated by it).

According to a further embodiment, the vapor outlet is arranged within the U-shape, in particular in the middle of it.

This results in favorable flow conditions.

According to a further embodiment, the compensating opening is offset from an axis of symmetry of the U-shape.

As a result, vortex formation can advantageously be achieved. In particular, it can thus be achieved that air from the blow-out area is guided into the U on one side via the equalizing opening and a corresponding semi-annular flow is generated along the inner wall of the U-shape. In particular, the vapor can also be mixed with the (cooling) air flowing in the U-shape.

• Fig. 1 zeigt schematisch einen Ausschnitt aus einem Gargerät gemäß einer Ausführungsform;
• Fig. 2 zeigt eine Ansicht II aus Fig. 1;
• Fig. 3 zeigt einen Teilbereich III aus Fig. 1 gemäß einer weiteren Ausführungsform; und
• Fig. 4 zeigt die Ansicht aus Fig. 2, jedoch gemäß einer noch weiteren Ausführungsform.

Further advantageous configurations and aspects of the cooking appliance are the subject of the dependent claims and the exemplary embodiments of the cooking appliance described below. The cooking appliance is explained in more detail below on the basis of preferred embodiments with reference to the enclosed figures.

• 1 schematically shows a section of a cooking appliance according to one embodiment;
• 2 shows a view II 1 ;
• 3 shows part III 1 according to another embodiment; and
• 4 shows the view 2 , but according to yet another embodiment.

In the figures, the same reference symbols designate the same components or components with the same function, unless otherwise stated.

1 shows a cooking appliance 1 in a schematic view. The cooking appliance 1 can, for example, be in the form of an oven or a steam cooker.

The cooking appliance 1 includes a cooking chamber 2 for receiving items to be cooked, which are not shown. The cooking space 1 is delimited by a cooking space wall 3 . Part of the cooking chamber wall is usually a door, not shown. The cooking chamber can be loaded with the food to be cooked via the door.

When the cooking appliance 1 is cooking, the cooking chamber 2 is heated by means of heating elements (not shown). The cooking chamber wall 3 sometimes gets hot and has to be cooled. Next to of the cooking chamber wall 3, it may also be necessary to cool an electrical controller, for example in the form of a control circuit board (not shown), of the cooking chamber 1.

A two-channel ventilation system 5 is arranged on the outside 4 of the cooking chamber wall 3 (and/or the control circuit board) for the purpose of cooling it. The two-duct ventilation system 5 comprises a (first) duct 6, a (second) duct 7 and a fan housing 8. In the fan housing 8 there is a fan 10 which can be driven about an axis of rotation 9 with the aid of an electric motor (not shown), in the form of a fan in the exemplary embodiment a radial fan provided. The channel 6 and the channel 7 are separated by a partition wall 11 which extends at least in sections parallel to the outside 4 of the cooking chamber wall 3 . The partition wall 11 together with the cooking chamber wall 3 forms the first channel 6.

A partition wall 12 is also provided. Together with the partition wall 11, this forms the second channel 7.

An opening 13 is formed in the partition wall 11 and is opposite an axial suction side 14 of the radial fan 10 in the region of its axis of rotation 9 . The channel 6 is thus in air-conducting connection with the axial intake side 14 of the radial fan 10 . On the other hand, a radial outlet side 15 of the radial fan 10 is in air-conducting connection with the duct 7 .

Furthermore, the cooking chamber wall 3 is provided with a circular hole, for example, which forms a vapor outlet 16 . Vapors 17 can escape from the cooking chamber 2 into the channel 6 through the vapor outlet 16 .

2 shows a view II 1 . This illustrated in connection with 1 a partition structure 18 of the cooking appliance 1, which partially surrounds the vapor outlet 16. The partition structure 18 comprises a (first) partition which is in particular U-shaped. The U-shape 19 is in 2 apparent. The U-shape 19 or the volume 20 enclosed by it is closed by means of a (second) partition opposite the cooking chamber wall 3 . In the exemplary embodiment, the second partition is formed by a section 21 of the partition 11 . The U-shape 19 forms a seal with the cooking chamber wall 3 on the one hand (in the exemplary embodiment according to 1 below) and on the other hand with the section 21 sealing (in the embodiment after 1 above) connected. The U-shape 19 is provided with an opening 22 . The opening 22 is directed toward the radial fan 10 .

Furthermore, the cooking appliance 1 has a short-circuit device 23 . This is set up to generate a short-circuit air flow 24, as will be explained in more detail later. For this purpose, the short-circuit device 23 has a compensating opening 25 which is formed as an opening in the section 21 of the partition wall 11 and thus connects the duct 6 to the duct 7 in an air-conducting manner. The compensation opening 25 can be provided immediately adjacent to the opening 22 of the U-shape 19 . In the exemplary embodiment, the compensating opening 25 is provided in such a way that it opens into a part of the volume 20 which is assigned to end sections 26 of the U-shape 19 . 2 shows only the compensation opening 26, but not the section 21 of the partition 11.

The pressure conditions in the cooking appliance 1 and in particular the function of the short-circuit air flow 24 are explained below. In the figures, an intake area is labeled p-, a blow-out area is labeled p+ and a pressure-neutral area is labeled pn. Flow directions of the air are also indicated with arrows in the figures.

In the intake area p- there is a negative pressure compared to the environment U, while in the exhaust area p+ there is an overpressure. In the pressure-neutral area pn, the pressure corresponds to the ambient pressure.

The negative pressure and the positive pressure result from the activity of the radial fan 10, which moves air from the channel 6 into the channel 7. The corresponding air flow in the duct 6 sweeps past the outer wall 4 of the cooking chamber 3 and possibly electronic components (not shown) of the cooking appliance 1 and thus cools them.

The negative pressure in the suction area p- would lead to the vapor 17 being sucked out of the vapor outlet 16 . However, this is prevented at least in a first operating mode of the cooking appliance 1 in that the short-circuit device 23 allows the short-circuit air flow 24 . In the area of the equalization opening 25, this ensures pressure equalization between the blow-out area p+ and the intake area p-. Corresponding the equalizing opening 25 ensures local decoupling of the pressure in the volume 20 enclosed by the partition structure 18. In addition, the partition structure 18 itself also ensures pressure-related decoupling from the negative pressure surrounding the U-shape 19 on the outside (see 2 ) and Section 21 (see 1 ) surrounding overpressure. Accordingly, a pressure-neutral area pn results in the area of the vapor outlet 16 . This means that the vapor 17 can escape unhindered from the cooking chamber 2, so it is neither pulled out nor pushed back. This corresponds to a situation in which the vapor 17 is released directly into the environment. At the same time, however, the present construction ensures that the vapor 17 mixes with the cooling air flowing through the channel 6 after exiting the volume 20 via the opening 22 of the U-shape 19, is guided via the opening 13 to the radial fan 10 and from this is delivered via the second channel 7 to the environment U. Correspondingly, due to the mixing with the cooling air, the fumes 17 have a temperature that is harmless to furniture (not shown) adjoining the cooking appliance 1 and to people in the vicinity of the cooking appliance 1 .

It should be noted that in this preferred construction the vapor outlet 16 has the smallest cross-section that the vapor 17 has to overcome on its way to the environment U.

In a further embodiment, the short-circuit device 23 can have a slide 27 and optionally a moisture sensor 28 . The moisture sensor 28 can be arranged in the cooking chamber 2 . The humidity sensor 28 is set up to detect humidity in the cooking chamber 2 . The slider 27 is set up to be displaced linearly, for example, in order to selectively close the equalization opening 25 partially or completely. In other embodiments, the slider 27 can be provided in such a way that it does not allow any intermediate positions (e.g. half open), but only a completely closed and a completely open compensation opening 25 .

By partially or completely closing the equalization opening 25, the pressure in the region of the equalization opening 16 can be modified in a second operating mode of the cooking appliance 1, so that there is either overpressure or underpressure (instead of the pressure neutrality in the first operating mode). If a negative pressure is generated, This accelerates the removal of the vapor 17 from the cooking chamber 2. Conversely, excess pressure causes the vapor 27 to build up in the cooking chamber 2.

If the moisture sensor 28 is provided, the slider 27 can be controlled as a function of the moisture detected. There is thus the possibility of providing a control circuit which controls the slide 27 automatically and thus adjusts the cross section of the equalizing opening 25 and, as a result, the pressure prevailing at the vapor outlet 16 .

3 shows a view III 1 according to another embodiment. In this case, the short-circuit device 23 has a (first) air guiding element 29 and a (second) air guiding element 30 . In the exemplary embodiment, the air guiding elements 29, 30 are designed as tabs. Next, the tabs 29, 30, as in the embodiment 3 shown, be formed on an edge 31 of the section 21 of the partition wall 11 that delimits the equalizing opening 25 . The tabs 29, 30 and the edge 31 form a Y-shape. The result of this is that the tab 29 is directed against an air flow 32 which the radial fan 10 generates in the duct 7 . This leads to the deflection of the short-circuit air flow 24 into the compensation opening 25 . The orientation of the tab 30 causes the short-circuit air flow 24 to be guided back towards the radial fan 10 through the duct 6 . Advantageously, this has the result that the radial fan 10 flows evenly against the tab 29 in the blow-out region p+.

In embodiments it can be provided that an angle α, which the tab 29 forms with the plane 33 of the compensation opening 25, can be adjusted. In addition or as an alternative, it can be provided that an angle β, which the tabs 30 form with the plane 33 of the compensation opening 25, can be adjusted. The angles α and β have a significant impact on dewaxing. The smaller the angle β, the stronger the suction. The larger the angle β, the lower the suction. "Suction" here means that the pressure at the vapor outlet 16 is changed from pressure-neutral to a negative pressure. If the angle β exceeds a specific limit angle, this means that the short-circuit air flow 24 is partially guided into the cooking chamber 2 via the vapor outlet 16 . The angles α and β are preferably between 60 and 85°. As a result, a particularly favorable pressure can be set at vapor outlet 16 .

The adjustment of the orientation of the tabs 29, 30 can be done manually, via actuators or automatically. For example, an electromagnet or an electric motor can be provided as the actuator.

4 shows the view 2 , but according to yet another embodiment. In the embodiment according to 2 the vapor outlet 16, which is designed as a circular hole, is arranged with its center 36 on an axis of symmetry 34. The axis of symmetry 34 is the axis of symmetry of the U-shape 19 in a view perpendicular to the outside 4 of the housing wall 3 . This axis of symmetry 34 also lies in the exemplary embodiment 2 the equalization opening 25 running, for example, rectangular in the middle. Correspondingly, the axis of symmetry 34 is also an axis of symmetry of the vapor outlet 16 and the compensation opening 25. In contrast to this, the compensation opening 25 is in the exemplary embodiment according to FIG 4 offset relative to the axis of symmetry 34 . This in such a way that the compensating opening 25 only faces one side of the axis of symmetry 34 (in the exemplary embodiment according to 4 the top) is formed. This construction results in the short-circuit air flow 24 being guided into the U-shape 19 on one side, with a semi-annular flow 35 being produced along the inner wall of the U-shape 19 . As a result, the pressure in the area of the vapor outlet 16 is influenced. In particular, the vapor volume flow can be adjusted as a result. What is also achieved is that the vapor 17 led out of the vapor outlet 16 mixes with the flow 35 due to the formation of vortices, is thereby cooled and escapes via the opening 22 into the channel 6 . The flow 35 can also in the embodiment 4 be adjusted so that at the vapor outlet 16 in connection with the 1 and 2 described pressure neutrality.

Reference signs used:

1

cooking appliance

2

cooking chamber

3

cooking chamber wall

4

outside

5

Two channel ventilation system

6

channel

7

channel

8th

fan housing

9

axis of rotation

10

centrifugal fan

11

partition wall

12

partition wall

13

opening

14

suction side

15

discharge side

16

vapor outlet

17

vapors

18

partition structure

19

U shape

20

volume

21

section

22

opening

23

short-circuit device

24

short circuit airflow

25

compensation opening

26

end section

27

slider

28

humidity sensor

29

tab

30

tab

31

edge

32

airflow

33

level

34

axis of symmetry

35

flow

36

Focus

p+

exhaust area

p-

intake area

PM

pressure-neutral area

a

angle

β

angle

Claims (15)

1. Cooking appliance (1) with a cooking chamber (2) for receiving food to be cooked, which is delimited at least partially by a cooking chamber wall (3), a fan (10) for generating a cooling air flow for cooling an outer side (4) of the cooking chamber wall (3) with the result that an intake region (p-), in which there is a negative pressure in relation to the surrounding area (U), and a blow-out region (p+), in which there is an excess pressure in relation to the surrounding area (U), are produced,
   characterised by a short-circuit device (23) for generating a short-circuit air flow (24) between the blow-out and intake region (p+, p-) and in this way generating a pressure-neutral region (pn) and a vapour outlet (16) in the cooking chamber wall (3) for discharging vapour (17) from the cooking chamber (2) into the pressure-neutral region (pn).
2. Cooking appliance according to claim 1, characterised by a separating wall structure (18), which separates the pressure-neutral region (pn) from the blow-out and intake region (p+, p-) for pressure purposes.
3. Cooking appliance according to claim 2, characterised in that a volume (20) enclosed by the separating wall structure (18) is embodied to open out to the intake region (p-).
4. Cooking appliance according to claim 2 or 3, characterised in that the short-circuit device (23) has an equalisation opening (25), which is embodied and designed in the separating wall structure (18) for the short-circuit air flow (24) to pass therethrough.
5. Cooking appliance according to one of claims 2 to 4, characterised in that the separating wall structure (18) has a U shape (19).
6. Cooking appliance according to one of claims 1 to 5, characterised in that the short-circuit device (23) is designed to adjust a volume flow of the short-circuit air flow (24).
7. Cooking appliance according to claim 6, characterised in that the short-circuit device (23) has a blocking device (27) for partially or completely blocking the equalisation opening (25).
8. Cooking appliance according to one of claims 1 to 7, characterised in that the short-circuit device (23) has one or more air guide elements (29, 30) for guiding the short-circuit air flow (24).
9. Cooking appliance according to claim 8, characterised in that a first air guide element (29) is provided, which is directed against an air flow (32) in the blow-out region (p+).
10. Cooking appliance according to claim 8 or 9, characterised in that a second air guide element (30) is provided, which is designed to guide the short-circuit air flow (24) to the fan (10).
11. Cooking appliance according to one of claims 8 to 10, characterised in that one or more air guide elements (29, 30) are embodied as lugs.
12. Cooking appliance according to claim 10 or 11, characterised in that the first and second air guide element (29, 30) together with an edge structure (31) delimiting the equalisation opening (25) form a Y shape.
13. Cooking appliance according to one of claims 8 to 12, characterised in that an orientation (α, β) of the one or more air guide elements (29, 30) can be adjusted in relation to a plane (33), in which the equalisation opening (25) lies.
14. Cooking appliance according to one of claims 5 to 13, characterised in that the vapour outlet (16) is arranged within the U shape (19), in particular centrally herein.
15. Cooking appliance according to one of claims 5 to 14, characterised in that the equalisation opening (25) is arranged offset with respect to an axis of symmetry (34) of the U shape (19).

Images