Cooking appliance with fan wheel

Abstract

Cooking appliance (10) with a cooking chamber (14), a cooking chamber wall (18) and a fan wheel (20) which is arranged on the cooking chamber wall (18) in the cooking chamber (14), wherein the fan wheel (20) has several main blades (26) on the side facing the cooking chamber (14) and several auxiliary blades (28) on the side facing the cooking chamber wall (18), wherein the auxiliary blades (28) are provided with a cover (40) on the side facing the cooking chamber wall (18), characterized in that the cooking chamber wall (18) has a pot-shaped recess (19) in which the fan wheel (20) is arranged.

Description

[0001] The invention relates to a cooking appliance with a cooking chamber, a cooking chamber wall and a fan wheel which is arranged on the cooking chamber wall in the cooking chamber, wherein the fan wheel has a plurality of main blades on the side facing the cooking chamber and a plurality of auxiliary blades on the side facing the cooking chamber wall.

[0002] A cooking appliance of the type mentioned above is known from DE 103 51 476 A1. Like the cooking appliance according to the invention, it is a professional cooking appliance intended for use in restaurants, canteens, and large-scale catering. Different foods can be cooked in the cooking chamber, with a control system that can execute different cooking programs. In particular, it is intended that these are so-called intelligent cooking programs, i.e., cooking programs that adapt to the respective food without operator intervention, so that the desired cooking state of the food can always be reproduced as precisely as possible.

[0003] The fan wheel serves, on the one hand, to introduce fresh air into the cooking chamber, for example, for dehumidification purposes. The auxiliary blades, which can draw in air from a fresh air duct, are used to supply the fresh air. The fan wheel also serves to circulate the atmosphere in the cooking chamber. The main blades are used for this purpose.

[0004] Similar cooking appliances are disclosed in US 4 395 233 A and US 8 176 651 B2.

[0005] The object of the invention is to increase the efficiency of the fan wheel when supplying fresh air.

[0006] To achieve this object, the invention provides that the auxiliary blades are provided with a cover on the side facing the cooking chamber wall. The cover, which is attached to the fan wheel and rotates together with it, closes the flow channel located between the auxiliary blades in the axial direction. Only one inlet opening is provided on the radially inner side and one outlet on the radially outer side. This results in an air volume located between the auxiliary blades rotating at (at least approximately) the full speed of the fan, since not only the "underside" of the flow channel, i.e. the separation from the main blades, but also the "top side" of the flow channel, i.e. the cover, rotates at the speed of the fan wheel. The braking effect of the stationary cooking chamber wall, known from the prior art, is eliminated.This increases the suction effect of the fan wheel caused by centrifugal force. Furthermore, the short-circuit flow, which flows inward between the cooking chamber wall and the cover, is separated from the outward flow of the flow channel between the auxiliary blades, preventing mixing and thus reducing losses. At the same time, the short-circuit flow is impeded due to the resulting long paths and the sharp 180° deflection. Overall, this allows the maximum pressure jump (without volume flow) to be increased by approximately 50% and the maximum volume flow (with almost no back pressure) by approximately 25%.

[0007] According to one embodiment of the invention, the cover is a sheet metal disc. This can be attached to the fan wheel with particularly little effort, for example, directly onto the auxiliary blades. The cover can, for example, be welded to the auxiliary blades.

[0008] Preferably, the cover has an opening arranged concentrically to the rotational axis of the fan wheel. Fresh air, which is to be introduced into the cooking chamber, can flow through the access opening into the flow channel between the auxiliary blades.

[0009] According to one embodiment of the invention, the cover is provided with a nozzle that extends toward the cooking chamber wall. This allows short-circuit currents to be reduced.

[0010] The nozzle can be designed to extend through the cooking chamber wall. This further reduces short-circuit currents.

[0011] Alternatively, the cooking chamber wall can be provided with a nozzle extending toward the cover. This measure can also reduce short-circuit currents.

[0012] The nozzle of the cooking chamber wall can extend through the cover into the area between the auxiliary blades. This optimizes the flow of fresh air to the flow channel between the auxiliary blades.

[0013] According to the invention, the cooking chamber wall has a drip-proof groove in which the fan wheel is arranged. This design has proven advantageous with regard to the efficiency of the fan wheel.

[0014] According to a preferred embodiment of the invention, the dividing plane between the main and auxiliary blades lies approximately on a plane defined by the areas of the cooking chamber wall located outside the pot embossing. This design leads to particularly high efficiency of the main blades when they circulate the cooking chamber atmosphere.

[0015] The invention is described below with reference to an embodiment illustrated in the accompanying drawings, in which: - Fig. 1 schematically shows a cooking appliance according to the invention; - Fig. 2 shows, on a larger scale, a fan wheel according to a first embodiment mounted in a cooking appliance according to the invention; and - Fig. 3 a fan wheel according to a second embodiment, which is mounted in a cooking appliance according to the invention.

[0016] In Fig. 1 shows a cooking appliance 10 comprising a housing 12 within which a cooking chamber 14 is provided. Food can be cooked in the cooking chamber, for example, on food carriers (not shown) that are placed inside the cooking chamber. The cooking chamber can be closed with a door 16.

[0017] A fan wheel 20 is arranged on a cooking chamber wall 18 that defines the cooking chamber. This fan wheel is connected to a drive motor 24, for example, an electric motor, via a drive shaft 22. The electric motor enables the fan wheel 20 to rotate.

[0018] The fan wheel 20 has a plurality of main blades 26 arranged on the side 14 facing the cooking chamber, and a plurality of auxiliary blades 28 arranged on the side facing the cooking chamber wall 18. A support 30 is located between the main blades 26 and the auxiliary blades 28.

[0019] A partition plate 32 is arranged in the cooking chamber 14 so that the fan wheel 20 is not completely exposed in the cooking chamber 14. An opening 34 is provided in the partition plate 32 so that the cooking chamber atmosphere in the cooking chamber 14 can flow to an area centrally between the main blades 26.

[0020] On the side of the cooking chamber wall 18 facing away from the cooking chamber 14, a fresh air supply 36 is provided, shown here only schematically, with which fresh air can be directed to an area centrally between the auxiliary blades 28.

[0021] When the fan wheel 20 is rotated by the drive motor 24, the main blades 26 suck in cooking chamber atmosphere through the opening 34, which is then accelerated outwards between the main blades 26 due to centrifugal force, so that a circulating flow U is generated.

[0022] If fresh air is to be supplied to the cooking chamber 14, a control flap (not shown here) in the fresh air supply 36 is opened, and fresh air F is sucked in by the auxiliary vanes 28, so that it is introduced from the fresh air supply 36 along the auxiliary vanes 28 into the cooking chamber 14. The fresh air can be used in particular to dehumidify the cooking chamber 14, i.e., to displace cooking chamber atmosphere with a high vapor content from the cooking chamber 14.

[0023] The special feature of the fan wheel 20 is that it is provided with a cover 40 on the side facing the cooking chamber wall 18. In simple terms, this can be imagined as a disc that rests on the edges of the auxiliary blades 28 facing the cooking chamber wall 18.

[0024] The cover 40 has an opening 42 in the center so that there is access to the flow channels formed between each two auxiliary blades 28, the carrier 30 and the cover 40.

[0025] In Fig. 2 shows a first embodiment of the fan wheel 20 in detail.

[0026] In Fig. 2 shows that the cooking chamber wall 18 is provided with a pot embossing 19, in which the fan wheel 20 is centrally located. The depth of the drip embossing and the dimensions of the fan wheel 20 are coordinated such that the support 30 is located approximately at the level of the cooking chamber wall 18 outside the drip embossing 19. In other words: the auxiliary blades 28 are located inside the pot embossing 19, while the main blades 26 are located outside.

[0027] In Fig. Figure 2 also shows that the cover 40 is located at a certain distance from the cooking chamber wall in the area of ​​the pot embossing 19. This distance can be chosen as small as possible to avoid short-circuit currents. However, it is always chosen large enough to ensure that the fan wheel 20 can rotate without contact at all times, taking into account thermal expansion of all affected components.

[0028] The cooking chamber wall 18, more precisely the area centrally within the pot embossing 19, is provided here with a nozzle 50 which extends from the bottom of the pot embossing 19 to the fan wheel 20.

[0029] In the embodiment shown, the nozzle 50 ends just in front of the carrier 30 centrally between the radially inner ends of the auxiliary blades 28.

[0030] The drive shaft 22 for the fan wheel 20 is in Fig. 2 not shown for clarity.

[0031] The cover 40 can be used in Fig. 2, the cover 40 can be designed as a flat disc, for example made of sheet metal, which is attached to the auxiliary blades 28. As can be seen in detail X, the cover 40 can be welded to the auxiliary blades 28, for example.

[0032] By using the cover 40, a flow channel is created between each two adjacent auxiliary blades 28, which is closed in the axial direction on one side by the support 30 and on the other side by the cover 40. The fresh air flowing here is therefore not slowed down by stationary components of the cooking appliance.

[0033] In Fig.3 shows a second embodiment of the fan wheel 20. The same reference numerals are used for the components known from the first embodiment, and reference is made to the above explanations in this regard. The difference between the first and second embodiments is that in the second embodiment, the cover 40 is provided with a nozzle 60 that extends into the fresh air supply 36. Specifically, the nozzle 60 extends through an opening in the bottom of the cup embossment 19. Thus, a short-circuit flow through the area between the bottom of the cup embossment 19 and the cover 40 is largely prevented.

Claims

[1] Cooking appliance (10) with a cooking chamber (14), a cooking chamber wall (18) and a fan wheel (20) which is arranged on the cooking chamber wall (18) in the cooking chamber (14), wherein the fan wheel (20) has a plurality of main blades (26) on the side facing the cooking chamber (14) and a plurality of auxiliary blades (28) on the side facing the cooking chamber wall (18), wherein the auxiliary blades (28) are provided with a cover (40) on the side facing the cooking chamber wall (18), characterized by that the cooking chamber wall (18) has a pot embossing (19) in which the fan wheel (20) is arranged. [2] Cooking appliance according to claim 1, characterized by that the cover (40) is a sheet metal disc. [3] Cooking appliance according to claim 1 or claim 2, characterized by that the cover (40) has an opening (42) which is arranged concentrically to the axis of rotation of the fan wheel (20). [4] Cooking appliance according to one of the preceding claims, characterized bythat the cover (40) is provided with a nozzle (60) which extends towards the cooking chamber wall (18). [5] Cooking appliance according to claim 4, characterized by that the nozzle extends through the cooking chamber wall (18). [6] Cooking appliance according to one of claims 1 to 3, characterized by that the cooking chamber wall (18) is provided with a nozzle (50) which extends towards the cover (40). [7] Cooking appliance according to claim 6, characterized by that the nozzle extends through the cover (40) into the area between the auxiliary blades (28). [8] Cooking appliance according to one of the preceding claims, characterized by that the parting plane between the main and auxiliary blades (26, 28) lies on a plane which is defined by the areas of the cooking chamber wall (18) located outside the pot embossing (19).

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