Cooking appliance

Abstract

Cooking appliance (10) with a cooking chamber (12), at least one heating element (20) for heating the cooking chamber atmosphere, a blower (14) for circulating the cooking chamber atmosphere, wherein the blower (14) has a fan wheel (16), with a first ring (24) attached to the fan wheel (16) and rotatable with it, which extends from the fan wheel (16) at least partially in an axial direction away from the fan wheel (16), and a second ring (26) arranged at least partially within the first ring (24), wherein an annular gap (28) is present between the first ring (24) and the second ring (26), and with a fluid supply line (32) for supplying fluid into the annular gap (28) such that a centrifugal force acts on the fluid when the fan wheel (16) rotates.

Description

[0001] The invention relates to a cooking appliance with a heating element for heating the cooking chamber atmosphere, whereby a steam atmosphere can be generated in the cooking chamber.

[0002] The cooking appliance is specifically a combi steamer, which allows food to be cooked in a chamber atmosphere with widely adjustable temperature and humidity. The cooking appliance is intended for professional use, i.e., in restaurants, canteens, and large-scale catering.

[0003] It is known to create a steam atmosphere in a cooking chamber by wetting surfaces heated by a heating element to heat the cooking chamber atmosphere with a fluid, whereby the fluid evaporates.

[0004] Especially when the cooking chamber temperature is lower than the boiling point of the fluid, the fluid to be evaporated must be distributed as precisely as possible across the heated surfaces. Fluid that does not reach the heated surfaces flows into the drain in its liquid state and draws heat from the cooking chamber, which negatively impacts the efficiency of the cooking appliance. If too little fluid reaches the heated surfaces, the cooking chamber humidity will not reach the desired levels. Furthermore, a larger portion of the heat output is transferred directly into the gaseous cooking medium, which can cause the cooking chamber atmosphere to overheat.

[0005] DE 28 42 771 A1 describes a device for preparing food by means of a hot air stream circulating at atmospheric pressure.

[0006] DE 103 25 765 A1 discloses a cooking appliance with a cooking chamber in which hot air and steam can circulate.

[0007] DE 20 2015 107 082 U1 describes a fan wheel for a cooking appliance with a hub plate on which several moisture vanes are arranged on the front side.

[0008] DE 101 58 425 C1 discloses a cooking appliance with a fan having a radial fan wheel and an atomizing element rotating with the radial fan wheel.

[0009] US 2008 / 0 078 371 A1 describes an atomizing device for a cooking appliance, wherein the atomizing device has a rotating atomizing element. The atomizing element has a plurality of blades and conveys an atomized liquid toward a fan.

[0010] It is therefore an object of the invention to provide a cooking appliance that enables optimized steam generation.

[0011] This object is achieved according to the invention by a cooking appliance with a cooking chamber, at least one heating element for heating the cooking chamber atmosphere, and a fan for circulating the cooking chamber atmosphere, wherein the fan has a fan wheel. The cooking appliance also comprises a first ring which is fastened to the fan wheel and rotatable with the fan wheel, which extends away from the fan wheel at least in sections in the axial direction, and a second ring which is arranged at least in sections within the first ring, wherein an annular gap is present between the first ring and the second ring. Furthermore, a fluid supply line is provided for supplying fluid into the annular gap such that a centrifugal force acts on the fluid when the fan wheel rotates.

[0012] Due to the centrifugal force acting on the fluid as the fan wheel rotates, the fluid initially adheres to the rotating ring and is distributed circumferentially within the annular gap. With further acceleration, the fluid detaches from the ring in the form of fine droplets, which can be evaporated particularly quickly by the heating element.

[0013] The second ring prevents the supplied fluid from escaping and shields it from the fan flow. This allows the fluid to be distributed in a particularly controlled manner throughout the cooking chamber, particularly to the heating element.

[0014] The cooking appliance according to the invention therefore enables particularly efficient steam generation.

[0015] The fluid is usually water.

[0016] The first ring is preferably arranged on the intake side of the fan wheel.

[0017] The second ring is particularly stationary. As a result, when the first ring rotates, friction acts on the fluid in the annular gap, which promotes atomization of the fluid.

[0018] Alternatively, the second ring can also be attached to the fan wheel and rotate with it. This simplifies the assembly of the cooking appliance.

[0019] According to one embodiment, the second ring extends axially beyond the first ring. This projection simplifies the supply of fluid into the annular gap. For example, the fluid can be directed radially from the outside onto the projection via the fluid supply line, with the fluid distributing itself from the projection and flowing into the annular gap. Therefore, the fluid does not need to be introduced directly into the annular gap.

[0020] The first ring and / or the second ring may have a cylindrical, a concavely curved, a convexly curved or a corrugated outer surface.

[0021] The first ring, for example, has a concavely curved surface. This influences the trajectory of the droplets released from the first ring. In particular, the droplets are accelerated in both axial and radial directions, which transports them precisely to a specific area of ​​the heating element.

[0022] The second ring, for example, has a cylindrical surface. This makes the production of the second ring particularly simple.

[0023] The outer diameter of the first ring preferably corresponds to the outer diameter of the fan impeller. This is advantageous with regard to the attachment of the first ring to the fan impeller. It also achieves a compact design in the radial direction. A further advantage is that the largest possible diameter results in a higher relative speed of the ring segments of the first ring in the circumferential direction than with a ring with a smaller diameter, thus accelerating the fluid to the highest possible speed.

[0024] According to one embodiment, the cooking appliance comprises an air baffle, and the second ring is attached to the air baffle. The air baffle is particularly well suited for attaching the ring, as it is typically located close to the fan wheel and has a recess in the fan wheel's intake area.

[0025] The heating element can be a heating ring that concentrically surrounds the fan impeller. This arrangement allows the fluid accelerated by the first ring to impinge on the heating element as directly as possible after detaching from the ring, thus vaporizing the fluid particularly efficiently.

[0026] The first rotatably mounted ring can have a radially inward-facing collar at one free end. This allows the supplied water to be distributed even more evenly across the circumference of the ring.

[0027] Furthermore, the first rotatably mounted ring can have a radially inwardly extending dam edge at its end attached to the fan wheel. By initially damming the water at the dam edge, a particularly even distribution of the water over the circumference of the ring is achieved.

[0028] Further advantages and features of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings: - Fig. 1 schematically shows a cooking appliance according to the invention in a sectional view, - Fig. 2 schematically shows a plan view of a heating element and a fan wheel of the cooking appliance from Fig. 1 - Fig. 3 a fan for a cooking appliance according to another embodiment, - Fig. 4 another fan for a cooking appliance, - Fig. 5 to 22 schematically different ring pairings, and - Fig. 23 a fan wheel for a cooking appliance according to the invention.

[0029] Fig. 1 shows a schematic sectional view of a cooking appliance 10 with a cooking chamber 12.

[0030] The cooking appliance 10 has a fan 14 for circulating the cooking chamber atmosphere, which includes a fan wheel 16.

[0031] The fan wheel 16 has several fan wheel blades 18 distributed in the circumferential direction.

[0032] In particular, the fan wheel 16 is a radial impeller. This means that a central area of ​​the fan wheel 16 is free of fan blades 18 in order to draw in air parallel to a rotational axis.

[0033] Furthermore, the cooking appliance 10 has a heating element 20 in the form of a heating ring. In the exemplary embodiment, the heating ring has several windings.

[0034] The heating ring surrounds the fan wheel 16 concentrically, as is particularly evident in Fig. 2 can be seen.

[0035] As in Fig. 1 by arrows, the fan wheel 16 sucks in air in the central intake area so that the air circulates in the cooking chamber 12, whereby the air is passed over the heating element 20 and is heated in the process.

[0036] The desired flow is promoted by an air baffle 22, which partially shields the fan wheel 16 from the cooking chamber 12.

[0037] The cooking appliance 10 further comprises a first ring 24 which is attached to the fan wheel 16 and is rotatable therewith.

[0038] The ring 24 extends axially away from the fan wheel 16, particularly toward the cooking chamber 12. In other words, the ring 24 is attached to the intake side of the fan wheel 16.

[0039] The outer diameter of the first ring 24 corresponds to an outer diameter of the fan wheel 16.

[0040] The lateral surface of the first ring 24 is concavely curved.

[0041] In addition, a second ring 26 is provided, which is arranged at least partially within the first ring 24.

[0042] An annular gap 28 is present between the first ring 24 and the second ring 26.

[0043] The second ring 26 is fixed.

[0044] In the exemplary embodiment, the second ring 26 is attached to the air baffle 22.

[0045] The second ring 26 has a cylindrical outer surface.

[0046] However, other shapes of the first ring 24 and the second ring 26 are also conceivable, for example a convex or a corrugated shape.

[0047] The second ring 26 is spaced slightly from the fan wheel 16 to avoid friction.

[0048] As in Fig. 1, the second ring 26 projects axially beyond the first ring 24, specifically in the direction away from the fan wheel 16.

[0049] This results in an axial gap 30 between the first ring 24 and the air baffle 22.

[0050] The gap 30 serves to supply water into the annular gap 28.

[0051] For this purpose, a fluid supply line 32 is provided.

[0052] The fluid supply line 32 is arranged such that water can flow from the fluid supply line 32 into the annular gap 28.

[0053] As in the Fig. 1 and Fig. 2, an outlet opening 34 of the fluid supply line 32 is arranged outside the annular gap 28, in particular above the gap 30.

[0054] When water is supplied into the annular gap 28 during operation of the blower 14, the water is distributed in the annular gap 28 by the rotation of the first ring 24 and is accelerated by the friction acting on the water by the rotating first ring 24.

[0055] Due to the centrifugal force acting here, the water attaches itself to the first ring 24 and is accelerated radially outwards.

[0056] The second, inner ring 26 ensures that the water remains in the annular gap 28.

[0057] At the outer diameter of the ring 24, the water detaches from the ring in the form of droplets, which, due to the shape of the first ring 24 and the arrangement of the heating element 20, enter a flow area that specifically transports the droplets to the heating element 20. As a result, the heating element 20 is wetted particularly evenly, and the water supplied through the fluid supply line 32 is completely evaporated.

[0058] The resulting steam is fed into the cooking chamber 12 by the flow generated by the fan wheel 16, so that an optimal cooking chamber atmosphere is created in the cooking chamber 12.

[0059] Fig. 3 illustrates an alternative fan 14 for the cooking appliance 10.

[0060] The Fig. The blower 14 illustrated in Figure 3 differs from the one shown in Fig. 1 and Fig. 2 illustrated blower 14 by the shape of the rotatable ring 24.

[0061] The rotatable ring 24 according to Fig. 3 has at its free end, i.e. at the end directed away from the fan wheel 16, a radially inwardly projecting collar 36.

[0062] In particular, the collar 36 forms a barrier that reduces the volume flow of water into the annular gap 28. Furthermore, the collar 36 prevents water loss in the wrong direction.

[0063] The collar 36 serves in particular to influence the flow path of the water and to distribute it even more evenly over the circumference of the ring 24.

[0064] Fig. 4 shows a further alternative fan 14 for the cooking appliance 10, in which a baffle edge 38 is provided at the end of the rotatable ring 24, which is fastened to the fan wheel 16, in addition to the collar 36.

[0065] The dam edge 38 extends obliquely radially inward from the end of the rotatable ring 24, particularly into the fan wheel 16. In other words, the dam edge 38 is conical.

[0066] The damming edge 38 is, for example, designed to be circumferential and is only interrupted by the fan blades 18.

[0067] When the cooking appliance 10 is in operation, the supplied water initially accumulates at the dam edge 38.

[0068] When the water reaches the edge of the retaining edge 38, if more water is added, the water flows over the retaining edge 38 and is transported to the heating element 20.

[0069] In a further embodiment, only one retaining edge 38 may be present without an additional collar 36.

[0070] Further forms of the rotatable ring 24 and the fixed ring 26 are shown schematically in the Fig. 5 to 22 illustrates.

[0071] The Fig. 5 to 11 each illustrate an embodiment with a cylindrically shaped fixed ring 26 and differently shaped rotatable rings 24.

[0072] In Fig. 5 illustrates a convex-shaped rotatable ring 24.

[0073] Fig. 6 shows a conically shaped rotatable ring 26.

[0074] At the Fig. In the embodiment illustrated in Figure 7, both the rotatable ring 24 and the fixed ring 26 are cylindrical.

[0075] The Fig. The rotatable ring 24 illustrated in Figure 8 has an angled profile.

[0076] Fig. 9 shows an embodiment with a stepped rotatable ring 24.

[0077] In Fig. 10 illustrates a rotatable ring 24 which is a hybrid of a conical and a concave shaped ring.

[0078] In the Fig. 12 to 19 each illustrate a concavely shaped rotatable ring 24 in combination with differently shaped fixed rings 26.

[0079] The Fig. The fixed ring 26 shown in Figure 12 is conical in shape.

[0080] In Fig. 13 shows a concave shaped fixed ring 26.

[0081] Fig. 14 shows a convex shaped fixed ring 26.

[0082] Fig. 15 shows an angled fixed ring 26.

[0083] In Fig. 16 shows a stepped fixed ring 26.

[0084] In Fig. Figure 17 illustrates a double-concave-shaped fixed ring 26. Specifically, the fixed ring 26 has two sections that are curved differently.

[0085] Fig. 18 shows a fixed ring 26 which is a hybrid of a conical and a cylindrical ring.

[0086] The Fig. 19 to 21 illustrate embodiments with different types of jam edges.

[0087] Fig. Figure 19 illustrates an embodiment in which a radially outwardly projecting collar 40 is arranged at a free end of the stationary ring 26. The collar 40 forms a barrier that serves to better distribute the water circumferentially.

[0088] In Fig. 20 illustrates a rotatable ring 24 in which a vertical baffle edge 42 is arranged at the end of the rotatable ring 24, which is fastened to the fan wheel 16.

[0089] Water can initially collect at the dam edge 42 and be evenly distributed around the circumference before flowing over the dam edge 42.

[0090] In Fig. 21 shows a conical baffle edge 44 which is arranged in the center of the rotating ring 24.

[0091] Fig. 22 shows an embodiment with an additional fixed ring 46. The ring 46 prevents water loss in the wrong direction.

[0092] The Fig. The ring shapes illustrated in 5 to 22 can be combined with each other as desired.

[0093] Fig. 23 shows a fan wheel 16 which can also be used in a cooking appliance 10 according to the invention.

[0094] Instead of a rotating and a fixed ring, according to the Fig. In the embodiment shown in Figure 23, two rotatable rings 24, 26 are present.

[0095] The rings 24, 26 are both attached to the fan wheel 16 and are therefore fixed relative to each other.

Claims

[1] Cooking appliance (10) with a cooking chamber (12), at least one heating element (20) for heating the cooking chamber atmosphere, a fan (14) for circulating the cooking chamber atmosphere, wherein the fan (14) has a fan wheel (16), with a first ring (24) which is fastened to the fan wheel (16) and is rotatable therewith and which extends from the fan wheel (16) at least in sections in the axial direction away from the fan wheel (16), and a second ring (26) arranged at least partially within the first ring (24), wherein an annular gap (28) is present between the first ring (24) and the second ring (26), and with a fluid supply line (32) for supplying fluid into the annular gap (28) such that a centrifugal force acts on the fluid upon rotation of the fan wheel (16). [2] Cooking appliance (10) according to claim 1, characterized by that the second ring (26) is fixed. [3] Cooking appliance (10) according to claim 1, characterized by that the second ring (26) is attached to the fan wheel (16) and can rotate with it. [4] Cooking appliance (10) according to one of the preceding claims, characterized by that the second ring (26) projects beyond the first ring (24) in the axial direction. [5] Cooking appliance (10) according to one of the preceding claims, characterized by that the first ring (24) has a concavely curved surface. [6] Cooking appliance (10) according to one of the preceding claims, characterized by that the second ring (26) has a cylindrical outer surface. [7] Cooking appliance (10) according to one of the preceding claims, characterized by that the outer diameter of the first ring (24) corresponds to an outer diameter of the fan wheel (16). [8] Cooking appliance (10) according to one of claims 1 to 2 and 4 to 7, characterized by that the cooking appliance (10) comprises an air baffle (22) and the second ring (26) is attached to the air baffle (22). [9] Cooking appliance (10) according to one of the preceding claims, characterized by that the heating element (20) is a heating ring which concentrically surrounds the fan wheel (16). [10] Cooking appliance (10) according to one of the preceding claims, characterized by that the first rotatably mounted ring (24) has a radially inwardly projecting collar (36) at a free end. [11] Cooking appliance (10) according to one of the preceding claims, characterized by that the first rotatably mounted ring (24) has at its end fastened to the fan wheel (16) a dam edge (38) extending obliquely radially inwards.

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