fan wheel

Abstract

Fan wheel (1) - with a plurality of fan blades (2, 3) • which are arranged between a base plate (4) and a cover plate (5), • have the first and second blade surfaces (6, 7) pointing in opposite directions, and • which, viewed from a fan wheel center (M), have an outer edge (8) pointing radially outwards and an inner edge (9) pointing radially inwards, and - with a discharge device (10) for impurities contained in the air conveyed by the fan wheel blades (2, 3), such as in particular oil particles, characterized in that - that at least one air guide element (A, B) is provided which is attached to the base plate (4) and / or the cover plate (5) in the area of ​​the outer edge (8) and which defines a passage recess (21A', 21B') with the area of ​​the outer edge (8) and is arranged opposite the discharge device (10).

Description

[0001] The invention relates to a fan wheel according to the preamble of claim 1, which is particularly suitable for a commercial cooking appliance, such as a hot air steamer.

[0002] Such a fan wheel is known from EP 1 530 682 B1 or from DE 102 39 246 C1, which represents the priority application to this EP application.

[0003] WO 2011 120659 A1 relates to a fan wheel comprising a plurality of fan wheel blades arranged between a base plate and a cover plate, and comprising a deflection device for contaminants, in particular oil particles, contained in the air supplied by the fan wheel blades, wherein the deflection device is designed as a reinforcing profile assigned to each of the fan wheel blades and arranged between the base plate and the cover plate, maintaining a radial distance to the outer edge of the fan wheel blades.

[0004] DE 10 2005 047 457 A1 relates to a device for cleaning the cooking chamber climate in the form of a fan wheel in a steam and / or steam hot air and / or microwave appliance for cooking food on at least one baking tray.

[0005] DE 879 588 B relates to a blower for conveying gases or vapors for the purpose of separating dust particles, with a centrifugal wheel, the blades of which are bent in a trough-like manner at their outer edge in the direction of rotation of the centrifugal wheel in order to collect the dust contained in the gas.

[0006] JP 2001 050538 A refers to a convection oven that reduces unevenness when baking food.

[0007] The known fan wheel has fan blades on whose outer surface at least a raised area is arranged and / or formed, which is spaced away from a base plate of the fan wheel and extends away from the base plate, essentially diagonally from a front edge to a rear edge of the fan blades.

[0008] This is intended to prevent solid and / or liquid particles, especially grease particles, contained in the air circulated by the fan wheel from being deflected radially by the fan wheel. The raised edges on the outer surfaces of the fan blades stop the solid and / or liquid particles striking them, thus preventing devices arranged radially around the fan wheel, such as a heating element within a cooking appliance, from becoming contaminated by airborne particles.

[0009] However, this embodiment is technically problematic insofar as it requires a modification of the fan blades by attaching the aforementioned protrusions to their outer surface. Furthermore, since the fan blades are only attached to the outer surface, the fan of this type can only be operated in one direction of rotation with the same effect.

[0010] From DE 103 15 341 A1, a cooking appliance is known that has a radial fan wheel, on the blades of which a rotating separation element is provided for separating particles from the atmosphere in the cooking chamber. This results in similar problems to those of the prior art of this type.

[0011] DE 102 34 214 B4 teaches a cooking appliance with integrated grease separation, for which a disc is arranged between a rear wall of the cooking chamber and the fan wheel, which is designed in such a way that the heating device arranged around the fan wheel is essentially completely covered by the disc opposite the rear wall.

[0012] It is therefore an object of the present invention to provide a fan wheel of the type specified in the preamble of claim 1, the construction of which is simplified compared to the generic fan wheel and yet enables a safe removal of contaminants to prevent them from hitting the heating element of a commercial cooking appliance.

[0013] This problem is solved by the features of claim 1.

[0014] In detail, the fan wheel according to the invention comprises a plurality of fan blades arranged between a base plate and a cover plate, and preferably attached to both the base plate and the cover plate. The fan blades have first and second blade surfaces pointing in opposite directions. Furthermore, the fan blades have an outer edge pointing radially outwards and an inner edge pointing radially inwards, viewed from the center of the fan wheel (M). Finally, a discharge device is provided to allow the removal of contaminants, such as oil particles in particular, contained in the air conveyed by the fan blades.

[0015] This embodiment of the fan wheel according to the invention is further characterized in that one, but preferably two, air guide elements are provided in the region of the radially outer edge, which are attached at least to the base plate, but preferably to both the base plate and the cover plate. These air guide elements can define a passage recess in the case of one air guide element and two such air passage recesses in the case of two such air guide elements, through which contaminants can flow and are then directed by the air guide elements onto the discharge devices arranged radially outside the air guide elements, which in turn can be attached at least to the base plate, but preferably to both the base plate and the cover plate.

[0016] The air guide elements are arranged at an obtuse angle to the plane of the fan blades and extend outwards in a V-shape from the fan blade, thus ensuring a uniform supply of air and any contaminants to the discharge device. The inner edges of the air guide element(s) are located adjacent to the outer edge of the fan blade, with two of the alternative embodiments featuring the air guide elements as separate and independently arranged elements, distinct from both the fan blade and the discharge device.

[0017] In a third embodiment of this design of the fan wheel according to the invention, the air guide elements are combined with the discharge device, which in turn can be designed as a reinforcing element and in a channel shape, to form a single, integral part that can be fixed to the base plate and / or the cover plate. In this case as well, the inner edges of the air guide elements connected to the discharge device define a gap or a passage recess with the outer edge region of the fan wheel blade.

[0018] In another variant of this embodiment, the air guide elements are integrally connected to the fan blade in the region of the radial outer edge. This can be achieved, for example, by constructing the fan blade from two fan plates with outwardly curved outer edge end sections, as in the first embodiment, wherein the fan blade plates are joined together and thus form the fan blade in the final assembly state. In principle, an embodiment is preferred that has two such outer edge end sections which widen in a V-shape towards the outer edge of the base plate, wherein, in this embodiment, two channel-shaped discharge elements of the discharge device are provided, preferably in the form of reinforcing profiles, and these are associated with the two outer edge end sections.In this case, each of the two outer edge end sections directs the airflow, and thus the contaminants it contains, to the corresponding discharge element. This design therefore requires no passage openings, making it particularly cost-effective to manufacture.

[0019] The particular advantage of the first three variants of this embodiment lies in the fact that the fan blade can remain completely unchanged, since the air guide elements are separate components that do not need to be connected to the fan blade but can be attached to the base plate and / or cover plate. Furthermore, no openings need to be created, such as by drilling, as these openings or gaps result from the fact that the air guide elements can be attached to the base plate and / or cover plate in a suitable manner, spaced apart from the outer edge of the fan blades.

[0020] Further details, advantages and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows: Fig. 1 a cutaway top view of an embodiment of the fan wheel according to the invention to illustrate different design variants of reinforcement profiles, wherein, due to the position of the cut, a cover plate of the fan wheel is not visible; Fig. 2 a perspective partial view of the fan wheel according to Fig. 1; Fig. 3 a top view of a part of the fan wheel according to the invention Fig. 1 and Fig. 2; Fig. 4 a detail of the fan wheel according to the invention in the area of ​​an outer edge of a fan wheel blade, Fig. 5 A schematically simplified side view of an outer edge area of ​​a fan blade, Fig. 6 one of the Fig. 5. A corresponding schematically simplified perspective representation of a fan blade with two outwardly curved outer edge end parts, and Fig. 7 to 10 four alternative embodiments of the fan wheel according to the invention.

[0021] From a synthesis of Fig. Figures 1 to 3 initially show the basic structure of a fan wheel 1 according to the invention for a commercial cooking appliance, in particular a convection steamer, which, however, is not shown in the drawings. The fan wheel 1 has a plurality of fan blades, of which the Fig. Two adjacent fan blades, identified as reference numerals 2 and 3, are representative of the other fan blades. As can be seen from Fig. 1 results in the fan wheel blades 2, 3 being arranged radially around a fan wheel center point M on a base plate 4, on which they are, for example, mounted by means of Fig. 3 visible tabs 19 can be attached. In the example case, the fan wheel 1 has twelve such fan wheel blades, as can be seen from Fig. 1 equals 1.

[0022] From the presentation of Fig. 2 shows that the fan blades 2, 3 are arranged between the base plate 4 and a cover plate or a cover ring 5.

[0023] Each of the fan blades 2, 3 has a first blade surface 6 and a second blade surface 7, which, as can be seen, for example, from the Fig. 1 and Fig. 3, pointing in opposite directions. During operation of the fan 1, the air being directed from the fan 1 to a heating device strikes these blade surfaces 6, 7. It should be emphasized that, as can be seen from the figures, the fan blades 2, 3 are straight and preferably planar with curved outer edge end sections 8A, 8B, and are arranged at least substantially at right angles to the base plate 4 and the cover plate 5. Due to the straight and preferably planar design of the fan blades 2, 3, except for the outer edge end sections 8A, 8B, it is possible to operate the fan 1 reversibly, i.e., in opposite directions of rotation, so that, depending on the direction of rotation, the air strikes either the first or the second blade surface 6 or 7, and the air delivery rate remains constant.

[0024] Especially the Fig. 1 and Fig. As shown in Figure 3, the fan blades 2 and 3 also have an outer edge region 8 and an inner edge 9. From the fan wheel center M in the radial direction R (see Figure 3) Fig. 1) As seen, the inner edge 9 points radially inwards towards the center M.

[0025] The fan wheel 1 according to the invention is further equipped with a discharge device 10, which serves to separate impurities contained in the air conveyed by the fan wheel 1 or its fan wheel blades 2, 3. These impurities are, in particular, fat or oil particles that escape from the food being cooked during the cooking process and mix with the air conveyed by the fan wheel 1. To prevent these fat or oil particles or other impurities from being flung onto the heating element (not shown) surrounding the fan wheel 1, the aforementioned discharge device 10 is provided, which, in the illustrated example, has a plurality of reinforcing profiles 10A, 10B, 10C. Each of the provided fan wheel blades 2, 3 is assigned a reinforcing profile 10A, 10B, 10C, so that, in the example shown, twelve such reinforcing profiles are provided for twelve fan wheel blades.

[0026] Fig. Figure 1 shows three different training options for such reinforcement profiles, which are labeled with the reference numbers 10A, 10B and 10C respectively. It should be emphasized that Fig. Figure 1 merely shows these three different reinforcement profiles on a fan wheel 1 as an example for the sake of simplicity. In the actual design of the fan wheel 1, only one type of reinforcement profile is provided for each fan blade 2, 3, i.e. either reinforcement profile 10A for all fan blades, or reinforcement profile 10B for all fan blades, or reinforcement profile 10C for all fan blades.

[0027] The reinforcement profile 10A is arrowhead-shaped in plan view. The reinforcement profile 10B is a preferred embodiment in that it has a flow-optimized design, with the free end regions 12, 13 (see Fig. 1) Compared to the illustrated embodiment, the profiles may be bent towards each other to improve aerodynamic efficiency. Embodiment 10B represents, so to speak, a representative of aerodynamically efficient profiles, such as teardrop shapes or airfoil-like profiles.

[0028] The reinforcement profile 10C is U-shaped.

[0029] At the in Fig. In the embodiment shown in Figure 1, compared to the previously described U-shaped reinforcement profile 10C, an outer edge construction of a fan blade 20 is shown, in which outwardly bent outer edge end parts 8A and 8B of the fan blade are provided. According to the invention, "outwardly bent" means a bend as can be seen from the top view of the Fig. 1 results in a radius line R20 being drawn for clarification, from which the arrows AB8A and AB8B branch off at right angles, symbolizing the direction of the outward bending of the outer edge end parts 8A and 8B.

[0030] In the Fig. 5 and Fig. Figure 6 shows a further section of this outer edge area, again illustrating the outward bending of the outer edge end parts 8A and 8B and, in the illustrated example, the provision of passage openings 21A, 21B. In the embodiment shown in this figure, only the outer edge end part 8A is provided with such a passage opening 21. However, according to the invention, it is also possible for both outer edge end parts 8A and 8B to have one or two such passage openings.

[0031] Furthermore, within the scope of the invention it is possible to use more than just one fan wheel blade, as in Fig. 1 fan wheel blade 20 shown, to be provided with such outwardly bent outer edge end parts 8A and 8B, which is a particularly preferred embodiment in which all of these outwardly bent outer edge end parts 8A and 8B can then be provided with one or more passage recesses 21A, 21B, which can be arranged opposite the respective associated discharge device.

[0032] Preferably, both outer edge end parts 8A and 8B have the same radius of curvature.

[0033] Furthermore, the following is particularly evident from the top view of the Fig. 1, that the fan blades of the fan wheel according to the invention lie in a plane spanned by the radius lines R and the axis of rotation of the fan wheel 1 symbolized by the point M.

[0034] Fig. Figure 5 further illustrates that the outer edge end parts 8A, 8B are arranged at an angle. This results in an angle of inclination α to the base plate 4, which is an acute angle, and an angle of inclination β, which defines the inclination to the top plate 5 and is an obtuse angle.

[0035] Furthermore, the Fig. 5 and Fig. 6, that in the particularly preferred embodiment shown therein, the passage openings 21A, 21B can also be inclined and, furthermore, slightly offset from each other in the radial direction R. In the particularly preferred embodiment, the angle of inclination of the passage openings 21A and 21B, which in this embodiment are designed as slots or elongated holes, corresponds to the angle of inclination of the outer edge end parts 8A and 8B, if such passage openings 21A and 21B are arranged in both outer edge end parts 8A, 8B.

[0036] Fig. Figure 6 further clarifies that in the embodiment in which two outwardly curved outer edge end parts 8A, 8B are provided, the fan blade 2 can be formed from two fan plates 2A and 2B, each comprising the associated curved outer edge end parts 8A and 8B respectively, and which are attached to one another in the assembled state, so that the fan blade 2 is formed according to the illustration in the Fig. 5 and Fig. 6 shown embodiment results.

[0037] Furthermore, the Fig. 5 and Fig. 6 the radial distance of the reinforcing profile of the discharge device, designated by reference numeral 10C in these figures, to the outer surface of the outer edge end parts 8A, 8B. As explained at the outset, these reinforcing profiles can be fixed to the base plate 4 and / or the cover plate 5, as can be seen from the illustration of the Fig. 5 results, whereas Fig. Figure 6 only illustrates the base plate 4.

[0038] All reinforcement profiles form channels that, like Fig. Figure 2 illustrates the extension from the base plate 4 to the cover plate 5. The end section 18 of the reinforcing profiles 10A, 10B and 10C, which each rests on the base plate 4, corresponds to recesses 14, 15, 16 and 17 respectively, which are also shown by way of example in Fig. Figure 1 illustrates this. These recesses 14 to 17 represent the drainage of the particles, in particular the oil particles, collected in the respective reinforcement profile 10A, 10B, 10C, whereby the arrangement of the reinforcement profiles radially outside the outer edge 8 of the fan blades 2, 3 ensures that the collected and drained particles cannot hit the heating element surrounding the fan wheel.

[0039] The Fig. 3 and Fig. Figure 4 illustrates that a radial distance A is maintained between the outer edge 8 of each of the fan blades and the associated reinforcement profile, which may vary depending on the application, but has a value greater than 0.

[0040] Furthermore, each of the reinforcement profiles 10A, 10B and 10C is inclined at an angle α to the longitudinal centerline L of the fan wheel, which is in Fig. 3 is symbolized by the cross L. In Fig. 4, this longitudinal centerline L is shifted parallel to the outer edge of the fan wheel 1 in order to better illustrate the angle of inclination α.

[0041] As can be seen from Fig. 4 reveals, the outer edge 8 of the fan wheel blades 2, 3 preferably runs parallel to the respective associated reinforcement profile 10A, 10B or 10C, so that this outer edge 8 is inclined by the same angle α to the longitudinal center line L.

[0042] In the Fig. Figures 7 to 9 show an alternative embodiment of a second possible design of the fan wheel according to the invention.

[0043] To simplify the presentation, the Fig. 7 to 9 merely represent one fan blade 2 as a representative for all fan blades that such a fan wheel has, so that with regard to the overall configuration of the fan wheel according to the embodiment of the Fig. 7 to 9 on the description of the Fig. Reference can be made to 1 to 4.

[0044] As the Fig. Figures 7 to 9 illustrate that the fan blade 2 is completely flat, i.e., entirely unchanged or modified, as these embodiments provide air guide elements A and B, which are separate components. These separate components A and B can be attached to the base plate 4 and / or the cover plate 5. Fig. Figures 7 to 9 illustrate the orientation of the air guide elements A and B, which extend in a V-shape from the area of ​​the radial outer edge 8 towards the outer edge of the base plate 4, as can be seen in detail from the graphic representation of the Fig. 7 to 9 results.

[0045] The air guide elements A and B are arranged at a distance from the outer edge 8 or from the outer edge area of ​​the outer edge 8, which in turn enables the formation of passage recesses that function like the passage recesses 21A and 21B of the embodiment according to the Fig. 5 and Fig. 6 correspond and accordingly in the Fig. 7 to 9 are marked with the reference numbers 21A' and 21B'.

[0046] Radially outside these air guide elements A and B, the discharge device 10 is arranged, which in turn is attached to the base plate 4 and / or cover plate 5. In the Fig. 7 to 9, the drainage device 10 is again designed as a channel, for which reference is made to the preceding explanations regarding the Fig. Reference can be made to 1 to 6.

[0047] The special feature of the embodiment according to Fig. Figure 9 shows that the air guide elements A and B form a one-piece component with the drainage device or the reinforcement profile formed by it, and that this one-piece component can in turn be attached to the base plate 4 and / or the cover plate 5.

[0048] Fig. Figure 10, however, shows an embodiment that is essentially the same as that of Fig. 5 and Fig. 6 corresponds.

[0049] However, this embodiment of the fan blade 2 does not have any through-holes. Instead, the fan blade 2 has two outwardly curved outer edge end sections 8A and 8B in its outer edge region, each of which is associated with a discharge device 10 or a corresponding reinforcing profile 10A, 10B, or 10C. In this embodiment as well, the reinforcing profiles are naturally attached to the base plate 4 and / or the cover plate 5, and the design of the outer edge end sections 8A and 8B is such that they direct the air, along with the contaminants it contains, onto the two reinforcing profiles 10A, 10B, or 10C of the discharge device 10, without the need for through-holes.

[0050] As already explained at the outset, the design of the fan wheel 1 according to the invention offers the advantage that the fan wheel blades 2, 3 do not need to be modified, since the discharge device 10, which is formed by the majority of the reinforcing profiles assigned to the fan wheel blades 2, 3, is not arranged on the fan wheel blades, but on the base plate 4 and is attached to it, so that the design of the fan wheel blades 2, 3 remains completely unaffected by the arrangement of the discharge device 10.

[0051] In addition to the preceding written disclosure of the invention, explicit reference is hereby made to its graphical representation in the Fig. Reference is made to numbers 1 to 10. Reference symbol list 1 fan wheel 2, 3 fan blades 2A, 2B Ladder blade plates 4 Base plate 5 Cover plate / cover ring 6, 7 first and second blade surfaces 8 Outer edge 8A, 8B Outer edge end pieces 9 inner edge 10 Drainage device 10A, 10B, 10C Reinforcement profiles 11 Outer edge of the reinforcement profile 12, 13 free end areas 14, 15, 16, 17 exceptions 18 End area of ​​the reinforcement profiles resting on the base plate 4 19 tab 21A', 21B' Passage openings M Fan wheel center L Fan wheel longitudinal center line A radial spacing α Angle of inclination R, R20 radius lines A, B Air guide elements

Claims

[1] Fan wheel (1) - with a plurality of fan blades (2, 3) • which are arranged between a base plate (4) and a cover plate (5), • have the first and second blade surfaces (6, 7) pointing in opposite directions, and • which, viewed from a fan wheel center (M), have an outer edge (8) pointing radially outwards and an inner edge (9) pointing radially inwards, and - with a discharge device (10) for contaminants contained in the air conveyed by the fan blades (2, 3), such as in particular oil particles, characterized by , - that at least one air guide element (A, B) is provided which is attached to the base plate (4) and / or the cover plate (5) in the area of ​​the outer edge (8) and which defines a passage recess (21A', 21B') with the area of ​​the outer edge (8) and is arranged opposite the discharge device (10). [2] Fan wheel according to claim 1, wherein two air guide elements (A, B) are provided which extend from the area of ​​the outer edge (8) in a V-shape towards the outer edge of the base or cover plate (4 or 5). [3] Fan wheel according to claim 1 or 2, characterized by that the air guide elements (A, B) are integrally connected to the discharge device (10). [4] Fan wheel according to one of claims 1 to 3, characterized by , that the air guide elements are designed as curved outer edge end parts (8A, 8B) of the fan wheel blade (2) which are integrally connected to the fan wheel blade (2) and which are arranged opposite an associated discharge element (10A, 10B, 10C) of the discharge device (10).

Images