Fume hood device, cooktop hood, and method for operating a fume hood device

Abstract

The invention relates to a fume hood device (1) for a cooktop (14), comprising - a housing (5), - at least one fan (3) having at least one fan impeller (4), and - a separator or filter device (6), wherein the at least one fan (3) and the separator or filter device (6) are arranged in the housing (5), wherein the at least one fan (3) is a freely rotating radial fan and the at least one fan impeller (4) has backwardly curved blades, wherein the housing (5) delimits an intake space (8) and a pressure space (10) of the at least one fan (3).

Description

[0001] Extractor hood, cooktop extractor and method for operating an extractor hood

[0002] The present invention relates to an extractor device having the features of the preamble of claim 1 as well as a cooktop extractor with such an extractor device and a method for operating an extractor device.

[0003] Nowadays, it is known to place extractor hoods for extracting and cleaning cooking fumes and vapors rising from a cooking vessel placed on a hob beneath the hob or worktop, with the cooking fumes and vapors being extracted downwards from the space above the hob. The extractor hood can form an assembly unit with the hob. It is known that hobs have at least one recess through which the cooking fumes and vapors are drawn downwards, beneath the hob, by means of an exhaust air stream. At least one fan generates the exhaust air stream. At least one element for separating or filtering grease and oil particles from the drawn-in exhaust air is arranged between the at least one recess and the at least one fan in the flow direction of the exhaust air stream.

[0004] A disadvantage compared to extractor hoods is that these extractor devices are louder when operating at least one fan and have a higher energy consumption.

[0005] The invention is therefore based on the object of providing an extractor device that operates quietly and energy-efficiently. This object is achieved by an extractor device having the features of claim 1 and a cooktop extractor with such an extractor device, as well as a method for operating an extractor device having the features of claim 21.

[0006] Accordingly, an extractor device for a hob is provided

[0007] - a housing,

[0008] - at least one fan with at least one fan impeller (preferably a single fan impeller),

[0009] - a separation or filter device, wherein the at least one fan and the separation or filter device are arranged in the housing.

[0010] The at least one fan is a free-running radial fan and the at least one fan impeller has backward-curved blades, wherein the housing delimits an intake chamber and a pressure chamber of the at least one fan.

[0011] By using a free-running radial fan with a backward-curved impeller, the space saved compared to radial fans with a fan housing can be used to install a larger impeller, which has a positive effect on the acoustics of the extractor unit and on energy efficiency. In addition, backward-curved impellers offer high efficiency, high power density, and are quiet.

[0012] Preferably, the separation or filter device is arranged in the intake chamber, and an intake opening of the at least one fan is located in the intake chamber and decentralized to the separation or filter device. In a transverse lateral view, the at least one fan and the separation or filter device have a horizontal overlap of 0 to 75%. This arrangement allows for installation space for a larger fan impeller.

[0013] It is advantageous if the housing has a cover, a base, and an intermediate base, with the intermediate base separating the intake chamber from the pressure chamber. Such a design is particularly simple and cost-effective to manufacture.

[0014] Preferably, the intake chamber has a depression in which the separation or filter device is arranged. This allows the height of the housing or extractor unit to be kept particularly low, which is advantageous for installation in a kitchen.

[0015] Preferably, the cover and the intermediate floor delimit the suction chamber, wherein the cover has an opening and the separation or filter device is arranged below the opening.

[0016] Preferably, the at least one fan is mounted on the bottom of the housing. Such a mounting can be particularly simple. If the at least one fan is capable of drawing air from below, it is conceivable for the at least one fan to be mounted on the cover or the intermediate floor of the housing.

[0017] The housing preferably has two outlets, which is advantageous for the acoustics.

[0018] It is advantageous for the pressure conditions and the design of the housing if the pressure chamber of at least one fan has a constant height. For example, with two fans, both pressure chambers preferably have the same height.

[0019] It is also advantageous if the intake space of the at least one fan outside the depression has a constant height.

[0020] It is particularly advantageous if the ratio of the height of the intake chamber to the height of the discharge chamber is no more than 1.2, especially no more than 0.9. This allows the overall height to be kept particularly low, which is advantageous for installation in a kitchen.

[0021] The housing preferably has a width which is in a range of

[0022] 500 mm to 1,000 mm. The housing preferably has an overall height in the range of 100 to 250 mm.

[0023] Preferably, the area of ​​width x depth of the housing in relation to the hob area is at least 0.7 and a maximum of 1.

[0024] Preferably, the at least one fan impeller has a diameter of at least 175 mm, in particular at least 200 mm. Such a large fan impeller can generate a significantly higher volume flow than conventionally used radial fans. This improves vapor capture even under extreme cooking conditions. Fan impellers with a diameter of at least 200 mm are particularly preferably used in combination with a separation unit in which the exhaust air is cleaned by centrifugal force.

[0025] Preferably, the fan axis around which the fan impeller rotates is oriented perpendicular to the plane of the housing's floor. However, it is also conceivable for the fan axis to be inclined.

[0026] In a preferred embodiment, the extractor device has a single fan. It is conceivable that the separation or filter device is rotationally symmetrical and that the exhaust air flow emerging from the separation or filter device flows around it in the intake chamber at an angle of at least 300°.

[0027] Furthermore, a cooktop extractor comprising a cooktop and at least one previously described extractor device is provided. The cooktop preferably has at least one recess, wherein the extractor device is designed to extract vapor rising above the cooktop through the at least one recess in an exhaust air flow generated by the at least one fan downwards below the cooktop.

[0028] The fan axis of at least one fan can be aligned vertically or tilted to a hob surface.

[0029] The exhaust air can be drawn in by the at least one fan from above or below. It is advantageous if the cooktop comprises a glass plate, to the underside of which the housing of the extractor hood is attached. However, it is also conceivable for the cooktop to form the cover of the housing of the extractor hood.

[0030] Preferably, the cooktop extractor forms an assembly unit which, fully assembled, can be inserted into a recess in a worktop by a kitchen fitter.

[0031] Furthermore, a method for operating an extractor device for a hob comprising at least one fan with at least one fan impeller is provided, wherein the at least one fan is a free-running radial fan and the at least one fan impeller has backward-curved blades, and the method comprises the following steps: a) controlling the at least one fan in a normal stage to generate a volume flow through the extractor device (1) in a range from 0 to 650 m 3 / h, wherein the electrical power consumption of the at least one fan is at most 80% of a maximum electrical power consumption, in particular at most 75%, b) controlling the at least one fan in an intensive stage to generate a volume flow through the extractor device in a range of 700 to 750 m 3 / h.

[0032] The method can be provided for both exhaust air operation and recirculation operation of the extractor device. The extractor device is preferably designed as described above.

[0033] Two embodiments of the invention are explained in more detail below with reference to the drawings. Identical or functionally identical components are provided with the same reference numerals in the figures.

[0034] The figures show: Fig. 1 : a view of a cooktop extractor with a fan with backward curved blades,

[0035] Fig. 2: a spatial representation of an intake side of the fan of the

[0036] Cooktop extractor of Figure 1,

[0037] Fig. 3: a longitudinal section through the cooktop extractor,

[0038] Fig. 4: a spatial view of the pressure side of the fan of the

[0039] cooktop extractor,

[0040] Fig. 5: a longitudinal section through the cooktop extractor fan, and

[0041] Fig. 6: a spatial view of part of a cooktop extractor with two

[0042] fans.

[0043] Figure 1 shows an extractor device designed as a cooktop extractor

[0044] 1. The cooktop extractor comprises a cooktop (not shown), in particular an induction cooktop, with a recess that preferably forms a central opening. The vapors rising from the cooktop or from cooking vessels located thereon are drawn downwards through the recess, below the cooktop, in an exhaust air stream symbolized by the arrows.

[0045] 2 by means of a fan 3. The fan 3 is a free-running radial fan having a fan impeller 4 with backward-curved blades. The term "free-running" means that the fan 3 does not have its own outer casing. The fan 3 is thus free-intake, free-exhaust, and single-flow. The blades are curved in the direction opposite to the direction of rotation. It is also conceivable to use a fan impeller with double-curved blades. Double-curved blades are additionally curved in the axial direction, i.e., across the height. The curvature can vary in the axial and radial directions. The fan impeller 4 is closed, i.e., the blades are at least partially covered on the top and bottom. The fan impeller diameter is preferably at least 175mm, in particular between

[0046] 200 mm and 250 mm, preferably about 225 mm. The extractor hood device 1 has a housing 5 in which the fan 3 is placed. The housing 5 is rectangular in cross-section with a first long side 50 and a second long side 51 as well as a first transverse side 52 and a second transverse side 53. The housing 5 also has a cover (not shown) standing perpendicular to the sides and a base (not shown) arranged parallel to the cover. The housing 5 has a central plane 54 which pierces the long sides 50, 51 in the middle. The housing 5 has a width b in a range from 700 mm to 820 mm and a depth t in a range from 400 mm to 550 mm and a total height h from the cover to the base in a range from 150 mm to 200 mm. If we consider the area of ​​width b x depth t, this is in relation to the hob area of ​​at least 0.7 and a maximum of 1.

[0047] The housing 5 surrounds the fan 3 and a separation unit 6. The separation unit 6 is directly adjacent to the recess in the flow direction of the exhaust air flow 2. In the separation unit 6, the exhaust air flow 2 is split into two flows and deflected several times. The separation unit 6 is cuboid-shaped and mirror-symmetrical to a central plane and has two opposite outlets 60, 61. The two flow channels are formed by metal sheets located between two side walls 62, 63. The two side walls 62, 63 are closed and oriented parallel to each other. The deflections cause the water droplets as well as grease and oil particles in the exhaust air flow 2 to be accelerated outwards by centrifugal force, conglomerate, and are pressed against the wall of the separation unit 2 and separated. It is also conceivable to use other separation or filtering devices for separating or filtering grease and oil particles, e.g.Expanded metal filters can be used. The shape can also differ from the design described here and be, for example, round, hexagonal or rotationally symmetrical. In the embodiment shown in the figures, the exhaust air is sucked in from above by the fan 3. An intake opening 7 of the fan 3 thus points upwards towards the cover of the housing 5. The fan axis, around which the fan impeller 4 rotates, is aligned vertically and coincides with a normal of the cover of the housing 5. The housing 5 delimits an intake chamber 8 of the fan 3, which communicates directly with the intake opening 7 of the fan 3 in terms of flow. Since the fan 3 is free-intake, the intake opening 7 lies freely in the intake chamber 8. The fan 3 itself has no limited intake. The intake is limited by the housing 5. When the fan 3 is in operation, the pressure in the intake chamber 8 is below the air pressure surrounding the extractor hood 1.

[0048] The separation unit 6 is located with its center plane in the middle of the long sides 50, 51 of the housing 5. The center plane of the separation unit 6 is identical to the center plane 54 of the housing 5. The fan 3 is arranged decentrally to the separation unit 6. The fan 3 is arranged on one side of the center plane 54 of the housing 5. It lies entirely on one side of the separation unit 6. When viewed from the transverse side, the separation unit 6 partially conceals the fan 3. The fan wheel axis lies outside the separation unit 6.

[0049] The separation unit 6 rests with one of its closed side walls 62 against the inside of the second longitudinal side 51 of the housing 5. The exhaust air flowing from the outlet 60 near the fan is sucked in directly by the fan 3. The other part of the exhaust air flow, flowing from the outlet 61 far from the fan, flows along the closed side wall 63 of the separation unit 6, which is exposed in the intake chamber 8 and far from the housing, to the fan 3. The separation unit 6 is thus surrounded from three sides by the exhaust air flow 2 in the intake chamber 8.

[0050] Figure 2 shows the housing 5 in detail. The housing 5 has an intermediate floor 9 located between the cover (not shown) and the floor 55, which is flat and aligned parallel to the cover. The intermediate floor 9 separates the intake chamber 8 from a pressure chamber 10, which is also defined by the housing 5. The intermediate floor 9 has a cutout 11 that forms a shoulder and a depression 12 extending therefrom in the intake chamber 8. The depression 12 is defined by the shoulder, the cutout 11 and the floor 55 of the housing 5. The intake chamber 8 thus has two areas with different heights. The height of the intake chamber 8 is constant in both areas. To save installation space, the separation unit 6 is arranged in the depression 12. The two outlets 60, 61 of the separation unit 6 are thus located in the transverse direction of the housing below the intake opening 7 of the fan 3.The depression 12 is rectangular in cross-section except for a bevel at the corner near the fan. The depression 12 is dimensioned such that the separation unit 6 rests against the shoulder with the closed side wall 63 near the fan. The depression 12 is formed such that the exhaust air from the two outlets 60, 61 of the separation unit 6 is directed upwards toward the cover of the housing and thus to the higher intake opening 7 of the fan 3. The pressure chamber 10 is formed between the intermediate floor 9 and the floor 55 of the housing, in which excess pressure prevails when the fan 3 is operating, compared to the air pressure surrounding the extractor device.

[0051] Figure 3 shows in detail how the exhaust air flow 2, starting from the recess 13 of the cooktop 14, is drawn downwards through the separation unit 6, directed upwards in the depression 12, and reaches the intake opening 7 of the fan 3. The pressure chamber 10 has two outlets 15. The outlets 15 have an opening with a connecting flange. A first outlet 15 is arranged on the side closest to the fan, next to the depression 12, in a plan view. The first outlet 15 is located transversely at the level of the depression 12 and at the level of the fan impeller 4.

[0052] A second outlet 15 is located on the side of the depression 12 opposite the center plane of the housing. The second outlet 15 is also located transversely at the level of the depression 12 and at the level of the fan wheel 4. The two outlets 15 each have a flow cross-section of at least 120cm 2 up to 300cm 2By using two outlets 15 on the pressure side, the outflow behavior is optimized due to the total available cross-section, which has an additional positive influence on the energy efficiency and acoustics of the extractor device 1.

[0053] Figure 4 shows in detail the exhaust air flow 2 in the pressure chamber 10. The fan 3 is designed to blow out freely. The exhaust air flow 2 on the pressure side is, as on the suction side, guided only through the housing 5 of the extractor device 1. The pressure chamber 10 is essentially U-shaped, with the separation unit (not shown) arranged between the two legs. The fan 3 is located in the bend area between one leg and a transition area connecting the two legs. The exhaust air is thus split into two air flows that are at an angle of approximately 90° to each other starting from the fan wheel axis. The exhaust air in one exhaust air flow goes directly to the outlet 15 without deflection. The exhaust air in the second exhaust air flow, on the other hand, is deflected by 90° towards the second outlet 15. Deflectors are flanged to the two outlets 15, which redirect the exhaust air downwards by 90°.Odor filters can be connected to the deflectors for recirculation, or additional duct elements for air guidance.

[0054] Figure 5 shows a longitudinal section through the fan 3. The total height h of the schematically illustrated housing 5 is 170 mm. The housing 5 is thus particularly compact, which is very user-friendly, as the space beneath the cooktop extractor is available for kitchen cabinets, for example. The position of the intermediate level 9 is selected such that there is sufficient cross-sectional area for the exhaust air flow on both the intake and pressure sides. The ratio of the height FIA of the intake chamber 8 to the height FID of the pressure chamber 10 is a maximum of 1.2, preferably a maximum of 1.0.

[0055] It can be provided that the housing 5 is fastened to the underside of the hob, in particular to the underside of the glass plate of the hob, for example by means of fastening means 16 which are glued to the underside of the glass plate and to which the housing 8 is screwed.

[0056] However, it is also conceivable that the hob itself forms the lid of the housing.

[0057] Figure 6 shows an embodiment with two free-running radial fans 3 with backward-curved blades. As in the previous embodiments, the housing 5 forms an intake chamber 8 and a pressure chamber for the fans 3. The two fans 3 are each arranged decentrally relative to the separation device 6, with the separation device 6 located in the region of the center plane of the housing 5, and the two fans 3 each positioned on one side of the center plane and symmetrically to it. Starting from the depression 12, the exhaust air now flows directly to the respective fan 3. The separation unit 6 is not surrounded by exhaust air at the closed side walls. Each fan 3 has a pressure chamber, with the two pressure chambers being separate areas from each other. In both pressure chambers, the exhaust air flows essentially parallel to the transverse sides of the housing 5. Each pressure chamber has an outlet 15.

[0058] The use of one (or more) free-running impellers (ia II often with backward-curved blades) makes the previously used screw fan housings in extractor hoods obsolete. This allows a relatively large impeller to be used, which can be operated at low power during normal operation of the extractor. The resulting low speed leads to a lower noise level. The use of an impeller with backward-curved blades increases efficiency compared to forward-curved fans, thereby increasing energy efficiency.

[0059] The operating range or the volume flows in the normal stages of the extractor are in a range from 0 to 650 m 3 / h. At the same system pressure (generated by the separation unit or grease filter, a recirculation filter, or ductwork), the electrical power consumption can be reduced by 20 to 50% compared to a conventional forward-curved fan impeller arranged in a helical casing. The high efficiency means that at least one fan can be operated at lower speeds, especially in the normal operating modes, thus improving the acoustic performance both physically (dB(A)) and psychoacoustically (perception).

[0060] Furthermore, the use of free-running radial fans with backward curved blades offers the possibility of achieving a significantly higher volume flow of 700 to 800 m 3 / h. Maximum flow rates in the range between 600 and 650 m 3 / h. The higher volume flow improves vapor capture.

Claims

Extractor extraction device (1) for a hob (14) comprising - a housing (5), - at least one fan (3) with at least one fan impeller (4), - a separation or filter device (6), wherein the at least one fan (3) and the separation or filter device (6) are arranged in the housing (5), characterized in that the at least one fan (3) is a free-running radial fan and the at least one fan impeller (4) has backward-curved blades, wherein the housing (5) delimits an intake chamber (8) and a pressure chamber (10) of the at least one fan (3). Extractor extraction device according to claim 1, characterized in that the separation or filter device (6) is arranged in the intake chamber (8) and an intake opening (7) of the at least one fan (3) is located in the intake chamber (8) and decentralized to the separation or filter device (6). Extractor hood device according to claim 1 or 2, characterized in that the housing (5) has a cover, a base (55) and an intermediate base (9), wherein the intermediate base (9) delimits the suction chamber (8) from the pressure chamber (10).Extractor extraction device according to one of the preceding claims, characterized in that the suction chamber (8) has a depression (12) in which the separation or filter device (6) is arranged. Extractor extraction device according to one of claims 3 or 4, characterized in that the cover and the intermediate floor (9) delimit the suction chamber (8), wherein the cover has an opening and. the separation or filter device (6) is arranged below the opening.

6. Extractor extraction device according to one of the preceding claims, characterized in that the at least one fan (3) is attached to the bottom (55) of the housing (5).

7. Extractor hood device according to one of the preceding claims, characterized in that the housing (5) has two outlets (15).

8. Extractor extraction device according to one of the preceding claims, characterized in that the pressure chamber (10) of the at least one fan (3) has a constant height.

9. Extractor hood device according to one of the preceding claims 4 to 8, characterized in that the suction chamber (8) of the at least one fan (3) outside the depression (12) has a constant height.

10. Extractor device according to one of the preceding claims, characterized in that the ratio of the height of the suction chamber (FIA) to the height of the pressure chamber (FID) is a maximum of 1.

2.

11. Extractor hood according to one of the preceding claims, characterized in that the housing (5) has a width in a range from 500 mm to 1,000 mm.

12. Extractor hood according to one of the preceding claims, characterized in that the housing (5) has a total height in a range of 100 to 250 mm.

13. Extractor extraction device according to one of the preceding claims, characterized in that the at least one fan impeller (4) has a fan impeller diameter of at least 175 mm.

14. Extractor device according to one of the preceding claims 3 to 13, characterized in that a fan axis around which the Fan impeller (4) rotates, oriented perpendicular to the plane of the bottom (55) of the housing (5).

15. Extractor hood device according to one of the preceding claims, characterized in that the extractor hood device (1) has a single fan (3).

16. Cooktop extractor with a cooktop (14) and at least one extractor device (1) according to one of the preceding claims 1 to 15.

17. Cooktop extractor according to claim 16, characterized in that the cooktop (14) has at least one recess (13), wherein the extractor device (1) is designed to extract vapor rising above the cooktop (14) through the at least one recess (13) in an exhaust air flow (2) generated by the at least one fan (3) downwards, below the cooktop (14).

18. Cooktop extractor according to claim 16 or 17, characterized in that the cooktop (14) comprises a glass plate, to the underside of which the housing (5) of the extractor device (1) is attached.

19. Cooktop extractor according to claim 16 or 17, characterized in that the cooktop (14) forms the cover of the housing (5) of the extractor device (1).

20. Cooktop extractor according to one of the preceding claims 16 to 19, characterized in that the cooktop extractor forms an assembly unit.

21. A method for operating an extractor device (1) for a hob (14) comprising at least one fan (3) with at least one fan impeller (4), wherein the at least one fan (3) is a free-running radial fan and the at least one fan impeller (4) has backward-curved blades, and the method comprises the following steps: a) controlling the at least one fan (3) in a normal stage to generate a volume flow through the extractor device (1), wherein the generated volume flow is in a range from 0 to 650 m 3 / h and the electrical power consumption of the at least one fan (3) is at most 80% of a maximum electrical power consumption, b) controlling the at least one fan (3) in an intensive stage to generate a volume flow through the extractor device (1), wherein the generated volume flow is in a range of 700 to 750 m 3 / h.

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