EP4692649A1

EP4692649A1 - Extraction device

Info

Publication number: EP4692649A1
Application number: EP24193032.0A
Authority: EP
Inventors: Stefan Bayerlein; Raimund BÖHM
Original assignee: Electrolux Appliances AB
Current assignee: Electrolux Appliances AB
Priority date: 2024-08-06
Filing date: 2024-08-06
Publication date: 2026-02-11
Also published as: WO2026032655A1

Abstract

The present invention concerns an extraction device (14) comprising a fan (36) and an air channel (27, 44). The fan (36), which includes a fan housing (42) and a motor for driving air conveyance means, is configured to suck cooking fumes through a suction opening (24) into an interior of the extraction device (14). The air conveyance means are arranged in or allocated to the fan housing (42). The air channel (27, 44) comprises at least one channel wall (27') enclosing an interior of the air channel (27, 44). Noise dampening and/or reflecting means (64,66,68,78) are arranged at an essential part of the extraction device (14). The noise dampening and/or reflecting means (64,66,68,78) are adapted to prevent or to attenuate a transmission of an airborne sound.

Further disclosed is a combination appliance (10) with such an extraction device (14).

Description

The present invention relates to an extraction device for extracting cooking fumes according to claim 1. The present invention further relates to a combination appliance according to claim 18.
During the performance of cooking activities under use of a cooking hob, cooking fumes are generated, which are distributed over the cooking area. In order to avoid these cooking fumes to be spread throughout the entire kitchen space, an arrangement of an extraction device, particularly an extractor hood, is common. Said extraction device is operated in parallel to the cooking hob, thereby sucking in these cooking fumes in order to filter out particles and tiny droplets from the fumes and/or to blow the fumes to the outside of the building. Besides the possibility to arrange such an extractor hood above the cooking area, the application of downdraft extraction devices are common. Such kind of extraction device is usually arranged below a cooktop of the related cooking hob, which configuration forms a so-called combination appliance, and it comprises at least one fan for sucking air from the cooking area through an opening or recess arranged in the cooktop. In such systems, the exhaust air is either directly blown out on the reverse side of the combination appliance and distributed over the space behind a kitchen cabinet, in which the combination appliance is installed, or the exhaust air is moved through a ventilation channel from the cooking zone to the bottom of the kitchen cabinet, where it is blown out, particularly through an opening in a plinth panel, and returned to the ambient air. Due to the use of a fan for air conveyance, which fan is commonly driven by an electric motor, as well as the generated airflow conveyed streaming through an air channel in the interior of the extraction device, a corresponding operating noise causes annoyance and a respective stress level to the user of the cooking appliances, particularly disturbing a communication in the kitchen area especially when the fan is operated at a high speed level.
It is an object of the present invention to provide an extraction device for cooking fumes, in particular a range hood or an extractor unit of a combination appliance, and/or to provide a combination appliance, which extraction device or combination appliance provides for a noise-reducing capability during the operation of the extraction device.
According to a first aspect of the present invention, the object is achieved for an extraction device for extracting cooking fumes by the combination of features of claim 1.
Said extraction device according to the first aspect is an extraction device for extracting cooking fumes, which comprises a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. Said suction opening particularly forms a channel start for an entry of the cooking fumes in the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel comprises at least one channel wall, which encloses an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, the air channel may be or may comprise a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device, which outlet opening is particularly arranged at an end section of the air channel, and which may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. According to the first aspect of the present invention, noise dampening means and/or noise reflecting means are arranged at an essential part of the extraction device. Said noise dampening means and/or noise reflecting means are adapted to prevent or to attenuate a transmission of an airborne sound.
According to embodiments, the essential part of the extraction device is an essential part of at least one of (a) the air channel, particularly the first air channel section and/or the second air channel section, (b) a filter element of the extraction device, which filter element is arranged in the air channel downstream of the suction opening, (c) a cover element of the extraction device, in particular an air intake grid, which is arranged in the range of the suction opening, (d) an outlet grille of the extraction device, which is arranged in the range of the outlet opening, (e) a housing of the extraction device, which housing includes at least one housing wall and forms an outer shell of the extraction device, and the fan, in particular the fan housing.
According to a first example embodiment of the extraction device of the present invention, at least an essential part of an inner surface of the air channel, particularly at least an essential part of an inner surface of the at least one channel wall, comprises the noise dampening means and/or noise reflecting means, i. e. the noise dampening means and/or noise reflecting means may be arranged at said at least an essential part of the inner surface of the air channel, or channel wall, respectively.
More specifically, said extraction device according to the first example embodiment may be an extraction device for extracting cooking fumes and may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. Said suction opening particularly forms a channel start for an entry of the cooking fumes in the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel comprises at least one channel wall, which encloses an interior of the air channel. The at least one channel wall includes an inner surface, which is directed towards the interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, the air channel may be or may comprise a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device, which outlet opening is particularly arranged at an end section of the air channel, and which may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. According to the present invention in relation to the first example embodiment, noise dampening means and/or noise reflecting means are arranged at at least an essential part of the inner surface of the channel wall. Said noise dampening means and/or noise reflecting means are adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in a direction against the airflow, and particularly to prevent a passage, or at least an undampened passage, of this airborne sound through the suction opening. Additionally, or alternatively, said noise dampening means and/or noise reflecting means are adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in airflow direction, and particularly to prevent a passage, or at least an undampened passage, of this airborne sound through the outlet opening.
According to a second example embodiment of the extraction device of the present invention, at least an essential part of a filter element of the extraction device comprises the noise dampening means and/or noise reflecting means. The filter element particularly comprises a first filter surface, which is directed in airflow direction and which comprises the noise dampening means and/or noise reflecting means.
More specifically, said extraction device according to the second example embodiment may be an extraction device for extracting cooking fumes and may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. Said suction opening particularly forms a channel start for an entry of the cooking fumes in the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall enclosing an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, a second air channel section may also be included in the extraction device, which second air channel section is configured to guide the airflow from the fan housing to an outlet opening of the extraction device. The outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. According to the present invention in relation to the second example embodiment, the extraction device further comprises a filter element. The filter element is arranged in the air channel downstream of the suction opening. The filter element comprises a first filter surface directed in airflow direction. Noise dampening means and/or noise reflecting means are arranged at at least an essential part of the filter element, more specifically at at least an essential part of the first filter surface. The noise dampening means and/or noise reflecting means are adapted to prevent or to attenuate a transmission of an airborne sound upstream of the filter element along the channel interior, and particularly to prevent a passage, or at least an undampened passage, of this airborne sound through the suction opening. Said noise dampening means and/or noise reflecting means particularly comprise a roughened filter surface and/or any other noise absorbing means or elements, e.g. arranged at a filter carrier supporting said filter element.
According to a third example embodiment of the extraction device of the present invention, at least an essential part of a cover element of the extraction device and/or at least an essential part of an outlet grille of the extraction device comprises the noise dampening means and/or noise reflecting means.
More specifically, said extraction device according to the third example embodiment may be an extraction device for extracting cooking fumes and may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. Said suction opening particularly forms a channel start for an entry of the cooking fumes in the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall enclosing an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, a second air channel section may also be included in the extraction device, which second air channel section is configured to guide the airflow from the fan housing to an outlet opening of the extraction device. The outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air.
A first form according to the present invention in relation to the third example embodiment provides that the extraction device further comprises a cover element, which is in particular an air inlet grid. The cover element is arranged in the range of the suction opening. Further, the cover element, in particular a side or surface of the cover element that is directed to the interior of the air channel, comprises noise dampening means and/or noise reflecting means. Said noise dampening means and/or noise reflecting means are adapted to attenuate an airborne sound or to prevent the airborne sound from passing through the suction opening, or at least from passing it in an undampened manner. More specifically, any noise mirroring elements or surface areas may be provided at the cover element for providing said reflection function.
A second form according to the present invention in relation to the third example embodiment provides that the extraction device comprises an outlet grille, which is arranged in the range of the outlet opening. The outlet grille, in particular a side or surface of the outlet grille that is directed to the interior of the air channel, comprises noise dampening means and/or noise reflecting means, which are adapted to attenuate an airborne sound or to prevent the airborne sound from passing through the outlet opening, or at least from passing it in an undampened manner. This second embodiment is particularly an alternative of or an addition to the previously described first embodiment according to the third aspect of the invention. Likewise, also the outlet grille may comprise any one of the means or surface areas as previously proposed for the cover element.
According to a fourth example embodiment of the extraction device of the present invention, at least an essential part of a housing of the extraction device, in particular at least an essential part of a housing wall of the extraction device, comprises the noise dampening means and/or noise reflecting means.
More specifically, said extraction device according to the fourth example embodiment may be an extraction device for extracting cooking fumes and may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall enclosing an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Moreover, a second air channel section may also be included in the extraction device, which second air channel section is configured to guide an airflow from the fan housing to an outlet opening of the extraction device. Said outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. The extraction device also comprise a housing, which includes at least one housing wall and which forms an outer shell of the extraction device. According to the present invention in relation to the fourth example embodiment, noise dampening means are arranged at at least an essential part of the housing wall, more specifically at at least an essential part of an inner surface of the housing wall. The noise dampening means are adapted to prevent or to attenuate a transmission of an airborne sound inside the interior of the extraction device, and particularly to prevent a passage, or at least an undampened passage, of this airborne sound through the suction opening. Additionally, or as an alternative, the noise dampening means may be adapted to prevent a passage, or at least an undampened passage, of this airborne sound through the outlet opening of the extraction device. More specifically, any noise mirroring elements or surface areas may be provided at the housing wall. As an alternative example, noise absorbing layers may be provided at at least sections of the housing wall.
According to a fifth example embodiment of the extraction device of the present invention, the noise dampening means and/or noise reflecting means are arranged in the air channel interior, with an arrangement of at least parts or sections of the noise dampening means and/or noise reflecting means at least approximately in alignment with the direction of the airflow.
More specifically, said extraction device according to the fifth example embodiment may be an extraction device for extracting cooking fumes and may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall enclosing an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, a second air channel section may also be included in the extraction device, which second air channel section is configured to guide the airflow from the fan housing to an outlet opening of the extraction device. The outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. According to the present invention in relation to the fifth example embodiment, noise dampening means and/or noise reflecting means are arranged in the interior of the air channel. The arrangement of the noise dampening means and/or noise reflecting means is performed in that way that at least parts or sections of the noise dampening means and/or noise reflecting means are at least approximately in alignment with the direction of the airflow. These noise dampening means and/or noise reflecting means are adapted to prevent or to attenuate a transmission of an airborne sound inside the interior of the extraction device and particularly a passage of this airborne sound through the suction opening and/or through an outlet opening of the extraction device, which may be an arranged at an end section of the air channel, more specifically at an end section of the second air channel section. The noise dampening means and/or noise reflecting means is particularly arranged on a surface of at least one guide wall, which is positioned in the air channel interior and which may also be at least approximately in alignment with the direction of the airflow and/or the channel orientation. One specific embodiment is characterized by an arrangement of the noise dampening means and/or noise reflecting means and/or the guide wall in a half-pipe design, especially when the airflow in the air channel takes a curved route. Favourably, more than one noise dampening means and/or noise reflecting means and/or related guide walls are included in the air channel, and they may be aligned in parallel with each other. Advantageously, the noise dampening means and/or noise reflecting means include a surface with noise absorbing properties.
At least one of the afore-described extraction devices may be designed in such a way, that at least one of (i) the at least an essential part of the inner surface of the at least one channel wall, (ii) the filter element, which may be the first filter surface of the filter element, (iii) the cover element, in particular the cover element side or surface directed to the interior of the air channel, and (iv) the at least an essential part of the housing wall, is processed by a provision of a textured surface. Said textured surface may be a surface finish including at least an area with a surface roughness. Said textured surface is particularly capable of absorbing the propagating noise.
According to an embodiment, the textured surface is provided by a mechanical and/or a chemical processing, wherein the chemical processing may make use of an etching process. Alternatively, the textured surface may be obtained by an application of a surface coating, preferably an application of a soundproofing paint or a soundproofing foam.
One particularly practical solution for the implementation of the noise dampening means and/or noise reflecting means, e.g. comprising said textured surface, may be provided during a shaping process of concerned components of the extraction device, i.e. during any initial production process, and/or by an inclusion of a coating step or any other treatment step following a creation process of said component.
In some implementations, the noise dampening means comprise a surface structure or a layer with an egg-carton shape or a pyramid shape. Additionally, or alternatively, a noise dampening effect may be received by an assembly of an insulating wool. Moreover, according to another alternative or addition, a sound absorbing foam may be arranged, particularly at a surface, which is arranged in or is facing the interior of the air channel. Said insulating wool or sound absorbing foam preferably comprises a stain-resistant surface, which surface is particularly arranged at a side, which is facing the interior of the air channel. With such stain-resistant surface, a soiling of the surface as a result of a particle-laden airflow may be prevented. The sound absorbing foam favourably includes an open porous surface, in addition or as an alternative to said stain-resistant property, which surface finish further increases the noise absorbing capacity. According to yet another alternative or addition, a metal mesh may be arranged for operating as a sound absorbing element, particularly at a surface, which is arranged in or is facing the interior of the air channel. Finally, yet another alternative or addition provides for a noise dampening effect that is received by a sound dampening layer, in particular a bitumen layer. At least one of the sound dampening layer, the sound absorbing foam, and the surface structure or layer with egg-carton shape or pyramid shape may be provided on a surface of the channel wall or on at least one of a cover element, an outlet grille, and a housing wall of the extraction device. One particularly preferred embodiment is characterized in that the noise dampening or absorbing means are configured to transform acoustic waves into thermal energy, so that the noise-producing character of these acoustic waves disappears or decreases.
With respect to the provision of the sound dampening layer, more specifically, the related example embodiment may be an extraction device for extracting cooking fumes, which comprises a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means are arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall, which encloses an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or alternatively, the extraction device may comprise a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device. The outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. The extraction device further comprises at least one of a cover element, an outlet grille and a housing. The cover element is arranged in the range of the suction opening, and it may be an air intake grid. The outlet grille is arranged in the range of the outlet opening of the extraction device. The housing includes at least one housing wall and forms an outer shell of the extraction device. According to this example embodiment, a sound dampening layer is provided on a surface of the channel wall. The sound dampening layer is particularly a bitumen layer. The arrangement of the sound dampening layer, which may be a foam material or an insulating wool as an alternative to an optional bitumen layer, is preferably implemented on an outer surface of the channel wall, wherein the outer surface is opposite to an inner surface, which is facing the interior of the air channel. Additionally, or alternatively, the sound dampening layer may be provided on a side or surface of the at least one of the cover element, the outlet grille and the housing wall, more specifically at an outer surface of the housing wall. An attachment of the sound dampening layer, specifically of a bitumen layer, at the cover element, more specifically at a cover element that is formed as a grid, and/or at the outlet grille provides a particular benefit in the case of the cover element and/or the outlet grille being made of a plastic material.
One specific solution for the noise dampening means and/or noise reflecting means comprises at least one recess configured to receive and to hem acoustic waves. A more advanced noise reducing effect may be realized, when the at least one recess comprises a recess opening with an undercut, which is turned away from the interior of the air channel and/or from an interior of the extraction device in relation to a housing wall of the extraction device. The at least one recess may be designed in such a way that acoustic waves are transformed into thermal energy. More specifically, the design of the at least one recess is configured to provide for a petering out of the acoustic waves.
Favourably, the recess opening is facing the noise propagation and is turned away from the airflow. That way, a clogging of the at least one recess with grease or any other soiling sourcing from the conveyed cooking fumes is avoided. Said anti-soiling effect of the recess may be further increased by generating a negative pressure in the recess, e. g. by designing the area around the recess in a way that promotes a venturi effect at the recess opening. As an example, an upper edge, seen in airflow direction, of the recess opening may be arranged closer to a central axis or area of the air channel than the lower edge of the recess opening, which lower edge is situated downstream of the upper edge.
According to a specific embodiment of the extraction device with noise dampening and/or noise reflecting means arranged at at least an essential part of the inner surface of the channel wall with preventing a passage of the airborne sound through the suction opening and/or through the outlet opening, said noise dampening and/or noise reflecting means comprise at least sections of the at least an essential part of the inner surface of the channel wall, which at least sections having a design or means providing a reflection of acoustic noise waves for their propagation in airflow direction, i. e. returning the direction of these acoustic waves to their source, particularly to the fan, instead of allowing them to leave the extraction device through the suction opening.
More specifically, since a major origin of the noise emitted by an extraction device is the fan and since the air channel forms a major propagation path for the related airborne sound with a propagation both in upstream and in downstream direction, it may be a main intention to keep the generated acoustic noise waves inside of the extraction device by means of a reflection of the noise propagating towards the suction opening, namely by reflecting the respective sound waves in airflow direction, as well as a reflection of the noise propagating towards the outlet opening, namely by reflecting the respective sound waves in the direction against the airflow.
One particularly favourable solution for said design or means is a provision of a saw tooth structure at the channel wall, which could be realized either by a realization of a respective wall structure, particularly by an implementation of a saw tooth structure at at least sections of the at least an essential part of the inner surface of the channel wall. For example, the implementation can be performed with mechanical and/or chemical processing, or by a provision of respectively formed attachment or facing elements.
In some implementations, the air channel comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing and a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device, wherein, in order to obtain a particular level of the noise reflecting effect with returning their propagation to follow the airflow direction, said saw tooth structure advantageously comprises a first saw tooth flank with a first inclination to the airflow direction and a second saw tooth flank with a second inclination to the airflow direction, wherein the first sawtooth flank is arranged upstream of the second saw tooth flank. The noise reflecting effect may be further increased with a second inclination to the airflow direction, which is greater than the first inclination to the airflow direction in the first air channel section. A particularly preferred solution is characterized by a second inclination to the airflow direction, which is perpendicular to the airflow direction. Additionally, or as an alternative, the noise reflecting effect may be further increased with a first inclination to the airflow direction, which is greater than the first inclination to the airflow direction in the second air channel section. Also in the case of a saw tooth structure is the second air channel section the inclination of the saw tooth flank at the upstream side may be perpendicular to the airflow direction, but in order to avoid or to limit potential noise due to turbulences, the inclination of the flank at the upstream side is advantageously only marginally greater than that one of the downstream flank.
According to a sixth example embodiment of the extraction device of the present invention, the air channel is designed by a channel course including at least two direction changes having noise-reflecting properties, the channel course in particular being designed with a spiral structure or a labyrinth structure. A first alternative is characterized in that the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in a direction against the airflow and a passage of this airborne sound through the suction opening. A second alternative, which may be present in addition to the first alternative, is characterized in that the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in airflow direction and a passage of this airborne sound through the outlet opening arranged at an end section of the air channel of the extraction device.
More specifically, said extraction device according to the sixth example embodiment may be an extraction device for extracting cooking fumes, which may comprise a fan and an air channel. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device. The fan includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The air channel of the extraction device comprises at least one channel wall enclosing an interior of the air channel. In particular, the air channel is or comprises a first air channel section configured to guide an airflow from the suction opening to the fan housing. Additionally, or as an alternative, the extraction device may be or comprise a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device. The outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. According to the present invention in relation to the sixth example embodiment, the air channel is designed by a channel course including at least two direction changes. In particular, curves are included in the channel course. The at least two direction changes having noise-reflecting properties. Favourably, the channel course is designed with a spiral structure or a labyrinth structure. Moreover, the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in a direction against the airflow and a passage of this airborne sound through the suction opening. More specifically, this particular channel course is provided for the first air channel section. Additionally, or alternatively, the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in airflow direction and a passage of this airborne sound through the outlet opening arranged at an end section of the air channel of the extraction device. More specifically, this particular channel course is provided for the second air channel section.
In some implementations, for an even further enhanced noise reduction effect, at least one noise barrier element, preferably a plurality of noise barrier elements, is arranged in the channel course. In order to obtain a particularly enhanced noise dampening effect, said barrier elements may be arranged in the channel course in an irregular pattern.
According to a seventh example embodiment of the extraction device of the present invention, the air channel comprises at least one of a first air channel section configured to guide an airflow from the suction opening to the fan housing, and a second air channel section configured to guide an airflow from the fan housing to an outlet opening of the extraction device. Each one of the at least one of the first air channel section and the second air channel section comprises at least one channel wall. Noise decoupling means between the at least one of the first and second air channel sections and the fan motor and/or the fan housing are provided, which noise decoupling means are configured to prevent a structure-borne sound from being transmitted at the channel wall or to attenuate a structure-borne sound transmitted at the channel wall.
More specifically, said extraction device according to the seventh example embodiment may be an extraction device for extracting cooking fumes, which may comprise a fan and at least one of a first air channel section and a second air channel section. The fan is configured to suck the cooking fumes through a suction opening into an interior of the extraction device, and it includes a fan housing and a motor for driving air conveyance means, which may be a fan propeller. Said air conveyance means is arranged in or allocated to the fan housing. The first air channel section is configured to guide an airflow from the suction opening to the fan housing. The second air channel section is configured to guide an airflow from the fan housing to an outlet opening of the extraction device, which outlet opening is specifically arranged at an end section of the air channel and may form a channel mouth configured to exhaust the air from the interior of the extraction device into the ambient air. The at least one of the first air channel section and the second air channel section comprises at least one channel wall. According to the present invention in relation to the seventh example embodiment, noise decoupling means between the at least one of the first and second air channel sections and the fan motor and/or the fan housing are provided. Said noise decoupling means are configured to prevent a structure-borne sound from being transmitted at the channel wall or to attenuate a structure-borne sound transmitted at the channel wall.
A preferred solution of the present invention according to its seventh aspect provides that the air channel is an arrangement of an outer duct and an inner duct. The inner duct is disposed concentrically with and circumferentially distant from and surrounded by the outer duct. Moreover, a first one of the outer duct and the inner duct is connected to the suction opening or to the outlet opening, and a second one of the outer duct and the inner duct is connected to the fan housing. Preferably, inner and outer ducts are not rigidly connected with each other, but any hermetical connection in between them may be of a flexible nature. With such flexible connection any sound transmission from the first one to the second one of the outer and inner ducts is kept on an especially low level.
The extraction device according to any one of the first to seventh aspects of the present invention is in particular a range hood or an extractor unit of a combination appliance, which further comprises a cooking hob. In this case, the extraction device, more specifically the combination appliance including the extraction device, may be arranged in a cutout of a kitchen worktop, in which the cooking hob is operated, and a cooktop of the cooking hob may be a glass ceramic cooktop, which material is commonly used specifically for cooking hobs that are operated by electricity. Moreover, the suction opening of the extraction device is preferably included in cooktop, more specifically in a central area of the cooktop.
Moreover, it is noted that all herein disclosed first to seventh example embodiments may be included in the extraction device according to the present invention either as an exclusive feature or in any kind of combination of the features disclosed by the first to fifth example embodiments.
Finally, according to a second aspect of the present invention, the object is achieved by a combination appliance according to claim 18, notably by a combination appliance with an extraction device as herein disclosed, more specifically by a combination appliance with an extraction device comprising any one of the afore-described features or combination of features.
Novel and inventive features of the present invention are set forth in the appended claims.
The present invention will be described in further detail with reference to the drawings, in which

Fig. 1: is a perspective view of a general setup of a combination appliance comprising a cooking hob and a downdraft extraction device installed in a kitchen cabinet, wherein the combination appliance is structured according to a first embodiment;
Fig. 2: is a cross-sectional perspective view of the disassembled combination appliance of Fig. 1 with a frontal surface cut away;
Fig. 3: is a schematic front view of the combination appliance of Fig. 2, including a first example of a noise dampening and/or reflecting means;
Fig. 4: is an enlarged detail view of the schematic combination appliance according to Fig. 3;
Fig. 4': is an enlarged detail view analogous to Fig. 4, but with a second example of a noise dampening and/or reflecting means;
Fig. 5: is a top perspective view of a second embodiment for a combination appliance;
Fig. 6: is a bottom perspective view of the combination appliance according to Fig. 5;
Fig. 7: is a front view of the combination appliance according to Figs. 5 and 6;
Fig. 8: is a top perspective view of the isolated extraction device of the combination appliance according to Figs. 5 to 7, including an indication of a third example of a noise reducing means;
Fig. 9: is a cross-sectional view of the third example of the noise reducing means;
Fig. 10: is the top perspective view of the isolated extraction device according to Fig. 8, but including an indication of a forth example of a noise reducing means;
Fig. 11a: is a detail view in perspective illustration of a first example of the noise reducing means according to Fig. 10; and
Fig. 11b: is a detail view in perspective illustration of a second example of the noise reducing means according to Fig. 10.

In all figures the same or equivalent part are marked with the same reference numbers.
Fig. 1 illustrates a general setup of a first embodiment of a combination appliance 10 comprising a cooking hob 12 and a downdraft extraction device 14 installed in a kitchen cabinet 16. The cooking hob 12 is implemented in a cut-out of a kitchen countertop 18 forming a top cover plate of the kitchen cabinet 16. The downdraft extraction device 14 is configured to take away cooking vapours occurring during cooking processes, in particular when cooking with uncovered cookware. The cooking hob 12 comprises cooking regions 20a, 20b arranged on a left half and a right half of a cooktop 22 of the cooking hob 12, which left and right halves are separated from each other by a suction opening 24 for an intake of the cooking vapours, the suction opening 24 being arranged alongside a cooktop centreline. The suction opening 24 is covered by a cover grid 26 for preventing items, e. g. cookware, to fall into the suction opening 24. Instead of the cover grid 26 a lid may be used for entirely covering the suction opening when the extraction device 14 is out of use, but for the operation of the extraction device 14 the lid is pivotable into an upright open position.
A housing 28 of the extraction device 14 is shown in Fig. 1 in transparent illustration. Said housing 28 provides a closed outer shell or channel segment for a flow of the sucked-in cooking vapours on their way from the suction opening 24 to an exhaust opening 30 in a base area 32 of the kitchen cabinet 16. Said exhaust opening 30 is also covered, namely by an outlet grille 34.
The flow of the sucked-in cooking vapours through the extraction device 14 is driven by the operation of an extraction fan 36 arranged inside of the housing 28. Said extraction fan 36 comprises a bottom-sided intake opening 38 for sucking the cooking vapours from the interior space of the housing 28.
A rear-sided fan outlet is arranged for a horizontal exit of the air blown out backwards from the extraction fan housing 42. The fan outlet is connected to a first end of an air duct 44 designed as a rectangular tube and forms a second channel arranged downstream the above-mentioned first channel. Directly at the passage from the fan outlet to the air duct 44, an air duct bending by 90 degrees is implemented, which redirects the air flow from horizontal to vertical downwards. The air duct 44 may be guided alongside a rear side of the kitchen cabinet 16 and may be bent again by 90 degrees close to a rear lower edge of the kitchen cabinet 16 in order to direct the airflow towards exhaust opening 30 in the base area 32 of the kitchen cabinet 16. Accordingly, the second end of the air duct 44 is connected to the exhaust opening 30. The embodiment illustrated in Fig. 1 shows a solution of the air duct 44 with an inclined section of its downwardly directed portion, directed slightly to the right. Naturally, a solution with said portion arranged in an exact vertical direction is considerable as well.
The course of the cooking vapours from the cooking area through the extraction device 14 to a re-entry into ambient air is illustrated in Fig. 1 by dotted arrows 46¹ to 46⁵. On their way through the extraction device 14, the cooking vapours pass through a filter assembly 48, which is arranged downstream directly behind the suction opening 24 for providing a purification of the conveyed air. Said filter assembly 48 includes a filter carrier 50 supporting a filter element (not shown) that is usually configured for filtering out grease particles and droplets.
The cross-sectional view of Fig. 2 further shows two power boards 54, one for the left cooking region 20a and one for the right cooking region 20b, the power boards 54 providing cooking zones in the left and right cooking regions 20a, 20b with electrical power. In the present embodiment, the cooking hob 12 is an induction cooking hob and the cooking zones are defined by induction coils (not shown) that are arranged below the cooktop 22 of the cooking hob 12. Attached to the bottom side of the power board 54 assigned to the right cooking region 20b, a further circuit board is arranged forming a control electronics 56 for the combination appliance 10.
Fig. 3 illustrates schematically a front view of a combination appliance 10 having a structure similar to that one of Figs. 1 and 2. The extraction fan 36 and the filter carrier 50 are presented in a front view illustration. In contrast, inlet channel walls 27' of an inlet channel 27 are illustrated in a cross-sectional view.
In order to reduce operating noises of the extraction device 14 mainly arising from an operating extraction fan 36, the extraction device 14 may comprise a couple of noise dampening and/or reflecting means 64, 66, 68, 78. A first representative of such noise dampening and/or reflecting means 64, 66, 68, 78 is indicated in Fig. 3 and illustrated in more detail in Fig. 4. Said first representative of a noise dampening and/or reflecting means is a specific design of the surface of the inlet channel wall 27', more specifically of all inlet channel walls 27' of the inlet channel 27, which inlet channel 27 is cuboid in the embodiment of Fig. 3. Of course, the inlet channel 27 may have a design different from the related rectangular cross-section, e. g. a circular or an elliptical cross-section may be used. According to the present example, said specific surface design is formed as an array of saw tooth elements 64 arranged at the inlet channel wall 27'. Fig. 3 presents such saw tooth elements 64 only at two opposing lateral side walls, however, these saw tooth elements 64 may be arranged all around the inner surface of the inlet channel 27.
Each one of the saw tooth elements 64, which are illustrated in more detail in Fig. 4 showing an enlarged view of detail IV according to Fig. 3, comprise an upstream flank 64' facing the air channel section towards the suction opening 24, as well as a downstream flank 64'' facing the air channel section towards the intake opening 38 of the extraction fan 36. The saw tooth elements 64 may either be integrally formed with the inlet channel wall 27', e.g. by means of an injection moulding process, or alternatively arranged at the inlet channel wall 27' by a subsequent attachment, e.g. by means of glueing a layer with an array of saw tooth elements 64. Other treatment processes for an attachment or an application of the saw tooth elements or any saw tooth structure may be taken into account.
The inlet channel walls 27 comprising the previously described saw tooth structure work as a noise reflecting means, which are configured to partly reflect acoustic noise waves arising from the operating extraction fan 36 and propagating along the air channel interior towards the suction opening 26, so that a passage of said reflected waves through the suction opening 26 is prevented. Only a remaining proportion of non-reflected acoustic noise waves may pass the suction opening 26, so that, as a result, the remaining noise level leaving the extraction device 14 through the suction opening 26 is reduced. The noise waves reflecting sections of the saw tooth elements 64 are formed by the plurality of their downstream flanks 64'', which operate as acoustic barriers or reflectors due to their alignment at least approximately perpendicularly to the acoustic noise waves propagation. More specifically, the reflected noise waves return to their origin, i.e. the extraction fan 36, hence staying in the interior of the extraction device 14.
It is noted that the previously described inlet channel 27 forms only a first section of the air channel 27, 44, more specifically, even only a first section of the air channel part arranged on the suction side of the entire air channel 27, 44. A second section of the air channel part arranged on the suction side of the entire air channel 27, 44 is formed by the interior of the extraction device housing 28, more specifically that area of the housing interior, which in airflow direction is arranged upstream of the extraction fan 36. The surfaces of said second section of the air channel part may also be designed with similar saw tooth elements 64, notably with respective downstream flanks 64" facing the air channel section towards the intake opening 38 of the extraction fan 36.
Fig. 4', which may be an enlarged detail view of the same detail IV according to Fig. 3, illustrates a second representative of the noise dampening and/or reflecting means 64, 66, 68, 78 included in the extraction device 14. More in detail, in replacement of, or as an alternative to, the saw tooth elements 64 or the saw tooth structure at the inner surface of the inlet channel wall 27' according to Fig. 4, said inner surface comprises a roughened surface structure, which, in the same vain as what is valid for the described saw tooth elements 64, may not be limited to the illustrated area section, but may also cover the entire inner surface of the inlet channel 27 and/or the entire second section of the air channel part arranged on the suction side of the entire air channel 27, 44 that is formed by the interior of the extraction device housing 28, more specifically that area of the housing interior, which in airflow direction is arranged upstream of the extraction fan 36.
The roughened surface 66 works in a different way than the saw tooth elements 64 or surface structure. While the saw tooth solution according to Fig. 4 provides its noise reduction effect by the mechanism of noise reflection, the roughened surface according to Fig. 4' functions as a noise absorbing means. More in detail, the roughened surface 66 with its rifts and peaks works as a receiving and retention section for the acoustic noise waves, particularly by providing a diffuse reflectance and by absorbing the acoustic noise waves under transformation into thermal energy.
The roughened surface structure may be implemented in the related channel or housing part already during the part creation process, i.e. by a specific creation of the related injection mould. Alternatively, the roughened surface 66 may be obtained by a surface treatment after the manufacturing of the pure channel or housing part, in particular by a mechanical or chemical processing, e.g. using an etching process.
The embodiment illustrated in Figs. 5 to 8 is a structure of a combination appliance 10 according to a second embodiment. In contrast to the first embodiment, the combination appliance 10 according to the second embodiment provides a modular setup for a combination appliance 10 with a general downdraft extraction device 14, which can be combined with different models of cooking hobs 12. The second embodiment according to Figs. 5 to 8 generally differs from the setup of the combination appliance 10 according to Figs. 1 and 2 in that all parts or modules of the cooking hob 12, except the two power board modules 54, are aggregated in a hob assembly part 12', which is dimensioned such that this hob assembly 12' will entirely find place in a cut-out area provided by a kitchen installer in a standard kitchen countertop 18, whereas said non-accommodated power board modules 54 are attached to an outer surface of the housing 28 of the extraction device 14.
Figs. 5 to 8 show the combination appliance 10 according to the second example from various angles. As can be specifically seen in Fig. 8, which is an illustration from a similar view as that one of Fig. 5, but which is a presentation of the isolated extraction device 14, i. e. without the hob assembly 12' on the top side of the extraction device 14, core part of the extraction device 14 is the housing 28 having a standardized dimensioning. This housing part 28 is configured to receive nearly all the extraction device components except, on the one hand, the components accommodated in the cooking hob 12, which are the suction opening 24 including its cover grid 26 and an initial section of the suction duct, and, on the other hand, a fan control module 58, which is also attached to an outer surface of the housing 28 of the extraction device 14, as will be described more in detail further down below, as well.
The housing 28 of the general extraction device 14 is formed as a plastic box or plastic container of prism-shaped nature. Two opposing side walls of the housing 28, which are first 28a and second 28b side walls, are inclined from the vertical axis. The other two opposing and essentially trapezoid third 28c and fourth 28d side walls are vertically oriented in installation alignment. With this configuration, the four side walls 28a, 28b, 28c, 28d form a box, more precisely a container, which is tapered towards its bottom wall 28e. Said box or container is open at the top, but sealed by a bottom wall 60 of the housing 62 of the cooking hob 12 after completed assembling of the combination appliance 10.
Fig. 8 grants an inside from the top into the arrangement of components inside of the extraction device housing 28. As is visible, the construction of the assembled extraction device 14 is nearly axially symmetrical. An air transportation system including an extraction fan 36 for air conveyance is positioned along a central axis of the extraction device housing 28. The extraction fan 36 is arranged in a vertical orientation, i. e. a rotation axis of a fan wheel (not shown) is horizontally aligned. The extraction fan 36 comprises two intake openings 38, 38' arranged at opposing sides of a fan housing 42, which construction enables a symmetric intake of air from both halves of the interior of the extraction device housing 28. As can be also seen in Fig. 8, a filter assembly 48, which is axially symmetrical similarly to the extraction fan 36 and accommodated in a filter housing 50, with two flat filter elements positioned at opposing sides of the filter carrier 50, is included for a filtration of the conveyed air and for a separation of particles and/or droplets, e. g. grease, odour and/or vapour particles and/or droplets. Said filter assembly 48 and filter carrier 50 are arranged side-by side with the extraction fan 36. The cooking vapours aspirated through the suction opening 24 enter the filter assembly 48 from the top side, and are deflected by about 90 degrees from vertical to horizontal direction fairly equally to both sides and through the filter elements. After passing the filter elements another deflection by about 90 degrees, but in approximately horizontal direction, takes place, so that the conveyed air is forwarded to the two intake openings 38, 38' for its transportation via the fan housing 42 to exhaust opening 30 positioned at the fourth side wall 28d, which is a rear wall in installation orientation of the combination appliance 10. Although the filter assembly 48 only takes up space of a smaller extension in depth direction of the cooking hob 12, the suction opening 24 extends nearly over the entire cooking hob depth, which means that a portion of the suction opening 24 is arranged above the fan housing 42, however, the cooking vapours aspirated through that portion are immediately guided towards the filter assembly 48, i. e. initially nearly in parallel to the surface of the cooktop 22.
The extraction device housing 28 forms an airtight box or container with only an opening to the top, which is a connection opening that is connected to the suction opening 24, and an exhaust opening 30 at rear wall; i. e. the conveyed air only takes the way from the suction opening 24 to the exhaust opening 30, without any possibility to escape from this way in between.
Figs. 5 to 8 further illustrate, that both the power board modules 54 and the fan control module 58 are attached to the outer surfaces of housing walls, quasi in a backpack manner. According to the present embodiment, the two power board modules, i. e. first and second power board modules 54, are attached to the first and second side walls 28a, 28b, which are lateral walls of the extraction device housing 28 in installation orientation of the combination appliance 10, and which are said side walls inclined from the vertical. Further, the fan control module 58 is attached to the third side wall 28c, which is a front wall of the extraction device housing 28 in installation orientation. It goes without saying that a different arrangement of the individual electronic modules 54, 58, i. e. a different allocation of each electronic modules 54, 58 to any of the side walls 28a, 28b, 28c may also be selectable. Due to the present arrangement, the fan control module 58 is positioned at an opposing side in relation to the exhaust outlet 30, which is arranged in the fourth side wall 28d, which is the rear wall in the present embodiment.
Fig. 8 further indicates an implementation of a third representative of such noise dampening and/or reflecting means 64, 66, 68, 78, which in turn differs from the previously described first and second representatives as described and as illustrated by Figs. 4 and 4'. Said noise dampening and/or reflecting means 64, 66, 68, 78 are formed as a recess 68, more specifically as a plurality of recesses 68, which are spread over at least a relevant section of a housing wall 28a to 28e, preferably spread over the entire housing wall surface, which is not covered by any component of the extraction device 14. Only a few of said plurality of recesses 68 are indicated in Fig. 8, and only at the second and fourth side walls 28b, 28d. In order to provide a particular high noise reduction effect, these recesses 68 may be spread not only over the entire surfaces of these second and fourth side walls 28b, 28d, but also first and third side walls 28a, 28c, as well as bottom wall 28e, may include a greatest possible number of these recesses 68, too.
Fig. 9 provides an insight into the third representative, i.e. the recess 68 indicated in Fig. 8. The recess 68 is implemented in a housing wall 28a, 28b, 28c, 28d, 28e, additionally or alternatively in a channel wall 27, and comprises a hollow recess body 72 arranged at an outer side of the housing wall 28a, 28b, 28c, 28d, 28e or the channel wall 27, which outer side is opposite to the inner surface of the respective wall 27, 28a, 28b, 28c, 28d, 28e. The interior space 72' of the recess 68 is accessible via a recess opening 70 forming a passage through the wall 27, 28a, 28b, 28c, 28d, 28e. According to the illustrated embodiment, the recess body 72 is shaped like a fir tree, however, any other particularly outwardly tapering design may be considered as well. More specifically, the recess implementation may be produced by means of a blow moulding process.
Fig. 9 also illustrates the operating principle of the recess 68. To this end, an acoustic noise wave arrow 74 is delineated, which enters into the interior space 72' of the recess 68, especially due to one or more previous reflections at a housing or channel wall 27, 28a, 28b, 28c, 28d, 28e, by passing through the recess opening 70. As is shown with a route line in the interior space 72', after its passage through the recess opening 70, the acoustic noise wave is captured inside the interior space 72 of the recess 68 and is reflected several times at the inner surfaces of the recess wall. During the reflection events, the acoustic noise wave loses energy by a transformation into thermal energy. The particular design of the recess body 72 prevents to a great extent an escaping of the reflected acoustic noise wave. Moreover, an undercut 76, formed by the low ratio of the cross-section of the recess opening 70 and the base area of the interior space 72' of the recess 68, supports a possible escaping of the captured acoustic noise wave from the interior space 72' .
As already indicated, the solution according to the third representative of the noise dampening and/or reflecting means 64, 66, 68, 78, i. e. the recesses 68, may be implemented in the inlet channel walls 27', in that being used alternatively or in addition to the first or second representatives as illustrated by Figs. 4 and 4', i.e. the saw tooth elements 64 or the roughened surface 66.
Moreover, the first to third representatives of noise dampening and/or reflecting means 64, 66, 68 may be used also in the air channel section downstream of the extraction fan 36, in particular inside of air duct 44 according to Fig. 1, however, with the saw tooth design according to Fig. 4 being arranged inversely, i.e. with reversed flanks, so that the acoustic waves are reflected into a direction against the airflow towards the extraction fan 36. Particularly Fig. 2 illustrates an indication of the recesses 68 according to the third representative of noise dampening and/or reflecting means 64, 66, 68, 78, only exemplarily placed at one side wall of extraction device housing 28.
By Fig. 10 a fourth representative of noise dampening and/or reflecting means 64, 66, 68 is shown, which may be implemented in the extraction device 14 in addition or as an alternative to the first to third representatives. Said fourth representative is formed as at least one guide wall 78 shaped as an elongated half-pipe. Exemplarily, in Fig. 10 two of these guide walls 78 are included in the second section of the air channel part arranged on the suction side of the air channel 27, 44, i.e. directly upstream of the intake opening 38', with the two guide walls 78 being arranged in a parallel alignment. In other embodiments a different number of half-pipe guide walls 78, i.e. only one or more than two, may be used. Moreover, the half-pipe solution is also only one of a plurality of different shapings, in particular a flat design or any other concave depiction may be considered.
Each one of Figs. 11a and 11b illustrate one of the guiding half-pipe guide walls 78 indicated in Fig. 10, which only differ in their surface, which is facing the intake opening 38' of the extraction fan 36. The embodiment according to Fig. 11a comprises a metal mesh layer 80 attached on said surface, whereas the same surface of the embodiment according to Fig. 11b is covered by a sound-absorbing foam layer 82.
As is obvious by the usage of the just described layers 80, 82, the operating principle of the at least one guide wall 78 is likewise based on the principle of sound-absorption. Since this guide wall 78 is arranged to a great extent in parallel to the propagation path of the acoustic noise waves, a relevant proportion of these waves get caught by the surface structure of the guide wall 78, more specifically by the metal mesh layer 80 or by the sound-absorbing foam layer 82, respectively. Said catching of the acoustic noise waves is provided by the metal mesh structure operating similar to the roughened surface 66 as previously described with reference to Fig. 4', or by the foam layer, favourably comprising an open porous surface, operating as a noise dampening means. The acoustic noise waves sliding alongside the metal mesh layer 80 or the sound-absorbing foam layer 82 gradually lose sound energy, so that the remaining portion of the acoustic noise waves leaving the extraction device 14 lead to a reduced noise emission.
It is noted that the half-pipe guide walls 78, which are shown in Fig. 10 only in one suction space in the interior of the extraction device housing 28, namely directly upstream of the intake opening 38', is favourably also included in the other suction space in the interior of the extraction device housing 28, which is directly upstream of the other intake opening 38.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to these precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
Moreover, features which are described in the context of separate aspects and embodiments of the invention may be used together and/or be interchangeable. Similarly, features described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

List of reference numerals

10: combination appliance
12: cooking hob
12': hob assembly
14: downdraft extraction device
16: kitchen cabinet
18: kitchen countertop
20a,20b: cooking regions
22: cooktop
24: suction opening
26: cover grid
27: inlet channel
27': inlet channel walls
28: extraction device housing
28a: first side wall
28b: second side wall
28c: third side wall
28d: fourth side wall
28e: bottom wall
30: exhaust opening
32: base area
34: outlet grille
36: extraction fan
38, 38': intake openings
42: fan housing
44: air duct
461 to 5: arrows indicating air flow
48: filter assembly
50: filter carrier
54: power boards
56: control electronics
58: fan control module
60: hob bottom wall
62: hob housing
64: sawtooth elements
64',64'': upstream and downstream flanks
66: roughened surface
68: recesses
70: recess opening
72: recess body
72': interior space of the recess
74: acoustic noise wave arrow
76: undercut
78: half-pipe guide walls
80: metal mesh layer
82: foam layer

Claims

An extraction device (14) for extracting cooking fumes, in particular a range hood or an extractor unit (14) of a combination appliance (10), which further comprises a cooking hob (12), the extraction device (14) comprising
- a fan (36) configured to suck the cooking fumes through a suction opening (24) into an interior of the extraction device (14), which fan (36) includes a fan housing (42) and a motor for driving air conveyance means, in particular a fan propeller, said air conveyance means being arranged in or allocated to the fan housing (42),

- an air channel (27, 44), in particular a first air channel section (27) configured to guide an airflow from the suction opening (24) to the fan housing (42) and/or a second air channel section (44) configured to guide an airflow from the fan housing (42) to an outlet opening (30) of the extraction device (14), the air channel (27, 44) comprising at least one channel wall (27') enclosing an interior of the air channel (27, 44),

wherein noise dampening means and/or noise reflecting means (64, 66, 68, 78) are arranged at an essential part of the extraction device (14),

and wherein the noise dampening means and/or noise reflecting means (64, 66, 68, 78) are adapted to prevent or to attenuate a transmission of an airborne sound.
The extraction device (14) according to claim 1, wherein the essential part of the extraction device (14) is an essential part of at least one of
- the air channel (27, 44), particularly the first air channel section (27) and/or the second air channel section (44),

- a filter element (48) of the extraction device (14), which filter element (48) is arranged in the air channel (27, 44) downstream of the suction opening (24),

- a cover element (26) of the extraction device (14), in particular an air intake grid (26), which is arranged in the range of the suction opening (24),

- an outlet grille (34) of the extraction device (14), which is arranged in the range of the outlet opening (30),

- a housing (28) of the extraction device (14), the housing (28) including at least one housing wall (28a, 28b, 28c, 28d, 28e) and forming an outer shell of the extraction device (14),

- the fan (36), in particular the fan housing (42).
The extraction device (14) according to claim 1 or 2, wherein at least an essential part of an inner surface of the air channel (27, 44), in particular at least an essential part of an inner surface of the at least one channel wall (27'), comprises the noise dampening means and/or noise reflecting means (64, 66, 68, 78).
The extraction device (14) according to any one of the preceding claims, wherein at least an essential part of a filter element (48) of the extraction device (14) comprises the noise dampening means and/or noise reflecting means (64, 66, 68, 78), wherein the filter element particularly comprises a first filter surface, which is directed in airflow direction and which comprises the noise dampening means and/or noise reflecting means (64, 66, 68, 78).
The extraction device (14) according to any one of the preceding claims, wherein at least an essential part of a cover element (26) of the extraction device (14) and/or at least an essential part of an outlet grille (34) of the extraction device (14) comprises the noise dampening means and/or noise reflecting means (64, 66, 68, 78).
The extraction device (14) according to any one of the preceding claims, wherein at least an essential part of a housing (28) of the extraction device (14), in particular at least an essential part of a housing wall (28a, 28b, 28c, 28d, 28e) of the extraction device (14), comprises the noise dampening means and/or noise reflecting means (64, 66, 68, 78) .
The extraction device (14) according to any one of the preceding claims, wherein the noise dampening means and/or noise reflecting means (64, 66, 68, 78) are arranged in the air channel interior, with an arrangement of at least parts or sections of the noise dampening means and/or noise reflecting means (64, 66, 68, 78) at least approximately in alignment with the direction of the airflow.
The extraction device (14) according to any one of the claims 2 to 7, wherein the at least an essential part of the inner surface of the at least one channel wall (27') and/or the filter element (48), in particular the first filter surface of the filter element (48), and/or the cover element (26) and/or the at least essential part of the housing wall (28) is or are processed by a provision of a textured surface, in particular a surface finish including at least an area with a surface roughness.
The extraction device (14) according to claim 8, wherein the textured surface is provided by a mechanical and/or a chemical processing or by an application of a surface coating, preferably an application of a soundproofing paint or a soundproofing foam.
The extraction device (14) according to any one of the preceding claims, wherein the noise dampening means (66, 68, 78) comprises at least one of
- a surface structure or layer with an egg-carton shape or a pyramid shape,

- an insulating wool,

- a sound absorbing foam (82), preferably with open porous surface,

- a metal mesh (80),

- a sound dampening layer, in particular a bitumen layer, wherein at least one of the sound dampening layer, the sound absorbing foam (82), and the surface structure or layer with egg-carton shape or pyramid shape is provided on a surface of the channel wall (27'), or on at least one of a cover element (26), an outlet grille (34), and a housing wall (28) of the extraction device (14), and wherein the noise dampening means (66, 68, 78) are preferably configured to transform acoustic waves into thermal energy.
The extraction device (14) according to anyone of the preceding claims, wherein the noise dampening means and/or noise reflecting means (64, 66, 68, 78) comprise at least one recess (68) configured to receive and to hem acoustic waves, the at least one recess (68) preferably comprising a recess opening (70) with an undercut (76), which is turned away from the interior of the air channel (27, 44) and/or from an interior of the extraction device (14) in relation to a housing wall (28a, 28b, 28c, 28d, 28e) of the extraction device (15).
The extraction device (14) according to claim 11, wherein the recess opening (70) is facing the noise propagation and is turned away from the airflow, in particular with generating a negative pressure in the recess (68).
The extraction device (14)according to claim 1 or 2, wherein the noise reflecting means (64) comprise at least sections of the at least an essential part of an inner surface of the channel wall (27') with a design or with means adapted to reflect acoustic noise waves in a direction of the source of the acoustic noise wave, preferably in the direction of the fan (36), the at least sections of the at least an essential part of the inner surface of the channel wall (27') particularly comprising a sawtooth structure.
The extraction device (14) according to claim 13, wherein the air channel (27, 44) comprises a first air channel section (27) configured to guide an airflow from the suction opening (24) to the fan housing (42) and a second air channel section (44) configured to guide an airflow from the fan housing (42) to an outlet opening (30) of the extraction device (14), wherein the sawtooth structure comprises a first sawtooth flank (64') with a first inclination to the airflow direction and a second sawtooth flank (64'') with a second inclination to the airflow direction, wherein the first sawtooth flank (64') is arranged upstream of the second sawtooth flank (64''), and wherein preferably
- the second inclination to the airflow direction is greater than the first inclination to the airflow direction in the first air channel section (27), the second inclination to the airflow direction particularly being perpendicular to the airflow direction,
and/or

- the first inclination to the airflow direction is greater than the second inclination to the airflow direction in the second air channel section (44).
The extraction device (14) according to any one of the preceding claims,
wherein the air channel (27, 44) is designed by a channel course including at least two direction changes having noise-reflecting properties, the channel course in particular being designed with a spiral structure or a labyrinth structure, wherein
- the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in a direction against the airflow and a passage of this airborne sound through the suction opening (24),
and/or

- the channel course is adapted to prevent or to attenuate a transmission of an airborne sound along the channel interior in airflow direction and a passage of this airborne sound through the outlet opening (30) arranged at an end section of the air channel (27, 44) of the extraction device (14),

and wherein noise barrier elements are particularly arranged in the channel course, preferably in an irregular pattern.
The extraction device (14) according to any one of the preceding claims, wherein the air channel (27, 44) comprises at least one of
- a first air channel section (27) configured to guide an airflow from the suction opening (24) to the fan housing (42), and

- a second air channel section (44) configured to guide an airflow from the fan housing (42) to an outlet opening (30) of the extraction device (14),

wherein each one of the at least one of the first air channel section (27) and the second air channel section (44) comprises at least one channel wall (27'),

wherein noise decoupling means between the at least one of the first (27) and second (44) air channel sections and the fan motor and/or the fan housing (42) are provided, which noise decoupling means are configured to prevent a structure-borne sound from being transmitted at the channel wall (27') or to attenuate a structure-borne sound transmitted at the channel wall (27').
The extraction device (14) according to claim 16, wherein the at least one of the first (27) and the second (44) air channel sections is an arrangement of an outer duct and an inner duct, which is disposed concentrically with and circumferentially distant from the outer duct, and wherein
- a first one of the outer duct and the inner duct is connected to the suction opening (24) or to the outlet opening (30), and

- a second one of the outer duct and the inner duct is connected to the fan housing (42).
A combination appliance (10) with an extraction device (14) according to any one of the claim 1 to 17.