EP1705430B1 - Extracting hood with grease filter - Google Patents

Description

The invention relates to an extractor hood with at least one grease filter and with air guiding means for generating a falling on the grease filter air flow according to the preamble of claim 1. Such an extractor hood is in FR 2 720 818 described.

Fat filters for extractor hoods have e.g. a filter plate having a plurality of openings. In the area of these openings water and fat drops are separated from the haze.

It has as its object to provide an extractor hood of the type mentioned, which can be easily manufactured.

This object is achieved by the extractor hood according to claim 1.

According to the claim, the filter plate is equipped with deflecting elements. These are designed so that air is deflected asymmetrically in a first direction along the filter plate. Here, the term "first direction along the filter plate" is to be understood as meaning that direction parallel to the filter plate, against which air perpendicular to the filter plate is deflected. According to claim 1, the filter plate is arranged so that the incident on the filter plate air flow has a velocity component counter to the first direction.

The filter plate consists of an expanded metal sheet or a stamped and deep-drawn sheet metal body and the deflection surfaces are formed by deformed parts of the filter plate. Such a filter plate is easy to produce.

For more detailed definitions of the terms "first direction" and "velocity component", reference is made to the following description.

• Fig. 1 einen Schnitt durch eine Dunstabzugshaube,
• Fig. 2 einen Schnitt durch Filterplatte und angrenzendem Filterkörper,
• Fig. 3 eine Ansicht der Oberfläche einer Filterplatte,
• Fig. 4 eine Illustration des Begriffs der "ersten Richtung",
• Fig. 5 die Richtung der einfallenden Luft im Vergleich zur ersten Richtung,
• Fig. 6 eine erste Ausführung des Fettfilters,
• Fig. 7 eine zweite Ausführung des Fettfilters,
• Fig. 8 eine dritte Ausführung des Fettfilters und
• Fig. 9 eine vierte Ausführung des Fettfilters.

Further preferred embodiments of the invention will become apparent from the dependent claims and from the Now following description with reference to the figures. Showing:

• Fig. 1 a section through an extractor hood,
• Fig. 2 a section through filter plate and adjacent filter body,
• Fig. 3 a view of the surface of a filter plate,
• Fig. 4 an illustration of the concept of the "first direction",
• Fig. 5 the direction of the incoming air compared to the first direction,
• Fig. 6 a first embodiment of the grease filter,
• Fig. 7 a second embodiment of the grease filter,
• Fig. 8 a third embodiment of the grease filter and
• Fig. 9 a fourth version of the grease filter.

The extractor hood after Fig. 1 is intended to be arranged above a cooking point and has an inlet region 1, which receives the rising steam upwards. In the entrance area 1, a horizontal baffle plate 2 is arranged, at which the steam is stowed and directed to the outside. The baffle plate 2 is surrounded by walls 3, wherein on at least two, preferably three or four sides of the baffle plate entrance gaps 4 between the baffle plate 2 and the walls 3 are provided. The steam enters the space above the baffle plate 2 through the entrance slits 4. As indicated by arrows 5, it is guided by the sloping, upwardly converging walls 5 against a grease filter 6 out. The grease filter 6 is arranged above the inlet region 1 and the baffle plate 2.

The steam enters through a lower portion 7 of the grease filter, passes through filter plates 8 and filter body 9 (the structure of which will be described later), and exits therefrom through an upper portion 10 of the grease filter 6. About the grease filter 6, a fan 11 may be arranged, which pulls the vapor through the hood.

The structure of the filter plates 8 and filter body 9 is made Fig. 2 seen. It is one each Filter plate 8 connected to an associated filter body 9 into a unit, wherein the steam passes first through the filter plate 8 and then through the filter body 9.

Each filter plate 8 is preferably made of an expanded metal sheet or a stamped and deep-drawn sheet metal body. How out Fig. 2 and 3 apparent (where Fig. 3 the filter plate 8 of Fig. 2 obliquely from above), a plurality of openings 13 are provided in the filter plate 8. Adjacent to each opening (or at least a part of the openings), a part 14 of the sheet is deformed upward and forms a deflecting surface 15, which deflects the haze in a manner to be described as a deflecting element.

The filter body 9, viewed in the direction of the steam, is arranged behind the filter plate 8. The filter body 9 also has a plurality of openings which allow the vapor to pass through the filter body 9. However, the openings of the filter body 9 preferably have a smaller diameter than the openings 13 of the filter plate 8. In addition, the filter body 9 is preferably thicker than the filter plate 8. Also in the filter body 9 there is a deflection of the vapor stream, but the deflection direction from place to Can change location.

The filter body 9 may e.g. consist of several layers of expanded aluminum metal or nonwoven, while the filter plate 8 is made of aluminum or chrome steel expanded metal.

The filter plate 8 has an asymmetrical structure, which leads to a one-sided deflection of the vapor in a first, preferred direction X out. This is in Fig. 4 illustrated by an imaginary, hardly occurring in normal operation, vertically incident airflow 16. As can be seen, all the deflection surfaces 15 extend obliquely in the same direction away from the plane of the filter plate 8, so that air occurring in the in Fig. 4 deflected as X direction. The direction X is referred to in the claims as "first direction".

Each deflecting surface 15 is disposed on each one of the openings 13, on the side of the opening opposite to the direction X, so that the air passing through the opening 13 strikes the deflecting surface 15 and is deflected against the direction X.

In normal operation, the air is not perpendicular, but obliquely at an angle α <90 ° to the filter plate 8, as this Fig. 2 and 5 is illustrated. For the oblique incidence provide air conduction of the hood, which in the execution of Fig. 1 are formed primarily by the horizontal baffle plate 2 and the walls 3 of the upwardly to the grease filter 6 tapered hood. Thus, the air entering through the mutually opposite inlet gaps 4 runs along the two walls 3 which converge obliquely and falls obliquely onto the filter plates 8.

Fig. 5 represents the average incidence velocity v of the air incident on the filter plate 8 at an angle α. The velocity v has a velocity component v1 parallel to the direction X and a velocity component v2 perpendicular thereto. As in Fig. 5 shown, the filter plate 8 is now arranged so that the direction X is opposite to the velocity component v1. This leads to a relatively strong deflection at the deflection surfaces 15, which favors the deposition of fat and water drops.

Preferably, the velocity v and the unit vector n _{X are} along the X direction in a common plane perpendicular to the filter plate 8. However, deviations are allowed as long as the component v 1 is antiparallel to n _X. This is guaranteed if the scalar product n _X · v is negative. In this case, the air flow incident on the filter plate 8 has a velocity component opposite to the first direction.

To clean the filter 6, the filter plates 8 can be removed together with their filter bodies 9 from the hood. However, they can be used, thanks to suitable mechanical design (not shown), only so that the air flow incident on the filter plate has a velocity component opposite to the direction X, as in Fig. 5 is shown.

Since the steam is led upwards in most extractor hoods, an oblique or vertical arrangement of the filter plates 8 can favor an oblique incidence of the steam on the filter plates.

Fig. 6 shows, for example, the arrangement of two filter plates 8 with associated filter bodies 9 in oblique, upwardly running together position, according to the arrangement Fig. 1 ,

Fig. 7 shows a second arrangement of the filter plates 8 with the associated filter bodies 9. In this embodiment, the filter plates are arranged in a pyramid shape. This version is particularly suitable for free-hanging cooker hoods with four walls 3 converging towards the grease filter.

While in Fig. 6 the filter plates 8 touch each other in the upper area of the grease filter is in Fig. 8 an embodiment shown in which this is not the case. Rather, at the top of the filter plates 8 connects to a horizontal end wall 18, which is not permeable to steam.

A similar design is in Fig. 9 shown. Here, however, the filter plates 8 are arranged vertically.

Claims (10)

1. Exhaust hood with at least a fat filter (6) and with air guiding means (2, 3) for generating at least an air stream (5) falling onto the fat filter (6), wherein the fat filter (6) has a filter plate (8) transversally to the air stream (5), which has a plurality of openings (13) with deviating elements (15) for deviating air asymmetrically in such a way that incoming air (5) receives by deviation a speed component in a first direction (X) along the filter plate (8), wherein the air guiding means (2, 3) are arranged in such a way with respect to the filter plate (8) that the air (5) hitting the filter plate (8) has a speed component (v1) in opposite direction of the first direction (X) and wherein the filter plate (8) has at least a deflection surface (15) arranged inclined with respect to the plate plane and adjacent to at least a part of the openings (13), wherein the deflection surface (15) is arranged on a side of the adjacent opening (13) which is opposite of the first direction (X), characterized in that the filter plate consists of an expanded metal sheet or a punchedout and deep-drawn sheet metal body and the deflection surfaces (15) are formed by deformed parts (14) of the filter plate (8).
2. Exhaust hood according to claim 1, wherein the filter plate (8) is removable from the exhaust hood and reinsertable therein, wherein it can only be inserted when the incoming air stream hitting the filter plate (8) has a speed component (v1) in opposite direction of the first direction (X).
3. Exhaust hood according to one of the preceding claims, wherein a filter body (9) inside which the air stream can be deflected again is arranged in streaming direction behind the filter plate (8).
4. Exhaust hood according to claim 3, wherein the filter body (9) is thicker than the filter plate (8).
5. Exhaust hood according to one of the claims 3 or 4, wherein the filter body (9) has openings with smaller diameters than the openings of the filter plate (8).
6. Exhaust hood according to one of the preceding claims, wherein the exhaust hood has:

   an inlet area (1) for the air, wherein the exhaust hood tapers from the inlet area (1) towards the fat filter (6), and

   a substantially horizontal impact plate (2) arranged in the inlet area (1), wherein inlet gaps (4) for steam run along at least two sides of the impact plate (2) facing one another, in such a way that an air stream is generated starting from each one of the inlet gaps (4), respectively,

   wherein the fat filter (6) has at least one filter plate (8) which are arranged obliquely with respect to the horizontal or vertically.
7. Exhaust hood according to claim 6, wherein the fat filter (6) has two filter plates (8) extending between a bottom area (7) and a top area (10) of the fat filter (6), wherein the air enters the fat filter (6) through the bottom area.
8. Exhaust hood according to claim 7, wherein the filter plates (8) converge towards the top.
9. Exhaust hood according to claim 6, wherein the filter plates (8) are arranged vertically.
10. Exhaust hood according to one of the claims 6 to 9, wherein the exhaust hood has at least two walls (3) arranged obliquely and converging towards the fat filter (6).

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