DE29709350U1 - Frame for extractor hoods and filters made with them - Google Patents

Description

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wmsmm

Utility model application 297 09 350.9

"Frames for cooker hood filters and filters made from them"

There are basically two systems for extractor hoods: the air is discharged outside or the air is returned to the kitchen after it has been cleaned of grease and odors.

Grease filters are also essential when venting air to the outside, as otherwise grease would settle in the exhaust air ducts and pose a fire risk. Systems where air is vented to the outside can cause a nuisance to the neighbours; however, the heat loss is much more detrimental, as 300 - 400 m ³ of fresh air per hour must be drawn in from outside, which must be heated up, except on warm summer days.

For this reason, the trend is towards recirculation systems that, in addition to the grease separator filter, must also have an adsorption filter to separate odors. Activated carbon is used without exception as the adsorbent. An adsorption filter with exceptionally high performance, in which the spherical adsorbent is fixed at points on and in large-pore carrier foam and is freely accessible, and with above-average capacity (service life) is described in DE 195 21 556. A1. This material, which also has the advantage that it can be regenerated by washing out the adsorbed substances, for example in a dishwasher, is known under the name NANOSORB®.

Extractor hoods have devices that make it easier to insert the grease filter; the latter often consists of a metal insert or a metal mesh pressed into a plate, which is held in place by a metal frame with a

Gebr.-Musteranmeldung 17 September 1997 edr/dh 142 ^{Page 1 of 5}

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an edge height of approx. 10 mm. In the extractor hood there are usually rails into which the frame can be inserted. The rails are designed so that the relatively flat grease filter insert can be inserted without any problems. Problems arise when it comes to thicker odor filters or the combination of a grease filter and an odor filter, which require a significantly thicker frame. The purpose of the present utility model was to offer a solution to the problem.

The solution according to the invention consists in forming the edges of the filter frame in a stepped manner so that the frame can be inserted into existing rails that were designed for relatively thin grease filter frames, despite the large height or thickness of the filter layer.

Fig. A shows the profile of the frame. The part (1) to be inserted into the rails has the usual height for grease filters of approx. 7-10 mm, while the actual height (2) is approx. 10 + × mm to take into account the greater height of the adsorption filter or the combined grease and adsorption filters. The inflow and outflow sides are marked with (3) and (4) respectively.

Fig. B shows the filter mat (1) manufactured according to DE 195 21 665 A1, which has sufficient elasticity to be easily inserted into the filter frame or removed for regeneration. The filter mat is held in position on the downstream side by two or more brackets (2).

Fig. C shows a grid or grease filter (1) made of plug-in metal on which the odor filter layer rests.

The filter frame has a spring on its rear edge that holds the frame

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men into the front holder after being pushed into the rear holder (rail). This arrangement is the one most commonly used today. It therefore does not need to be described further.

Since the adsorption filter layer also separates the majority of the grease, a separate grease filter is not absolutely necessary; however, it increases the service life of the adsorption filter, whose pores clog up more quickly without an upstream grease filter.

Design application 17, September 1997 edr/dh 142

Claims (4)

Expectations: 1. Filter for extractor hoods consisting of a frame and filter layers embedded therein, characterized in that the frame has a stepped profile (Figure A), whereby the outer and narrower part (1) of the profile fits into the holder intended for a normal grease filter, but is higher behind it in order to be able to accommodate filter layers that are thicker than a normal grease filter (2). 2. Filter for extractor hoods according to claim 1, characterized in that the air flows first through a grease filter and then through an adsorption filter. 3. Filter for extractor hoods according to one or more of the preceding claims, characterized in that the grease-separating layer (Figure C (1)) consists of plug-in metal. 4. Filter for extractor hoods according to one or more of the preceding claims, characterized in that the odor-adsorbing layer (Figure B (1)) consists of an open-pored carrier material, on which granular or spherical activated carbon particles with diameters of 0.1 - 2.0 mm, preferably 0.3 - 1.0 mm, are fixed by means of an adhesive.