ITTO20120332A1 - ODOR FILTER FOR KITCHEN HOOD AND RELATED KITCHEN HOOD - Google Patents

Description

"ODOR FILTER FOR KITCHEN HOOD AND RELATED KITCHEN HOOD"

DESCRIPTION

[FIELD OF TECHNIQUE]

The present invention relates to the sector of suction or recirculating hoods, in particular for the treatment of fumes and odors in domestic environments, for example to a kitchen hood.

The invention relates in particular to a hood filter, to a filter-housing assembly in a hood, and to a relative hood.

[ART NOTE]

Nowadays suction and / or filtering devices are known, to be installed near places where fumes or odors are generated. For example, these suction and / or filtering devices are called "hoods" and are typically installed in domestic environments, such as a kitchen.

In the context of the present invention, the term "fumes" designates an aeriform, typically air, contaminated by suspended liquid, solid or ethereal particles. In the case of kitchen hoods, the aspirated fumes typically carry suspended fatty particles, and odors deriving from cooking food.

Some hoods suck in the fumes from the environment, discharging the sucked air into a ventilation duct that evacuates the fumes and odors to the open; these hoods are therefore called "suction hoods".

Other hoods collect the fumes from the environment, to filter them and re-enter the purified air in the same environment; this second type of hood is called "recirculating hoods", and the present invention finds a particularly advantageous application for this type of recirculating hood.

An example of a hood and of a relative filter is known from the document DE202009017271U1, which describes a filter element comprising several filtering layers in series, between which there are filtering layers against odors, which include activated carbon.

However, known hood filters have the problem of not making the best use of their filtering elements. In fact, activated carbon has a tendency to exhaust its adsorbing power after a certain amount of working hours, and therefore there is a decrease in the effectiveness of the filter itself.

[OBJECTIVES AND SUMMARY OF THE INVENTION]

The object of the present invention is to solve some of the problems of the known art.

In particular, the aim of the present invention is to present a hood filter in which the filtering elements are used more effectively.

Finally, the object of the present invention is to present a hood filter which improves the performance of the hood, in terms of filtering efficiency and improved use.

These and other objects of the present invention are achieved by means of a hood filter, a housing filter assembly and a relative hood, incorporating the characteristics of the attached claims, which form an integral part of the present description.

An idea underlying the present invention is to provide a hood filter comprising at least two consecutive filtering layers on the flow direction; the filter has a substantially cylindrical shape, defining a lateral filtering surface in which the two filtering layers are concentrically arranged on the lateral surface, one inside the other.

In this way the filter has a greater filtering surface, with the same volume occupied, and allows the filtering elements to be exploited more effectively. These advantages also have a beneficial effect on the performance of the hood that uses the filter, in terms of filtering efficiency and improved use.

Preferably, the first filtering layer comprises a folded fabric and the second filtering layer comprises activated carbon.

Preferably, the filter comprises at least one inlet for an air flow which is substantially transverse to the lateral filtering surface, positioned on a base of the filter. In this way it is possible to build a compact filter, particularly suitable for domestic use in filter hoods.

Preferably, in the filter, the first filtering layer with folded fabric is internal with respect to the second filtering layer with activated carbon, so as to be upstream on the flow direction. The flow of air to be filtered is therefore filtered first by the fabric, and only subsequently by the activated carbons; in this way the filtering efficiency in eliminating odors is improved, and the duration of the active elements, such as the carbons, is also improved.

Preferably, the folded fabric filter layer comprises in turn activated carbon. Furthermore, again preferably, the second filtering layer (402) comprises activated carbon in granular form. In this way, odors can be filtered even more effectively.

The present invention also provides a filter-housing assembly, to be used in a hood, or a special element suitable for housing the filter according to the present invention, which contributes synergistically together with the latter to the realization of an improved filtering system, particularly suitable to be used in a filter hood. The assembly comprises a filter according to the present invention, and further comprises a housing adapted to receive the filter; the housing comprises at least one lower opening which makes a fluid connection between the hood and the filter, and further comprises at least one opening for the outflow of filtered air from the filter.

The housing also makes it possible to simplify the maintenance of the hood, making it easier to maintain and / or replace a filter in the assembly.

Preferably, the housing has a substantially boxed shape to contain the filter inside, and the outlet for the outflow is positioned on at least one of the side faces of the housing. In this way it is possible to minimize the overall dimensions of the filter-housing assembly.

Preferably, the housing is made of stainless steel, that is a material suitable for domestic use, easy to clean and resistant to agents present in the environment, such as grease and dust.

Preferably, the filter is of a shape suitable for coupling, as a whole, with the lower opening of the housing, providing a fluid connection for a flow of air inside the filter itself. This further improves the compactness of the assembly.

Finally, the present invention relates to a hood comprising a filter according to the present invention, or comprising a filter-housing assembly according to the present invention, in particular downstream of air circulation means in the hood. In this way, the filter is protected from the humidity sucked in by the hood and the performance and life of the filter elements are improved.

Further objects and advantages of the present invention will become clearer from the detailed description which follows, and from the attached drawings.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Some preferred and advantageous embodiments are described by way of non-limiting example, with reference to the attached figures, in which:

Figure 1 illustrates an embodiment example of a hood comprising a filter according to the present invention.

Figure 2 illustrates a section of the hood of Figure 1.

Figure 3 illustrates in detail the filter housing of the hood of Figure 1.

Figure 4 illustrates a cross section of the housing of Figure 3, inside which a filter according to the present invention is visible.

Figure 5 illustrates a perspective view of a filter according to the present invention.

Figure 6 illustrates a perspective view in transparency of a filter according to the present invention.

The figures illustrate different aspects and embodiments of the present invention and, where appropriate, similar structures, components, materials and / or elements in different figures are indicated by the same reference numerals.

[DETAILED DESCRIPTION OF THE INVENTION]

Figure 1 represents an example of a kitchen hood 101 of the recirculation type. The hood 101 comprises a smoke manifold 102, typically to be positioned above a hob; the fumes manifold 102 can comprise further filtering elements (not shown) designed to filter the fat particles entrained by the air, which are filters according to the teachings of the prior art.

The hood 101 further comprises air circulation means (not shown), for example a fan, adapted to collect air from the flue manifold 102 and make it pass through the chimney 104. At the upper top of the hood 101, there is a housing 106 for a filter , especially for an odor filter. The housing 106 comprises a plurality of openings to allow the outflow of the air sucked by the hood into the domestic environment, after having been suitably filtered. In this way it is possible to purify the air collected by the hood 101 from ethereal substances which carry unpleasant odors. In the preferred embodiment, the housing 106 has a substantially cubic shape, having the three side faces facing the environment which include openings. In an alternative embodiment, particularly suitable in "island" -type hoods that is far from the walls of the environment, the housing may comprise openings on all four side faces of the housing.

The openings of the housing 106 have a reduced section with respect to the lateral surface of the housing 106, preferably less than 10% of the total lateral surface. In this way, it is possible to create a hood in which there is a concentrated pressure drop downstream of the odor filter, improving filtering by the latter with an appropriate reduction in the speed of the air flow.

The housing 106 also has an aesthetic function, since it hides the filter from the view of users who are in the room in which the hood 101 is located. In fact, it should be remembered that the hood 101 is of the "recirculation" type, and introduces the air collected by the smoke manifold 102, once purified, into the environment itself and is therefore typically visible to the user. The housing 106 is preferably made of a metallic material, such as stainless steel in particular suitable for the conditions of domestic use, with a surface finish that is pleasing to the eye.

Figure 2 illustrates a lateral section of the hood 101, in which it is possible to view the air circulation means 103, which introduce the air from the chimney 104 to the duct 107 (between which the air circulation means, for example the fan, are interposed) , which is in fluid connection with the filter 105 which will be described in greater detail below.

Figure 3 illustrates in greater detail the housing 106, separated from the hood 101. It is in particular possible to appreciate the presence of a lower opening 301 on the base of the housing 106, through which the air to be filtered is introduced into the filter. from the duct 107. It is also possible to appreciate in greater detail the configuration of the lateral surfaces 302 of the housing, which form the openings of reduced section described above. Preferably, at least one of the side surfaces 302 comprises removable mounting means, to be removed by a user or an operator for maintenance of the filter housed inside.

In particular, the housing comprises a frame designed to structurally support a plurality of panels fixed to the frame itself and arranged on the faces of the housing in such a way as to provide a structure which houses the filter inside.

Furthermore, the panels are of such size as to create an interspace between each of the panels and the frame, creating a plurality of openings for the outflow of filtered air. Figure 4 illustrates a sectional view along a horizontal plane of the housing 106, in which a section of the filter 105 housed therein is visible.

The filter 105 comprises a substantially cylindrical structure, hollow inside and housed in correspondence with the opening 301 in such a way as to allow the introduction of air to be filtered inside the filter 105. The side walls of the filter 105 are permeable to air and comprise filter materials as described below, and are therefore adapted to filter the air, for example by reducing its odors.

The filter 105 provides a double concentric filter structure, comprising an internal filtering portion 401 comprising folded filtering fabric, and an external filtering portion 402 comprising activated carbon.

Preferably the internal filtering portion 401 comprises a folded fabric having the folds substantially longitudinal with respect to the filter.

Preferably, the external filtering portion 402 comprises a structure in micro-stretched sheet metal comprising holes or a reticular structure, suitable for providing a containment volume for the activated carbons. Preferably the activated carbons are in granular form, preferably carbons with characteristics such as to have CC14 Index> 80% (calculated with the ASTM3467-89 method) and surface area> 1100 Mq / g (calculated with the BET method with Nitrogen).

Preferably, the folded fabric has a number of folds comprised between 50 and 100, preferably between 60 and 75, even more preferably between 65 and 70.

In a preferred embodiment, the internal opening of the filter 105 has a diameter between 160 mm and 180 mm. In a preferred embodiment, the internal filter portion 401 made of folded fabric has a thickness of between 35 mm and 50 mm. Preferably, the external filtering portion 402 comprising activated carbon has a thickness comprised between 10 mm and 20 mm.

Preferably the filter 105 has an overall diameter between 280 mm and 320 mm, and a height between 270 mm and 300 mm.

Figure 5 illustrates an overall view of the filter 105. The structure of the filter 105 is made of such a shape as to define an inlet 501 in correspondence with the lower face of the filter 105, arranged transversely with respect to the cylindrical symmetry structure. The inlet 501 is adapted to be coupled to the opening 301 of the housing 106, in such a way as to allow the passage of air inside the filter 105 without leakage. For example, the interface between the opening 301 and the inlet 501 has a suitable shape coupling. Advantageously, the diameter of the inlet 501 is greater than the diameter of the opening 301 so as to suitably slow down the flow immediately upstream of the filtering layers. The upper face 502 of the filter 105 is preferably closed for example by a plate made of a material such as steel. In this way, the filtering of the air occurs only through the lateral surface 503 of the filter 105. In an alternative embodiment, the upper face of the filter 502 could be open, and its closure be achieved by coupling with a further surface of the housing 106. For example, the plate in correspondence with the upper face of the housing 106 could abut the upper face 502 of the filter 105, and additionally a sealing gasket could be provided.

Figure 6 illustrates a transparent view of the filter 105, in which it is possible to appreciate the concentric arrangement of the filtering elements 401 and 402 of the filter 105. Thanks to this concentric arrangement, the filtering surface is maximized with the same overall dimensions, and it is possible to realize a more efficient and compact filter, in which the activated carbon filter elements have a longer life. Furthermore, by providing a lateral filtering surface in the filter 105, when inserted in a hood 101, it is possible to provide for a deviation of the flow of filtered air with respect to the direction of the chimney 104. In this way it is possible to improve the fluid dynamics inside the filter 105 , improving suction and filtering. Furthermore, it is possible to efficiently divert the flow inside the housing 106, in such a way as to increase the silent operation of the hood 101, and to avoid that the filtered air directly invests the walls surrounding the hood 101, for example the back wall or ceiling. In this way, the walls of the home environment are avoided.

It is obvious that those skilled in the art could conceive further variants of the present invention, without however departing from the scope of protection resulting from the claims.

For example, a plurality of embodiments of the structure of the hood 101 are conceivable, provided that it is adapted to house a filter such as the filter 105.

Furthermore, the filter 105 could comprise a greater number of filtering layers, even of different types, whether they are arranged externally, or internally, or intermediate between the filtering layers described above.

Furthermore, it would be possible to conceive a variant according to which the internal diameter of the filter is not constant along the longitudinal development of the latter, but is for example decreasing according to a law which takes into account the progressive loss of flow rate through the lateral surface of the filter.

Furthermore, it is evident that a "substantially cylindrical" shape indicates a solid whose projection on a plane perpendicular to the axis of symmetry is a closed figure, such as for example a circumference or an ellipse. For example, it is to be understood that a truncated cone, a solid developed on an elliptical base or the like are to be considered as having a "substantially cylindrical" shape.

It is clear that the present invention, although it has been described with reference to a preferred application in recirculating hoods, could equally well be used in combination with extractor hoods, in particular if specific environmental standards require it.

Furthermore, it is to be understood that a filter according to the present invention can be used in hoods of any type, not limited to kitchen hoods, but for example also in industrial or laboratory hoods.

Claims (11)

CLAIMS Filter (105) specifically adapted to be used in a hood (101), comprising at least two consecutive filtering layers (401, 402) on the flow direction, characterized by the fact that said filter (105) has a substantially cylindrical shape defining a filtering surface lateral (503), in which said filter layers (401, 402) are concentrically arranged on said lateral surface (503), being one inside the other. Filter according to claim 1, wherein a first filter layer (401) comprises a folded fabric and a second filter layer (402) comprises activated carbon. Filter according to claim 1 or 2, further comprising at least one inlet (501) for an air flow, said inlet (501) being substantially transverse to said lateral filtering surface (503) on a base of said filter (105). Filter according to claim 1 or 2 or 3, wherein said first filter layer (401) is internal with respect to said second filter layer (402) in said filter (105), so as to be upstream of said second filter layer (402) on said flow direction. Filter according to any one of claims 1 to 4, wherein said first filter layer (401) comprises activated carbon, and said second filter layer (402) comprises activated carbon preferably in granular form. Assembly (105, 106) specifically adapted to be used in a hood (101), comprising a filter according to one of claims 1 to 5, and further comprising a housing (106) adapted to receive said filter (105), wherein said housing (106) comprises at least one lower opening (301) suitable for making a fluid connection between said hood (101) and said filter (105), and further comprising at least one opening for the outflow of filtered air from said filter (105). 7. Assembly (105, 106) according to claim 6, in which said housing (106) has a substantially box-like shape and is adapted to contain said filter (105) inside itself, and in which said at least one opening for the outflow is positioned on at least one of the side faces of said housing. Assembly (105, 106) according to claim 6 or 7, wherein said housing (106) is made of stainless steel. Assembly (105, 106) according to any one of claims 6 to 8, wherein said filter (105) is of a shape suitable for coupling with said lower opening (301) making a fluid connection for a flow inside a said filter (105). 10. Hood (101) comprising a fume collector (102) in fluid connection with a chimney (104), and air circulation means (103) for collecting air through said fume collector (102) and directing it into said chimney (104) , and further comprising a filter (105) adapted to filter said air, characterized in that said filter (105) is a filter according to one of claims 1 to 5. Hood according to claim 10, wherein said filter (105) is in fluid connection with a housing (106), making an assembly (105, 106) according to any one of claims 6 to 9, wherein said assembly ( 105, 106) is downstream of said air circulation means (103).