MODULAR FILTRATION DEVICE FOR EXTRACTOR AND/OR FILTERING HOODS

Abstract: A modular filtration device for extractor and/or filtering hoods which forms, with the inside of the hood, a suction compartment (32), comprising: at least one supporting panel (1) which is fixed hermetically in the enclosure of the hood and on which there are provided slots (2, 2a, 2b) spaced by supporting regions (4); box-like filtration elements (9), constituted by an upper wall (10) and a lower wall (11) which form labyrinth ducts (12) which are substantially zigzag-shaped, the upper wall (10) being laterally provided with first diffuser means (16) which are connected to the suction compartment (32) and said lower wall (11) having, in its central region, second diffusion means (22) which are connected to suction chambers (30) formed by the seating of the filtration elements on the supporting regions (4), the chambers (30) being adapted to aspirate vapors through the slots (2, 2a, 2b) and send them to the labyrinth ducts (12) in order to separate the heavy particles from the vapors.

Description: MODULAR FILTRATION DEVICE FOR EXTRACTOR AND/OR FILTERING HOODS Technical Field The present invention relates to a modular filtration device for extractor and/or filtering hoods, particularly for cookers. Background Art It is known that extractor and/or filtering hoods are currently commercially available and are used to eliminate grease, fumes and vapors produced by cookers and the like. For this purpose, said hoods are provided with appropriate filtration means which are adapted to retain unwanted substances. In particular, it has been observed that hoods that support, on their grilles, multilayer metallic filters and acrylic filters periodically require replacement of said filters in order to maintain good efficiency and moreover do not offer adequate fire protection. Filtering panels are also known being constituted by a multilayer metallic mesh, made for example of aluminum, which are particularly suitable to retain greasy substances. These panels do not require periodic replacement and can be washed with conventional means. In these panels it is noted that the washing often does not allow to fully clean the panels, due to the clogging of the metal mesh. Moreover, such filtering panels also offer no fire protection, and this problem worsens when easily flammable greasy particles accumulate. Another problem usually suffered by conventional filtering means is that the liquids produced by the condensation of the aspirated vapors, in the gaseous state, drip onto the cooking surface. Another problem commonly suffered in the manufacture of extractor and/or filtering hoods is the need to conveniently vary their dimensions according to the requirements, for example for large and small cookers or other fields in general. Such filtering means in fact have poor modularity. Said filtering means further usually face difficulties in assembly which hinder cleaning and maintenance operations in general. Disclosure of the Invention The aim of the present invention is to obviate said drawbacks, by providing a modular multipurpose filtration device for extractor and/or filtering hoods which ensures broad operating functionality and particularly optimum filtering of grease. Within this aim, an object of the present invention is to provide a multipurpose filtration device for extractor and/or filtering hoods which allows easy and thorough cleaning. Another object of the present invention is to prevent the passage of the flame in the suction region where the motor is accommodated. Another object of the present invention is to prevent the return of the condensed vapors onto the cooking surface. Another object of the present invention is to prevent the occurrence of flow-rate losses of the aspirated vapors due to the clogging of the filtering means. Another object of the present invention is to ensure excellent deadening of the noise generated by the motor during vapor aspiration. Another object of the present invention is to achieve the above aim with a structure which is simple, relatively easy to provide in practice, safe in use, effective in operation and has a relatively low cost. This aim and these and other objects are all achieved by the present modular filtration device for extractor and/or filtering hoods which defines, with the inside of the hood, a suction compartment, characterized in that it comprises: at least one supporting panel which is fixed hermetically in the enclosure of said hood and on which there are provided slots spaced by supporting regions; box-like filtration elements, constituted by an upper wall and a lower wall which form labyrinth ducts which are substantially zigzag-shaped, said upper wall being laterally provided with first diffuser means which are connected to said suction compartment and said lower wall having, in its central region, second diffusion means which are connected to suction chambers formed by the seating of said filtration elements on said supporting regions, said chambers being adapted to aspirate vapors through said slots and send them to said labyrinth ducts in order to separate the heavy particles from said vapors. Brief description of the drawings Further features will become better apparent from the detailed description of a preferred but not exclusive embodiment of a modular filtration device for extractor and/or filtering hoods, according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a perspective view of a supporting panel; Figure 2 is a perspective view of a box-like filtration element; Figure 3 is a front view of said filtration element; Figure 4 shows in a perspective view the positioning and mutually adjacent arrangement of multiple filtration elements on said panel; Figure 5 is a perspective view of the means for locking said filtration elements on said panel; Figure 6 shows in a perspective view the locking of said filtration elements on said panel; Figure 7 is a bottom view of the arrangement of one of said panels in the enclosure of said hood; Figure 8 is a sectional front view of a variation of said panel. Ways of carrying out the Invention With reference to the figures, 1 generally designates a panel for supporting a modular filtration device for extractor and/or filtering hoods according to the invention. The supporting panel 1, as shown in Figure 1, has a rectangular shape and is provided with slots which are grouped in pairs of slots 2 which are mutually equidistant with respect to planes A which pass through the central region 3 of each one of the pairs of slots 2. The pairs of slots 2 are separated by supporting regions 4 which are distributed with a constant spacing. Moreover, the slot 2a of each pair 2 is equidistant with respect to said plane A from the other slot 2b. The slots 2a and 2b of each pair of slots 2 have perimetric protruding edges 5 so that they form, at the central region 3 with respect to the planes A, a drip rail 6 for collecting the liquids produced by condensation of the vapors. The supporting panel 1 further has, on its opposite sides 7, a U-like shape which forms a guide 8. Finally, the supporting regions 4 are designed to accommodate the filtration elements 9, which are arranged longitudinally adjacent to each other. Each one of the filtration elements 9, as shown in Figures 2 and 3, is box-like and is constituted by an upper wall 10 and a lower wall 11 which form zigzag labyrinth ducts 12. The upper wall 10 centrally comprises a flat surface portion 10a and is laterally provided with respective first and second surface portions 10b, 10c. The portions 10b, 10c are constituted by a vertical part 13, which is connected in an upward region to the flat surface portion 10a; a vertical side 14 which is connected, in a downward region, to the lower wall 11; an inclined part 15, which is connected by means of the end 15c to the vertical portion 13 and by means of the end 15b to the vertical side 14. First diffuser means are provided along each inclined part 15 and are constituted by elongated slots 16 which are adapted to connect the suction compartment of the inside of the hood to the labyrinth ducts 12. The lower wall 11 is laterally constituted by two flat and parallel supports 17 and 18 which are designed to arrange themselves in said resting regions 4 so as to occupy part of the area of the resting regions 4. The other part of the area is occupied by one of the two supports 17 and 18 of the other filtration elements which are arranged adjacent to the filtration element 9. Thin tabs 29 further protrude longitudinally from the supports 17 and 18; their method of use is described hereinafter. The central region of the lower wall 11 comprises internal sides 19 which are shaped like an inverted L, in which the lower ends 20 are connected to the supports 17 and 18 and the upper ends 21 are arranged frontally, so as to form the second diffusion means, which are constituted by a longitudinally elongated rectangular opening 22, which is connected to a suction chamber 30 formed by the resting of the filtration element 9 on the supporting panel 1. The vertical projection of the upper ends 21 on the drip rail 6 is such that it falls inside the protruding perimetric edges 5 in order to facilitate the dripping of the condensed vapors in the drip rail 6. The fixing and retention of the filtration elements 9 on the supporting panel 1 are achieved by means of box-like heads 31. The heads 31, with the lateral ends 23, are made to slide in the guide 8 until they abut, with the front 24, against the head of the filtration elements 9, which are locked by means of the combined engagement of grooves 25, provided at the edge 24a, with the tabs 29. The heads 31 are fixed, in the position for locking the filtration elements 9, through conventional connecting means, such as for example screws, nails and the like. One of the two heads 31 is provided with conventional engagement means 31a which allow, in the hermetic insertion of the device thus formed in the compartment 32 of the hood, the locking/release of said device. One or more devices can be inserted in the compartment 32 of the hood by arranging contiguously to each other one or more panels 1 for supporting the filtration elements 9, depending on the dimensions of the hood enclosure. In practical operation, the suction produced inside the hood by the suction motor is transmitted to the suction chambers 30 through the elongated slots 16, the labyrinth ducts 12 and the openings 22 which lead into the suction chambers 30. The suction that occurs in each one of the suction chambers 30 causes the fumes and vapors laden with greasy particles to be drawn through the pairs of slots 2 into the suction chambers 30 and merge, along a path which skims the inner sides 19, in the labyrinth ducts 12, which due to their slightly varying cross-section accelerate the fumes and vapors, now cleaned of the greasy particles, toward the inside of the hood in the manner specified below. A first separation of the greasy particles occur by retaining them along the inner sides 19; along the path, designated by the arrows B in Figure 3, the fumes laden with heavy particles in fact initially skim over the internal sides 19, which retain a certain amount of greasy particles, until the fumes strike frontally the upper ends 21; in this context, the upper ends 21, owing to their particular wing-like shape and their orientation transversely to the direction of the fume path B, in addition to retaining a considerable amount of greasy particles, determine a substantial change in the direction of the path A of the fumes, which now have a reduced grease content. In particular, the change in direction of the path B of the fumes determines the frontal impact of said fumes, with consequent vortical motion, which by centrifugal force allows to expel other heavy particles toward the inner sides 19. All this produces a considerable increase in the greasy particle retention capacity of the suction chamber. The remaining greasy particles, together with the fumes and the vapors, are then conveyed and accelerated in the labyrinth ducts, which by virtue of their particular zigzag shape constitute a hindrance for the remaining greasy particles, which have considerable kinetic energy; the remaining greasy particles, owing to their considerable speed, are in fact unable to follow the zigzag bends of the labyrinth ducts and are therefore destined to impact on the internal surface of the labyrinth ducts. It has thus been shown that the present invention achieves the intended aim and objects. In particular, the fact is stressed that the grease retention provided by the filtration device according to the invention is substantially complete. The liquids produced by the condensation of the vapors and fumes that condense during the suction process do not drip onto the cooking surface. Moreover, the device thus conceived does not allow the passage of flames, since flames cannot propagate downward in the labyrinth ducts. Moreover, the filtration elements, together with the supporting panel, provide an excellent barrier to the propagation of the noise that is present inside the hood. Noise shielding, owing to the particular configuration of the filtration element, is also optimized by lining the upper wall of the filtration elements with sound-deadening paint, multilayer soundproofing products, microperforated metal plates or a double metal sheet between which insulating material is internally interposed. Moreover, the device thus conceived, by being easy to disassemble, can be easily cleaned in conventional washing devices; this allows the motor to have excellent efficiency and therefore no loss of flow-rate thereat, differently from what occurs in conventional filters, which often remain impregnated with grease, obstructing the passage of the vapors through it. Moreover, since the device is constituted by a supporting panel whose exposed surface is practically smooth, there are no obstacles that protrude outward, allowing easy external cleaning of the supporting panel. Finally, the modularity of the supporting panels and of the filtration elements allows to adapt the device to any size of extractor hoods, be they for small cookers or for large cookers. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept. A first variation of the filtration device consists in the possibility to accommodate, in each one of the suction chambers, additional supplemental filters, such as for example a thin aluminum mesh and optional odor- eliminating filters in the case of filtering hoods with recycling of the aspirated air. Advantageously, Figure 8 illustrates a variation of the panel 1. In this variation, in the central region 3 that lies between the pair of slots 2 an additional slot 2c is provided which is peripherally provided with protruding edges 5a, so as to form, together with the pair of slots 2a, 2b, a pair of drip rails 6a and 6b which are adapted to collect liquids produced by condensation. This solution considerably improves the flow-rate of the grease-laden fumes and vapors inside the suction chamber 30, thus achieving higher efficiency of the hood during aspiration and filtration of the fumes and vapors. All the details may further be replaced with other technically equivalent ones. In practice, the materials employed, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims. The disclosures in Italian Patent Application No. BO99A000638 from which this application claims priority are incorporated herein by reference.

Claims: CLAIMS 1. A modular filtration device for extractor and/or filtering hoods which forms, together with the inside of the hood, a suction compartment (32), characterized in that it comprises: at least one supporting panel (1) which is fixed hermetically in the enclosure of said hood and on which there are provided slots (2, 2a, 2b) spaced by supporting regions (4); box-like filtration elements (9), constituted by an upper wall (10) and a lower wall (11) which form labyrinth ducts (12) which are substantially zigzag-shaped, said upper wall (10) being laterally provided with first diffuser means (16) which are connected to said suction compartment (32) and said lower wall (11) having, in its central region, second diffusion means (22) which are connected to suction chambers (30) formed by the seating of said filtration elements (9) on said supporting regions (4), said chambers (30) being adapted to aspirate vapors through said slots (2, 2a,2b) and send them to said labyrinth ducts (12) in order to separate the heavy particles from said vapors. 2. The filtration device according to claim 1, characterized in that said slots (2, 2a, 2b) are distributed in pairs (2) which are mutually equidistant with respect to planes (A) that pass through the central region (3) of each one of said pairs (2). 3. The filtration device according to claim 1, characterized in that said supporting regions (4) are distributed with a constant spacing. 4. The filtration device according to claim 1, characterized in that said supporting panel (1) is substantially U-shaped on two mutually opposite sides. 5. The filtration device according to claim 1, characterized in that said slots (2, 2a, 2b) have peripheral protruding edges (5, 5a) which are directed toward said lower wall (11). 6. The filtration device according to claims 1, 2 and 5, characterized in that said protruding edges (5, 5a) form, at said central region with respect to said planes, a driprail for collecting the condensed vapors. 7. The filtration device according to claim 1, characterized in that said upper wall (10) centrally comprises a flat surface portion (10a) and laterally comprises first and second surface portions, each of which is constituted by a vertical portion (13) which is connected in an upward region to said flat surface portion (10a), a vertical side (14) which is connected to said lower wall (11) in a downward region, an inclined portion (15) which is connected with one end (15c) to said vertical portion (13) and, with the other end (15b), to said vertical side (14). 8. The filtration device according to claims 1 and 7, characterized in that said first diffuser means consist of elongated slots (16) formed in said inclined portion (15). 9. The filtration device according to claim 1, characterized in that said lower wall (11) is constituted laterally by two flat and parallel supports (17, 18) and, in said median region, by internal sides (19) shaped like an inverted L, said sides (19) being connected, with their lower ends (20), to said supports (17, 18) and having upper ends (21) which are arranged frontally so as to form said second diffuser means (22), which are constituted by a rectangular opening. 10. The filtration device according to one or more of the preceding claims, characterized in that the vertical projection of said upper ends (21) onto said drip rail (6) is internal to said peripheral protruding edges (5), so as to facilitate the dripping of the condensed vapors into said drip rail (6). 11. The filtration device according to one or more of the preceding claims, characterized in that the cross-section of said labyrinth ducts (12) decreases from said elongated slots (16) to said opening (22). 12. The filtration device according to one or more of the preceding claims, characterized in that it comprises box-like heads (31) which are adapted to lock and retain said filtration elements (9) on said supporting panel (1). 13. The filtration device according to claim 12, characterized in that at least one of said heads (31) is provided with locking means (31a) which can detachably engage the compartment (32) of said hood.

Inventors: BEFERA LUCIO, BEFERA, LUCIO
Applicants: BEFERA LUCIO, FABER SPA, BEFERA, LUCIO, FABER S.P.A.
Application year: 2000
Main classification: B01D45
IPC codes: B01D45, F24C15