Anti-drip system for a kitchen hood

Abstract

Anti-drip system (100) for kitchen hood (200) comprises: a collection receptacle (2) suitable for receiving the condensation formed in the hood, and a grease filter (1) suitable for being arranged in the hood (200) in an inclined position with respect to a horizontal plane, so as to make the condensation generated inside the grease filter flow toward said collection receptacle (2), wherein said grease filter (1) comprises: a lower plate (3) made of non-metallic material having a thermal conductivity λ less than 1 W / mK, and an upper plate (4) made of sheet metal.

Description

[0001] ANTI-DRIP SYSTEM FOR A KITCHEN HOOD

[0002] DESCRIPTION

[0003] The present invention relates to an anti-drip system for a kitchen hood suitable for preventing the dripping due to the formation of condensation in the hood.

[0004] As it is well known, a hood is suitable for operating with a kitchen hob, with the function of forcedly extracting the fumes and consequently the odors generated when food is cooked. The hood comprises an electric fan that draws the fumes into the hood. The hood has an inlet with a grease filter made of metal material that is suitable for retaining the grease contained in the extracted cooking fumes.

[0005] Condensation is formed on the grease filter because the fumes have a higher temperature than the surrounding environment and the grease filter of the hood. Such a phenomenon occurs during cooking because there is a temperature difference between the vapors and the grease filter. As a result, the condensation causes a dripping that is poured onto the hob and onto the food being cooked.

[0006] Such a dripping increases significantly when the hood is switched off because, due to the absence of the depression generated by the electric fan, the condensation is no longer retained inside the grease filter and is detached by dripping.

[0007] Condensation dripping is even more significant in hobs with induction plates. In fact, with the induction plates, the heat only affects the bottom of the pot and not the air that surrounds the vertical walls of the pot, as it occurs with gas hobs. Due to the exclusive heating of the pot, which is typical of induction plates, the vapors rising towards the hood are less hot than those produced by gas hobs. The less hot vapors therefore require a longer time to heat the surface of the grease filter.

[0008] The technical solutions that are currently available to solve the problem of condensation and dripping are: - heat resistances arranged in the walls affected by condensation to raise the temperature of the surfaces (to approximately 40°C), eliminating the thermal gap with the hot steam that causes the condensation;

[0009] - dedicated extraction systems that convey ventilated air into the surfaces affected by condensation;

[0010] - absorbent filters with multiple absorbent layers that retain the condensation and prevent it from falling onto the hob;

[0011] - anti-condensation filters that convey the condensation internally and minimize the condensation externally.

[0012] Evidently, all these technical solutions increase the complexity and the dimensions of the hood, with a consequent increase in costs and, in the aforementioned first and second case, in the consumption of the product, decreasing its energy efficiency.

[0013] CN203928053U describes an anti-drip system for kitchen hoods according to the preamble of claim 1 .

[0014] US9372004B2 describes a filtering system for kitchen hoods, configured to remove grease, oil and other particles from the extracted air.

[0015] The purpose of the present invention is to eliminate the drawbacks of the prior art by providing an efficient anti-drip system for kitchen hoods that minimizes the formation of condensation and prevents the condensation from dripping onto the hob.

[0016] Another purpose is to provide such an anti-drip system for kitchen hoods that is versatile and easy to install in the hood.

[0017] A further purpose is to provide such an anti-drip system for kitchen hoods that is inexpensive and simple to make, without affecting its environmental impact.

[0018] These purposes are achieved in accordance with the invention with the characteristics of the attached independent claims.

[0019] Advantageous embodiments of the invention appear from the dependent claims. Further features of the invention will become clearer from the following detailed description, which refers to a merely illustrative and therefore nonlimiting embodiment, illustrated in the accompanying drawings, wherein:

[0020] Fig. 1 is a diagrammatic view of a kitchen hood with the anti-drip system according to the invention;

[0021] Fig. 2 is a sectional view of a lower part of the hood in Fig. 1 , illustrating the anti-drip system according to the invention in greater detail;

[0022] Fig. 3 is a graph illustrating the temperature curves as a function of time for steam, plastic, and metal;

[0023] Fig. 4 is a perspective view illustrating a grease filter forming part of the anti-drip system according to the invention;

[0024] Fig. 4A is an enlarged detail of Fig. 4;

[0025] Fig. 4B is a sectional part of the grease filter of Fig. 4;

[0026] Fig. 5 is a top view of the grease filter of Fig. 4;

[0027] Fig. 6 is a sectional view of the grease filter taken along the section plane VI-VI of Fig. 5; and

[0028] Fig. 6A is an enlarged detail enclosed in circle A of Fig. 5.

[0029] With the aid of the Figures, the anti-drip system according to the invention is described, which is comprehensively indicated with reference numeral 100.

[0030] With reference to Fig. 1 , the anti-drip system (100) is suitable for being installed in a kitchen hood (200) to prevent the condensation formed in the hood (200) from dripping onto a hob (300).

[0031] The hood (200) is installed above the hob (300). The hood (200) comprises a casing (201 ) having an extraction inlet (202) and an electric fan (203) arranged in the hood so as to draw the air from the extraction inlet (202).

[0032] Fig. 1 shows a cooking vessel (301 ) disposed on a hob (300). The food that is cooking in the vessel (301 ) generates fumes (F). When the electric fan (203) is activated, the fumes (F) are sucked through the extraction inlet (202) of the hood. The hood (200) comprises a grease filter (1 ) disposed in the casing (201 ) of the hood at the extraction inlet (202) to filter the grease contained in the extracted fumes (F).

[0033] The anti-drip system (100) comprises the grease filter (1 ) and a collection receptacle (2) disposed in the casing (201 ) of the hood to collect the condensation formed in the grease filter (1 ). In particular, the anti-drip system (100) refers to the structure and arrangement of the grease filter (1 ).

[0034] With reference to Fig. 2, the grease filter (1 ) has a plate-like shape and is arranged in the casing (201 ) of the hood, like an inclined plane, with an inclination angle (a) of 10°-30° with respect to a horizontal plane, so that the condensation and grease that are formed inside the grease filter (1 ) can slide by gravity and flow in the direction of the arrow (C), towards the collection receptacle (2) that is disposed at one end of the grease filter (1 ).

[0035] In particular, the grease filter (1 ) comprises a lower plate (3) with holes (30) through which the fumes (F) enter and an upper plate (4) with slots (40) (shown in Fig. 5) through which the fumes exit. A cavity (I) is provided between the lower plate (3) and the upper plate (4), wherein the condensation can flow towards the collection receptacle (2).

[0036] Unlike the grease filters of the prior art that are entirely made of sheet metal, the grease filter (1 ) comprises a lower plate (3) made of a material other than metal, with a thermal conductivity (X) of less than 1 W / mK, and an upper plate (4) made of sheet metal.

[0037] Advantageously, the lower plate (3) can be made of plastic, for example by injection molding. Preferably, among the various plastic materials, a technopolymer with high mechanical characteristics can be used. Among the various technopolymers, thermoplastic polyester, such as polybutylene terephthalate (PBT), is preferably used. In fact, PTB not only has a low thermal conductivity ( )= 0.33 W / mK, but also excellent properties in terms of mechanical resistance, flame resistance and self-extinguishing, these characteristics being mandatory to comply with safety regulations of the product. The upper plate (4) is made of sheet metal, preferably rolled steel, which has a thermal conductivity ( )= 53 W / mK, that is to say 160 times greater than the thermal conductivity of the lower plate (3).

[0038] The reason for using a material with low thermal conductivity for the lower plate (3) is to reduce the thermal gap between the fumes (F) coming from the hob and the lower plate (3) of the grease filter, which causes condensation to form.

[0039] The metal material used in the anti-grease filters of the prior art has a high thermal conductivity and therefore tends to dissipate the accumulated heat rapidly and the temperature difference between the surface and the aqueous vapor remains high, thus generating condensation.

[0040] On the contrary, the plastic material used for the lower plate (3) of the grease filter (1 ) according to the present invention has a much lower thermal conductivity, and therefore it dissipates less heat, which tends to accumulate. As a result, the surface temperature of the lower plate (3) rises, reducing the temperature difference with the fumes (F) that causes condensation to form.

[0041] Fig. 3 shows three indicative temperature curves as a function of time, starting from an ambient temperature Ta of max. 100°C.

[0042] The highest temperature curve corresponds to the temperature of the fumes (F) coming from the hob.

[0043] The lowest temperature curve corresponds to the temperature of the metal surface of the upper plate (4) of the filter.

[0044] The intermediate temperature curve corresponds to the temperature of the plastic surface of the lower plate (3) of the filter.

[0045] Evidently, between the fumes (F) from the hob and the lower plate (3) of the grease filter there is a smaller thermal gap (G1 ) than the thermal gap (G2) between the fumes (F) from the hob and the upper plate (4) of the grease filter.

[0046] In view of the above, the formation of condensation on the lower plate (3) is minimized, thus avoiding the condensation dripping onto the hob, and the formation of condensation on the upper plate (4) is maximized. However, the condensation formed on the upper plate (4) is detached from the upper plate and falls into the cavity (I) between the lower plate (3) and the upper plate (4) and is then conveyed towards the collection receptacle (2).

[0047] With reference to Figs. 4A and 4B, the holes (30) in the lower plate (3) are designed to convey fumes (F) into the cavity (I) between the lower plate (3) and the upper plate (4) and to generate turbulence in the cavity (I) between the lower plate and the upper plate.

[0048] For such a purpose, the holes (30) in the lower plate are substantially elliptical slots with a major axis of about 12-16 mm and a minor axis of 5-9 mm.

[0049] Each hole (30) in the lower plate has an edge consisting of a collar (31 ) that protrudes towards the inside of the filter. The holes (30) have a tapered rounded opening (32) to better convey the air, which continues with a rectilinear portion at 90° to purposely cause the detachment of the limit layer of the fluid, generating turbulence (33).

[0050] The fumes (F) enter the holes (30) in the lower plate and generate turbulence (F1 ) in the cavity (I) between the lower plate and the upper plate, causing the detachment of suspended particles (P) of water and grease on the upper plate (4), which fall on the inner surface of the lower plate (3) and flow towards the collection receptacle (2).

[0051] The upper plate (4) is specially made of a metal material to favor the formation of condensation and suspended particles (P) due to the thermal gap (G2) between the upper plate (4) and the fumes, which is greater than the thermal gap (G1 ) between the lower plate (3) and the fumes.

[0052] With reference to Fig. 4 and 4A, the lower plate (3) has a plurality of grooves (35) on the outer surface, namely on its down-facing surface. The grooves (35) are directed towards the collection receptacle (2).

[0053] By way of example, the holes (30) are aligned in rows in the direction towards the collection receptacle (2). The grooves (35) are arranged between the rows of holes (30).

[0054] Each groove (35) comprises a rectilinear primary channel (36) that extends substantially for the entire length of the lower plate. In addition, in order to optimize the effect of the technical solution described herein, each groove (35) may have a plurality of secondary channels (37) that flow into the primary channel (36).

[0055] By way of example, without any limiting purpose, each groove (35) has a herringbone shape comprising a rectilinear primary channel (36) extending substantially for the entire length of the lower plate and a plurality of secondary channels (37) flowing into the primary channel (36). By way of example, the secondary channels (37) are oriented like arrows with respect to the primary channel (36) in the direction of the flow towards the collection receptacle (2). Each secondary channel (37) begins between two adjacent holes (30) and ends in the primary channel.

[0056] By way of example, without any limiting purpose, each groove (35) may also have a branched shape.

[0057] The primary channel (36) and the secondary channels have a width of 1 .5-2.5 mm.

[0058] The purpose of the grooves (35) is to channel the condensation droplets that are still attached to the outer surface of the lower plate (3) and tend to aggregate to form water droplets. In such a way, before forming a drop that would inevitably fall on the hob, the droplets are aggregated with each other and, finding the grooves (35) nearby, are conveyed and flow towards the collection receptacle (2) where they are collected.

[0059] The peculiarity of the grooves (35) is their capability to convey the maximum quantity of micro condensation drops due to the fact that the grooves (35) have a single channel, herringbone, branched shape, covering the majority of the external surface of the lower plate.

[0060] With reference to Figs. 5, 6 and 6A, the upper plate (4) comprises a plurality of slots (40) alternating with a plurality of covers (41 ). The slots (40) and covers (41 ) extend substantially along the entire length of the upper plate (4).

[0061] The covers (41 ) are arranged in register with the rows of holes (30) in the lower plate. In this way, the fumes (F) that enter the holes (30) in the lower plate hit the covers (41 ) of the upper plate and exit through the slots (40) in the upper plate. With reference to Fig. 6A, each cover (41 ) of the upper plate has the shape of an equilateral trapezoid in cross section and comprises a central portion (42) and two lateral wings (43) sloping with respect to the central portion (42). In view of the above, the fumes (F) enter the holes (30) in the lower plate, hit the central portion (42) of the covers (41 ) of the upper plate and follow a sinuous path (F2) around the lateral wings (43) to exit through the slots (40) in the upper plate.

[0062] Equivalent variations and modifications may be made to the present embodiment of the invention by a technician in the field, while still falling within the scope of the invention as expressed by the appended claims.

Claims

CLAIMS1. Anti-drip system (100) for a kitchen hood (200), comprising:- a collection receptacle (2) suitable for receiving the condensation formed in the hood, and- a grease filter (1 ) suitable for being arranged in the hood (200) in an inclined position with respect to a horizontal plane, so as to make the condensation generated inside the grease filter flow toward said collection receptacle (2), wherein said grease filter (1 ) comprises:- a lower plate (3) made of non-metallic material having a thermal conductivity X less than 1 W / mK, and- an upper plate (4) made of sheet metal; characterized in that the lower plate (3) has a plurality of grooves (35) on the outer surface, that is to say on the downward-facing surface; said grooves (35) being directed toward the collection receptacle (2).

2. The anti-drip system (100) according to claim 1 , wherein said lower plate (3) is made of plastic material.

3. The anti-drip system (100) according to claim 2, wherein said lower plate (3) is made of technopolymer.

4. The anti-drip system (100) according to claim 3, wherein said lower plate (3) is made of thermoplastic polyester, such as polybutylene terephthalate (PBT).

5. The anti-drip system (100) according to any one of the preceding claims, wherein a cavity (I) is defined between said lower plate (3) and said upper plate, wherein the condensation flows toward said collection receptacle (2).

6. The anti-drip system (100) according to any one of the preceding claims, wherein said lower plate (3) has holes (30) for the entrance of fumes (F) from a hob and said upper plate (4) has slots (40) for the exit of fumes from the interior of the grease filter.

7. The anti-drip system (100) according to claim 6, wherein the holes (30) of the lower plate have the shape of substantially elliptical slots.

8. The anti-drip system (100) according to claim 6 or 7, wherein each hole (30) of the lower plate has an edge formed by a collar (31 ) that protrudes toward the interior of the filter.

9. The anti-drip system (100) according to any one of the preceding claims, wherein the holes (30) of the lower plate are aligned in rows in the direction toward the collection receptacle, and the grooves (35) are arranged between the rows of holes (30).

10. The anti-drip system (100) according to any one of the preceding claims, wherein each groove (35) has a herringbone shape comprising a rectilinear primary channel (36) extending substantially for the entire length of the lower plate and a plurality of secondary channels (37) flowing into the primary channel (36).

11. The anti-drip system (100) according to any one of the preceding claims, wherein the upper plate (4) comprises a plurality of slots (40) alternating with a plurality of covers (41 ); the slots (40) and the covers (41 ) extend substantially for the entire length of the upper plate (4); and the covers (41 ) are arranged in register with the rows of holes (30) of the lower plate.

12. The anti-drip system (100) according to claim 11 , wherein each cover (41 ) of the upper plate has an equilateral trapezoid shape in cross-section and comprises a central portion (42) and two lateral wings (43) sloping from the central portion.

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