Extractor hood

Abstract

The invention relates to an extractor hood for a kitchen unit comprising: - a suction member; - a body (1) having an internal volume that is placed under negative pressure by the suction member and a wall formed by a filtration panel (10) comprising a rear surface (102) facing the internal volume of the body (1) and a front surface (101) opposite the rear surface (10) through which air is discharged to the internal volume of the body (1); - a device for applying liquid to the filtration panel (10); characterised in that the front surface (101) of the filtration panel (10) is facing upwards and in that the liquid application device is configured to apply the liquid to the front surface (101).

Description

[0001] "Extraction hood"

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to an extractor hood and a kitchen installation comprising such a hood. In particular, a hood for professional use is presented, equipped with a liquid duplication system, such as water, preferably comprising a tank and a recycling pump. The invention relates to the field of equipment for extracting and filtering fumes and greasy vapors.

[0004] It is particularly suitable for use in extractor hoods for catering and restaurants.

[0005] STATE OF THE ART

[0006] The catering industry is increasingly equipping itself with cooking equipment (charcoal ovens, open grills, rotisseries) that uses heavy fuel (charcoal). The significant heat load produced by this cooking method generates large quantities of smoke, grease and carbon particles at high temperatures.

[0007] Consequently, it is mandatory to pay particular attention to cleaning, maintenance and prevention of the risk of fire that these cooking devices can cause.

[0008] To try to overcome these constraints, there are currently two types of hoods on the market in which a water mist is sprayed.

[0009] In both existing cases, the water is sprayed after an initial stainless steel filter. An existing model is equipped with spray nozzles operating using the pressure of the water supply network. This first method has several major drawbacks:

[0010] - the sprayed water is not recovered, and flows directly into the drain; thus this method generates excessive water consumption which can easily reach 90 m 3 per month for a medium-sized restaurant.

[0011] - spray injectors must be replaced regularly as they become clogged with scale.

[0012] - the water mist is partly sucked into the ducts; this causes sealing problems. To recover as much water mist as possible, it is necessary to install droplet separators which become clogged and require a lot of maintenance; in addition, droplet separators generate a significant pressure drop on the suction, which requires increasing the power of the extractors, leading to increased electricity consumption.

[0013] The second existing model is also equipped with spray nozzles positioned behind the filters. However, this one operates in a closed circuit. The recovered water is directed to a tank equipped with a filter and a recycling pump.

[0014] This process also has several major drawbacks:

[0015] - the spray injectors must be replaced even more regularly because they become clogged with scale and grease and carbon particles that have not been properly filtered from the recycled water.

[0016] - the water mist is partly sucked into the ducts; this causes sealing problems.

[0017] - to recover as much water mist as possible, it is necessary to install droplet separators. These become clogged and require a lot of maintenance. As in the other model, droplet separators generate a significant pressure drop on the suction, which requires increasing the power of the extractors, leading to increased electricity consumption.

[0018] - it is necessary to install a bulky tank near the hood and to make the pipe connections between the hood and the tank.

[0019] There is a need to offer a hood that overcomes all or part of the disadvantages of current techniques.

[0020] SUMMARY

[0021] To achieve this objective, according to one embodiment, an extraction hood for kitchen installation is provided, comprising: an extraction member;

[0022] - a body whose internal volume is put under depression by the suction member and one wall of which is formed by a filtration panel which comprises a rear face directed towards the internal volume of the body and a front face opposite the rear face and through which air is extracted towards the internal volume of the body; a device for applying liquid to the filtration panel; characterized in that the front face of the filtration panel is oriented upwards and in that the liquid application device is configured to apply the liquid to the front face.

[0023] Counterintuitively, the proposed orientation of the front face leads to a "re-entrant" configuration of the filtration panel, with a progressive narrowing of the internal volume of the body at this level. Thanks to this orientation, the liquid, particularly water-based, can be applied to the front face. The action of the water is more effective, because it is upstream of the hood, which allows immediate treatment of the charges present in the air and any possible sparks. The air entering the body is therefore already purified, the filtration panel is moistened and regularly cleaned by the liquid and the latter constitutes an element of protection against flames and heat for the entire hood.

[0024] According to an advantageous possibility, the hood comprises a liquid reservoir; it can be positioned under the body of the hood, below it; it can be attached to a technical compartment, for example containing a liquid recirculation pump. Both the technical compartment and the reservoir can be arranged immediately below the body; preferably, they do not protrude from this body, in depth and / or in width of the hood. The base wall of the body preferably serves as a top wall for the reservoir and / or the technical compartment containing the pump.

[0025] Another aspect relates to a kitchen installation comprising at least one cooking appliance and a hood as indicated above. Preferably, the hood is arranged above the cooking appliance.

[0026] Another aspect relates to an extraction method comprising applying a liquid to a front face of a filtration panel of a hood.

[0027] BRIEF DESCRIPTION OF THE FIGURES

[0028] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

[0029] Figure 1 represents a sectional view of a hood according to one embodiment. Figure 2 represents a perspective view according to this same embodiment.

[0030] Figure 3 shows a perspective view of a filtration panel and a liquid application device.

[0031] Figure 4 shows a perspective view of a liquid application device.

[0032] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications.

[0033] DETAILED DESCRIPTION

[0034] Before commencing a detailed review of embodiments of the invention, optional features which may optionally be used in combination or alternatively are set out below:

[0035] - the body 1 comprises a base wall 21 in fluid communication with the front face 101 of the filtration panel 10, the hood comprising a liquid reservoir 18 capable of receiving the liquid by gravity flow from the base wall 21;

[0036] - the reservoir 18 is located at least partially below and facing the base wall 21;

[0037] - a liquid recirculation system is included from the reservoir 18 to the application device;

[0038] - the application device comprises a ramp 9 extending transversely relative to the front face 101 and configured to apply a blade of liquid to the front face 101;

[0039] - the ramp 9 is positioned at the level of an upper edge of the front face 101;

[0040] - the ramp 9 has a liquid outlet slot whose width is less than or equal to 1 mm and / or greater than or equal to 0.3 mm;

[0041] - the filtration panel 10 is a baffle filter defining corridors directed from top to bottom on the front face 101;

[0042] - a gutter 12 projects beyond the lower edge of the front face 101 of the filtration panel 10 and is configured to receive the liquid applied to the front face 101;

[0043] - the front face 101 has an acute angle relative to the horizontal greater than or equal to 60° and / or less than or equal to 80°.

[0044] Figure 1 illustrates a cross-sectional view of a hood according to one embodiment of the invention. This hood can be fitted to a kitchen installation and in particular be positioned above an area where cooking is carried out. This can be an oven, a barbecue, a griddle, or any other cooking appliance. The hood allows fumes to be extracted. Figure 1 shows a typical solution in which the hood comprises a fairing extending from a rear area A, for example at the level of a wall of the kitchen against which the cooking appliance is positioned, to a front area B which corresponds to the front of the hood. Typically, there is a recess reducing the height dimension of the fairing from the rear area A to the front area B so as to form a volume for confining the fumes while freeing up space overhead for the personnel involved.

[0045] The hood fairing delimits a space for positioning the components allowing the suction of the air containing the fumes. In particular, a body 1 forms a space for receiving the sucked air at the rear of a filtration panel 10 forming an air intake surface in the hood. The suction is produced by any common means for putting the volume of the body 1 under depression, for example with a suction plenum 2 whose mouth is connected to an air exhaust duct advantageously equipped with an extraction fan.

[0046] The filtration panel 10 comprises a front face 101 through which the air is admitted and a rear face 102, which is opposite the front face and which is located in the volume of the body 1. It is understood that the filtration panel 10 is configured to filter the air received in the hood, in particular to retain particles such as particles of grease or materials resulting from combustion.

[0047] For example, a filtration panel can be implemented comprising a peripheral frame visible in Figure 3 and having juxtaposed plates each having filtration elements. On the front face, the plates can be in the form of juxtaposed profiles 103 delimiting between them longitudinal grooves and extending on the front face 101 from top to bottom. The interlocking of the profiles creates a system of baffles making it possible to trap particles and slow the entry of air to allow suitable filtration. Such filters are also called shock filters. They are typically made of stainless steel.

[0048] Preferably, the filtration panel 10 may be wholly or partly removable, for example by removing individual filter parts along the filtration panel, so as to access the interior volume of the body 1. Figure 2 reveals this possibility in a perspective view in which a part of the filtration panel 10 is shown, but also in which another part is removed so as to access the volume of the body 1. It is understood that this access allows easy maintenance and cleaning. As can be seen in Figure 1, the filtration panel 10 has an inclination such that the front face 101 is directed upwards. Usually, the inclination of the filtration panel 10 follows the same arrangement as the fairing, so that the interior volume of the body 1 widens upwards.The configuration adopted here is the opposite, in that the filtration panel 10 tends to enter the interior volume of the body 1 upwards. Thus, the depth of the body 1 is greater at the bottom than at the top. It is understood that, in this way, water or another liquid can flow onto the front face 101 from an area located towards the top of the panel 10 towards the bottom of the panel. This arrangement is, in this sense, completely opposite to the state of the art which provides for spraying on the rear face 102.

[0049] The figures represent an example of a liquid application device, at the upper edge of the filtration panel 10. In a simple manner, a liquid consisting of or based on water can be used; it can be water with at least one additive, for example a disinfectant and / or a degreaser. According to one option, a disinfectant and / or degreaser product is arranged, for example in the form of pebbles, in the volume of the body so as to gradually treat the circulating liquid.

[0050] Preferably, the liquid application device is configured to produce a laminar flow from its mouth. More specifically, as shown in Figure 4, the liquid outlet may be in the form of a ramp 9 extending transversely to the filtration panel 10 and whose mouth is located close to the upper edge of the panel 10. Preferably, the width dimension of the ramp 9 is identical to the width dimension of the filtration panel 10. The liquid outlet slot may have a width (here extending along the height of the panels) less than or equal to 1 mm. This allows good efficiency in producing a laminar flow, that is to say a homogeneous and continuous distribution of the liquid outlet over the entire width of the ramp 9. According to one possibility, this width is greater than or equal to 0.3 mm.This allows for a significant quantity of liquid to flow through the ramp 9 while remaining within dimensions that facilitate maintenance, in particular by reducing, or even eliminating, scaling problems.

[0051] Preferably, the liquid application device is configured to produce retention upstream of the outlet slot of the ramp 9. According to one example, to achieve this, a buffer tank 8 equips the ramp 9 and this volume is supplied with water via a tube 7; in the example shown, the tube 7 is then connected to a supply conduit of the buffer volume 8 so as to distribute the liquid inlet into the ramp 9. The buffer volume 8 is larger than that of the slot of the ramp 9 so that the liquid is distributed in the buffer volume 8 to supply the ramp over its entire width.

[0052] This produces a preferably continuous application over the entire width of the filtration panel 10.

[0053] In their illustrated embodiments, the profiles 103 of the filtration panel 10 produce intermediate spaces promoting the flow of the liquid from top to bottom, along the front face 101. Thus, a cascade fountain effect is produced, with a regular flow watering the front face 101. Thus, preferably, the application of liquid is not a spraying of droplets, but a flow, preferably laminar, along the front face 101. According to one possibility, the flow rate of the pump can be greater than or equal to 10001 / h per linear meter of ramp and / or less than or equal to 20001 / h per linear meter of ramp. For example, for a hood with a width of 2 meters, a flow rate of the recycling pump which will make it possible to obtain a homogeneous and regular sheet of water is 3200 liters / hour.

[0054] For this flow rate, the tank capacity is advantageously 60 liters.

[0055] In the lower part of the front face 101, the liquid is preferably recovered at a base wall 21 of the body 1 of the hood. Preferably, the lower part of the frame of the filtration panel 10 comprises one or more openings 104 through which the liquid can flow towards the interior of the body 1. Preferably, as shown in FIG. 1, a gutter 22 projects outwards at the base of the front face 101 so as to ensure the recovery of the liquid; advantageously, the gutter 22 has an inclined face configured to direct the liquid towards the base wall 21 through the openings 104.

[0056] To partition the water, or another liquid, in the volume of the body 1, and in particular to prevent the passage of droplets towards the plenum 2, a separator 3 is arranged in the upper part of the panel 10, on the side of its rear face 102. This separator 3 can have the form of a flap extending over the entire width of the rear face 102. In this way, an upward movement of droplets is prevented; the water impacting this surface condenses and falls back onto the wall 21.

[0057] Another aspect of the invention is to provide a compact arrangement for ensuring the circulation of the liquid. Preferably, the hood operates in a closed circuit, which involves recovering the liquid which has sprayed the front face 101 of the panel 10 to reinject it at the level of the ramp 9.

[0058] For this purpose, the base wall 21 is in fluid communication with a reservoir 18 arranged under this wall, as shown in Figure 2. Preferably, at least one opening is made in the wall 21 so as to allow the liquid to descend. As shown in Figure 2, a filter basket 11 is advantageously arranged at this level to filter the liquid after its action of cleaning the front face 101 of the panel 10.

[0059] Preferably, the tank 18 is entirely arranged under the wall 21, that is to say under the body 1 of the hood; this arrangement is particularly compact and avoids the need for a remote tank. Preferably, the tank 18 has a depth less than or equal to that of the wall 21 of the body 1.

[0060] In the embodiment shown in the figures, a pumping compartment is made juxtaposed with the reservoir 18, preferably by exploiting the width dimension of the filtration panel 10. The pumping compartment participates in the recirculation of the liquid. For this purpose, it comprises a suction duct 6 whose mouth is arranged in an accessible manner from the reservoir 18 so as to pump the liquid from the reservoir 18. The pump 20 is visible in Figure 2 and ensures the rise of liquid through the tube 7, up to the ramp, as described previously.

[0061] Advantageously, the pumping compartment also comprises a discharge tube 13 having an opening in the reservoir 18 and a discharge to the outside. In addition, a solenoid valve 12 is advantageously present to vary the liquid circuit configurations. In particular, when emptying of the reservoir 18 is desired, the solenoid valve 12 is controlled so as to pump the liquid from the reservoir 18 through the tube 13.

[0062] To ensure monitoring of the proper functioning of the system and to take any corrective or signaling actions in the event of a fault, a sensor 15 detecting a low level for the operation of the pump and / or a sensor 16 for the low filling level of the tank 18 and / or a sensor 17 for the high filling level of the tank 18 is also advantageously provided.

[0063] Also, one option is an overflow 14 whose mouth is located projecting from the base wall 21 so that, if the liquid rises on the wall 21 beyond the height of the projection, the overflow can be discharged through the distal portion of the tube 13.

[0064] Preferably, the technical compartment is kept sealed relative to the tank 18 and is regularly ventilated via a ventilation chimney 4.

[0065] In use, the liquid is pumped so as to circulate in the tube 7 to supply the ramp 9. The flow of water is regular and in the form of a blade which is applied by the top of the front face 101 of the filtration panel 10. A portion of the water passes through the filtration panel. Another portion descends by gravity along the entire length of the front face 101 and is recovered by the gutter 22 to reach the base wall 21 of the body 1. The water passes through the opening and the filter basket 11 to then be reinjected by means of the pump via the suction tube 6.

[0066] In summary, a hood is proposed here in which the position of the filtration panel 10 is reversed compared to what is known so far. The water spray which is usually introduced after the filters and which therefore never moistens the filters is positioned upstream of the filters.

[0067] Advantageously, it is no longer a question of spraying using injection nozzles, but of a very abundant cascade flow which is introduced by a fountain-type water blade from the upper part of the filters. While it was thought until now that spraying was necessary to distribute the water on the surface of the filter and to limit its consumption, the present invention takes a contrary approach with abundant watering coupled, preferably, with recirculation of the liquid.

[0068] In addition to continuously moistening the entire surface of the filters, this high water flow allows the filters to be rinsed and kept clean.

[0069] Since these are no longer injection nozzles that are sensitive to the phenomenon of clogging by scale or impurities, the water blade having a relatively wide section is not likely to encounter clogging problems.

[0070] Furthermore, unlike nozzles which spray a highly volatile water mist which must be intercepted using droplet separators so that it is not drawn into the air intake flow, the low-volatile water layer diffused from the upper part of the front face of the filters is not or is unlikely to be drawn into the ducts, especially since the filter itself constitutes a droplet separator.

[0071] The water blade diffused over the entire surface of the filters also helps to cool and reduce fumes much more effectively than spraying a simple water mist.

[0072] While current techniques apply a completely separate design for the extractor hood and the filtration unit, the present invention also has the principle of combining the two pieces of equipment. To achieve this, the liquid recovery tank also includes a filter and a circulation pump which are directly assembled in the bottom of the hood. With this level of integration, the assembly is compact and installation is greatly facilitated; in particular, there is no need for a remote tank or complex connection to a water drain.

[0073] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention. DIGITAL REFERENCES

[0074] 1. Hood body

[0075] 2. Suction plenum

[0076] 3. Droplet separator

[0077] 4. Ventilation chimney

[0078] 5. Tank filling pipe

[0079] 6. Suction duct

[0080] 7. Pump outlet tube

[0081] 8. Buffer volume

[0082] 9. Ramp

[0083] 10. Filtration panel

[0084] 101. Front face

[0085] 102. Back side

[0086] 103. Profile

[0087] 104. Opening

[0088] 11. Filter basket

[0089] 12. Solenoid valve

[0090] 13. Drain tube

[0091] 14. Overflow

[0092] 15. Low level safety sensor for pump

[0093] 16. Low liquid fill level sensor

[0094] 17. Liquid fill high level sensor

[0095] 18. Tank

[0096] 19. Support

[0097] 20. Pump

[0098] 21. Base wall

[0099] 22. Gutter

[0100] A. Back area

[0101] B. Front Zone

Claims

CLAIMS 1. Extractor hood for kitchen installation, comprising: a suction member; a body (1) whose interior volume is depressurized by the suction member and whose wall is formed by a filtration panel (10) which comprises a rear face (102) directed towards the interior volume of the body (1) and a front face (101) opposite the rear face (10) and through which air is extracted towards the interior volume of the body (1); a device for applying liquid to the filtration panel (10); characterized in that the front face (101) of the filtration panel (10) is oriented upwards and in that the liquid application device is configured to apply the liquid to the front face (101).

2. Hood according to the preceding claim, in which the body (1) comprises a base wall (21) in fluid communication with the front face (101) of the filtration panel (10), the hood comprising a liquid reservoir (18) capable of receiving the liquid by gravity flow from the base wall (21).

3. Hood according to the preceding claim, in which the reservoir (18) is located at least partially below and facing the base wall (21).

4. Hood according to any one of the two preceding claims, comprising a system for recirculating the liquid from the reservoir (18) to the application device.

5. Hood according to any one of the preceding claims in which the application device comprises a ramp (9) extending transversely relative to the front face (101) and is configured to apply a blade of liquid to the front face (101).

6. Hood according to the preceding claim, in which the ramp (9) is positioned at an upper edge of the front face (101).

7. Hood according to either of the two preceding claims, in which the ramp (9) has a liquid outlet slot whose width is less than or equal to 1 mm and / or greater than or equal to 0.3 mm.

8. Hood according to any one of the preceding claims, in which the filtration panel (10) is a baffle filter defining corridors directed from top to bottom on the front face (101).

9. Hood according to any one of the preceding claims, comprising a gutter (12) projecting beyond the lower edge of the front face (101) of the filtration panel (10) and configured to receive the liquid applied to the front face (101).

10. Hood according to any one of the preceding claims, in which the front face (101) has an acute angle relative to the horizontal greater than or equal to 60° and / or less than or equal to 80°.

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