EP1194721B1 - Air extraction device for a workplace - Google Patents

Abstract

This invention relates to an air extraction device (12) for a work station (14), especially one where food is subjected to heat, for example a grill. One air inlet (36, 38) each is provided on each side of the work station (14), said inlets being connected to a fan (26) and a filter system (28) and communicating with them and with an area (42) disposed above the work station (14) in a closed air cycle (48) that produces an air blast (44) in said area. About 75% of the air are continuously discharged from the air cycle via an air discharge (50) so that only 25% of the air form the air blast (44). The discharged portion of the air is continuously replaced by taking in ambient air via the down-stream air inlet (38) and/or via a separate, additional air inlet (63). The filter system (28) is provided with a grease trap filter (30) upstream of the fan and an odor filter (32) downstream of the fan. The inventive air extraction device prevents odors and grease from reaching the surroundings of the work station and allows for a simple and unproblematic maintenance of the filters.

Description

The invention relates to an air suction device in the Claim 1 specified Art.

A similar air extraction device is in combination with a grill from FR-A-2619198 known, which will be discussed in more detail below.

Nowadays it turns out in the gastronomy, especially in the System catering, and for the catering in Canteens and the like, so in cases where the guest is served itself, often the requirement that before the Eyes of guests being cooked, grilled or fried. With this So-called front cooking, the problem arises that the resulting vapors must be extracted. Because often no stationary extractor hoods available or suitable are and often are not portable extractor hoods A mobile kitchen station is already available or can be used (see the SMOG-STOPP brochure from Bohner the year 2000) and a stationary kitchen module (see the essay "Odorless in front of the guests' eyes" in the magazine Cooking practice and catering, October 1999, p. 52) have been developed with an air extraction device in the Preamble of claim 1 provided type are. In the known air extraction device, the two serve Air vents on both sides of the workplace where it is each is a grill, for edge suction. There is suctioned off the two side edges of the workplace, the suction effect above the center of the workplace is natural relatively low. It therefore becomes a large area above of the workplace through the one sucked into the edges Airflow not detected effectively. A particular disadvantage the edge suction is that unpurified room air partially over the workplace is vacuumed. In addition, the well-known Air extraction device in a base under the workplace several pre-filters for integrated odor control Fleece filter and several activated carbon filters, between which one double sided suction gate is arranged. The whole the lower surface of the substructure takes up a grease drip tray. This filter system is labor-intensive and cost-intensive, because the activated carbon filters have to be replaced frequently and represent an environmental impact.

An odor extraction device known from DE 24 02 615 A1 comes with a simpler filter system for fat separation and odor removal, however an intake funnel with a grease retention filter above the Workplace used, which is an upward-facing Airflow requires an air curtain to shield the air Generate work place.

From US-A-3 260 189 a ventilation system is known from the one above the workplace diagonally towards the workplace inclined suction device provided with several grease filters is. On one side of the workplace from one Air leakage air is thus over the workplace passed obliquely upwards to the suction device. moreover are not special in this known ventilation system Precautions to eliminate odors.

From the FR-A-2619198 already mentioned at the beginning is a grill with an air suction device known, each with an air opening on both sides of the grill, with a fan and a filter system are connected, the air openings, the blower, the filter system and an area between the air vents and just above the grill lie in a closed air circulation circuit that is in operation of the air extraction device in the area between the air opening on an upstream side of the Grills and the air vent on a downstream side of the grill creates an air curtain, wherein the filter system is housed in a room in the air circulation circuit lies and is connected to the air openings on both sides of the grill, the Air circulation circuit via an air outlet for part of the air from the air circulation circuit has, and wherein the air outlet downstream of the fan and the filter system is arranged. On the upstream and downstream side of the grill a sideboard is provided on which dishes can be placed. The sideboard on the upstream side has warming plates, the underside with hot Circulating air can be heated. The air outlet is adjustable and is used to set the temperature the circulating air and therefore the temperature of the warming plates. Of the blower is only the impeller is arranged in the space which is in the air circulation circuit. The Blower motor is outside of the hot air circulation circuit in the circulating air external environment arranged to ensure the cooling of the engine. Below the warming plates are arranged on the upstream side of the grill, a hard glass plate, which is horizontally slidable to adjust the flow of the upstream Allow air to escape. The upstream side of the grill is more or less through the tempered glass plate instead of through the air curtain covered.

The object of the invention is in an air extraction device of the type mentioned to improve the suction so that the suction process effectively covers the entire work area and that food in the workplace is not uncleaned Air come into contact.

This object is achieved by an air suction device solved with the features specified in claim 1.

In the air suction device according to the invention, a Air circulation circle formed, which extends over the entire workplace extends over which it creates an air curtain. The air curtain is formed by air coming from the Air opening flows out on one side of the workplace and into the air vent on the opposite side of the workplace flows. According to the air extraction device The air curtain produced according to the invention thus covers the entire Area above the workplace. The air that the Air curtain is circulating air, i.e. Air that only over the Workplace flows after being sucked by means of the suction fan has been sucked through the filter system, i.e. cleaned Air. The compact housing of the blower and the Filter system in a special room, which is in the air circulation circuit lies and with the air openings on both sides the workplace is connected via at least one vertical air duct, made possible with the air extraction device according to the invention, within a limited space of the air circuit to separate grease from the air and rid them of smells at the same time. With the air extraction device According to the invention, the air to be cleaned sucked through the grease trap filter and through the odor filter pressed. Because a grease trap filter and an odor filter can have different pressure drops through the arrangement of these two filters according to the invention upstream or downstream of the fan, the speed of the air can be optimally set for the respective filter.

Since further in the air extraction device according to the invention Air circulation circuit via an air vent for one part the air from the air circulation circuit can be a Part of the air in the air circulation circuit constantly through Room air to be replaced, which then also first by the Filter system is passed through before it to form the Contributes to the air curtain over the workplace. Since continue with the air extraction device according to the invention the air discharge one has adjustable in size opening, the Proportion of fresh room air in the air circulation circuit adjust as required. Since further with the air suction device according to the invention the air outlet downstream of the fan is arranged; the air has passed the filter system and is thus already cleaned before being released into the environment becomes. Since further with the air extraction device according to the invention the blower between at least two filters of the filter system is arranged, the blower is before contamination protected. Furthermore, since the filter is upstream of the blower Grease trap filter and the filter downstream of the fan is an odor filter, especially the blower will not is affected by air laden with grease and is to that Recirculated air returned to the workplace not only greasy but also odorless.

It is known per se from DE 473 883 C, in one Facility to protect workspaces from the open Vapors escaping and other impurities in the Air is generated by an air curtain at the same time of the air flow and fan used to remove the vapors to provide, the suction nozzle in one over the edge a hopper arranged funnel opens out while its discharge nozzle, that on the opposite edge of the container has a nozzle directed towards the funnel, one Exhaust duct branches, are in this known device however, no precautions for fat separation or odor removal met. The exhaust duct is simple into the open.

Advantageous embodiments of the air suction device according to the invention form the subject of the dependent claims.

If in one embodiment of the air extraction device according to the Invention that the blower is a radial blower, both result constructive as well as fluidic advantages the formation of the air suction device.

If in a further embodiment of the air suction device the invention the grease separating filter is a cyclone filter, as he e.g. is manufactured by Rentschler & Reven, 99.5% of the air that is extracted Separate fat. Furthermore, such a filter is very easy to maintain, because it can easily be put in a dishwasher washed out and then reinserted.

If in a further embodiment of the air suction device of the invention under the grease trap filter a grease drip pan is attached, this can be done by the fat separating filter Easily collect separated fat.

If in a further embodiment of the air suction device Odor filter is a zeolite filter, so the odor filter can easily regenerated, is therefore particularly maintenance and environmentally friendly.

If in a further embodiment of the air suction device the invention the air circulation circuit in the area below of the workplace has a further vexical air duct, over the the room in which the flour fan and the filter system are housed, with the other of the two air openings on both sides of the workplace connected, can be in the space between the vertical air ducts conveniently for heat application equipment required by food such as a hob or grill plate with the electrical power supply in addition to the assigned control device.

If in a further embodiment of the air suction device the invention of the room in which the blower and the filter system are housed, arranged to the side of the workplace is the way the one loaded with fat and smells Air from the downstream air opening of the workplace has to cover up to the filter system, minimal, so that the possibilities of pollution of the air suction device are minimal through fat.

If in a further embodiment of the air suction device the invention of the grease trap filter and the odor filter are inclined to the vertical ', constructive results and fluidic advantages because of the space between the two filters to accommodate the fan can be exploited or because the filter effect in this constellation is particularly good.

If in a further embodiment of the air suction device the invention of the grease trap filter at an angle of 40 is inclined to 50 °, preferably 45 °, against the vertical and if in yet another embodiment of the air extraction device according to the invention of the odor filter at an angle of 30 to 40 °, preferably 35 °, inclined to the vertical is particularly constructive and fluidically great advantages, which can be demonstrated with a prototype to let.

If in a further embodiment of the air suction device of the invention in the room in which the blower and the filter system are accommodated by the two filters one Antechamber or a post-chamber are divided, the one below of the workplace or space available next to the workplace particularly well exploited.

If in a further embodiment of the air suction device the invention, the air outlet is arranged in a wall of the post-chamber is odor and grease-free air in the environment drain because this air is already the entire filter system has flowed through.

If in a further embodiment of the air suction device the invention the workplace is a grill that is above the room in which the blower and the filter system are housed or extends next to this room, show the fluidic achieved according to the invention Advantages, because the air curtain covers the entire area above the grill so that there are no smells when grilling fat can get into the surrounding space.

If in a further embodiment of the air suction device the invention of the air vent so designed or adjusted is that 75% of the air is released from the air circulation circuit and the remaining 25% as circulating air to the workplace get and form its air curtain, the will Room surrounding workplace particularly effective against smells and Protected against fat, because tests have shown that such Air curtain, which is only 25% of that originally in the Air circulation circuit contains sucked air completely on the downstream side of the workplace Air intake can be sucked in without causing air build-up comes before this air opening.

If in a further embodiment of the air suction device the invention at least one air inlet for sucking in ambient air in the air circulation circuit to replace the over the air discharge from the air circulation circuit into the environment vented air is provided, can be via the Location of these air intakes the addition of room air to replace the air discharged through the air vent as required Taxes. Through this air inlet, the inflow on the grease filter becomes Air volume increased. This reduces the vapor density, and at the same time the air temperature is lowered, which is both for an optimal efficiency of the odor filter is decisive. The reduction in vapor density prevented a brief saturation of the odor filter. The air intake causes a reduction in the vapor density, and thus associated is a temperature drop in the unfiltered air, which in turn is important for the effect of the odor filter especially if this is a zeolite filter is.

If in a further embodiment of the air suction device the invention of the air inlet the air opening on the downstream Side of the workplace, it is guaranteed that the cleaned air curtain covers the entire workplace, so no uncleaned ambient air to the food get to work and still let out the air can be replaced by fresh ambient air.

If in a further embodiment of the air suction device the invention of the air inlet downstream of the air opening on the downstream side of the workplace and upstream of the fan arranged additional air opening, the deflated air in the air circulation circuit replace as needed, without the air curtain and its effects over the workplace are impaired. The secondary air drawn in through the additional air opening causes the filter to process, with Vapors and smells laden air volume increased significantly becomes. Because of the air opening, the inflow on the grease filter becomes Air volume increased. This reduces the vapor density. At the same time, the air temperature is reduced. Both components are for an optimal efficiency of the Significant sizes of zeolite filters. The reduction in vapor density prevents a brief saturation of the Zeolite filter. So with strong fumes / odors Filter effect of the zeolite filter optimized. simultaneously the resulting increase in air volume leads to a reduction in temperature of the air extracted from the workplace, which is also advantageous for the optimal effect of the zeolite filter is. These advantages generally result from the previous one mentioned further embodiment of the air suction device according to the invention, according to which at least one air inlet for Intake of ambient air into the air circulation circuit to replace the air vent from the air circulation circuit air released into the environment is provided.

If in a further embodiment of the air suction device the invention integrates this with a kitchen workstation forms a kitchen module, this can be modular Cooking equipment program such as insert the varithek® system like it is known from DE 197 57 004 A1.

If in a further embodiment of the air suction device the invention, the two air openings with respect to each other are arranged that a symbolizing the air curtain Air jet axis towards the downstream air opening slightly is inclined downwards against the horizontal, so it looks light downward air jet of a thermal flow the forms better over the work surface than, for example a horizontal jet of air. In this there is the danger that the thermal flow grill and cooking steam over carries the effective area of the downstream air opening and thus they can not or only partially be recorded.

If in a further embodiment of the air suction device the invention the upstream air opening as a narrower Blow slot is formed and the opposite downstream Air opening as a much wider suction slot is designed, the detection effect, i.e. the Effect of the downstream air opening on the supplied air as complete as possible, optimize. Here will with a large distance between upstream and downstream Air opening of the blow slot preferably narrower executed than at a small distance between the two Air openings. The width of the suction slot is preferred larger with a large distance between the air openings trained than at a small distance.

If in a further embodiment of the air suction device the invention of the blow slot and the suction slot by air guide elements are formed in the vertical air channels, so can by the air guide elements in the vertical air duct the upstream air opening the upward flowing one Concentrate and redirect air, tapering the canal upwards and the deflection is designed to be streamlined are that turbulence is avoided as much as possible and the lowest possible pressure loss occurs. In the as a suction slot trained downstream air opening and one adjoining vertical air duct, the air is over Air guide elements deflected in the form of baffles and through this flow-optimized configuration has the detection effect of the suction slit significantly improved.

If in a further embodiment of the air suction device the invention of the blow slot slightly downwards against the horizontal is inclined and the suction slot at its opposite Inner walls are provided with radii, so can the detection effect of the trained as a suction slot optimize downstream air opening, preferably by radii on the upper and lower edge of the suction slot.

If in a further embodiment of the air suction device the invention is behind the downstream air opening extending section of the vertical air duct upwards is covered by an air guiding element, so that Flow detection of the downstream air opening optimize. The air guide element is preferably at a small work surface or a short distance between the upstream and downstream air openings as a radius at the top edge of the downstream air vent educated. With a large work surface or a large one The distance between the air openings is the air guiding element preferably S-shaped in the transition from the downstream Air opening to the vertical channel.

If in a further embodiment of the air suction device the invention with increasing size of the workplace and thus increasing distance between the upstream and the downstream air opening the covering upper air guide is increasingly shortened, it becomes part of the recording effect the downstream air opening is deflected upwards and optimized. This is due to the emergence an increasing amount of vapors due to an increasing Distance between the upstream and the downstream Air opening and one due to the thermal flow occurring upward deflected air jet of the upstream air opening.

If in a further embodiment of the air extraction device according to the invention the air guide element in cross section S-shaped is, this has the advantage that at a greater distance between the upstream and downstream air openings the transition from the downstream air opening to the vertical channel is fluidically optimized. In particular becomes the detection effect of the downstream air opening improved.

If in a further embodiment of the air suction device the invention the workplace above the air vents three pages, to which an operating page does not belong, from one Air baffle, in particular a splash guard, is surrounded, that from the operating side in the direction transverse to the air curtain and to the opposite side of the workplace increases in height, which is generated by the air opening on one side to the air opening on the other side of the workplace moving air stream (blow jet) in the Air curtains a stable vortex flow. This is an extension connected by air route. That in turn increases the absorption capacity of the vapors to be removed. A the air baffle plays an important role in this context, which in a further embodiment of the invention from a U-shaped There is a border plate that when grilling as Splash guard serves, but here in this embodiment of the invention additionally causes the creation of the aforementioned Eddy flow is guaranteed to be stable. Only through that geometric design of the air baffle or the splash guard according to the mentioned embodiment of the invention reached the optimal vortex flow. A special role plays the increase that results from the operator side the air baffle in the rear part of the workplace. This means that the shape of the aerodynamics is decisive affected.

Fig. 1 eine Prinzipskizze eines Küchenmoduls mit integrierter Luftabsaugvorrichtung nach der Erfindung,

Fig. 2 ein praktisches Ausführungsbeispiel des Küchenmoduls nach Fig.1,

Fig. 3 eine Einzelheit des Küchenmoduls nach Fig. 2,

Fig. 4 ein weiteres praktisches Ausführungsbeispiel des Küchenmoduls nach Fig. 1, bei dem aber der Arbeitsplatz wesentlich länger ist,

Fig. 5 eine Einzelheit einer Abwandlung des Ausführungsbeispiels nach Fig. 4,

Fig.6 ein Diagramm, in welchem der Abscheidewirkungsgrad eines Zyklonfilters über der Anströmgeschwindigkeit aufgetragen ist,

Fig. 7 ein weiteres Ausführungsbeispiel, bei welchem der Raum, in welchem ein Gebläse und eine Filteranlage untergebracht sind, seitlich neben dem Arbeitsplatz angeordnet ist,

Fig. 8 eine Abwandlung des Ausführungsbeispiels nach Fig. 7, bei welchem eine Einrichtung, mit der Lebensmittel mit Wärme beaufschlagt werden, wie z.B. ein Grill, ein Kochfeld od. dgl., höhenverstellbar ist, und

Fig. 9 in einer perspektivischen Teilansicht von oben eine abgewandelte Ausführungsform des Küchenmoduls mit integrierter Luftabsaugvorrichtung nach Fig. 1, bei der zusätzlich ein Spritzschutz oberhalb des Arbeitsplatzes auf den Küchenmodul aufgesetzt ist.

Embodiments of the invention are described below with reference to the accompanying drawings. It shows:

1 is a schematic diagram of a kitchen module with an integrated air extraction device according to the invention,

2 shows a practical embodiment of the kitchen module according to FIG. 1,

3 shows a detail of the kitchen module according to FIG. 2,

4 shows a further practical embodiment of the kitchen module according to FIG. 1, but in which the workplace is considerably longer,

5 is a detail of a modification of the embodiment of FIG. 4,

6 shows a diagram in which the separation efficiency of a cyclone filter is plotted against the flow velocity,

7 shows a further exemplary embodiment, in which the space in which a blower and a filter system are accommodated is arranged on the side next to the workplace,

Fig. 8 is a modification of the embodiment of FIG. 7, in which a device with which food is subjected to heat, such as a grill, a hob or the like, is height adjustable, and

9 is a perspective partial view from above of a modified embodiment of the kitchen module with an integrated air extraction device according to FIG. 1, in which a splash guard is additionally placed on the kitchen module above the work station.

Fig. 1 shows an overall designated by the reference number 10 Kitchen module with a total of 12 air extraction device. The air suction device 12 is a workplace 14 assigned to which food is heated become. Such a workplace can be a grill, a Hob or the like., So a workplace where smells and fat-laden vapors arise that are in the air must be extracted from the area of the workplace, if the environment of the kitchen module 10 is not affected by such vapors should be affected. Workplace 14, here one electric grill plate is inserted into a housing 16 and rests therein on pads formed on the inner walls of the housing 18. The housing encloses a superstructure 20 and one Substructure 22, between which an intermediate structure 23 for receiving of control devices, for example an electrical one Power supply or the like. Is provided. The substructure 22 contains a closed space 24 in which a blower 26, here a radial fan, and one with the reference number 28 designated filter system, here consisting of a Grease trap filter 30 and an odor filter 32, housed are. The kitchen module 10 can be moved on swivel castors 34. Air openings are on both sides of the workplace 14 provided, namely an upstream air opening 36 or a downstream air opening 38. From the downstream Air opening 38 leads a vertical air duct 39 in the closed Room 24. Introduces from the closed room 24 vertical air duct 40 to the upstream air opening 36. The air openings 36, 38, the blower 26, the filter system 28 and one between the air vents and just above the Work area 14 located area 42 are in a closed Air circulation circuit that operates the air extraction device 12 in the area 42 between the air opening. 36 and the air opening 38 of the workplace 14 an air curtain 44 generated. The air circulation circuit is through Air flow arrows 46 shown in solid lines and with short arrows, which are supposed to indicate the air curtain 44, shown and overall in the drawing and below designated with the reference number 48.

The air circulation circuit 48 has an air outlet 50 for a part 52 shown as a dashed arrow in FIG Releases air from the air circulation circuit. The vent 50 has an opening which is adjustable in size. The This opening can be adjusted by a next to the air outlet 50 shown double arrow 54 indicated. The vent 50 is arranged downstream of the blower 26.

The illustrated grease trap filter 30 is preferably a Cyclone filter. The odor filter 32 shown is preferred a zeolite filter. Of course, the filter system more than a grease trap filter and more than an odor filter exhibit. The blower 26 is preferably between arranged at least two filters of the filter system 28, which are preferably a grease trap filter, like the grease trap filter 30 upstream of the blower 26, and an odor filter such as the odor filter 32 downstream of the blower 26 is. Under the grease trap filter 30, a fat drip pan 56 is arranged. The closed one Space is in use of the kitchen module 10 on the front closed by a door which has been omitted in Fig. 1 to visualize the interior of the closed space 24.

The grease trap filter 30 and the odor filter 32 are inclined arranged against the vertical air channels 39 and 40, as shown in Fig. 1. The grease trap filter 30 is at an angle of 40 to 50 ° and preferably 45 °, as shown, against the associated vertical air duct 39 inclined. The odor filter 32 is at an angle of 3 ° to 5 °, as shown, against the assigned vertical Air duct 40 inclined.

The air channels 39 and 40 are at their 14 to the workplace opposite ends with a prechamber 58 and one respectively Post chamber 60 connected in the closed space 24th through the two filters 30, 32, i.e. through partitions on which these filters are attached, as shown in Fig. 1, are divided. The air vent 50 is in a bottom wall Post-chamber 60 arranged. The blower 26 is on an intermediate wall 62 attached so that its upstream side with the downstream side of the grease trap filter 30 and its downstream side with the upstream side of the Odor filter 32 is connected.

The air outlet 50 is so by choosing a fixed or adjustable Opening aperture or the like. Adjustable, that 75% of the air drained from the air circulation circuit 48 via the air outlet 50 and the remaining 25% as circulating air to the workplace 14 arrive and form its air curtain 44. The downstream one Air opening 38 into which the air curtain is due the suction effect of the blower 26, serves at the same time as an air inlet for drawing ambient air into the Air circulation circuit to replace the air vent 50 drained from the air circulation circuit into the environment Air. The air intake could also come from an air vent 63 exist, which are also on the downstream side of the Workplace 14 is provided, e.g. in the vertical Air duct 39 or, as indicated by dashed lines at 63, in Area of the antechamber 58. The air inlet 63 provided at least upstream of the grease separating filter 30 ambient air that is free of both grease and odor reaches the air curtain 44 via the air duct 40. The secondary air sucked in through the additional air opening 63 causes the filter to process Air volume laden with vapors and smells significantly increased becomes. This in turn has the effect that in the event of strong fumes / odors optimized the filter effect of the zeolite filter becomes. At the same time, the resulting increase in air volume leads to lower the temperature of those extracted from the workplace Air, which also ensures the optimal effect of the zeolite odor filter 32 is advantageous.

The filter system 28 from the cyclone grease filter 30 and the zeolite odor filter 32 is a completely easily regenerable Filter system: the grease separating filter 30 is in the dishwasher cleaned; the zeolite odor filter 32 desorbed at 200 ° C in the oven or in the combi steamer.

2 to 5 are practical embodiments of the Air suction device according to the generally described above Invention shown, which instead of the housing 16, the superstructure, Substructure and intermediate structure exists, a so-called System carrier 116 have the closed space below 24 and above, separated from it, the workplace 14, which consists of an electric grill plate. Fig. 2 shows the schematic structure of the system carrier 116 with a relatively small or short work place 14. The structural Details with the embodiment of FIG. 1st match, are not described again below. The same parts are the same in FIGS. 2 to 5 Reference numbers as in Fig. 1 provided. The air flow is again indicated by arrows. The differences of the embodiment 2 and 3 compared to the embodiment 1 are described in more detail below.

In the vertical air channels 39 and 40 in Fig. 2 are air guide elements 64, 65 and 66 arranged. The air guiding element 66 is a sheet that extends obliquely upwards, the top turns horizontally so that the air opening 36 acts as a blow slot is trained. The air guide element 66 forms with the Vertical an angle of preferably 13.7 °. The air control elements 64 and 65 are designed so that the air opening 38th is designed as a suction slot, the cross section of lights is much larger than that of the blow slot of the air opening 36th

In which due to the air guide 66 upwards tapered vertical air duct 40 becomes the upward flowing one Air bundled and redirected approximately horizontally. The rejuvenation of the air duct 40 upwards and the deflection aerodynamically designed so that turbulence as possible be avoided and the lowest possible pressure loss occurs. The blow slot of the air opening 36 is somewhat against that Horizontal inclined downwards so that the air curtain, i.e. the axis of a blow jet emerging from the air opening 36, on the lower edge of the downstream air opening 38 falls. Research has shown that a slight downward Directed air jet from the air opening 36 a horizontal Air jet from this opening is superior. The down directed air jet affects the workplace better counteracting thermal flow. With a horizontal one Air jet there is a risk that the thermal flow Grill and cooking vapors over the effective range of the downstream Wear air opening 38 and thus not or only can be partially recorded. The air duct 40 is through a further air guiding element 67 in the direction of the grease separating filter 30 increasingly wider, as shown in FIG. 2 is shown.

In the embodiment shown in Fig. 4, in which the workplace 14 is longer than in the exemplary embodiment 2, is due to the larger distance between the upstream air opening 36 and the downstream one Air vent 38, the blow slot of the upstream air vent 36 less inclined. An air jet from the upstream Air opening 36 has the property of air from to induce the environment. The induced air volume increases strongly increases with the beam length and depends among other things on the Beam thickness. To the steam-laden air flow on the other Side over the downstream air opening 38 if possible The upstream air opening is able to suction completely 36 for a system carrier with a relative large workspace, as shown in Fig. 4, narrower executed as for a leadframe with a proportional small workplace, as shown in Fig. 2. The downstream air opening 38 has the function in each case that supplied through the upstream air opening 36 Air as completely as possible and above the vertical Discharge air duct 39 down.

In Fig. 3 is such a downstream air opening as a detail 38 shown in cross section showing the shape of a suction slit Has. The lower and the upper edge of the Provide the suction slot with radii. Inside the downstream Air opening 38, the air through the air guide 64, 65, which are guide plates, deflected. The detection effect is achieved by this flow-optimized design the downstream air opening 38 essential improved.

In the system carrier shown in Fig. 4 arise due to the larger work surface of the workplace 14 essential more vapors. The thermal flow that occurs also guides causes the air jet of the upstream air opening 36 due to the longer way upwards. The downstream one Air opening 38 is therefore in shape and orientation this behavior matched. For this is the laterally oriented Suction slot of the downstream air opening 38 from FIG. 2 only suitable to a limited extent. The downstream one is expedient in FIG. 4 Air opening 38 formed so that part of the detection effect is diverted upwards. 4 is for this the optimized downstream air opening 38 is shown. there is the width of the air guide element 65 'compared to the air guide element 65 in Fig. 3 halved.

Fig. 5 shows an optimized embodiment in which the Transition from the downstream air opening 38 to the vertical one Air duct 39 through an S-shaped air guide element 65 '' is fluidically optimized. On the opposite On the side, no internals hinder the inflow of the suction Air. Overall, the downstream air opening becomes 38 of a system carrier with a large work surface as shown in Fig. 5 designed as a kind of suction channel, which in its length relative to the downstream air opening 38 3 and 4 remains unchanged, whereas its width opposite the downstream air opening 38 of a leadframe with a small work surface is doubled and its area compared to this is enlarged by more than twice. On such a suction channel is oriented laterally and upwards.

In the system carrier with the large workplace, as in 4, the odor filter 32 forms an angle from 30 ° to 40 °, preferably 35 °, with the vertical Air duct 40 or 60 ° with the bottom of the closed Room 24.

In the exemplary embodiment according to FIG. 2, the odor filter is 32 arranged much steeper than in the embodiment 4 is therefore in the embodiment 2 the air outlet 50 is not in the bottom of the closed Room 24 arranged, but in the left side wall. The Angle that the air filter 32 in the embodiment according to Fig. 2 forms with the vertical, is 2 to 10 °, preferably 3 °. The air outlet 50 is with a commercially available ventilation grille provided, the mutually displaceable slats Has. By changing the discharge cross-section, the Set the exhaust air volume.

In all exemplary embodiments, the blower 26 is arranged that it doesn't cover part of the filter area. As a blower it is advisable to use a double-sided suction radial fan used, which can be easily integrated into the system carrier. The arrangement is chosen so that the subsequent odor filter 32 is not blown directly by the blower 26. Thereby a pressure chamber forms in front of the odor filter, which leads to a uniform flow through the odor filter.

The separation efficiency of the fat separation filter is different from that The flow velocity of the air flow to be cleaned depends on. To assess the separation performance of the grease separation filter used is the layout diagram provided by the manufacturer used. About the determined airflow and the Filter area, the mean inflow velocity is calculated and the degree of separation of the grease filter via the layout diagram certainly. 6 shows the mean inflow velocities and the corresponding degrees of separation are shown. The average flow velocity of the grease separating filter for the system carrier with a smaller workplace (Fig. 2) is 1.9 m / s. This results in a degree of separation of 98%. The system carrier with the larger workstation (Fig. 4) is the mean flow velocity of the Grease trap filter 1.6 m / s and the degree of separation 96%. For this it should also be noted that in practical examinations with steam and frying fat and subsequent assessment the components are not contaminated on the grease separating filter following components were recorded. 6 three curves are drawn for different particle sizes. The lower curve (dash-dotted) applies to a particle size from 1.0 to 3.0 µm, the middle (dotted) curve applies to a particle size of 3.0 to 5.0 µm and the upper one (Dashed) curve applies to a particle size of 5.0 to 10.0 µm.

7 shows an air suction device designated overall by 12 ', in which the space 24 'in which the fan 26 and the filter system 28 are housed, to the side of the Workplace 14 is arranged. The room 24 'is through one wall 25 inclined against the horizontal. Above the wall 25, the fan 26 is arranged, the outlet port leads through the wall 25. Upstream of the blower 26, the fat separating filter 30 is arranged. downstream the fan 26, the odor filter 32 is arranged. By doing Space 24 'is the pre-chamber 58 through the two filters 30, 32 or the post-chamber 60 divided. The downstream air opening 38 directly forms the entrance to the antechamber 58 air laden with fat, vapors and odor from the area above the workplace 14 thus gets into the shortest way Room 24 'and thus has minimal opportunity for the air extraction device with fat, smoke particles or the like. to pollute.

The air first enters the grease trap filter in space 24 ' 30 and is freed of fat particles. By The air is sucked by the blower 26 through the grease separating filter 30 sucked. Then the fat particles freed air by means of the blower 26 through the odor filter 32 pressed, which is a zeolite filter is. Finally, the air passes through a horizontal one Air duct 37 in the vertical air duct 40 and from this out to the upstream air opening 36.

The lateral arrangement of the space 24 ', the blower 26 and The filter system 28 contains the advantage that filters and fans are easily accessible and that moreover in there is no technology in the area below the workplace. The latter area can therefore also be used become. The exemplary embodiment shows such a possibility of use according to Fig. 8.

8 is below the workplace 14, a device 70 is arranged on which in there is a container in the example shown here. The top opening of the container can be adjusted with the aid of the device 70 be brought to the optimum height so that the air curtain smells and optimally remove vapors that escape from the container can.

The area of application of the air extraction device described above is not limited to a workplace where food be subjected to heat, but also includes Areas of application such as welding and soldering, mixing chemicals, Working with galvanic baths and the like

In the exemplary embodiment according to FIG. 9, the workplace is 14 above the air openings 36, 38 on three sides, to which an operating side 13 is not heard from an air baffle in Form of a splash guard 11 surrounded. The splash guard 11 takes from the operating side 13 in the direction transverse to the air curtain 44 (shown in Fig. 1) and to the opposite Side of the workplace towards the height. The splash guard 11 consists of a U-shaped border plate, which is an aerodynamic Air baffle that forms a stable vortex flow builds up over the workplace 14. Responsible for this is the special one from the operating side 13 rear rising geometry of the air baffle, d. H. of Splash guard 11. The splash guard 11 can simply be on top the top of the kitchen module 10, which in Fig. 9 in a perspective Partial view is shown to be put on of course without the air openings 36, 38 of the Cover air channels 40 or 39. The air baffle or the Splash guard 11 can not only in the embodiment 1, but also for all others Embodiments shown in the remaining figures are. If the work place is not one, where food is heated where The air baffle fills up if grease can splash only the function of an aerodynamic air guiding device and can then develop its advantages in areas of application such as welding and soldering, mixing chemicals, working with galvanic baths and the like

Claims (28)

1. An air extraction apparatus for a work station, especially one at which heat is supplied to food, having formed on both sides of the work station respective air openings which are connected to a blower and a filter arrangement,
      wherein the air openings (36, 38), the blower (26), the filter arrangement (28) and a region (42) located between the air openings (36, 38) and immediately above the work station (14) form a closed air circulation loop (48) which produces an air curtain (44) during operation of the air extraction apparatus (12) in the region between the air opening (36) on an upstream side of the work station (14) and the air opening (38) on a downstream side of the work station (14),
      wherein the blower (26) and the filter arrangement (28) are housed in a space (24, 24') which lies within the air circulation loop (48) and is connected to the air openings (36, 38) on both sides of the work station (14),
      wherein the air circulation loop (48) includes an air outlet (50) for a portion (52) of the air from the air circulation loop (48), the air outlet (50) being located downstream from the blower (26) and the filter arrangement (28),
      wherein the blower (26) is located between at least two filters (30, 32) of the filter arrangement (28), the filter upstream of the blower (26) being a grease separating filter (30) and the filter downstream of the blower (26) being an odor filter (32), and
      wherein the air circulation loop (48) has at least one vertical air channel (40) in the region below the work station (14), through which at least one vertical air channel the space in which the blower (26) and the filter apparatus (28) are housed is connected to one of both air openings (36, 38) on both sides of the work station (14).
2. The air extraction apparatus according to claim 1, characterized in that the air outlet (50) has an opening of adjustable size.
3. The air extraction apparatus according to claim 1 or 2, characterized in that the blower (26) is a centrifugal blower.
4. The air extraction apparatus according any one of the claims 1 to 3, characterized in that the grease separating filter (30) is a cyclone filter.
5. The air extraction apparatus according to any one of the claims 1 to 4, characterized in that a grease collecting pan (56) is located beneath the grease separating filter (30).
6. The air extraction apparatus according to any one of the claims 1 to 5, characterized in that the odor filter (32) is a zeolite filter.
7. The air extraction apparatus according to any one of the claims 1 to 6, characterized in that the air circulation loop (48) has a further vertical air channel (39) in the region below the work station (14), through which further vertical air channel the space in which the blower (26) and the filter apparatus (28) are housed is connected to the other one of both air openings (36, 38) on both sides of the work station (14).
8. The air extraction apparatus according to any one of the claims 1 to 6, characterized in that the space (24') in which the blower (26) and the filter installation (28) are housed, is located beside the work station (14).
9. The air extraction apparatus according to any one of the claims 1 to 8, characterized in that the grease separating filter (30) and the odor filter (32) are positioned inclined with respect to the vertical (39, 40).
10. The air extraction apparatus according to claim 9, characterized in that the grease separating filter (30) is inclined with respect to the vertical at an angle of 40 to 50°, preferably of 45°.
11. The air extraction apparatus according to claim 9 or 10, characterized in that the odor filter (32) is inclined with respect to the vertical at an angle of 30 to 40°, preferably of 35°.
12. The air extraction apparatus according to any one of the claims 9 to 11, characterized in that the space (24, 24') in which the blower (26) and the filter arrangement (28) are housed, is divided by the two filters (30, 32) into an entry and exit chamber (58, 60) respectively.
13. The air extraction apparatus according to claim 12, characterized in that the air outlet (50) is located in a wall of the exit chamber (60).
14. The air extraction apparatus according to claim 7 or 8, characterized in that the work station (14) is a grill which extends above the space in which the blower (26) and the filter installation (28) are installed or beside that space (24').
15. The air extraction apparatus according to any one of the claims 1 to 14, characterized in that the air outlet (50) is so-shaped or adjusted that 75 % of the air is released from the air circulation loop (48) and the remaining 25 % reach the work station (14) as recirculating air and form its air curtain (44).
16. The air extraction apparatus according to any one of the claims 1 to 15, characterized by at least one air intake (38; 63) for drawing ambient air into the air circulation loop (48) to replace the air released into the surroundings through the air outlet (50) from the air circulation loop (48).
17. The air extraction apparatus according to claim 16, characterized in that the air intake is the air opening (38) on the downstream side of the work station (14).
18. The air extraction apparatus according to claim 16, characterized in that the air intake is an additional air opening (63) located downstream from the air opening (38) on the downstream side of the work station (14) and upstream of the blower (26).
19. The air extraction apparatus according to any one of the claims 1 to 18, characterized in that it forms a kitchen module (10) when it is integrated into a kitchen work station.
20. The air extraction apparatus according to any one of the claims 1 to 19, characterized in that both air openings (36, 38) are so located relative to each other that an air flow axis symbolizing the air curtain (44) is inclined slightly downwardly with respect to the horizontal toward the downstream air opening (38).
21. The air extraction apparatus according to any one of the claims 1 to 20, characterized in that the upstream air opening (36) is formed as a narrow blowing slot and that the opposite downstream air opening (38) is formed as a substantially broader intake slot.
22. The air extraction apparatus according to claim 21, characterized in that the blowing slot and the intake slot are formed by air guiding elements (64 - 67) in the vertical air channels (39, 40).
23. The air extraction apparatus according to claim 22, characterized in that the blowing slot is inclined slightly downwardly with respect to the horizontal and in that the intake slot is provided with radii located on its oppositely positioned inner walls.
24. The air extraction apparatus according to any one of the claims 1 to 23, characterized in that a segment of the vertical air channel which extends behind the downstream air opening (38) is covered upwardly by an air guiding element (65).
25. The air extraction apparatus according to claim 24, characterized in that, for increasing size of the work station and resulting increasing spacing between the upstream and downstream air openings (36, 38), the covering upper air guiding element (65', 65") is increasingly shortened.
26. The air extraction apparatus according to claim 25, characterized in that the air guiding element (65 ") has an S-shaped cross-section.
27. The air extraction apparatus according to any one of the claims 1 to 26, characterized in that the work station (14) above the air openings (36, 38) is surrounded on three sides, not including its operator's side (13), by an air guiding wall, especially a splash guard (11), which increases in height starting from the operator's side (13) in a direction transverse to the air curtain (44) toward the opposite side of the work station.
28. The air extraction apparatus according to claim 27, characterized in that the air guiding wall (11 ) is a U-shaped edge-encircling metal sheet.

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