EP1502057B1 - Device for effectively removing suspended particles from an airflow - Google Patents

Abstract

A device for removing suspended particles from an airflow has an intake opening, an air conveying the duct, and a fan. The air conveying duct deflects the airflow with regard to its flow direction at least sectionally. In order to filter the suspended particles almost completely from the air, the airflow is guided in the air conveying duct by positive guiding elements along a general conveying direction such that the airflow is subjected to at least a twofold sequentially arranged curve-shaped deflection in different directions. The height of at least one positive guiding element projecting into the air conveying duct is smaller than the free height of the flow cross-section of the air conveying duct in the area of the positive guiding element.

Description

The invention relates to a device for separating suspended particles from an air flow, wherein the device has a suction opening, an air conveying channel and a suction fan and the air conveying channel deflects the air flow in sections in its flow direction. The suspended particles can arise in particular through the operation of stove systems and are separated by generic extractor hoods.

In the prior art, an extractor hood is known, which consists of a suction chamber and an exhaust air chamber, wherein a arranged in an air passage grease separator having a cleaning device with spray nozzles for spraying and a collecting channel for collecting and discharging cleaning liquids. The conventional extractor hood, as disclosed in EP-A-0703 414, characterized by the annular arrangement of the exhaust air chamber around the central suction chamber, wherein above a cover plate of the suction chamber, the central spray device is arranged with spray nozzles, via which the spray nozzles Liquid to be exempted to liberate the extracted via the conventional hood air flow of solid and liquid particles.

The conventional extractor hood has, inter alia, the disadvantage that not only a constant consumption of detergent and solvent is required and the supply of washing and solvent must be controlled and monitored by metering devices, but also the spray device from a rotatably mounted about a vertical axis spray arm with spray nozzles, which spray arm always turned during operation and whose movements must also always be monitored.

Furthermore, not only the supply of washing and solvent is to monitor, but also is enriched with solid particles and liquid particles from the sucked air stream washing and solvent as wastewater permanently dissipate. Consequently, separate feeders and removal devices for washing and solvents and the washing and solvents as waste water are required for the extractor hood.

The conventional cooker hood requires an increased amount of maintenance as well as spatial dimensions to accommodate the conventional cooker hood, not to mention the requirement of comprehensive monitoring and maintenance of the conventional extractor hood spray and control equipment.

Also in the case of the ventilation hood described in DE-OS 26 504 35, which consists of a primary chamber arranged above the cooking range and a secondary chamber communicating with the primary chamber, the sucked-in air flow is guided via a filter below which nozzles are arranged. Via these nozzles cleaning water is injected into the area below a grid as a filter for collecting and removing the solid and liquid particles removed from the air stream.

Also, the conventional ventilation vent makes special facilities for the supply of the cleaning water and the particle-enriched cleaning water as wastewater and such for discharging required. Likewise, the conventional ventilation hood on means for operating the mesh used as a filter with spray nozzles. In addition, it appears that moisture from the highly enriched with water molecules air flow is also reflected above the filter in the secondary chamber and in the pipes for discharging the air flow from the secondary chamber to the outside outside of the stove receiving space.

The precipitation of moisture from the air stream enriched with water molecules often leads to fungal growth and bacterial growth. Mushroom growth and bacterial growth, due to their sporulation, contribute to increased health hazards to personnel staying in the conventional ventilation vent receiving space.

The kitchen ventilation hood disclosed in DE-OS 199 60 589 is also distinguished by an aerosol separator which is arranged opposite an inlet opening, wherein the housing forms a cylinder in whose wall the inlet opening extends in the longitudinal direction of the cylinder below the guide surface, wherein the aerosol separator opposite the inlet opening forms a longitudinal portion of the wall of the cylinder and the base surfaces of the cylinder each have outlet openings for the air flow above the output side of the passage.

The structure of the conventional kitchen hood is very complicated to remove suspended particles, steam and grease droplets, dust and soot particles from the air stream.

Finally, in DE 299 18 312 an extractor hood is described, which comprises a housing with back plate, side plates and an upper plate, wherein the upper plate includes at least one outlet opening and at least one motor attached thereto. This extractor hood comprises a passage communicating with the outlet port which is connected to an outlet chamber. Above the inlet opening an inclined bottom plate is arranged, over which there is a separating device. The separator communicates with at least one nozzle which is supplied with water to produce a curtain of water. The sucked air stream flows through the water curtain for the purpose of oil separation. The separated oil is in a collecting device.

Again, it appears that the highly enriched with water molecules air flow tends to form condensate in the region of the outlet opening and in the region of the discharge ports connected to outlet. As a further disadvantage, in addition to the requirement of supplying, discharging and controlling the cleaning water, bacterial growth and fungal growth occur, which should be avoided as far as possible in areas of food production and processing.

In US-PS 4,617,909 a cooker hood is described, in which the air flow from an inlet opening via a water bath and an air conveying channel in an exhaust chamber, which is connected to a blower chamber, out. As the air drawn in through the inlet port is passed through the water bath, the water is swirled so that parts of it can enter the air stream and remove fats and contaminants from it. The resulting contaminated water collects again in the water bath and can be drained for the purpose of cleaning.

Another fume extraction device is described in U.S. Patent No. 2,868,108, in which the vapors generated over a hotplate panel are drawn in via an inlet port and passed through a narrow passage into an elongate chamber in which the pressure is maintained below atmospheric pressure , The deposition of impurities and in particular fats takes place substantially in the front region of a pan, which forms the bottom plate of that elongated chamber.

All the above solutions have the common disadvantage that they are able to separate only relatively small amounts of suspended solids from the intake air despite high construction costs. In all solutions remain residual parts of airborne particles in the exhaust air, which sit in the fan and air ducts and there cause a stubborn pollution, which can hardly be removed.

The object of the invention is to provide a compact, simple device, which reliably eliminates a high proportion of suspended particles from the sucked air flow at a low operating and maintenance costs and low operating costs.

In addition, the operation of the device should be quiet, around which the cookers operating personnel are only exposed to low noise emissions.

Likewise, the separated from the sucked air flow suspended particles should be easily removable for the operator.

The above objects are achieved according to the invention with a device according to claim 1. In other words, by controlling the flow of air through forced guidance means located in the air delivery passage, i. the airflow undergoes an at least two consecutive curvilinear deflections in different directions through the inlet chamber designed in accordance with the invention, so that suspended particles guided in the airflow can at least partially deposit on the upper inner surface of the inlet chamber. The height dimension of at least one forced guiding means projecting into the air conveying channel is smaller than the free height of the throughflow cross section of the air conveying channel in the region of this forced guiding means. According to a further embodiment of the invention, the bottom plate and the upper plate, the sections at least approximately parallel to each other, spaced apart from each other between the air conveyor channel and have at least two successive, opposing arcuate curvatures, wherein the front portion of the upper plate and the front portion of the bottom plate to limit the inlet chamber with the inlet opening.

In the device according to the invention, the advantage is exploited that the gaseous components of the sucked air flow and the air particles moved in the air flow have a different specific gravity and, consequently, a different mass moment of inertia. As a result of the forced deflection of the air flow by means of the forced guidance means, the fractions of the gaseous media and the suspended particles moved therein are accelerated or decelerated differently across the flow cross section, and the fractions occupy different trajectories in the area of the forced guidance means. Due to the different direction of the successive deflections based on the positive guidance means the separation effect between the fractions is enhanced. While the suspended particles tend due to their greater inertia to a trajectory with a larger radius, the gaseous media can also move in trajectories with narrower radii in the deflection area. In the region of the first deflection, therefore, there is a segregation in such a way that the suspended particles accumulate in the outer region of the air flow.

In addition to the demixing results in a further effect in the area of the first deflection: The suction effect generated by the fan acts statically equal over the entire flow area of the air conveyor channel. However, since the moving in the air flow fractions in the air conveyor channel in the field of forced guidance means paths are of different lengths, depending on whether they are in the inner or outer radius of the deflection, they experience depending on their trajectory in dynamic terms, a different degree of acceleration , While the inside of the curve of the air flow is accelerated the most, the fractions moving in the outer curve area are hardly accelerated or decelerated, depending on the conditions and the concrete design. The acceleration differences are all the greater, the closer the inner radius of the deflection is chosen in relation to the free height of the flow cross-section.

The sum of these two effects produces the following effect in the region of the first deflection: while the gaseous media are sucked past the first positive guidance means at high speed near the inner radius of the deflection, the suspended particles collect in the region of the outer radius at low speeds of movement Deflection, and due to their speed of movement and acting on the suspended particles gravitational forces tend to take a trajectory whose bending radius is greater than the free radius of the air conveyor channel in the field of positive guidance means. These physical conditions mean that a good part of the suspended air particles in the air flow collide with the outer wall of the air conveyor channel and adhere there. Because of the comparatively low flow velocities in the outer radius, such suspended particles are not detached again and entrained by the air flow, so the separation of these suspended particles from the air flow is permanent.

In this zone, however, not all suspended particles may be separated. Some airborne particles still move in the air flow, in the outer radius of the deflection. The safe separation of these suspended particles is now achieved by the second deflection in the opposite direction: the deflection in the opposite direction causes an acceleration of the previously slowly moved in the outer radius gaseous media. Due to their inertia, the suspended particles can not participate in this acceleration. Due to the acceleration of the previously surrounding gaseous media, the slowly moving gas envelope becomes thinner, and the faster in the middle Radius range moving air currents press into the area of the accelerated by accelerating the gas envelope. Due to these currents, suspended particles still moving in the air stream receive a movement impulse towards the near outer wall. By means of this effect, also those suspended particles collide with the outer wall and adhere there, which could not be separated with the previously known devices. In the manner described, it is possible to deposit 90% and more of the airborne suspended particles in the form of fat and / or water droplets.

These high separation rates are achieved with very little technical effort. The air conveyor duct according to the invention is comparatively small and flat. The air flow is only slightly hindered, so that only a comparatively low fan performance is required. The lower fan performance reduces operating noise and operating costs due to lower power consumption. The operation is simple, since the hood only needs to be switched on or off and no other operating materials, monitoring and maintenance are required. It suffices to occasionally wipe the surface of the inner wall in the area of the positive guidance means. The surface can be made easy to clean in this area. Due to the high degree of separation of airborne particles, the fan, the downstream exhaust air ducts and the recirculation mode, the room air is hardly burdened by not separated suspended particles. The purified air stream is also characterized by a lower content of moisture compared to the air stream outside the inlet chamber, so that neither fungal growth nor bacterial growth can be observed in the exhaust chamber and in the air conveying channel. The device remains permanently clean, there are no more hygienic loads or health hazards for the operating personnel from the presence of the hood. Also, the efficiency during long-term operation of the device according to the invention largely remains due to the sufficiently large the floating particles serving as baffle and Abscheidefläche front portion of the upper plate and the front portion of the bottom plate.

For the realization of the invention it may be sufficient to arrange simple rectangular, triangular, round or any other cross-section having transverse profiles spaced apart in the flow direction on opposite sides of an otherwise smooth air conveyor channel. However, the guidance of the air flow preferably takes place arcuately by means of correspondingly designed smooth inner surfaces of the Air duct to avoid disturbing stalls or turbulence through which also suspended particles could be thrown back into the air flow. This reduces drag and noise, and smooth surfaces are easier to maintain. It is also advantageous to keep the air delivery channel as short as possible, since the design and the production cost can be kept very small. For this purpose, the inlet opening is bounded by the air conveyor channel limiting side walls, and the deflection zones are immediately adjacent to the inlet opening. In such an embodiment, the separation of the suspended particles takes place immediately following the inlet opening. The separation zone is then easily accessible and easy to clean. Also, because of the compact design, a plurality of inlet openings in any position - longitudinal, transverse, diagonal, staggered in height, etc. - with each subsequent thereto inventively designed air conveyor channels above a work surface, such as a stove, are arranged.

In addition, a deflection element and / or a tubular filter part can be used in the device according to the invention, which serve to separate remaining suspended particles, odor molecules and / or moisture from gaseous media from the air stream. The performance of the device is thereby increased again. The tubular filter part proposed here is capable of binding a far greater amount of odor molecules than conventional filters, so that the operating time of this tubular filter part is significantly increased.

The subclaims relate to preferred embodiments and further developments of the invention.

Under suspended particles is also understood in the context of the invention, for. As vapors, fat and oil particles of greater consistency, dust particles and / or smoke particles, which may arise, for example, during operation of cookers.

Under finest particles is also understood in the context of the invention z. As liquid Fetteilchen and oil particles with low-viscosity unsaturated fatty acids and vapor droplets, which may arise, for example, in the operation of cookers.

For the purposes of the invention is also understood to mean steam or vapors dense mist, which arise during operation of water boilers, upon heating of aqueous solutions, etc., and pass as a vapor in the suctioned air flow.

Under blower is understood, for. B. operable by electric current fan for the transport of air flow, wherein the current-operated unit can be coupled directly to the fan or spaced from it via shafts.

Under gaseous media is also understood in the context of the invention z. As gases, such as air, volatile vapors of organic and / or aqueous solvents.

Fig. 1

die Schrägansicht auf die erfindungsgemäße Vorrichtung mit Einlaßöffnung, Einlaßkammer, Luftförderkanal, Abluftkammer im Querschnitt,

Fig. 2

den Querschnitt durch die erfindungsgemäße Vorrichtung mit der Darstellung des Verlaufs der angesaugten Luftmassen, welche aus der Auslaßöffnung in die Gebläsekammer des Mantelgehäuses eintreten,

Fig. 3

die Schrägansicht von oben auf die ovale Auslaßöffnung der erfindungsgemäßen Vorrichtung,

Fig. 4

die Draufsicht auf das hintere Mantelgehäuseteil,

Fig. 5

die Schrägansicht auf die erfindungsgemäße Vorrichtung im Querschnitt mit dem Mantelgehäuse, das zusammengefügt ist aus einem vorderen Mantelgehäuseteil mit Ausnehmungen für Steuereinrichtungen und Versorgungsleitungen des Gebläses und einem hinterem Mantelgehäuseteil,

Fig. 6

eine Innenansicht auf das vordere Mantelgehäuseteil,

Fig. 7

die Draufsicht auf das vordere Mantelgehäuseteil,

Fig. 8

eine Sicht von schräg oben auf das hintere Mantelgehäuseteil,

Fig. 9

die Schrägansicht auf ein aufgeklapptes zweiteiliges Mantelgehäuse mit zwei Mantelgehäuseteilen,

Fig. 10

die Draufsicht auf das erfindungsgemäße Umlenkelement mit einem Modul 43 mit Lagen aus Stäben,

Fig. 11

den Schnitt A - A gemäß Fig. XI als Querschnitt durch das erfindungsgemäße Umlenkelement mit einem Modul mit 3 Lagen aus Stäben, mit Abstand X als Horizontalabstand zwischen zwei unmittelbar benachbarten Stäben einer Lage 41 und mit Abstand X als Horizontalabstand zwischen zwei unmittelbar benachbarten Stäben einer Lage 42 soweit mit diagonalem Abstand Y zwischen Stab 43 der Lage 41 und Stab 43 der Lage 42,

Fig. 12

die Schrägansicht auf das erfindungsgemäße Umlenkelement,

Fig. 13

die Draufsicht auf das erfindungsgemäße Rohrfilterteil,

Fig. 14

den Schnitt A - A gemäß Fig. XIII als Längsschnitt durch das erfindungsgemäße Rohrfilterteil,

Fig. 15

den Längsschnitt durch die luftdurchlässigen Wandungen des erfindungsgemäßen Rohrfilterteils.

The invention will now be explained in more detail with reference to exemplary embodiments. The drawings show, by way of simplified illustration, in a schematic, greatly enlarged manner without claim to a scale reproduction, embodiments and further developments of the invention without being limited thereto. Show it:

Fig. 1

the oblique view of the device according to the invention with inlet port, inlet chamber, air conveyor channel, exhaust chamber in cross section,

Fig. 2

the cross section through the device according to the invention with the representation of the course of the sucked air masses which enter from the outlet opening in the fan chamber of the jacket housing,

Fig. 3

the oblique view from above of the oval outlet opening of the device according to the invention,

Fig. 4

the top view of the rear shell housing part,

Fig. 5

the oblique view of the device according to the invention in cross-section with the jacket housing, which is assembled from a front shell housing part with recesses for controls and supply lines of the fan and a rear shell housing part,

Fig. 6

an interior view of the front shell housing part,

Fig. 7

the top view of the front shell housing part,

Fig. 8

a view obliquely from above on the rear shell housing part,

Fig. 9

the oblique view of an unfolded two-part jacket housing with two jacket housing parts,

Fig. 10

the top view of the deflecting element according to the invention with a module 43 with layers of rods,

Fig. 11

the section A - A of FIG. XI as a cross section through the deflecting element according to the invention with a module with 3 layers of rods, with distance X as a horizontal distance between two immediately adjacent bars of a layer 41 and at a distance X as a horizontal distance between two immediately adjacent bars of a layer 42 so far with diagonal distance Y between rod 43 of the layer 41 and rod 43 of the layer 42,

Fig. 12

the oblique view of the deflection element according to the invention,

Fig. 13

the top view of the pipe filter part according to the invention,

Fig. 14

the section A - A according to FIG. XIII as a longitudinal section through the pipe filter part according to the invention,

Fig. 15

the longitudinal section through the air-permeable walls of the pipe filter part according to the invention.

In Fig. 1, an embodiment of a separating device according to the invention in the form of an extractor hood is shown. The extractor hood has an elongated inlet opening 1 with the length L, which is quadrangular in the plan view of the bottom plate 4. Adjoining the inlet opening 1 is an inlet chamber 2, through which an air stream enters the subsequent air-conveying channel 3. The air conveyor channel is bounded laterally by the bottom plate 4, a spaced from the bottom plate 4 arranged upper plate 5 and not shown side walls. The air conveyor channel 3 opens into an exhaust chamber 6, the bottom of which still from the Bottom plate 4 is formed. The exhaust chamber 6 is bounded to one side by an inner plate 7 and to the opposite side by a back plate 11, in which the bottom plate 4 passes in the flow direction seen. The rear plate 11 is at an angle of 80-90 ° to the bottom plate 4. In the region of the transition, the bottom plate 4 is pivotally coupled to the rear plate 11 by means of conventional hinges. Due to the pivotal connection, the base plate 4 can be folded for maintenance and cleaning purposes, in particular also to be able to clean the separation surface 10. Instead of a hinge connection, the bottom plate 4 can also be detachably and detachably connected to the frame of the extractor hood.

The back plate 11 is upright, arranged vertically and can be supported against a wall of a cooker. In particular, the central portion 4a of the bottom plate 4 and the central portion 5a of the upper plate 5 form an air conveying channel 3, which is traversed by the air flow in the direction of exhaust air chamber 6 (see arrow). As air conveying channel 3, however, not only this section, but the entire route, which flows through a device according to the invention, should generally be understood.

The inlet chamber 2 is limited upper side of the front portion 9 of the upper plate 5 and the lower side of the front portion 8 of the bottom plate 4. The front portion 9 of the upper plate 5 is in Cross-section approximately semicircular arc-shaped. The side of the front portion 8 of the bottom plate 4, which faces the inlet chamber 2, is formed in cross-section approximately three-quarter circular arc-shaped. The angular degrees of the front portion 9 and the front portion 8 may also be provided with deviating from the representation of angular degrees, which appear suitable for an application. Due to the special cross-sectional configuration of the front portion of the upper plate and the cross-section particular circular arc configuration of the front portion of the bottom plate 4 are no disturbing corners and edges, so that the air flow can be sucked at a high speed substantially without friction losses ,

In one embodiment of the bottom plate 4 and / or the upper plate 5 of the device according to the invention, this can be wholly or partly as a continuous casting 16 to provide cavities for increasing the dimensional stability of the upper plate 5 and / or the tongue plate 15 may be configured. In addition, in the embodiment of the upper plate 5 in the form of extruded parts 16, the device according to the invention is characterized by a low weight.

The terms "front portion 8" and "front portion 9" are not to be understood as limiting spatially to the front region of a device, but relate only to the embodiment. The deflection of the air flow in accordance with the invention can also be done in a middle, side or rear portion of an air conveyor channel 3.

The center P1 of the arcuate portion of the bottom plate 4 may be concentric with the center of the circle of the front portion 9 of the top plate 5 as shown. It is also possible that the center P1 of the front portion 8 of the bottom plate 4 and the center of the front portion 9 of the top Plate 5 is offset in the direction of the rear plate 11 by 1.5 to 3.0 times the radius of the front portion 9 of the upper plate 5. Concentric position of the centers results in the front region of an air conveying channel 3, the free height h of the flow cross-section remains approximately the same, while results in staggered arrangement of the center points in one direction ausschnürender air conveyor channel 3.

These sides of the front portion 9 and the front portion 8 are characterized by the streamlined absence of corners and edges, so that the sucked air flow without the emergence of regularly formed by corners and edges air swirling the inlet chamber 2 can flow through friction.

Since preferably the length of the inlet opening 1 is greater than the length of the outlet opening 12, a trapezoidal in the plan view flow movement of the air flow within the air conveyor channel 3 can be observed. In the embodiment, the length of the inlet opening 1 is larger by 2 times than the length of the outlet opening 12, and there is a trapezoidal in plan view flow movement of the air flow within the air conveyor channel 3. The length L of the inlet port 1 can 1.5 to 3.5-fachem the length of the outlet opening 12 correspond.

Due to the trapezoidal movement of air, the air masses are sucked during operation of the device according to the invention so that set in the effective range of the suction outside the device air flow rollers, which are helical move in the direction of the inlet opening 1. The axes of rotation of the air rollers can be aligned perpendicular to the center longitudinal axis of the elongated inlet opening L. The helical movements of the air streams, which are to be observed on both sides of the bottom plate 4, show that even air masses are sucked in, which are offset laterally far from the device according to the invention. These air rollers support and tear adjacent air masses, so that the length of the inlet opening 1 of the device according to the invention does not have to correspond to the extent of the length or width of the cooker systems, but may also be lower. By entering at high speed through the inlet port 1 via the air conveying passage 3 in the outlet chamber 6 air flow it is deflected by the front portion 9 of the upper plate 5, so that the suspended particles from the air flow on the front portion 8 side facing the front Area 9 of the upper flap 5 is able to accumulate. Due to this effect, the device according to the invention builds comparatively very small with nevertheless large effective range.

In one embodiment, the front portion 9 of the upper plate 5 is bisected to form two quarter-circular front portions 9a, 9b. The tongue plate 15 with the first quarter-circle-shaped front portion 9a can be moved away from the back plate 11. By the degree of extraction of the tongue plate 15, the degree of extraction of the air masses is controlled. Bubble-like particles which occur suddenly when liquids boil up are effectively sucked off in the direction of the inlet opening 1 by the air flow which increases through the inlet opening 1. Furthermore, air masses are sucked far laterally offset from the provided with the device according to the invention extractor hood by pulling out the tongue plate.

In one embodiment of the upper plate 5 of the device according to the invention, this may be wholly or partly designed as a continuous casting with provision of cavities for increasing the dimensional stability of the upper plate and / or the tongue plate. In addition, in the embodiment of the upper plate 5 in the form of extruded parts, the device according to the invention is characterized by a low weight.

The air flow is conveyed via the air conveyor channel 3 in the exhaust chamber 6 almost frictionless and quiet. The exhaust chamber 6 is laterally bounded on the front by the inner plate 7 and back through the back plate 11th Die inner plate 7 and the back plate 11 merge into each other and form the oval-shaped in plan view exhaust chamber 6 with an oval outlet opening 12 and the length L. A the exhaust chamber 6 delimiting component, in which the back plate 11 and the inner plate 7 and the rest Side walls are integrated in a component, is shown in Figure 3. The outlet opening 12 may also be designed round or circular.

Due to the smooth-surfaced embodiments of the inlet chamber 2, the air conveyor duct 3, the exhaust chamber 6 facing sides of the upper plate 5, bottom plate 4, inner plate 7 and the back plate 11 also occur no dead spaces, which arise in comparison to the prior art air vortex to let. Likewise, by the smooth surface configuration of the sides, of which also the o.g. Inlet chamber 2, the air conveyor channel 3, the exhaust chamber 6 are limited, the device of the invention are operated extremely quiet.

It turns out that the device according to the invention as z. b. Extractor hood under favorable circumstances approximately up to 100% of all suspended particles removed from the air flow. This can be easily and without residue cleaned by removing the deposits in the region of the front portion 9 of the upper plate 5 without risk of injury by corners and edges.

It also appears that the air flow in the region of the inlet opening 1 is greatly accelerated by the suction taking place in the front region 9 of the device according to the invention as so-called edge suction. The edges which form the inlet opening 1 of the inlet chamber 2 are formed so smooth surface that the flow does not break off in these areas and thereby air can be sucked or sucked before, above and from the rear region and lateral regions of the device according to the invention by means of the device according to the invention. This success arises inter alia from the connection of the trapezoidal flow from the inlet chamber 2 via the air conveying channel 3 and the exhaust chamber 6 to the outlet 12th

In addition, right and left on the underside of the bottom plate from front to rear running rotating air vortex, called air rollers, which ensure that even from hearths in the wider area ascending suspended particles, such as Wrasen, are also detected laterally and not escape, but rather be detected and sucked by the device according to the invention.

The tongue plate 15, the upper plate 5 and other components are designed as extruded parts 16 to provide cavities 14 to increase their dimensional stability, which are also characterized by a low weight.

Directly after the intake of the sucked air flow into the device according to the invention, the air flow is deflected twice. In conjunction with the high air velocity, about 95% of suspended in the airflow suspended particles, such as fat particles, oil particles and water vapor, moisture, etc., centrifugally thrown from the air and in the deflections, here the front portion of the top plate targeted and certainly deposited.

The casing casing 21 according to the invention consists of two casing casing parts, a front 21a and a rear 21b, wherein the casing casing 21 according to the invention, as shown in Figure 9, is cut along the air flow direction. Other divisions are possible. Due to the detachable coupling of the jacket 21 to the exhaust chamber 6 all components of the device according to the invention are quickly and easily accessible.

To the outlet opening 12, which is arranged on the upper side of the device according to the invention, a shell housing 21 connects, which is preferably made of plastic-like material, such as polyurethane foam. Plastic-like polymers such as polystyrene, polycarbonates, polyolefins, polyurethanes, polyamides, etc. can be used in the production of the casing casing 21 according to the invention from foamed plastics. The foam structure can arise due to chemical reactions, for example in the case of polyurethanes, by addition of blowing agents, which at a certain temperature during the Decompose with formation of gas or with the addition of volatile solvents during polymerization. The foaming can take place when leaving the extrusion die or in open molds or during injection molding. The jacket casing 21 according to the invention dampens to a high degree by the fan noise.

The installation position of the jacket 21, its components and details of the inner and outer surface design are shown in Figures 4 to 9.

The shell casing 21 has a suction opening 22 through which the air flow occurring from the outlet opening 12 is conveyed via the suction opening 22 shown in Figure 2 into the suction chamber 23 of the shell casing 21 according to the invention and finally via the fan, which in the fan chamber 25 in the middle in the Sheath housing 21 is arranged, is discharged to the outside via the blow-out chamber 26 and the exhaust opening 27. Again, the intake chamber 23, the intake ports 24 and the exhaust chamber 26 facing sides of the shell 21 are smooth and flat. Due to the smooth-surfaced and aerodynamically designed surfaces, the generation of unwanted noise is avoided, and there are hardly any power losses due to disturbing turbulence of the air flow and so-called dead space in the air conveyor channel 3. The speed of the sucked by the fan air flow can be 3.0 to 30M / sec, preferably 5, 0 to 20.00 m / sec, wherein the blower arranged in the jacket housing 21, the air flow with a volume between 200 and 1100 m ³ / hr. sucks. These values are exemplary for extractor hoods that are designed for use in non-commercial areas. For other applications, other values may result.

The fan power can be selected via a control panel in different stages, wherein the different fan levels have little influence on the flow path of the air flow along the air conveyor duct 3. Therefore, there is hardly any effect on the effectiveness of the separation effect by the diversion of the air flow. The air flow sucked in through the inlet opening 1 barely has suspended particles or very fine particles after passing through the forced guidance means. In the inlet opening 1 of the device according to the invention, the speed of the sucked air flow may be a value in the range of about 6.0 to 11.0 m / sec, wherein the blower arranged in the shell 21 in the embodiment in one of several possible blower levels only the air flow aspirated with 610 m ³ / h.

Smooth surface is also understood in the context of the invention that the sides have no edges and corners and the formation of so-called dead spaces are avoided.

Likewise, the risk of injury when cleaning the jacket housing 21 due to the absence of edges and corners and due to the smooth surface of the suction chamber 23, intake ducts 24, and blow-out chamber 26 facing sides of the shell casing 21 avoided. Due to the high efficiency of the deposition by the device according to the invention and optionally the deflection element 40 according to the invention, deposits no longer regularly occur in the chambers and channels of the jacket casing 21 according to the invention. Furthermore, the jacket 21 of the invention insulates and dampens not only the noise occurring during operation of the fan, but also possible vibrations, which can be caused in conventional devices by not previously filtered out deposits in the fan.

The jacket casing 21 according to the invention has recesses 29 for outside feeders such as cable ducts and control devices for the fan. The suction chamber 23 merges into two intake passages 24 in that the air flow is divided by a distributor piece 28 triangular in plan view.

The two-part shell casing 21 allows by simple coupling and the streamlined guidance of the air flow to the fan minimum manufacturing and operating costs. The present invention does not necessarily require the air flow through the shell casing described above to ensure the function of the separation of suspended particles. To save costs, can also be dispensed with the jacket 21 and the fan is then arranged in a conventional manner at a position of the air conveyor between the suction and exhaust.

The air flow can flow through a deflection element 40 in the course of its flow through the device according to the invention. The deflection element 40 according to the invention serves for the fine separation of very fine particles from the air flow and thus has a filter function. It may be arranged at one point in the air delivery channel 3, but in particular between the exhaust chamber 6 and the suction chamber 23 in the region of the suction opening 22 of the shell 21. This position is advantageous because a large proportion of the suspended particles is already separated from the air stream, Nevertheless, still residual suspended particles, dust, etc. can be separated from the air flow by the deflection element 40 before the air flow arrives at the fan.

The deflection element 40 according to the invention is shown in more detail in FIGS. 10 and 11. It consists of a module 43a of at least two layers 41, 42 with a The walls 41, 42 consist of several juxtaposed, parallel aligned, spaced apart rods 43, 44. All rods 43, 44 are in their outer diameters D match each other. The bars 43 of the layer 41 are equidistant from each other by the distance X. The bars 44 of the other layer 42 are also equidistant from each other by the distance X. All the distances X of the bars 43, 44 of the deflecting element 40 according to the invention are constant. The distances X of the rods 43, 44 to each other are smaller than the outer diameter D of the rods 43, 44 of the deflecting element according to the invention.

The rods 43, 44 of each layer 41, 42 form so-called gaps 45 due to the mutual spacing of each other. The two layers 41, 42 of the module 43a are aligned with their rods 43, 44 to each other such that the rods 44 of the other layer 42 gaps 45th the her immediately adjacent, at least approximately cover a layer 41 seen in the flow direction of the air flow. It can also be several modules 43 a stacked with parallel alignment of the rods 43, 44 to each other, but this is not shown in detail in the drawings.

In the arrangement of the two layers 41, 42 on gap 45 one above the other is the one bar 44 of the other layer 42, which is disposed on the gap 45 of two bars 43 of a layer 41, at a certain distance Y to these two bars 43 of a layer 41. This distance Y is called in the context of the invention, diagonal distance or diagonal distance Y. The distances Y of the rods 43, 44 of two adjacent layers 41, 42 of the deflecting element according to the invention are constant and the same in the embodiment, but may also be different, especially if several modules come to rest on each other.

The distances Y of the deflection element according to the invention are smaller than the outer diameter D of the rods of the deflection element according to the invention. The distances X coincide with the distances Y.

At the incoming air flow facing active surface of the rods 43, 44 of the module 43 of the deflection element 40 according to the invention are deposited on the finest particles from the air flow. By this arrangement of the deflecting element according to the invention in the exhaust chamber 6, the air flow is deflected again, but with less air resistance, and causes at most low noise. by virtue of the easy pivoting of the bottom plate 4 in the exhaust air chamber 6 opposite direction, the exhaust chamber 6 is easily accessible from the outside, so that the deflection element 40 z. B. from the exhaust chamber 6 readily removed, cleaned and can be used again. The rods 43, 44 are hollow cylindrical or solid, z. B. of metal and / or plastics.

Instead of the proposed embodiment of the deflecting element 40, however, this can also be formed in another form, for example, consisting of single or multi-layered wire mesh.

In addition, in the air delivery channel 3, in the exemplary embodiment of the exhaust opening 27 of the shell 21, a pipe filter part 50 are coupled, which is shown in more detail in Figures 12-15. The tubular filter part is cylindrical with an inner, hollow cylindrical distribution chamber 51, wherein the distribution chamber 56 is bounded laterally by a first air-permeable wall 51, which also has a hollow cylindrical shape. The air flow and distribution can be favorably influenced by special air guide elements, such as, for example, a distributor cone arranged in the distributor chamber 51 and directed counter to the air flow.

On the outside of the first air-permeable wall 51, a layer 52 of anthracite coal is formed as a filter medium. This layer of the filter medium is permeable to gas. As a filter medium, a preferably lean type of coal is used, from shiny deep black shape with mussel break. The anthracite coal can consist of less than 1% water and 7 to 12% volatiles. A second air-permeable wall 57 abuts the outside of the layer 52 of anthracite coal.

On the outside of the second air-permeable wall 57, a further, optional and also gas-permeable layer 53 of activated carbon is formed as a filter medium, which is externally bounded by a third air-permeable wall 58. The activated carbon layer used as a filter medium may consist of carbon structures of the smallest graphite crystals and amorphous carbon with a porous structure and an inner surface of between 500 and 1500 m ² / g. For example, powder activated carbon, grain activated carbon or cylindrically shaped activated carbon may be used as the ingredient. This double stratification of filter media brings better filter performance.

The tube filter part 50 is flowed through radially by an air flow, wherein the air flow flows from below through a lower opening 55 in the distribution chamber 56. From there, the air flow passes through the apertures 70 of the first air-permeable wall 51 radially to the layer 52 of anthracite coal for residual moisture removal from the air flow. Subsequently, the air flow passes through openings 70 in the second air-permeable wall 57 in the layer 53 of activated carbon to remove the odor molecules and exits through openings of the third air-permeable wall 58 laterally. Due to the arrangement of the tube filter part 50 at the end of the air conveyor channel 3, the air flow is best possible cleaned of almost all suspended particles, moisture, etc., so that the tube filter part 50 almost only absorbs the odor molecules. This and the high filter capacity of the proposed tube filter part 50 have a positive effect on the service life of the tube filter part 50.

The pipe filter part 50 according to the invention is used in particular for the removal of odor molecules from the air stream, so that it can be supplied after essentially complete cleaning of airborne particles and odor molecules again the space which accommodates the cooker. The inventive device in conjunction with the deflecting element 40, the casing 21 according to the invention and possibly with the pipe filter part 50 according to the invention allows as z. B. Extractor hood, the separation of suspended particles in a closed air flow circuit system.

After the invention has been explained above with reference to exemplary embodiments, the principle underlying the invention will now be explained in more detail with reference to sketches.

In Fig. 16, an air conveying channel 3 is shown, in which flows through an inlet port 1, an air flow in an air conveying passage 3 associated with the inlet chamber 2. In principle, the air flow through the air conveying channel 3 is directed from an intake point A in the direction of a point B located downstream in the air conveying channel 3. In the air conveyor channel 3 thus results in a general conveying direction AB. The positive guidance means 60 are positioned in the air conveying channel 3 and relative to each other so that the air flow along its general conveying direction AB undergoes an at least two successive curved deflection in different directions. Such a deflection results when the positive guidance means 60 are spaced apart and viewed in the conveying direction are arranged to each other in the air conveyor channel 3. To achieve the effect according to the invention - namely the forced separation of airborne suspended particles - the shape of the coercive means is not of crucial importance. Thus, the constraining means 60 shown in Fig. 16 are shown in solid lines as rectangular ridges, but they may also be embodied as ridges of triangular cross-section as shown in dotted lines. Other cross sections are possible as long as only the double deflection takes place along the general conveying direction AB. The front section 8 explained in more detail in the preceding exemplary embodiment, viewed from the working principle, is nothing else than the lower positive guide means 60 arranged on the base plate 4 in FIG. 16. The separating surface 10 explained in more detail in the preceding exemplary embodiment is a forced guiding means 60, such as it is shown in Fig. 16 in the upper region of the air conveying channel 3 at the bottom of the upper plate 5. The path that the air flow through the arranged in the air conveyor channel 3 forced guidance means must be outlined by the outgoing from the point A arcuate arrow in its course.

The positive guidance means 60 protrude by the height H into the air conveying channel 3. In the region of a forced guidance means 60, the free height of the flow cross-section of the air conveying channel 3 is thereby reduced to the dimension h. Characterized in that the dimension H is smaller than the dimension h, the air flow is guided around a forced guidance means 60 in a particularly narrow radius. Due to the different ways that the air flow must travel at different heights of the flow cross-section along the respective radius, considerable differences in speed occur in the air flow.

In Fig. 17, the bending radii, around which the air flow is guided around in the region of the positive guidance means 60, explained in more detail. The forced guidance means 60 are shown in dashed lines. In order to meet the requirement of a streamlined and low-loss designed air conveyor channel 3, the air conveyor channel 3 is designed by arcuate baffles so that the air flow can flow through the region of the double deflection in a laminar flow as possible. In place of the force guide means 60 arranged on the base plate 4, there is also the front section 8, which is also contained in the embodiment explained in more detail above, the circular arcuate surface of which is guided around a transverse axis lying on the point P1. In this case, the deflection of the guided in the air conveyor duct 3 air flow corresponds a deflection angle α, which is significantly greater than 90 ° in the embodiment. At the first deflection of the air flow is then followed by a second deflection by the angle β, which is smaller than 90 ° in the embodiment. The arc of the inner surfaces of the air conveyor channel 3 is guided in the region of the second deflection about a transverse axis, which is spatially approximately in the position P2.

As can be clearly seen in FIG. 17, the direction of rotation of the angle β deviates from that of the angle α. The angles shown in the embodiment are to be understood as exemplary only, a different size and distribution of the angle α, β is possible.

In Fig. 18, the different wind speeds of the air flow in the air conveying channel 3 are shown, in particular the different velocity distribution as a function of the position of the measuring point in the region of the respective deflections. While the wind speed over the free height h of the air conveyor channel 3 in the region of position I is still approximately the same, the air flow in the region of position II moves over the free height of the flow cross section at different speeds. While that portion of the air flow that moves along the inner surface of the first deflection must travel only a short distance and therefore undergoes additional acceleration, those components of the air flow that move in the outer region of the air flow in the region of the first deflection, a travel much larger way. In these zones, therefore, slows the air velocity. The velocity vectors shown in FIG. 18 are only to be understood as exemplary. They can vary and vary depending on the physical design of the air conveyor channel 3 and the ingredients of the air flow and the mixing of the ingredients. The position III shows the velocity distribution after passing the air flow of the second deflection. Since the parts of the air flow moving in the outer curve region in the region of the first deflection are in the inner curve in the region of the second deflection, these air flow components must travel a shorter distance here, while the parts of the air flow previously moved in the inner curve now move outside. Due to these reverse track conditions, inverse acceleration or deceleration effects result. Since a small dead space 61 forms in the slipstream of the front section 8, in which turbulence can occur, the outside portion of the air flow becomes in the region of the second deflection slowed down more than the more central parts of the air flow.

A kind of "nozzle effect" can be achieved if the air delivery channel 3 is formed so that between the peak H1 shown in Figure 19 of the first positive guidance means 60 and the high point H2 of the second forced guidance means 60 in the flow direction, a height offset by the amount V in the free height (h) of the flow cross-section of the air conveyor channel 3 results. At such a height offset, a medium-flow zone may be formed in which the airflow may flow through the air delivery passage 3 at a high speed and low power loss.

FIG. 20 shows a preferred embodiment of the device according to the invention, in which the front region 9 of the upper plate 5 is divided into two parts. For this purpose, the front region 9 can consist of two, for example, quarter-arc-shaped front regions, made of z. B. a front portion 9a and a rear portion 9b exist. The tongue plate 15 with the front portion 9 a z. b. be pulled out parallel to the center longitudinal axis of the air conveyor channel 3 by the maximum length e. the free height h in the region of the inlet opening 1 thereby increases approximately by the amount e to the height h (e). Such a measure has only negligible effects on the flow conditions essential to the invention in the region of the height h shown in FIG. In a preferred embodiment of the device according to the invention, the front region of the upper plate can be divided into two. The front region may consist of two, for example, quarter-arc-shaped front areas, z. B. a front portion and a rear portion, exist. The tongue plate with the front portion can z. b. parallel to the center longitudinal axis of the air conveyor channel, to be pulled out.

In Fig. 21, the different trajectories of the air flow and the suspended particles in the course of the air conveyor channel 3 are shown. While the airflow is shown in a continuous curved line, the various possible trajectories of the suspended particles are shown in dashed lines. An influence on the trajectory has first of all the density and spatial form of a suspended particle. Depending on how large and heavy a suspended particle and how its outer shape is designed, a single suspended particle is accelerated to different degrees by the surrounding air flow. In general, it can be stated that the suspended particles moving in the region of the inner curve - assuming the same shape and density - experience a stronger acceleration pulse than in the outer curve area moving suspended particles. Due to the stronger acceleration of a suspended particle moving in the inner circle but also increases its inertia. A suspended particle moving at a relatively higher velocity will find it harder to move within a tight radius of curvature. The faster a suspended particle moves, the stronger the trajectory is directed in a straight line direction. The situation is different with the comparatively slowly moving suspended particles: Since these particles have only a small kinetic energy, the direction of these particles can be easily reversed, accordingly slowly moving suspended particles first follow the contour of the conveying channel 3 in the outer circle. Nevertheless, the suspended particles in the outer circle have a different mass inertia than the gaseous components of the air flow, so that inevitably results in the course of the flow through the region of the first deflection, a trajectory that differs from a beaten around the pivot point P1 circular path. Due to the interaction of the kinetic energy inherent in the suspended particles, their inertia and the gravitational forces acting on them, the suspended particles invariably reach the area of the outer air flow during the passage through the zone of the first deflection and inevitably collide with the inner surface of the latter due to the course of their trajectory upper plate 5. In this way forms on the upper plate 5 a Abscheidefläche 10, the spatial extent is indicated by the line shown in Fig. 21. As can be seen from Fig. 21, trajectories of suspended particles may intersect.

In Fig. 22, an example is shown in which the suspended particles occupy trajectories that do not cross. While the airborne particles moved in the curve inner area initially follow the flow direction of the air flow and are accelerated in the inner radius, they take after the acceleration an approximately straight trajectory. The suspended particles moving in the outer area follow the air flow over a longer distance, but finally collide with the inner surface of the upper plate 5. Whether the trajectories of the suspended particles intersect more as shown in Fig. 21, or rather run parallel as in Fig. 22 is ultimately dependent on the specific flow conditions in the air conveyor channel 3, the density and shape of the suspended particles, the density and speed of the air in the conveying channel 3 moving gases and the selected radii of curvature and dimensions of the air conveyor channel 3.

In order to pollute only a short portion of the inner surface of an air conveying duct 3 with adhering suspended particles, it is advantageous to arrange the double deflection of the air flow in a front section of an air conveying duct 3 viewed in the flow direction. However, the deposition of the invention also works when the double deflection is arranged in a middle or rear portion of a conveyor channel 3. The inlet opening 1 need not be rectangular, but may have any geometry. Thus, for example, it is also conceivable to provide the inlet opening 1 in an annular arrangement, in which case the air conveying channel 3 consists of a flow space, whose outflow opening is arranged centrally to the fan. It is also possible to switch a plurality of deflections according to the invention-optionally with different angles and bending radii-one behind the other, in order thereby to deposit even ultrafine particles.

Claims (17)

1. Device for separating floating particles from an air stream, the device having an inlet opening (1), an air transport channel (3) and an outgoing-air chamber (6) connected to a blower chamber (25), the air transport channel (3) having a bottom plate (4) and an upper plate (5), characterized in that the bottom plate (4) and the upper plate (5) each have a front portion (8; 9) forming the inlet opening (1) and a thereto connected inlet chamber (2) and each have a middle portion (4a, 5a) forming a middle portion of the air transport channel (3), said middle portion of the air transport channel (3) being connected to the outgoing-air chamber (6), wherein the inlet chamber (2) is formed such that at least some of the floating particles carried in the air stream are deposited on the inside surface of the front portion (9) of said upper plate (5).
2. Device according to claim 1, characterized in that the front portions (8; 9) are each substantially arc-shaped.
3. Device according to claim 2, characterized in that the front portion (8) of the bottom plate (4) is substantially three-quarter-circular and the front portion (9) of the upper plate (5) is substantially semicircular.
4. Device according to claim 3, characterized in that the substantially three-quarter-circular form of the front portion (8) of the bottom plate (4) and the substantially semicircular form of the front portion (9) of the upper plate (5) have a common centre point (P1).
5. Device according to any one of the preceding claims, characterized in that the front portion (9) of the upper plate (5) has a first, substantially quarter-circular portion (9a) and a second, substantially quarter-circular portion (9b), and a tongue plate (15) connected to the first portion (9a).
6. Device according to any one of the preceding claims, characterized in that the middle portions (4a; 5a) of the bottom plate (4) and the upper plate (5) are substantially parallel to each other.
7. Device according to any one of the preceding claims, characterized in that the bottom plate (4) has a rear portion forming the bottom of the outgoing-air chamber (6).
8. Device according to any one of the preceding claims, characterized in that the outgoing-air chamber (6) has an inner plate (7) connected to the middle portion (5a) of the upper plate (5) and a back-plate (11) to which the rear portion of the bottom plate (4) is releasably connected.
9. Device according to claim 8, characterized in that the rear portion of the bottom plate (4) is pivotally connected to the back-plate (11).
10. Device according to claim 8 or 9, characterized in that the back-plate (11) of the outgoing-air chamber (6) and the middle portion (4a) of the bottom plate (4) are disposed at an angle of substantially 80° to 90°, wherein the rear portion of bottom plate (4), said rear portion providing the bottom of the outgoing-air chamber (6), is arc-shaped.
11. Device according to claim 8 or 9, characterized in that the inner plate (7) of the outgoing-air chamber (6) and the middle portion (5a) of the upper plate (5) are disposed at an angle of substantially 80° to 90° and the connection between the inner plate (7) and said middle portion (5a) is arc-shaped.
12. Device according to any one of the preceding claims, characterized in that the outgoing-air chamber (6) has an outlet opening (12) of a length which is at least 1.5 times smaller than the length L of the inlet opening (1).
13. Device according to claim 12, characterized in that the blower chamber (25) has an air intake chamber (23) with a lower air intake opening (22) and the air intake opening (22) is connected to the outlet opening (12) of the outgoing-air chamber (6).
14. Device according to claim 13, characterized in that disposed in the region of the air intake opening (22) is a deflecting element (40) consisting of at least one module (43a) having at least two layers (41; 42) and a peripheral wall (49), wherein the layers (41; 42) each have a multiplicity of parallel and spaced rods (43; 44) and wherein the gaps (45) formed by the rods (43) of the one layer (41) are each covered by the rods (44) of the other layer (42).
15. Device according to any one of the preceding claims, characterized in that the blower chamber (25) is connected to a blow-out chamber (26) having a blow-out opening (27).
16. Device according to claim 15, characterized in that a tubular filter portion (50) for separating odour molecules is connected to the blow-out opening (27).
17. Device according to claim 15 or 16, characterized in that the blower chamber (25) and the blow-out chamber (26) are disposed in a shell housing (21).

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