EP2420738B1 - Extractor hood with an air guidance unit for the suction opening - Google Patents

Description

The invention relates to an extractor hood with an air guide element inserted into the intake opening.

In extractor devices, in particular extractor hoods, it is known to cover the intake of the hood with a baffle plate as far as possible. Here, the suction of contaminated air, which is also referred to below as fumes or vapor, in the extractor device via a gap formed on the edge of the baffle plate between the baffle plate and the hood, in particular the extractor housing. After the passage of Wrasens through the gap, this passes to a behind the baffle plate, for example, in or behind the suction, attached grease filter, are removed from the impurities from the fumes and vapors.

In the EP 1 624 254 A1 An extractor hood is described with a horizontal baffle around which a slot is arranged to form a take-off area. Along a part of the take-off area, a guide plate is arranged, which extends obliquely downward from the take-off area.

From the EP 1 705 430 A1 an extractor hood with a grease filter with two filter plates is known, on which the air is incident obliquely. On the filter plates deflecting elements are arranged, which deflects the air in a direction opposite to the direction of incidence.

In the DE 10 2006 055 001 A1 discloses a Funstabsaugeinrichtung having at least one Dunsteingrenzungsmodul and at least one Dunsteingrenzungsmodul, wherein the Dunsteinzugsmodul is adapted to limit haze to a first space and the mist is sucked through a suction opening from the first space area.

In the EP 2 516 930 A1 a filter unit for a fume extraction device is disclosed with a filter element, which covers the suction opening of the extractor hood at least partially. The filter unit comprises an air baffle, which the Filter element at least surrounds and a baffle plate, which completely covers the filter surface of the filter element. The baffle plate is connected to the air baffle
From the DE 10 2008 020 149 A1 a filter unit is known in which a Wrasenleitblech is combined with a grease filter to a filter unit. Here, a part of the Wrasenleitblechs forms a baffle region and this is surrounded by a Randabsaugbereich in which at least one passage opening is provided. The Randabsaugbereich is inclined in this filter unit with respect to the impact area upwards.

A disadvantage of this filter unit, which in DE 10 2008 020 149 A1 is described that it is necessary for a reliable supply of air, which is sucked through the hood to the passage openings that they are at least partially in a vertical projection on the impact area outside the impact area. As a result, on the one hand, the visual impression of the filter unit is deteriorated and, on the other hand, flow losses can occur due to the direct flow of the grease filter.

Object of the present invention is therefore to provide a cooker hood with an air guide, with which the flow losses can be minimized when inflating a filter element.

The invention is based on the finding that this object can be achieved by an optimized inflow geometry to the passage openings and optimized positioning of the passages.

According to the invention, the object is therefore achieved by an extractor hood with an air guide element inserted into the intake opening, which comprises a Wrasenleitblech having a baffle plate, at least one passage opening, which is above the baffle plate, and a baffle plate at least partially surrounding Einströmgeometrie with at least one inflow surface. The air guide element is characterized in that the inflow surface is inclined upward from the outer region of the Wrasenleitblechs in the direction of the passage opening, wherein at least at a part of the edge of the baffle plate a guide surface is provided which extends from the baffle plate upwards and the inclination angle the guide surface to the horizontal is greater than or equal to the inclination angle between the inflow surface and the horizontal, wherein the Wrasenleitblech is formed by a one-piece plate.

Directional information, as above and below, relate, unless otherwise stated, to the air guiding element in an operating state used in an extractor hood with a horizontal intake opening. Also, angle information to the horizontal or information, such as horizontal or inclined to the horizontal, refer to the air guide in this mode.

As an air guide element is referred to in the context of the invention, an element having at least one passage opening for fumes and vapors and which is mounted in or on the intake of the hood and the vapors and fumes, which are sucked from the hood, to passages in the Air guiding element are passed. The air guide element may have, in addition to the vapor guide plate, for example, one or more filter elements. Alternatively, a filter element is provided separately in the extractor hood above the air guide element. The Wrasenleitblech is according to the invention a one-piece component, which is preferably a metal sheet. The shape of the Wrasenleitblechs in bottom view is preferably rectangular. As a baffle plate is meant a portion of the Wrasenleitblechs which is impermeable to air and by the direct entry of fumes and vapor into the suction port and a provided above the Wrasenleitblechs filter element is prevented. The Einströmgeometrie refers to the part of the Wrasenleitblechs that leads except the baffle plate for a supply of vapors and fumes, which flow to the air deflector from below, to the passage openings.

The baffle plate and the Einströmgeometrie be generated by bending the material of the Wrasenleitblechs. The Wrasenleitblech forms a three-dimensional geometry. The passage openings can be introduced for example by punching before bending. The passage openings are provided in the vicinity of the edge of the baffle plate above the baffle plate in the material of the Wrasenleitblechs. Preferably, through openings are introduced in the vicinity of all four edges of the baffle plate. Preferably, a plurality of passage openings are provided at each of the edges of the baffle plate in the vicinity of the edge thereof, which are separated by webs. In the following, in some explanations, for reasons of clarity, only one passage opening is referred to. However, it goes without saying that these explanations relate to the preferably several passage openings. Through the passage openings of the so-called Randabsaugbereich is formed, can pass through the vapor and vapor into the interior of the air guide element and a filter element.

The inflow surface is used according to the invention for the conduction of anströmendem Wrasen in the edge region of the Wrasenleitblechs to the passage openings of the Wrasenleitblechs. In particular, the inflow angle with which the vapor reaches the passage opening is set via the inflow surface. According to the inflow surface of the inflow geometry is aligned so that it extends from an edge of the Wrasenleitblechs to the passage opening upwards. Since the passage opening is also introduced above the baffle plate, the end of the inflow surface, which faces away from the edge of the Wrasenleitblechs, in a plane which lies above the plane of the baffle plate.

In the case of the inventive air guiding element, the inflow surface of the inflow geometry is inclined upwards in the direction of the passage opening, the amount of deflection which the inflowing vapor must perform in order to reach the passage opening can be minimized. Nevertheless, the passage opening can be arranged due to the Einströmgeometrie invention so that it is not readily visible to the user of the hood. In addition, a filter element in the form of a filter mat or filter cassette is usually arranged above Wrasenleitblech as part of the air guide or as a separate component. This extends parallel to the baffle plate. By an inclined inflow surface, which is directed to the passage opening, the flow direction of Wrasens can be adjusted so that it impinges obliquely on the filter element after passing through the passage opening. As a result, the turbulence of Wrasens can be further reduced.

By the achievable with the air guide element according to the invention obliquely directed to the filter element air or Wrasenströmung low flow losses are achieved and thus obtained high volume flow values relative to the extractor hood.

Finally, the construction height of the Wrasenleitblechs lower than in an air guide, in which a Anströmbereich is directed from an opening upwards by the inventive design of the air guide. In the case of the air-guiding element according to the invention, the height of the Wrasenleitblechs may be limited to the distance between the upper edge of the Anströmfläche and the plane of the baffle plate.

Preferably, the lower edge of the inflow surface lies in the plane of the baffle plate or by a small amount above or below the plane of the baffle plate. In this way, the length of the inflow surface can be maximized and, moreover, a reliable supply of vapor to the passageways located above the impact plate is ensured.

According to a preferred embodiment, the passage opening lies in perpendicular projection on the baffle plate in the surface of the baffle plate. This means that, when the top view of the underside of an air guiding element introduced into a horizontal intake opening of the extractor hood, only the baffle plate and a part of the inflow geometry are visible to the viewer. In particular, at least the inclined inflow surface of the Einströmgeometrie is visible. The view of the passage openings, however, is blocked by the baffle plate. This improves the visual impression of the air guide element, since the visible surfaces represent only continuous surfaces and thus the view of the arranged behind the Wrasenleitblech filter element is thus blocked. In addition, a direct, vertical flow against the filter element of vapors can be prevented, which would lead to an uncontrolled passage of contaminated vapor through the filter element. This arrangement of the passage opening above the baffle plate and concealed in vertical projection of this baffle plate is possible with the air guide element according to the invention, since the individual deflections of the oncoming Wrasens are small despite this position of the passage openings due to the inclined inflow surface. Thus, despite the arrangement of the passage openings, the risk of turbulence of the oncoming Wrasens and condensate associated therewith can be prevented.

At least a part of the edge of the baffle plate according to the invention a guide surface is provided which extends from the baffle plate upwards and the inclination angle of the guide surface to the horizontal is greater than or equal to the inclination angle between the inflow surface and the horizontal. In particular, the guide surface serves to guide vapors which pass along the baffle plate to the inflow geometry which surrounds the baffle plate. The guide surface is generated in particular by a bending up of the edge of the baffle plate by more than 90 °. Here, a Umströmkante is formed, which is preferably rounded, that is, has a radius of curvature greater than zero. The area which is directed upwards and inwards after bending up the edges of the baffle plate, forms a guide surface to which the passage opening adjoins. By there is a Umströmkante with subsequent guide surface at the edge of the baffle plate, on the one hand Wrasen, which passes from the baffle plate to the Einströmgeometrie, passed with small deflections to the passage opening. In addition, by the guide surface and a turbulence of vapor, which is passed over the inflow surface to the passage opening, prevented.

In addition, by the angle of inclination between the horizontal and the guide surface is greater than the inclination angle of the inflow surface to the horizontal, a tapering of the Einströmgeometrie is achieved to the passage opening. It has been found that at such an angular ratio the flow losses are reduced and thus the volume flow values of the extractor hood are improved overall.

The angle of inclination of the guide surface to the horizontal is according to the invention is small and may for example be in the range of 30-70 °, preferably in the range of 45 ° -60 °. Flow simulations and practical measurements have shown that, in particular with a rounded overflow edge and its outlet over the guide surface at an oblique angle α of less than 60 °, preferably less than 45 ° to the filter element, particularly low values for the flow losses and thus particularly good volumetric flow rates of the Extractor hood can be achieved.

The angle of inclination of the inflow surface to the horizontal is preferably less than the angle of inclination between the guide surface and horizontal and may for example be in the range of 20 to 60 °.

By the inclination angle of the inflow surface is small, in particular in an embodiment in which the lower edge of the inflow surface is in the region of the plane of the impact plate, the surface of the inflow surface can be maximized.

According to one embodiment, a horizontal connection region, which at least partially forms an inflow surface to form a passage opening, adjoins an inner end of the inflow surface. As the inner end of the inflow surface, the end of the inflow surface is referred to, which is spaced from the edge of the Wrasenleitblechs, that is, facing the baffle plate. The inflow surface thus serves as an extension of the inflow surface, wherein the flow direction of vapor is changed from the inflow surface to the inflow surface, before the vapor enters through the passage opening in the air guide element. By the inflow area merges into a horizontal area, the Einströmgeometrie is also tapered. The length of the inflow surface, that is to say the extent of the inflow surface inward, is however preferably kept low.

The passage opening preferably extends over a part of the connection area and over part of a transition area connecting the connection area with the baffle plate. The transition region, in which the guide surface is formed, is inclined inwardly from the edge of the baffle plate. By extending the passage opening from the connection area into this transition area, the size of the opening can be maximized.

The passage opening may be positioned so that the end of the passage opening in the transition region in perpendicular projection on the baffle plate closer to the edge of the baffle plate than the end of the passage opening in the connecting region in a perpendicular projection on the baffle plate. In this way, an escape of vapor, which gets along the inflow surface and the inflow surface to the passage opening, can be prevented downwards. alternative but it is also possible that the two ends of the passage opening lie in vertical projection one above the other.

According to one embodiment, the Wrasenleitblech on two opposite edge regions each have an inflow surface. The two edge regions on which the inflow surfaces are provided, preferably represent the front and rear edge region of the Wrasenleitbleches with an air guide inserted into the intake of the hood. At the other two edges, the Einströmgeometrie may be limited to a horizontal inflow. It has been found that the provision of inflow surfaces at the front and rear edge of the Wrasenleitblechs are sufficient to reduce the flow losses at the air guide element so far that good volume flow values of the hood can be obtained.

Alternatively, however, an inflow surface can also be provided on all four edge regions of the Wrasenleitblechs. This embodiment has the advantage that the supply of vapor to the passage openings on all four edges of the baffle plate is alike. In particular, in this embodiment, a converging on all sides obliquely to a rear or above the Wrasenleitbleches filter element is achieved.

Furthermore, it is within the scope of the present invention to use a Wrasenleitblech in which only three edge regions of the baffle plate passage openings are provided. Also in this embodiment, an inflow surface may be provided at two opposite edge regions of the Wrasenleitblechs or at all four edge regions. The advantage of the recess of passage openings on one side of the baffle plate is the possibility on this side grease or oil that accumulates in the Wrasenleitblech catch or at least prevent its dripping. This embodiment is particularly preferred for extractor hood, in which the suction port is inclined to the horizontal. In these hoods, the air guide can be used so that the closed side of the baffle plate is directed to the rear. With the inflow geometry according to the invention, nevertheless, sufficient penetration of vapor into the air-guiding element can be ensured via the three sides provided with passage openings.

The Wrasenleitblech is formed according to the invention by a one-piece, bent sheet. In this way, the overall structure of the air guide element and thus also its production is simplified Moreover, in this embodiment, no separate connection elements, for example for connecting the baffle plate with the Einströmgeometrie required, which could lead to disturbance of the flow and thus turbulence of Wrasens. In the case of a one-piece sheet metal, the connection between the impact plate and the inflow surface can be effected via webs which are present between the passage openings. These webs are obtained by punching out the material in the region of the passage opening and are thus aligned with the guide surface and the inflow surface and obstruct the flow path of the vapor only directly at the inlet into the passage opening.

According to a preferred embodiment, the air guide element comprises at least one filter element, which is held above the baffle plate. By representing the filter element or the filter elements part of the air guide element, the relative orientation of the individual surfaces of the Wrasenleitblechs can be set to the filter element already in the production of the air guide. An alignment of the filter element when inserting the air guide in the intake of the hood is therefore not required. Preferably, the air guide element has at least one flat filter element which is arranged parallel to the baffle plate. The filter element may, for example, rest on the upper side of the connection region and thus on the upper side of an inflow surface optionally formed in this region and be connected to the vapor guide plate.

With the air guiding element according to the invention as few and very small deflection points are arranged on the way up to the filter element fluidly. At deflection points, there is always the risk of additional turbulence, which has the consequence of condensate formation. This can be avoided with the spoiler element according to the invention.

Figur 1:

eine schematische, perspektivische Unteransicht einer ersten Ausführungsform des erfindungsgemäßen Luftleitelementes;

Figur 2:

eine schematische, perspektivische Unteransicht einer zweiten Ausführungsform des erfindungsgemäßen Luftleitelementes;

Figur 3:

eine schematische, perspektivische Schnittansicht durch den Randbereich der Ausführungsform des erfindungsgemäßen Luftleitelementes nach Figur 2;

Figur 4:

eine schematische, perspektivische Schnittansicht durch den Randbereich der Ausführungsform des erfindungsgemäßen Luftleitelementes nach Figur 1;

Figur 5:

eine schematische Darstellung der Wrasenströmung an dem Luftleitelement nach Figur 3; und

Figur 6:

eine schematische Darstellung der Wrasenströmung an dem Luftleitelement nach Figur 4.

The invention will be explained again below with reference to the accompanying drawings. Hereby show:

FIG. 1:

a schematic, perspective bottom view of a first embodiment of the air guide element according to the invention;

FIG. 2:

a schematic, perspective bottom view of a second embodiment of the air guide element according to the invention;

FIG. 3:

a schematic, perspective sectional view through the edge region of the embodiment of the air guide element according to the invention FIG. 2 ;

FIG. 4:

a schematic, perspective sectional view through the edge region of the embodiment of the air guide element according to the invention FIG. 1 ;

FIG. 5:

a schematic representation of the Wrasenströmung on the air guide after FIG. 3 ; and

FIG. 6:

a schematic representation of the Wrasenströmung on the air guide after FIG. 4 ,

In FIG. 1 an embodiment of the air guide element 1 according to the invention is shown. In the illustrated embodiment, the air guiding element 1 comprises a vapor guide plate 10 and a base element 2, of which only the connecting straps 21 are visible in the illustrated view. The middle region of the Wrasenleitblechs 10 is formed by a baffle plate 11, which is a flat rectangular plate. The baffle plate 11 is surrounded by a Einströmgeometrie 12. In the illustrated embodiment, the inflow geometry 12 comprises four inflow surfaces 120, which extend from the four edges of the Wrasenleitblechs 10 inwardly in the direction of the baffle plate 11. The inflow surfaces 120 are adjoined in each case by an inflow surface 122. As will be explained in more detail later, the inflow surface 122 is connected to the baffle plate 11 via the Umströmkanten 14, which form the edges of the baffle plate 14.

In the in FIG. 2 shown embodiment differs from the embodiment according to FIG. 1 merely in that only two inflow surfaces 120 are provided in the inflow geometry 12. These are located at the short edges of the Wrasenleitblechs 10. At the two long edges of the Wrasenleitblechs 10 only horizontal inflow surfaces 122 are provided. In the inserted state in an intake opening of an extractor hood (not shown) The short edges of the Wrasenleitblechs are at the front and the back of the intake.

In FIG. 3 is a schematic sectional view of the embodiment according to FIG. 2 shown. From this view, the structure of the Wrasenleitblechs 10 can be seen more accurately. From the outer edge of the Wrasenleitblechs 10 from an inflow surface 120 extends obliquely upward and merges into a horizontally extending connecting portion 121. The inclination angle β of the inflow surface 120 to the horizontal is preferably in a range of 20 ° to 60 °. The end of the connecting region 121, which faces away from the inflow surface 120, is bent downwards and outwards from the horizontal and merges into a transition region 140. This transition region 140 is at an inclination angle α to the connection region 121. The inclination angle α is greater than or equal to the inclination angle β of the inflow surface 120. The transition region 140 terminates at an inflow edge 14, which forms the edge of the impact plate 11. The baffle plate 11 is aligned horizontally. The baffle plate 11, the transition portion 140 and the connecting portion 121 together form a Z-shape.

In the transition region 140 and the connecting portion 121 through openings 13 are introduced. These are separated from one another by webs 15 which extend over part of the length of the transition region 140 and the connecting region 121. The passage openings 13 thus extend from the transition region 140 into the connection region 121. The part of the transition region 140 which is not covered by the passage opening 13 forms a guide surface 141 and the part of the connection region 121 which is not covered by the passage opening 13 In vertical projection, in the illustrated embodiment, the end of the passage opening 13 located in the connection portion 121 lies farther inside the surface of the baffle plate, that is farther from the edge of the baffle plate 14 than the end of the passage opening 13, which lies in the transition region 140. However, the two longitudinal ends of the passage opening 13 may also lie one above the other in a vertical projection.

The Umströmkante 14 of the baffle plate 11 is in a perpendicular projection on the connecting portion 121 in the inflow 122. However, it is also possible that the flow-around edge 14 coincides with the end of the inflow surface 120 in perpendicular projection onto the connection region 121, that is, covers it. In this case, it is optionally possible to dispense with an inflow surface in the connection region 121 and this can consist exclusively of the webs 15 between the passage openings 13 and the passage openings 13.

In FIG. 4 is a schematic, perspective sectional view of the embodiment of the air guide 1 according to FIG. 1 shown. The structure of this embodiment substantially corresponds to that in FIG FIG. 3 shown construction and will therefore not be explained again in detail. Identical components of the two embodiments are provided with the same reference numerals. However, at the in FIG. 4 shown embodiment, that at each of four edges of the Wrasenleitblechs 10 each an inflow surface 120 is provided. Furthermore, in the embodiment shown in FIG FIG. 4 the basic element 2 of the spoiler 1 partially indicated. This represents in the illustrated embodiment, a frame into which a flat filter element (not shown) can be introduced. The filter element can be held in the frame and in particular abut against the top of the connection region. The connecting lug 21 of the base element, which extends through a side wall of the Wrasenleitblechs 10 therethrough, serves for fastening of the air guide element 1 in the suction opening of a fume hood. However, the connection tab can also be formed on the Wrasenleitblech 10 itself. A basic element 2 according to the in FIG. 4 shown can also according to the embodiment Figures 2 and 3 be used.

The flow direction of the vapors which flow to the air guide element 1, with reference to the FIGS. 5 and 6 described in more detail.

Steam and vapor, which flow to the air guide 1 from below, first reach the baffle plate 11 and the outer edge of the Wrasenleitblechs 10. The outer edge of the Wrasenleitblechs 10 and the baffle plate 10 are in the illustrated embodiments on the same horizontal plane. The air which impinges on the baffle plate 10 is passed along this to the inflow geometry 12 at the edges of the Wrasenleitblechs 10. Air that impinges on the inflow geometry 12 from below, is along the inflow surface 120 to the Admitted inflow 122 and enters from there into the passage opening 13 a. Also, air, which reaches the inflow surface 122 directly from below or is guided via the baffle plate 11 to the inflow surface 122, is due to the flow which forms along the inflow surface 120, passed to the passage opening 13.

A number of advantages can be achieved with the present invention. In particular, an optimized flow and air flow in the Randansaugbereich is obtained. Furthermore, the flow losses can be reduced by the fact that the filter element is flowed at an acute angle of the sucked vapor. Finally, the optimized flow geometry according to the invention, which leads to as few flow losses as possible, can be realized on an extremely small installation depth.

LIST OF REFERENCE NUMBERS

1

air guide

10

Wrasenleitblech

11

flapper

12

Einströmgeometrie

120

inflow area

121

connecting area

122

inflow area

13

Through opening

14

Umströmkante

140

Transition area

141

baffle

15

web

2

basic element

21

connecting strap

Claims (7)

1. Extractor hood with an air guidance element which is inserted into the suction opening and which comprises a vapour guide plate (10) which has a baffle plate (11), at least one through opening (13), which lies above the baffle plate (11), and an inflow geometry (12) at least partially surrounding the baffle plate (11) and having at least one inflow surface (120), wherein the inflow surface (120) is upwardly inclined from the outer edge of the vapour guide plate (10) in the direction of the through opening (13), characterised in that a guide surface (141) is provided at least on one part of the edge of the baffle plate (11) and extends upwards from the baffle plate (11) and the angle of inclination (α) of the guide surface (141) with respect to the horizontal is greater than or equal to the angle of inclination (β) between the inflow surface (120) and the horizontal, wherein the vapour guide plate (10) is formed by a single piece of bent sheet metal.
2. Extractor hood according to claim 1, characterised in that the through opening (13) in the vertical projection on the baffle plate (11) is present on the surface of the baffle plate (11).
3. Extractor hood according to one of claims 1 or 2, characterised in that a horizontal connection region (121) adjoins an inner end of the inflow surface (120), said connection region (121) at least partially forming an inflow surface (122) to a through opening (13).
4. Extractor hood according to claim 3, characterised in that the through opening (13) extends across part of the connection region (140) and across part of a transition region (140) connecting the connection region (140) to the baffle plate (11).
5. Extractor hood according to claim 4, characterised in that the end of the through opening (13) in the transition region (140) in the vertical projection on the baffle plate (11) lies closer to the edge of the baffle plate (11) than the end of the through opening (13) in the connection region (121) in the vertical projection on the baffle plate (11).
6. Extractor hood according to one of claims 1 to 5, characterised in that the vapour guide plate (10) has an inflow surface (120) on two opposing edge regions.
7. Extractor hood according to one of claims 1 to 6, characterised in that this comprises at least one filter element which is held above the baffle plate (11).

Images