EXTRACTOR HOOD
An extractor hood (10) for the separation of dirt particles, and especially fat and oil droplets from airflow is described. Extractor hood (10) includes a fan unit (18) for the creation of exhaust airflow through the extractor hood and a separator unit (20) to deposit dirt particles from the exhaust air flow. The separator unit (20) defines at least one air duct (25a, 25b). Along the at least one air duct (25a, 25b) an impact element (40) is arranged, featuring at least in certain areas capillary holes (44) for separating dirt particles through the capillary holes (44) along the at least one air duct (25a, 25b).
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The present invention concerns an extractor hood for the removal on dirt particles and especially fat and oil droplets from the airflow.
BACKGROUND OF INVENTIONExtractor hoods are especially deployed in kitchens to filter and remove cooking vapors above a stove or cooking area.
Generally extractor hoods are differentiated in two groups according to the type of airflow. In so-called exhaust air extraction hoods the exhaust air is channeled through ducting to the atmosphere outside the building, where the stove or cooking area is positioned to avoid smells and build-up of dirt within the kitchen and the building in general. In so-called air circulation extractor hoods the air absorbed by the extractor hood is cleaned by a filter and returned to the kitchen.
Conventional extractor hoods usually consist of a separator unit where the dirt particle separation occurs, and a fan or blower unit for removing the exhaust air. Separation can take place by means of separator elements and/or a suitable ducting of the airflow. In EP 1 502 057 for instance an extractor hood is described, in which by means of dual redirection of an airflow containing dirt particles the majority of the dirt particles is already deposited on the impact or separation surfaces.
Generally conventional extractor hoods contain a filter element between the first separation surface and the downstream fan unit, for instance a lint filter. Such lint filter consists of fine-woven fabric, which catches almost all remaining solid materials and dirt particles in the exhaust air before entering the fan unit. The higher the dirt particle concentration in the exhaust air, the faster the lint filter is saturated or blocked and can thus no longer fulfill its filter function. In this case the lint filter must be removed and cleaned or replaced with a new lint filter. It must also be considered that the lint filter presents a resistor within the flow system, which in comparison to an extractor hood without lint filter leads to a higher strain on the fan unit, meaning that the fan unit must produce a higher pressure difference. Higher strain on the fan unit inevitably leads to more operating noise, which can be annoying.
The task of this present invention is to create an extractor hood without aforementioned disadvantages.
SUMMARY OF INVENTIONThe task is solved by an extractor hood according to claim 1. The extractor hood includes a fan unit to create exhaust airflow through the extractor hood and a separator unit for the separation of dirt particles from the exhaust airflow. The separator unit defines at least one air duct, in which the exhaust airflow is several times redirected. Here it is essential that along the at least one air duct one impact element is arranged, which at least in certain areas has capillary holes, so that dirt particles can be separated from the airflow through the capillary holes along the at least one air duct. These capillary holes are of a size to allow dirt particles deposited in the impact surface to be removed by the capillary effect from the impact surface. These dirt particles are no longer exposed to the exhaust airflow on the impact surface and can thus no longer be entrained by the exhaust airflow. Furthermore, the size of the capillary holes must be chosen in such way that the airflow cannot significantly pass through the impact surface. The diameter of the capillary holes is preferably in the range of 0.5 to 5 mm, and further preferably in the range of 1 to 3 mm.
According to another preferred design the separator unit is executed with two mirror-symmetric exhaust air ducts to a center line of the extractor hood, where the at least in certain areas arranged capillary holes in each of the exhaust air ducts have impact surfaces opposing and via a curved connecting area are joined sides of the impact element.
Further advantages of the invention and preferred designs arise from the following concrete description, characteristics and drawings.
A preferred design of the invention is shown in the attached drawings.
The invention is now explained in detail by means of a preferred design.
The attached Figures show extractor hood 10 as well as components of this extractor hood 10 according to the invention. Extractor hood 10 has a hollow cubic or shaft-like casing. Exemplary casing dimensions are: width 60 cm, depth 40 cm and height 80 cm. The casing consists mainly of a frame covered with stainless steel plates. On front 12 of this casing a detachable control knob 14, connected to the control unit (not shown) is attached, which allows the control of extractor hood 10 and especially its fan unit or blower 18. As can be seen in
Within the casing of extractor hood 10 fan unit 18 and separator unit 20 are installed. As described in the following in more detail, during the operation of extractor hood 10 by means of fan unit 18 two exhaust airflows, in
Aforementioned multiple redirection of the airflows in separator unit 20 of extractor hood 10 is mainly achieved by the shape and array of base element 30, impact element 40, central element 50 and ceiling element 60, which are part of separator unit 20. As can be seen especially in
Separator unit 20 consists, as already mentioned, mainly of base element 30, impact element 40, and central element 50 and ceiling element 60. As can be especially seen in cross section drawing
Front section 50a and rear section 50b of central element 50 are each designed in such way and positioned in relation to base element 30 that front section 50a of central element 50 and front section 30a of base element 30 together define the first section of front air duct 25a, and that rear section 50b of central element 50 and rear section 30b of base element 30 together define the first section of rear air duct 25b. As can be especially seen in the cross section drawing of
The shape of the respective first sections of air ducts 25a, 25b, which are defined by the shape and relative array of base element 30 and central element 50, can best be seen in the cross section drawing of
After the previously described first redirection the exhaust air flowing through the first section 20a of separator unit 20 is redirected again due to the further shape of air duct 25a, which is mainly defined by the front bowl-like section 36a of base element 30 in the mainly horizontally running fourth flat section 56a of central element 50. Due to the widening of air duct 25a in this area the airflow is slowed. Again a part of the dirt particles, such as fat and oil droplets, which are still contained in the exhaust airflow, will deposit on the front bowl-like section 36a of base element 30, especially in that part of front bowl-like section 36a bordering central area 34 of base element 30.
As can be seen in the cross section drawing of
As can be seen especially in
After the previously described deposits of dirt particles contained in the airflow especially on the mainly vertically downward running third and fourth sections 55a, 55b of front 50a and/or rear section 50b of central element 50, on front 36a and/or rear bowl-like section 36b of base element 30 and front 40a and/or rear section 40b of impact element 40 the respective airflows through air ducts 25a, 25b are basically free of dirt particles. Any further dirt particles in the airflows through air ducts 25a, 25b are deposited due to two further redirections each, which are affected downstream of impact element 40. The flow direction through air duct 25a is for instance downstream of impact element 40 twice nearly completely redirected, i.e. 180 degrees, by first a right hand bend and then a left hand bend by the design of front section 60a of ceiling element 60 and its array in respect of front section 50a of central element 50 and impact element 40. As described above the route of the airflow along air duct 25b through rear section 20b of separator unit 20 is mirror-symmetric to the previously described route of the airflow along air duct 25a through front section 20a of separator unit 20.
Ceiling element 60 consists mainly of a flat central section 62 with two side sections joining the side rims, running downward in an approx. 70 degree angle with respect to the horizontal, which are front side section 64a and rear side section 64b of ceiling element 60. As can be seen in the cross section drawing of
Preferably the individual elements of separator unit 20, which are base element 30, impact element 40, central element 50 and ceiling element 60 are in such way installed inside extractor hood 10, that these elements can be easily removed and reinstalled for cleaning in extractor hood 10. Preferably base element 30, impact element 40, central element 50 and ceiling element 60 are made from a dishwasher-safe material, such as stainless steel, to be easily washed in a dishwasher in case of soiling for restoring the separation efficiency of separator unit 20. Especially base element 30, which will have to be cleaned most frequently, could be made of two telescopic metal sheets, so that the length of base element 30 can be adjusted to dishwasher dimensions. Separator unit 20 and its elements could be made removable by means of frictionally engaged connectors and/or magnets in extractor hood 10, as shown in
As before described in detail, separator unit 20 of extractor hood 10 defines according to the preferable design of the invention two mirror-symmetric air ducts 25a and 25b with respect to center line B of separator unit 20. But as the expert will have detected, these two air ducts 25a and 25b are not running completely separate through separator unit 20. Especially in the area of impact element 40 the airflows through air ducts 25a and 25b interact beneficially. On the one hand the mutual impact of impact element 40 contributes, if selecting the suitable size of capillary holes 44, that the respective airflow cannot pass through impact element 40. On the other hand a certain gap can be left between V-shaped depression 38 in the central area 34 of base element 30 and the complementary shaped or curved connecting section 42 of impact element 40, since here the airflows from both sides meet and thus prevent continuous flow of further exhaust air in this area. In other words: for the respective exhaust airflows this gap between depression 38 in central area 34 of base element 30 and the complementary shaped connecting section 42 of impact element 40 to a certain degree virtually does not exist. The distance between the V-shaped depression 38 in the central area 34 of base element 30 and the curved connecting section 42 of impact element 40 is preferably in the range of 2 to 10 mm. Further preferred the distance is 5 mm.
Control knob 14 is preferably detachable and, like the elements of separator unit 20, made from a dishwasher-safe material. Control knob 14 of the preferred design of the invention of extractor hood 10 allows in connection with a control unit the control of fan unit 18, for instance the setting of different power levels, as well as the control of further electric components, such as lights. Preferably the setting of different power levels is affected by turning control knob 14 and switching the lights on and off by pressing control knob 14.
The preceding detailed description of the invention only serves as an explanation. The invention by no means is limited to the described design example, but can be adapted by an expert in a suitable way to individual operating requirements, which may deviate from the described operating conditions. The extractor hood according to the invention can for instance be favorably deployed in the industrial and commercial fields as well as in the non-commercial field. The expert will further detect that instead of the described symmetry the separator unit with regard to a section running parallel to the extractor hood front, such symmetry of the separator unit alternatively or in addition with regard to a vertical section of the extractor hood front through its center line can be achieved. It is further conceivable that the described separator unit shows a different geometry, for instance radial symmetric or elliptical. It is only essential that an air duct is formed by the separator unit, along which an impact element is arranged, which at least in certain areas has capillary holes to remove deposited dirt particles on the impact element.
The expert will further detect that the terms used, such as “front” and/or “rear”, “top” and/or “bottom”, “outer” and/or “inner”, etc. are not intended to limit the orientation of the described elements according to the invention, but only serve to differentiate these elements.
REFERENCE SIGN LIST10 Extractor hood
12 Front14 Control knob
16 Top end of extractor hood
18 Fan unit
20 Separator unit
20a Front section of separator unit
20b Rear section of separator unit
22a Front air inlet
22b Rear air inlet
25a Front air duct
25b Rear air duct
30 Base element
30a Front section of base element
30b Rear section of base element
32a Front outer rim
32b Rear outer rim
34 Central area
36a Front bowl-like section
36b Rear bowl-like section
40 Impact element
40a Front section of impact element
40b Rear section of impact element
42 Connecting section
44 Capillary holes
50 Central element
50a Front section of central element
50b Rear section of central element
52a First section of front section of central element
52b First section of rear section of central element
54a Second section of front section of central element
54b Second section of rear section of central element
55a Third section of front section of central element
55b Third section of rear section of central element
56a Fourth section of front section of central element
56b Fourth section of rear section of central element
58a Fifth section of front section of central element
58b Fifth section of rear section of central element
60 Ceiling element
60a Front section of ceiling element
60b Rear section of ceiling element
62 Central section
64a Front side section of ceiling element
64b Rear side section of ceiling element
A Center line of section
B Center line of separator unit
Claims
1. Extractor hood (10) for separation of dirt particles and especially fat and oil droplets from airflow, including:
- a fan unit (18) to create an exhaust airflow through extractor hood (10); and
- a separator unit (20) to deposit dirt particles from the exhaust airflow;
- characterized by
- the separator unit (20) defining at least one air duct (25a, 25b), where along the at least one air duct (25a, 25b) an impact element (40) is arranged, which has at least in certain areas capillary holes (44) for separating dirt particles from the air flow along the at least one air duct (25a, 25b) through the capillary holes (44).
2. Extractor hood (10) according to claim 1, where the impact element (40) in the at least one air duct (25a, 25b) is arranged in such way downstream from a redirection of the redirection flow that dirt particles, due to the centrifugal forces on the impact element (40), are deposited.
3. Extractor hood (10) according to claim 1, where the capillary holes (44) have a diameter of approx. 0.5 to 5 mm.
4. Extractor hood (10) according to claim 3, where the capillary holes (44) have a diameter in the range of approx. 1 to 3 mm.
5. Extractor hood (10) according to claim 1, where the separator unit (20) defines a first air duct (25a) and a second air duct (25b), where the first air duct (25a) with regard to a symmetry plane of the separator unit (20) is mirror-symmetric to the second air duct (25a).
6. Extractor hood (10) according to claim 5, where the impact element (40) is designed both along the first air duct (25a) as well as along the second air duct (25b).
7. Extractor hood (10) according to claim 5, where the impact element (40) has a flat front section (40a), a flat rear section (40b) and a curved connecting section (42), which connects the flat front section (40a) with the flat rear section (40b).
8. Extractor hood (10) according to claim 7, where the impact element (40) has a U-shaped profile, where the flat front section (40a) runs mainly parallel to the flat rear section (40b).
9. Extractor hood (10) according to claim 7, where both the flat front section (40a) as well as the flat rear section (40b) of the impact element are provided with capillary holes.
10. Extractor hood (10) according to claim 9, where the separator unit (20) further includes a base element (30), a central element (50) and a ceiling element (60), which define by their shape and relative array together with impact element (40) the first air duct (25a) and the second air duct (25b).
11. Extractor hood (10) according to claim 10, where the first air duct (25a) and the second air duct (25b) are designed in such way that the airflow direction entering through the air inlets (22a, 22b) into the separator unit (20) is several times redirected to deposit dirt particles.
12. Extractor hood (10) according to claim 11, where the impact element (40) above base element (30) is arranged in such way that between the curved connecting section (42) of impact element (40) and a complementary shaped depression (38) in a central area (34) of the base element a gap is formed.
13. Extractor hood (10) according to claim 12, where the curved connecting section (42) of impact element (40) is designed in such way that dirt particles collecting on the inner side of connecting section (42) can drain off to the depression (38) defined by the central area (34) of base element (30).
14. Extractor hood (10) according to claim 10, where base element (30), impact element (40), central element (50) and ceiling element (60) are designed to be removable from separator unit (20).
15. Extractor hood (10) according to claim 1, where the extractor hood (10) further features a removable control knob (14), with which in connection with a control unit the fan unit power and light of the extractor hood (10) can be controlled.
16. Extractor hood (10) according to claim 8, where both the flat front section (40a) as well as the flat rear section (40b) of the impact element are provided with capillary holes.
17. Extractor hood (10) according to claim 16, where the separator unit (20) further includes a base element (30), a central element (50) and a ceiling element (60), which define by their shape and relative array together with impact element (40) the first air duct (25a) and the second air duct (25b).
18. Extractor hood (10) according to claim 17, where the first air duct (25a) and the second air duct (25b) are designed in such way that the airflow direction entering through the air inlets (22a, 22b) into the separator unit (20) is several times redirected to deposit dirt particles.
19. Extractor hood (10) according to claim 18, where the impact element (40) above base element (30) is arranged in such way that between the curved connecting section (42) of impact element (40) and a complementary shaped depression (38) in a central area (34) of the base element a gap is formed.
20. Extractor hood (10) according to claim 19, where the curved connecting section (42) of impact element (40) is designed in such way that dirt particles collecting on the inner side of connecting section (42) can drain off to the depression (38) defined by the central area (34) of base element (30).
21. Extractor hood (10) according to claim 17, where base element (30), impact element (40), central element (50) and ceiling element (60) are designed to be removable from separator unit (20).
Type: Application
Filed: Sep 16, 2009
Publication Date: Sep 8, 2011
Applicant: BERBEL ABLUFTTECHNIK GMBH (Rheine)
Inventor: Josef Wübker (Munich)
Application Number: 13/119,613
International Classification: F24C 15/20 (20060101);