Grease extraction system, particulate extractor, and method
A grease extractor is provided with a frame, a first array of convex baffle plates, a second array of concave baffle plates, and a steam ejector. The first array of convex baffle plates is carried by the frame in spaced-apart relation, so as to provide a first ventilation slot between adjacent, convex baffle plates. The second array of concave baffle plates is carried by the frame in spaced-apart relation, so as to provide a second ventilation slot between adjacent, concave baffle plates. A selected one of the concave baffle plates is offset from a respective, downstream convex baffle plate such that the first ventilation slot opens into a base portion of the concave baffle plate. The steam ejector is supported proximate each ventilation slot for delivering steam into the first ventilation slot and toward a respective one of the concave baffle plates. A method is also provided.
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/637,264, which was filed Dec. 17, 2004, and which is incorporated by reference herein.
TECHNICAL FIELDThe present invention pertains to kitchen ventilation systems. More particularly, the present invention relates to grease extractors for kitchen ventilating systems, such as kitchen exhaust hood assemblies.
BACKGROUND OF THE INVENTIONIt is previously known to use porous filter-type grease extractors supported within a frame to extract grease from contaminated air that is being drawn into a kitchen exhaust hood assembly. One such construction uses a metal mesh that is contained within an outer peripheral frame to provide a modular grease filter for an exhaust hood. However, porous filter-type grease extractors tend to be relatively inefficient at extracting grease from contaminated air in an exhaust hood. Hence, grease is typically carried into exhaust ducts and components of the exhaust hood, which reduces airflow over time and creates a potential fire hazard. Secondly, the screens tend to clog, and they have to be removed and cleaned periodically.
Another technique uses a series of baffles configured in a frame to extract grease and other contaminants from air that is being drawn into a kitchen exhaust hood assembly. U.S. Pat. No. 3,945,812 discloses one such baffle-type grease extractor that is configured in a removable, modular assembly that can be used to replace porous-type grease extractors. The modular assembly facilitates installation and cleaning of the baffle-type grease extractor. The baffles creates a circuitous airflow paths that redirect and divert exhaust air that is being drawn into an exhaust hood which causes grease and contaminants to be deposited onto the interior surfaces of the baffles. However, the circuitous paths do not trap enough of the grease, in many cases, more than half of the grease may still pass through the grease extractor and up into the ventilation system of the hood, including the airflow ducts and hood. This has an undesirable effect of reducing airflow and efficiency of the ventilation system. Secondly, buildup of grease within the ventilation system, downstream of the baffles, increases a risk of fires in the ventilation system. In many cases, the baffle-type grease extractors need to be periodically removed and cleaned.
Accordingly, further improvements are needed for grease extractors in order to increase efficiency and performance of grease extraction systems for cooking environments including those for commercial (or restaurant) usage and home usage.
SUMMARY OF THE INVENTIONA highly efficient grease extractor includes multiple arrays of baffle plates that are configured to provide a circuitous path in combination with a steam ejector in order to generate more efficient and effective extraction of grease from ventilated cooking gases and air.
According to one aspect, a grease extractor is provided with a frame, a first array of convex baffle plates, a second array of concave baffle plates, and a steam ejector. The first array of convex baffle plates is carried by the frame in spaced-apart relation, so as to provide a first ventilation slot between adjacent, convex baffle plates. The second array of concave baffle plates is carried by the frame in spaced-apart relation, so as to provide a second ventilation slot between adjacent, concave baffle plates. A selected one of the concave baffle plates is offset from a respective, downstream convex baffle plate such that the first ventilation slot opens into a base portion of the concave baffle plate. The steam ejector is supported proximate each ventilation slot for delivering steam into the first ventilation slot and toward a respective one of the concave baffle plates.
According to another aspect, a ventilation filter for a cooking device is provided with an array of parallel, spaced-apart convex channels, an array of parallel, spaced-apart concave channels, an array of parallel, spaced-apart plates, and a steam pipe. The array of parallel, spaced-apart concave channels is offset a half-mode and internested with the convex channels to provide circuitous flow paths therebetween. The array of parallel, spaced-apart plates is offset a half-mode from the concave channels. The steam pipe is provided between adjacent ones of the concave channels and is configured to direct steam into a slot between the adjacent convex channels.
According to yet another aspect, a method is provided for extracting grease from cooking exhaust fumes. The method includes: providing a grease extractor with convex baffle plates, adjacent axial slots, and concave baffle plates offset a half-mode from the convex baffle plates; directing flow over the convex baffle plates and into the adjacent axial slots; delivering steam into the axial slots in a same direction as flowing exhaust fumes; splitting flow of exhaust fumes and steam exiting the axial slots into the concave baffle plates into lateral, opposing directions, and directing the flow into a direction reversing the direction of flow in the axial slots, and into the concave side of the convex baffle plates; and diverting flow from the concave side of the convex baffle plates into the second axial slots provided between adjacent concave baffle plates.
One advantage is provided by more efficient and thorough extraction of grease from exhaust fumes entering a kitchen ventilation system.
BRIEF DESCRIPTION OF THE DRAWINGSPreferred embodiments of the invention are described below with reference to the following accompanying drawings.
This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
Reference will now be made to preferred embodiments of Applicant's invention comprising grease extractors for use with kitchen ventilation systems over kitchen ranges, grills, griddles, and/or fryers. While the invention is described by way of preferred embodiments, it is understood that the description is not intended to limit the invention to such embodiments, but is intended to cover alternatives, equivalents, and modifications which may be broader than the embodiments, but which are included within the scope of the appended claims.
In an effort to prevent obscuring the invention at hand, only details germane to implementing the invention will be described in great detail, with presently understood peripheral details being attached as an appendix, as needed, as being presently understood in the art.
Hood manifold 14 mates with an exhaust duct 18 that draws air, fumes, contaminants and grease up into grease extractors 20 where the grease and contaminants are separated from the air and fumes and collected for delivery via an effluent pipe 26 for collection within a waste housing, or weir 28. Exhaust duct 18 is couple at a downstream location with a ventilation exhaust fan (not shown) that pulls exhaust through grease extractors 20 up into duct 18 for delivery (typically) outside of a building.
Hot steam is generated at a source, such as a steam generator 32 for delivery via a steam inlet pipe 30 to grease extractors 20 by way of individual steam inlet assemblies 44 into each grease extractor 20. The steam helps capture grease particles and contaminants that are airborne within the air and fumes being pulled through grease extractors 20. Assemblies 44 are covered up by a metal facia plate 24 that is removably mounted onto grease extractors 20.
Accumulated grease and contaminants are collected in the bottom of each grease extractor 20 where they are drawn out via individual effluent outlet assemblies 46 for delivery via effluent pipe 26 to waste housing 28. Assemblies 46 are covered up by a metal facia plate 22 that is removably mounted onto grease extractors 20.
As shown in
Hood 1012 also includes a fire suppression system comprising supply pipes 50 and fire suppression emitters 52 that suspend in front of front wall 1016. Either fire retardant, or water, can be emitted from such system in order to put out cooking fires.
Additionally, baffles 64 and 66 of array 54 are constructed from stainless steel according to one configuration. Also, baffles 68 of array 56 are constructed from aluminum. Likewise, baffles 70 and 72 are also constructed from aluminum. Finally, diffuser panel 74 is constructed from a sheet of 1/16″ thick aluminum that is perforated with apertures, or holes (see
As shown in
Baffles 64 and 66 of first array 54 each have a flange 94 that forms a convex portion. Each flange 94 turns back toward pipe 76 to form a reverse flange 96. Slot 78 is provided between adjacent flanges 94 for passage of contaminated air, as well as for injection of steam therein from apertures along steam pipe 76. Furthermore, baffles 70 and 72 include concave portions provided by flanges 100. A front flange 92 covers a square tube 76 that forms an effluent collection manifold 130 that collects grease and contaminants via drain holes 97 (see
In operation, contaminated air is drawn through slots 78 and into grease extractor 20 in response to a kitchen ventilation system pulling air through extractor 20. The contaminated air goes through slot 78 and splits into two diverging paths 82 and 84 which double back 180 degrees. The air then reverses again after clearing flange 98 of baffle 68. The air then follows a respective path 86 and 88 when the split paths rejoin and exit via slot 80. The air further passes through perforations in perforated diffuser panel 74 before being drawn through an exhaust duct (not shown).
According to one implementation, steam in the range of 140-180 degrees Farenheight is delivered into slots 78. When contaminated air drops below approximately 140 degrees Farenheight, suspended contaminants and grease tend to precipitate out from the steam and onto baffle surfaces. As the steam and contaminated air is mixed in slot 78, the contaminants and grease are put into suspension. After contacting aluminum baffles 68 (which tend to cool down due to the relatively good thermal conductivity of aluminum), grease and contaminants tend to collect on the surfaces of baffle 68. Additionally, grease and contaminants also tend to collect onto the surfaces of baffles 70 and 72. The grease and contaminants also tend to slide downward and collect along the bottom edge of each baffle. As grease extractor 20 is tilted forward when in use, the grease and contaminants also tend to slide forward for collection and drainage through holes 97 (see
By providing smooth surfaces on baffles 64, 66, 70 and 72, accumulated grease tends to slide down the surfaces and collect at the bottom for delivery through holes 97 and 99. According to one construction, steam is continuously emitted via holes 77. According to another construction, steam is intermittently emitted via holes 77.
Steam pipe 13 is shown prior to assembly in
In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.
Claims
1. A grease extractor, comprising:
- a frame;
- a first array of convex baffle plates carried by the frame in spaced-apart relation providing a first ventilation slot between adjacent, convex baffle plates;
- a second array of concave baffle plates carried by the frame in spaced-apart relation defining a second ventilation slot between adjacent, concave baffle plates, a selected concave baffle plate offset from a respective, downstream convex baffle plate such that the first ventilation slot opens into a base portion of the concave baffle plate; and
- a steam ejector supported proximate each ventilation slot for delivering steam into the first ventilation slot and toward a respective one of the concave baffle plates.
2. The grease extractor of claim 1 wherein a selected concave baffle plate is offset a half-mode from a respective convex baffle plate.
3. The grease extractor of claim 1 further comprising a third array of baffle plates in spaced-apart relation and defining a third ventilation slot therebetween and downstream of the second array of baffle plates.
4. The grease extractor of claim 3 wherein each baffle plate in the third array of baffle plates is supported offset a half-mode from a respective one of the concave baffle plates in the second array such that the third ventilation slot aligns substantially with the base of the concave baffle plate and the first ventilation slot.
5. The grease extractor of claim 4 wherein the first array, the second array and the third array of baffles plates are each in substantially parallel relation with one another.
6. The grease extractor of claim 1 wherein the first array of convex baffle plates and the second array of concave baffle plates are provided in substantially parallel, spaced-apart relation.
7. The grease extractor of claim 3 wherein the baffle plates in the third array are convex baffle plates.
8. The grease extractor of claim 7 wherein the convex baffle plates in the third array are u-shaped plates having a base and a pair of substantially parallel, right-angle legs.
9. The grease extractor of claim 1 wherein the convex baffle plates each comprise a central, convex portion and a pair of concave, turned-back outer portions, wherein the first ventilation slot is provided between adjacent turned-back portions of respective, adjacent convex portions.
10. The grease extractor of claim 6 wherein the turned-back outer portions are parallel and provide the first ventilation slot between adjacent turned-back portions of adjacent, respective convex baffle plates.
11. The grease extractor of claim 6 wherein the turned-back outer portions are parallel to a flow direction through the grease extractor and perpendicular to the first, second, and third arrays of baffle plates.
12. The grease extractor of claim 1 wherein the concave baffle plates are more thermally conductive than the convex baffle plates.
13. The grease extractor of claim 3 wherein the third array of baffle plates are more thermally conductive than the convex baffle plates.
14. The grease extractor of claim 1 further comprising a third array of baffle plates in substantially spaced-apart relation and defining a third ventilation slot therebetween and downstream of the second array of baffle plates
15. The grease extractor of claim 13 wherein the concave baffle plates and the third array of baffle plates are each more thermally conductive than the convex baffle plates.
16. The grease extractor of claim 12 wherein the concave baffle plates are made from aluminum.
17. The grease extractor of claim 13 wherein the baffle plates in the third array are made from aluminum.
18. The grease extractor of claim 1 wherein the steam ejector comprises a steam supply rod provided upstream of the first ventilation slot, the steam supply rod including a plurality of spaced-apart ejection nozzles on a downstream side of the rod configured to eject steam into the first ventilation slot.
19. The grease extractor of claim 18 wherein the steam supply rod is substantially parallel to the first ventilation slot.
20. The grease extractor of claim 1 wherein the frame is configured to support the first array and the second array and encircle an outer periphery of the first array and the second array.
21. The grease extractor of claim 20 wherein a top edge of the frame includes a steam manifold communicating with the steam ejector to deliver a supply of steam to the steam ejector.
22. The grease extractor of claim 21 wherein the steam ejector comprises a steam supply rod provided upstream of and parallel to the first ventilation slot, the steam supply rod including a plurality of spaced-apart ejection nozzles on a downstream side of the rod configured to eject steam into the first ventilation slot.
23. The grease extractor of claim 20 further comprising a plurality of drainage apertures provided along a bottom edge of the frame for draining grease that accumulates along the bottom edge from the concave and convex baffle plates.
24. The grease extractor of claim 23 wherein the drainage apertures are provided upstream of the first ventilation slots.
25. The grease extractor of claim 23 wherein the drainage apertures are provided downstream of the first ventilation slots and upstream of the second ventilation slots.
26. The grease extractor of claim 23 wherein the drainage apertures are provided upstream of the first ventilation slots.
27. The grease extractor of claim 23 wherein the frame includes a drainage manifold along a bottom edge of the frame communicating with the drainage apertures to accumulate grease from the drainage apertures for collection and transfer to a collection device.
28. The grease extractor of claim 1 wherein the convex baffle plates of the first array have a u-shaped, convex cross-sectional configuration relative to an upstream side of the grease extractor.
29. The grease extractor of claim 1 wherein the concave baffle plates of the second array have a u-shaped concave cross-sectional configuration relative to an upstream side of the grease extractor.
30. The grease extractor of claim 29 wherein the u-shaped concave baffle plates have square corners between a central base and a pair of opposed edges.
31. The grease extractor of claim 30 wherein the square corners have a bend radius.
32. The grease extractor of claim 30 further comprising a third array of baffle plates in substantially spaced-apart relation and defining a third ventilation slot therebetween and downstream of the second array of baffle plates, and wherein the central base includes an angled channel provided on a back face of the central base configured to divert flow into a respective third ventilation slot.
33. The grease extractor of claim 1 wherein each of the concave baffle plates includes a pair of lateral edges each folded back to provide an inverted cuff-portion.
34. A ventilation filter for a cooking device, comprising:
- an array of parallel, spaced-apart convex channels;
- an array of parallel, spaced-apart concave channels offset a half-mode and internested with the convex channels to provide circuitous flow paths therebetween;
- an array of parallel, spaced-apart plates offset a half-mode from the concave channels; and
- a steam pipe provided between adjacent ones of the concave channels and configured to direct steam into a slot between the adjacent convex channels.
35. The ventilation filter of claim 34 wherein slots are provided between adjacent convex channels.
36. The ventilation filter of claim 34 wherein slots are provided between adjacent concave channels.
37. The ventilation filter of claim 34 wherein slots are provided between adjacent plates.
38. The ventilation filter of claim 34 wherein each plate includes an edge flange extending in a forward direction.
39. The ventilation filter of claim 38 wherein a pair of the edge flanges on one of the plates provides a concave plate.
40. The ventilation filter of claim 34 further comprising a steam plenum configured to deliver steam to the steam pipe.
41. A method for extracting grease from cooking exhaust fumes, comprising:
- providing a grease extractor with convex baffle plates, adjacent axial slots, and concave baffle plates offset a half-mode from the convex baffle plates;
- directing flow over the convex baffle plates and into the adjacent axial slots;
- delivering steam into the axial slots in a same direction as flowing exhaust fumes;
- splitting flow of exhaust fumes and steam exiting the axial slots into the concave baffle plates into lateral, opposing directions, and directing the flow into a direction reversing the direction of flow in the axial slots, and into the concave side of the convex baffle plates; and
- diverting flow from the concave side of the convex baffle plates into the second axial slots provided between adjacent concave baffle plates.
42. The method of claim 41 further comprising directing flow from the second axial slots along the concave side of the convex baffle plates and through a third longitudinal slot in a third array of baffle plates.
43. The method of claim 41 further comprising providing a base ridge on a bottom, outside portion of the concave baffle plates and directing flow along the bottom of the concave baffle plates into the third longitudinal slot.
44. The method of claim 41 further comprising providing a second array of baffle plates having a higher thermal conductivity than the first array of baffle plates, and collecting grease on the second baffle plates at least in part from thermal cooling of the second baffle plates relative to the first baffle plates.
45. The method of claim 41 wherein the first baffle plates have an m-shaped cross-sectional configuration viewed from an upstream side of the grease extractor.
46. The method of claim 45 wherein the m-shaped baffle plates have a pair of vertical, outer legs.
47. The method of claim 41 wherein the second baffle plates have a u-shaped cross-sectional configuration viewed from a downstream side of the grease extractor.
48. The method of claim 47 wherein the u-shaped baffle plates have right angle corners.
49. The method of claim 41 further comprising providing drainage apertures along a bottom edge of the grease extractor, and draining accumulated grease through the apertures.
Type: Application
Filed: Dec 7, 2005
Publication Date: Jul 20, 2006
Inventor: Nikolaus Heilman (Carnation, WA)
Application Number: 11/296,744
International Classification: F24C 15/20 (20060101);