CA2081823A1 - Range hood fan assembly - Google Patents
Range hood fan assemblyInfo
- Publication number
- CA2081823A1 CA2081823A1 CA 2081823 CA2081823A CA2081823A1 CA 2081823 A1 CA2081823 A1 CA 2081823A1 CA 2081823 CA2081823 CA 2081823 CA 2081823 A CA2081823 A CA 2081823A CA 2081823 A1 CA2081823 A1 CA 2081823A1
- Authority
- CA
- Canada
- Prior art keywords
- casing
- range hood
- lobes
- fan
- baffle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
RANGE HOOD FAN ASSEMBLY
Abstract of the Disclosure A kitchen range hood fan for exhausting grease-laden air generated during cooking. The range hood fan has dual, counter-rotating centrifugal blowers and a generally B-shaped fan casing for enclosing the blowers. A central, baffle divides the casing into two lobes which are gen-erally volute-shaped.
Abstract of the Disclosure A kitchen range hood fan for exhausting grease-laden air generated during cooking. The range hood fan has dual, counter-rotating centrifugal blowers and a generally B-shaped fan casing for enclosing the blowers. A central, baffle divides the casing into two lobes which are gen-erally volute-shaped.
Description
2 ~
RA~C~E HOOD F~N ASSEMBL~
Field of the Invention This application pertains to a range hood ~an for exhausting grease-laden air general:ed during cooking.
More particularly, this application relates to a range hood fan having dual, counter-rotating centrifugal blowers and a generally B-shaped fan casing for enclosing the blowers.
Background of the Invention Range hoods are typically installed directly above kitchen elements or burners to ventilate steam, grease and related odours generated during cooking.
Various range hood ventilators having centrifugal blowers are known in the prior art. For example, United States patent No. 3,719,137, which issued to Gould on 6 March, 1973, discloses a ventilating system which includes dual blowers enclosed within a vertically oriented double-lobed shroud. The shroud consists of a U-shaped casing and a volute-shaped casing, each housing one of the blowers. The blowers may be operated individually or in tandem depending upon the exhaust speeds required.
United States patent No. 3,109,358, which issued to Meyer on 5 November, 1963, teaches a range hood ventila-tor having a pair of counter-rotating blowers. The blowers are housed in a casing having generally cylindrically-shaped lobes. The blowers channel the ventilated air to a single outlet duct.
United States patent No. 4,500,331, which issued to Cheng on February 19, 1985 discloses a kitchen exhaust apparatus having a volute-shaped housing for enclosing a single centrifugal fan. The Cheng apparatus is contoured to facilitate drainage of oleaginous and liquid particles entrained in the ventilated air. Such particles condense 2 ~ 2 3 on the inner wall of the housing due to the action of the centrifu~al fan.
As a result of the design of conventional fan casings housing dual blowers, the blowe~rs tend to generate turbulent air streams proximate the exhaust outlet(s) which results in reduced fan efficiency and output. Another primary drawback of many prior art range hood fan assem-blies is that the fan blowers are not positioned for maximum exhaust output. Often the blowers are offset away from the cooking elements which allows vapours to circulate before being expelled from the kitchen.
The need has therefore arisen for a range hood fan which employs the combined advantages o~ counter-rotating centrifugal blowers and a casing having volute-shaped lobes surrounding the blowers for enhancing fan efficiency.
Summary of the Invention In accordance with the invention there is pro-vided a range hood fan comprising a generally B-shaped casing having a central baffle dividing the casing into generally volute-shaped first and second lobes; and first and second count~r-rotating centrifugal blowers mountable in respective first and second casing lobes.
Preferably the fan casing includes a vertical sidewall and a bottom wall having spaced-apart first and second air inlet apertures formed therein to allow entry of air into the first and second casing lobes. The range hood fan may also include a panel sealingly covering an open upper end of the casing and having an exhaust outlet formed therein overlying a portion of the baffle. Advantageously, the casing may be removably attachable to the panel.
2 ~ 2 ~
The range hood fan may al50 include a pair of annular grease collection rings removably attachable to the casing botto-m wall underneath the first and second air inlet apertures. The casing bottom wall may bs downwardly inclined relative to the casing sidewall to ~acilitate drainage of grease from the casing into the grease collec-tion rings.
Preferably, the range hood also includes at least one grease collection cup removably attachable to an undersurface of the range hood fan in communicAtion with the grease collection rings. Each of the grease collection rings may have an outlet tube in communication with a corresponding collection cup, the upper surface of the collection rings being inclined toward the outlet tube to facilitate drainage of grease into the collection cup.
Preferably, the first and second centrifugal blowers are offs~t within respective first and second volute-shaped lobes such that the clearance between the periphery of the blowers and the adjacent casing sidewall increases from a minimum at the air cutoff point of the casing to a maximum in the vicinity of the fan exhaust outlet. The -fan casing is contoured so that the cutoff points of the first and second lobes are immediately adjacent proximate a forward portion of the baffle.
Advantageously, the baffle comprises opposed cylindrically concave sidewalls tapering toward a common apex, the baffle substantially preventing the mixing of air between the first and second casing lobes.
This application also relates to a generally B-shaped fan casing adapted for enclosing a pair of counter-rotating centrifugal blowers, the casing comprising a `` 2 ~ 2 3 central baffle dividing the casing into first and second lobes, each of the first and second lobes being generally volute-shaped for surrounding one of the blowers.
Brief Description of the Drawinqs In drawings which illustrate embodiments of the invention, but which should not be construed as restricting the spirit or scope of the invention in any way, Figure 1 is an exploded, bottom isometric view of the range hood fan of the present invention illustrating the direction of air flow;
Figure 2 is a top plan view of the range hood fan of Figure 1 showing the exhaust outlet formed in the upper range hood panel;
Figure 3 is a sectional view of the range hood fan taken along section lines 3-3 of Figure 2;
Figure 4 is a partially fragmented, bottom plan view of the range hood fan of Figure 1; and Figure 5 is an enlarged, sectional view of a bottom portion of the range hood fan casing illustrating one of the grease collection rings and a corresponding grease collection cup.
Detailed Description of the Preferred Embodiment With reference to Figure 1, range hood fan 10 is mountable above kitchen elements or burners to ventilate steam, grease, and related odours generated during cooking.
Range hood fan 10 includes a metal housing 12 having an upper panel 14. A fan casing 16 is securely mounted onto 2 ~
range hood panel 14. As described further below, panel 14 has an exhaust outlet 34 formed therein for enabling expulsion of ventilated air from fan casing 16 into ducting (not shown) leading to the exterior of the dwelling in question.
Preferably, fan casing 16 is formed o* moulded plastic and is removably connected to panel 14 with fas-teners, such as nuts and bolts. A rubber gasket (not lo shown) may be provided to seal the connection between fan casing 16 and panel 14 to prevent air leakage. This eliminates problems associated with conventional metal fan casings tack welded to range hood panels, such as air leakage and excessive vibration.
As shown best in Figures 1 and 4, fan casing 16 is generally B-shaped in plan view and consists of dual lobes 18 and 20 separated by a central baffle 22. Each lobe 18, 20 is generally volute or spiral-shaped and is defined by a vertical sidewall 24 and a bottom wall 27 (Figure 4). casing bottom wall 27 has a pair of air inlet apertures formed therein on either side of baffle 22.
Baffle 22 is generally triangular in transverse section (Figure 3) and includes opposed sidewalls 23 which are cylindrically concave. Baffle sidewalls 23 taper toward a common apex 25.
Fan casing 16 is designed to surround a pair of counter-rotating centrifugal blowers 28 and 30. In par-ticular, counterclockwise rotating blower 28 is mounted within casing lobe 18 and clockwise rotating blower 30 is mounted within casing lobe 20 (Figure 4)O Each blower 28, 30 includes a motor 31 for actuating rotation of a plural-ity of blower impeller blades 32.
2t~
~ s shown in Figure 1, a pair of annular greasecollection rings 26 may be removably fastened to casing bottom wall 27 immediately beneath respective blowers 28 and 3 n . A bottom range hood panel 17 having air inlet apertures 19 and 21 may then be removably secured to housing 12 underneath collection rinys, 26.
As shown best in Figure 5, each grease collection ring 26 has an outlet tube 38 which drains into a corre-sponding grease collection cup 40 removably fastenable tothe undersurface of casing bottom panel 17. Range hood housing 12 and bottom panel 17 have apertures 42 therein for receiving respective collection ring outlet t~lbes 38 when range hood 10 is fully assembled (Figures 1 and 5).
Figure 1 illustrates the flow of ventilated air through fan casing 16. The rotating action of blowers 2~,30 causes grease~laden air to be drawn into fan casing 16 through apertures 19 and 21 formed in range hood bottom panel 17. Separate streams o-f ventilated air are drawn into casing lobes 18 and 20 through the air inlet apertures formed in casing bottom wall 27. Centrifugal forces created by blower impeller blades 32 cause grease particles entrained in the ventilated air to be flung radially against the surface of baffle sidewalls 23 or casing side-wall 24. The grease droplets condensing on sidewalls 23,24 drain by gravity into the underlying collection rings 26 and the corresponding collection cup 40, which must be periodically emptied.
In the embodiment shown in Figure 5, casing bottom wall 27 may have a tapered upper surface 44 to facilitate drainag~ of grease into collection rings 26.
Similarly, each collection ring 26 may have an inclined upper surface 46 to facilitate drainage of grease toward 2 ~ 3 outlet tube 38 and hence into the corresponding collection cup 40.
As shown best in Figure 4, blowers 28, 30 are mounted in respective fan casing lobes 18, 20 in positions offset toward a forward portion of central baffle 22. The point at which the blower impellers 32 most closely ap-proach the adjacent casing sidewall 24 is referred to as the air "cut off" point and is desiynated 36. As the blower impellers 32 rotate away from the respective cut-off point 36, the distance between the impeller tips and casing sidewall 24 increases due to the volute shape of fan casing lobes 18, 20. Accordingly, the air flow passage within respective lobes 18, 20 increases as the ventilated air approaches exhaust outlet 34. This casing design serves to convert a portion of the air velocity into a static head proximate exhaust outlet 34. In other words, casing 16 is designed to convert the high velocity pressure of the blower impeller blades 32 into a high static pres-sure in the vicinity of exhaust outlet 34. This results insignificantly increased fan output and efficiency.
The inventor has determined that dual, counter-rotating blowers are more efficient than dual blowers rotating in the same direction. The applicant's design results in air streams which are directed upwardly by the cylindrically concave contour of baffle sidewalls 23 and which con~erge at baffle apex 25 as the ventilated air is exhausted from casing 16 through outlet 34. This consti-tutes a significant improvement over prior art Z-shaped baffles, which are typically used with dual blowers rotat-ing in the same direction within volute-shaped lobes. Z-shaped baffles result in partial counterflow of the air streams generated by the dual blowers, thereby causing increased air turbulence proximate exhaust outlet 34. ~his in turn results in reduced fan efficiency an~ output.
, As will be apparent to those skilled in the art in the light of the ~oreyoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
:
.. . . ................... .
,
RA~C~E HOOD F~N ASSEMBL~
Field of the Invention This application pertains to a range hood ~an for exhausting grease-laden air general:ed during cooking.
More particularly, this application relates to a range hood fan having dual, counter-rotating centrifugal blowers and a generally B-shaped fan casing for enclosing the blowers.
Background of the Invention Range hoods are typically installed directly above kitchen elements or burners to ventilate steam, grease and related odours generated during cooking.
Various range hood ventilators having centrifugal blowers are known in the prior art. For example, United States patent No. 3,719,137, which issued to Gould on 6 March, 1973, discloses a ventilating system which includes dual blowers enclosed within a vertically oriented double-lobed shroud. The shroud consists of a U-shaped casing and a volute-shaped casing, each housing one of the blowers. The blowers may be operated individually or in tandem depending upon the exhaust speeds required.
United States patent No. 3,109,358, which issued to Meyer on 5 November, 1963, teaches a range hood ventila-tor having a pair of counter-rotating blowers. The blowers are housed in a casing having generally cylindrically-shaped lobes. The blowers channel the ventilated air to a single outlet duct.
United States patent No. 4,500,331, which issued to Cheng on February 19, 1985 discloses a kitchen exhaust apparatus having a volute-shaped housing for enclosing a single centrifugal fan. The Cheng apparatus is contoured to facilitate drainage of oleaginous and liquid particles entrained in the ventilated air. Such particles condense 2 ~ 2 3 on the inner wall of the housing due to the action of the centrifu~al fan.
As a result of the design of conventional fan casings housing dual blowers, the blowe~rs tend to generate turbulent air streams proximate the exhaust outlet(s) which results in reduced fan efficiency and output. Another primary drawback of many prior art range hood fan assem-blies is that the fan blowers are not positioned for maximum exhaust output. Often the blowers are offset away from the cooking elements which allows vapours to circulate before being expelled from the kitchen.
The need has therefore arisen for a range hood fan which employs the combined advantages o~ counter-rotating centrifugal blowers and a casing having volute-shaped lobes surrounding the blowers for enhancing fan efficiency.
Summary of the Invention In accordance with the invention there is pro-vided a range hood fan comprising a generally B-shaped casing having a central baffle dividing the casing into generally volute-shaped first and second lobes; and first and second count~r-rotating centrifugal blowers mountable in respective first and second casing lobes.
Preferably the fan casing includes a vertical sidewall and a bottom wall having spaced-apart first and second air inlet apertures formed therein to allow entry of air into the first and second casing lobes. The range hood fan may also include a panel sealingly covering an open upper end of the casing and having an exhaust outlet formed therein overlying a portion of the baffle. Advantageously, the casing may be removably attachable to the panel.
2 ~ 2 ~
The range hood fan may al50 include a pair of annular grease collection rings removably attachable to the casing botto-m wall underneath the first and second air inlet apertures. The casing bottom wall may bs downwardly inclined relative to the casing sidewall to ~acilitate drainage of grease from the casing into the grease collec-tion rings.
Preferably, the range hood also includes at least one grease collection cup removably attachable to an undersurface of the range hood fan in communicAtion with the grease collection rings. Each of the grease collection rings may have an outlet tube in communication with a corresponding collection cup, the upper surface of the collection rings being inclined toward the outlet tube to facilitate drainage of grease into the collection cup.
Preferably, the first and second centrifugal blowers are offs~t within respective first and second volute-shaped lobes such that the clearance between the periphery of the blowers and the adjacent casing sidewall increases from a minimum at the air cutoff point of the casing to a maximum in the vicinity of the fan exhaust outlet. The -fan casing is contoured so that the cutoff points of the first and second lobes are immediately adjacent proximate a forward portion of the baffle.
Advantageously, the baffle comprises opposed cylindrically concave sidewalls tapering toward a common apex, the baffle substantially preventing the mixing of air between the first and second casing lobes.
This application also relates to a generally B-shaped fan casing adapted for enclosing a pair of counter-rotating centrifugal blowers, the casing comprising a `` 2 ~ 2 3 central baffle dividing the casing into first and second lobes, each of the first and second lobes being generally volute-shaped for surrounding one of the blowers.
Brief Description of the Drawinqs In drawings which illustrate embodiments of the invention, but which should not be construed as restricting the spirit or scope of the invention in any way, Figure 1 is an exploded, bottom isometric view of the range hood fan of the present invention illustrating the direction of air flow;
Figure 2 is a top plan view of the range hood fan of Figure 1 showing the exhaust outlet formed in the upper range hood panel;
Figure 3 is a sectional view of the range hood fan taken along section lines 3-3 of Figure 2;
Figure 4 is a partially fragmented, bottom plan view of the range hood fan of Figure 1; and Figure 5 is an enlarged, sectional view of a bottom portion of the range hood fan casing illustrating one of the grease collection rings and a corresponding grease collection cup.
Detailed Description of the Preferred Embodiment With reference to Figure 1, range hood fan 10 is mountable above kitchen elements or burners to ventilate steam, grease, and related odours generated during cooking.
Range hood fan 10 includes a metal housing 12 having an upper panel 14. A fan casing 16 is securely mounted onto 2 ~
range hood panel 14. As described further below, panel 14 has an exhaust outlet 34 formed therein for enabling expulsion of ventilated air from fan casing 16 into ducting (not shown) leading to the exterior of the dwelling in question.
Preferably, fan casing 16 is formed o* moulded plastic and is removably connected to panel 14 with fas-teners, such as nuts and bolts. A rubber gasket (not lo shown) may be provided to seal the connection between fan casing 16 and panel 14 to prevent air leakage. This eliminates problems associated with conventional metal fan casings tack welded to range hood panels, such as air leakage and excessive vibration.
As shown best in Figures 1 and 4, fan casing 16 is generally B-shaped in plan view and consists of dual lobes 18 and 20 separated by a central baffle 22. Each lobe 18, 20 is generally volute or spiral-shaped and is defined by a vertical sidewall 24 and a bottom wall 27 (Figure 4). casing bottom wall 27 has a pair of air inlet apertures formed therein on either side of baffle 22.
Baffle 22 is generally triangular in transverse section (Figure 3) and includes opposed sidewalls 23 which are cylindrically concave. Baffle sidewalls 23 taper toward a common apex 25.
Fan casing 16 is designed to surround a pair of counter-rotating centrifugal blowers 28 and 30. In par-ticular, counterclockwise rotating blower 28 is mounted within casing lobe 18 and clockwise rotating blower 30 is mounted within casing lobe 20 (Figure 4)O Each blower 28, 30 includes a motor 31 for actuating rotation of a plural-ity of blower impeller blades 32.
2t~
~ s shown in Figure 1, a pair of annular greasecollection rings 26 may be removably fastened to casing bottom wall 27 immediately beneath respective blowers 28 and 3 n . A bottom range hood panel 17 having air inlet apertures 19 and 21 may then be removably secured to housing 12 underneath collection rinys, 26.
As shown best in Figure 5, each grease collection ring 26 has an outlet tube 38 which drains into a corre-sponding grease collection cup 40 removably fastenable tothe undersurface of casing bottom panel 17. Range hood housing 12 and bottom panel 17 have apertures 42 therein for receiving respective collection ring outlet t~lbes 38 when range hood 10 is fully assembled (Figures 1 and 5).
Figure 1 illustrates the flow of ventilated air through fan casing 16. The rotating action of blowers 2~,30 causes grease~laden air to be drawn into fan casing 16 through apertures 19 and 21 formed in range hood bottom panel 17. Separate streams o-f ventilated air are drawn into casing lobes 18 and 20 through the air inlet apertures formed in casing bottom wall 27. Centrifugal forces created by blower impeller blades 32 cause grease particles entrained in the ventilated air to be flung radially against the surface of baffle sidewalls 23 or casing side-wall 24. The grease droplets condensing on sidewalls 23,24 drain by gravity into the underlying collection rings 26 and the corresponding collection cup 40, which must be periodically emptied.
In the embodiment shown in Figure 5, casing bottom wall 27 may have a tapered upper surface 44 to facilitate drainag~ of grease into collection rings 26.
Similarly, each collection ring 26 may have an inclined upper surface 46 to facilitate drainage of grease toward 2 ~ 3 outlet tube 38 and hence into the corresponding collection cup 40.
As shown best in Figure 4, blowers 28, 30 are mounted in respective fan casing lobes 18, 20 in positions offset toward a forward portion of central baffle 22. The point at which the blower impellers 32 most closely ap-proach the adjacent casing sidewall 24 is referred to as the air "cut off" point and is desiynated 36. As the blower impellers 32 rotate away from the respective cut-off point 36, the distance between the impeller tips and casing sidewall 24 increases due to the volute shape of fan casing lobes 18, 20. Accordingly, the air flow passage within respective lobes 18, 20 increases as the ventilated air approaches exhaust outlet 34. This casing design serves to convert a portion of the air velocity into a static head proximate exhaust outlet 34. In other words, casing 16 is designed to convert the high velocity pressure of the blower impeller blades 32 into a high static pres-sure in the vicinity of exhaust outlet 34. This results insignificantly increased fan output and efficiency.
The inventor has determined that dual, counter-rotating blowers are more efficient than dual blowers rotating in the same direction. The applicant's design results in air streams which are directed upwardly by the cylindrically concave contour of baffle sidewalls 23 and which con~erge at baffle apex 25 as the ventilated air is exhausted from casing 16 through outlet 34. This consti-tutes a significant improvement over prior art Z-shaped baffles, which are typically used with dual blowers rotat-ing in the same direction within volute-shaped lobes. Z-shaped baffles result in partial counterflow of the air streams generated by the dual blowers, thereby causing increased air turbulence proximate exhaust outlet 34. ~his in turn results in reduced fan efficiency an~ output.
, As will be apparent to those skilled in the art in the light of the ~oreyoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
:
.. . . ................... .
,
Claims (17)
1. A range hood fan comprising:
(a) a generally B-shaped casing having a central baffle dividing said casing into first and second lobes, wherein said first and second lobes are generally volute-shaped; anal (b) first and second counter-rotating centrifugal blowers mountable in respective first and second casing lobes.
(a) a generally B-shaped casing having a central baffle dividing said casing into first and second lobes, wherein said first and second lobes are generally volute-shaped; anal (b) first and second counter-rotating centrifugal blowers mountable in respective first and second casing lobes.
2. The range hood fan of claim 1, wherein said casing comprises a vertical sidewall and a bottom wall having spaced-apart first and second air inlet apertures formed therein to allow entry of air into respective first and second casing lobes.
3. The range hood fan of claim 2, wherein said range hood further comprises a panel sealingly covering an open upper end of said casing, said panel having an exhaust outlet formed therein overlying a portion of said baffle.
4. The range hood fan of claim 3, wherein said casing is removably attachable to said panel.
5. The range hood fan of claim 3, further comprising a pair of annular grease collection rings removably attach-able to said casing bottom wall underneath said first and second air inlet apertures.
6. The range hood fan of claim 5, wherein said casing bottom wall is downwardly inclined relative to said casing sidewall to facilitate drainage of grease from said casing into said grease collection rings.
7. The range hood fan of claim 6, further comprising at least one grease collection cup removably attachable to an undersurface of said range hood fan in communication with said grease collection rings.
8. The range hood fan of claim 7, wherein each of said grease collection rings has an outlet tube in communi-cation with a corresponding collection cup and wherein an upper surface of each of said collection rings is inclined toward said outlet tube to facilitate drainage of grease into said collection cup.
9. The range hood fan of claim 3, wherein the point whereat said first and second fan blowers most closely approach the casing sidewall within respective first and second volute-shaped lobes is referred to as the air cut-off point and wherein said first and second blowers are offset within respective first and second lobes such that the clearance between the periphery of said blowers and the adjacent casing sidewall increases from a minimum at the air cut-off point to a maximum in the vicinity of the said fan exhaust outlet.
10. The range hood fan of claim 9, wherein the air cut-off points of said first and second lobes are immedi-ately adjacent proximate a forward portion of said baffle.
11. The range hood fan of claim 3, wherein said baffle comprises opposed, cylindrically concave sidewalls tapering toward a common apex, said baffle substantially preventing mixing of air between said first and second casing lobes.
12. The range hood fan of claim 11, wherein said baffle apex bisects said exhaust outlet, said baffle substantially preventing counter-flow of air exhausted from said casing.
13. A generally B-shaped fan casing adapted for enclosing a pair of counter-rotating centrifugal blowers, said casing comprising a central baffle dividing said casing into first and second lobes, wherein each of said first and second lobes is generally volute-shaped for surrounding one of said blowers.
14. The fan casing of claim 13, wherein said casing comprises an open upper end, a vertical sidewall and a bottom wall having spaced-apart first and second air inlet apertures formed therein to allow entry of air into re-spective first and second casing lobes.
15. The fan casing of claim 14, wherein said baffle comprises opposed, cylindrically concave sidewalls tapering toward a common apex, said baffle substantially preventing mixing of air between said first and second casing lobes.
16. The fan casing of claim 15, wherein said casing is of unitary plastic construction.
17. A range hood fan comprising:
(a) a generally B-shaped casing having a central baffle dividing said casing into first and second lobes, wherein said first and second lobes are generally volute-shaped, said casing having an open upper end, a vertical sidewall, and a bottom wall having a pair of air inlet apertures formed therein to allow entry of air into respective first and second lobes;
(b) a panel sealingly covering said casing upper end, said panel having an exhaust outlet formed therein overlying a portion of said baffle; and (c) first and second counter-rotating centrifugal blowers mountable in respective first and second casing lobes in positions offset toward said central baffle.
(a) a generally B-shaped casing having a central baffle dividing said casing into first and second lobes, wherein said first and second lobes are generally volute-shaped, said casing having an open upper end, a vertical sidewall, and a bottom wall having a pair of air inlet apertures formed therein to allow entry of air into respective first and second lobes;
(b) a panel sealingly covering said casing upper end, said panel having an exhaust outlet formed therein overlying a portion of said baffle; and (c) first and second counter-rotating centrifugal blowers mountable in respective first and second casing lobes in positions offset toward said central baffle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US78483091A | 1991-10-30 | 1991-10-30 | |
| US07/784,830 | 1991-10-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2081823A1 true CA2081823A1 (en) | 1992-11-30 |
Family
ID=25133657
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2081823 Abandoned CA2081823A1 (en) | 1991-10-30 | 1992-10-30 | Range hood fan assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2081823A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6240916B1 (en) * | 2000-01-18 | 2001-06-05 | Sung-Lin Huang | Wind box with an oil guiding device |
| EP3287702A1 (en) * | 2011-04-28 | 2018-02-28 | Wilhelm Bruckbauer | Assembly unit comprising a hotplate and steam extractor |
| CN110500294A (en) * | 2019-07-25 | 2019-11-26 | 宁波方太厨具有限公司 | A kind of centrifugal blower and application have the range hood of the centrifugal blower |
| CN111089068A (en) * | 2018-10-24 | 2020-05-01 | 宁波方太厨具有限公司 | Series double-fan type range hood |
-
1992
- 1992-10-30 CA CA 2081823 patent/CA2081823A1/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6240916B1 (en) * | 2000-01-18 | 2001-06-05 | Sung-Lin Huang | Wind box with an oil guiding device |
| EP3287702A1 (en) * | 2011-04-28 | 2018-02-28 | Wilhelm Bruckbauer | Assembly unit comprising a hotplate and steam extractor |
| EP3287702B1 (en) | 2011-04-28 | 2019-09-18 | Wilhelm Bruckbauer | Hotplate and steam extractor |
| US10718528B2 (en) | 2011-04-28 | 2020-07-21 | Wilhelm Bruckbauer | Hob with central downward removal of cooking vapors through suction |
| CN111089068A (en) * | 2018-10-24 | 2020-05-01 | 宁波方太厨具有限公司 | Series double-fan type range hood |
| CN111089068B (en) * | 2018-10-24 | 2021-05-18 | 宁波方太厨具有限公司 | Series double-fan type range hood |
| CN110500294A (en) * | 2019-07-25 | 2019-11-26 | 宁波方太厨具有限公司 | A kind of centrifugal blower and application have the range hood of the centrifugal blower |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |