U.S. patent application number 11/690435 was filed with the patent office on 2007-09-27 for vent system for cooking appliance.
This patent application is currently assigned to DUKE MANUFACTURING CO.. Invention is credited to John J. Hake, Lawrence W. Hake.
Application Number | 20070221199 11/690435 |
Document ID | / |
Family ID | 38541823 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070221199 |
Kind Code |
A1 |
Hake; Lawrence W. ; et
al. |
September 27, 2007 |
VENT SYSTEM FOR COOKING APPLIANCE
Abstract
A vent system for venting hot gas and effluents from a cooking
appliance. The vent system includes a first direct vent structure
having an inlet for receiving hot gas and effluents and an outlet
communicating with atmosphere. The first direct vent structure
defines a first flow path. At least one effluent-removal device is
positioned in the first flow path for removing effluents from the
hot gas. An atmospheric flue communicates with the outlet of the
first direct vent structure for venting hot gas to atmosphere after
it has passed through the effluent-removal device. A damper system
and integrated control system are also disclosed.
Inventors: |
Hake; Lawrence W.; (Destin,
FL) ; Hake; John J.; (Edwardsville, IL) |
Correspondence
Address: |
SENNIGER POWERS
ONE METROPOLITAN SQUARE, 16TH FLOOR
ST LOUIS
MO
63102
US
|
Assignee: |
DUKE MANUFACTURING CO.
St. Louis
MO
|
Family ID: |
38541823 |
Appl. No.: |
11/690435 |
Filed: |
March 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60785745 |
Mar 24, 2006 |
|
|
|
Current U.S.
Class: |
126/299R |
Current CPC
Class: |
F24C 15/205 20130101;
F24C 15/2021 20130101; F24C 15/2042 20130101 |
Class at
Publication: |
126/299.R |
International
Class: |
F24C 15/20 20060101
F24C015/20 |
Claims
1. A vent system for venting hot gas and effluents from a cooking
appliance, said vent system comprising a direct exhaust vent
adapted to be positioned above the cooking appliance, said direct
exhaust vent comprising a first direct vent structure having an
inlet for receiving said hot gas and effluents and an outlet
communicating with atmosphere, said first direct vent structure
defining a first flow path from said inlet to said outlet for flow
of said hot gas and effluents along the flow path, at least one
effluent-removal device in said first flow path for removing
effluents from said hot gas, and an atmospheric flue communicating
with the outlet of the first direct vent structure for venting hot
gas to atmosphere after it has passed through said effluent-removal
device.
2. A system as set forth in claim 1 wherein said direct vent
structure is movable so that it may be positioned adjacent an
exhaust area of said cooking appliance.
3. A system as set forth in claim 2 wherein said direct vent
structure has an upper section and a lower section movable up and
down relative to the upper section to facilitate positioning
adjacent said exhaust area of the cooking appliance.
4. A system as set forth in claim 1 wherein said direct exhaust
vent further comprises a second direct vent structure having an
inlet for receiving hot gas and effluents and an outlet
communicating with said atmospheric flue, said second direct vent
structure at least partially defining a second flow path for
directing hot gas and effluents from the environment surrounding
said cooking appliance to said outlet of the second direct vent
structure.
5. A system as set forth in claim 4 further comprising a second
effluent-removal device in said second flow path.
6. A system as set forth in claim 5 wherein said second direct vent
structure surrounds said first direct vent structure and is spaced
from the first direct vent structure to define said second flow
path.
7. A system as set forth in claim 1 further comprising an exhaust
canopy having an exhaust duct and a powered exhaust fan for
collecting hot gas and effluents from an environment surrounding
said cooking appliance, said direct exhaust vent being mounted
inside said exhaust canopy.
8. A system as set forth in claim 1 further incorporating a damper
system comprising a damper member movable in the first direct vent
structure between an open position allowing flow along the first
flow path at a first flow rate and a closed position allowing flow
along the first flow path at a second flow rate less than the first
flow rate but greater than zero to allow venting of the cooking
appliance while also reducing heat loss from the cooking
appliance.
9. A vent system for cooking appliance having a first exhaust area
for exhausting cooking hot gas and effluents from the cooking
appliance and a second exhaust area through which cooking hot gas
and effluents escape the cooking appliance, said vent system
comprising a first direct vent structure defining a first flow path
for receiving hot gas and effluents from said first exhaust area, a
second direct vent structure defining a second flow path for
receiving hot gas and effluents from said second exhaust area, and
at least one atmospheric flue communicating with said first and
second flow paths.
10. A vent system as set forth in claim 9 wherein said second
direct vent structure surrounds said first direct vent structure
and combines with said first direct vent structure to define said
second flow path.
11. A vent system as set forth in claim 9 wherein said first and
second flow paths communicate with a single atmospheric flue.
12. A method of venting cooking gas and effluents from a cooking
appliance of the type having a cooking chamber, a first exhaust
area for exit of hot gas and effluents from the cooking chamber,
and a second exhaust area for exit of hot gas and effluents from
the cooking appliance into an environment surrounding the cooking
appliance, said method comprising venting cooking gas from said
first exhaust area into a first direct vent structure defining a
first flow path, venting cooking gas from said second exhaust area
into a second direct vent structure at least partially defining a
second flow path, and venting said cooking gas flowing along said
first and second flow paths into a common atmospheric flue.
13. A method as set forth in claim 12 further comprising catalyzing
said hot gas and effluents as they flow along at least one of said
first and second flow path.
14. A method as set forth in claim 12 further comprising catalyzing
said hot gas and effluents as they flow along said first and second
flow path.
15. A damper system for adjusting flow from an exhaust outlet of a
cooking appliance, said damper system comprising a damper housing
adapted to be connected to said exhaust outlet and defining a flow
path for exhaust from said exhaust outlet, and a damper member
movable in the damper housing between an open position allowing
flow along the flow path at a first flow rate and a closed position
in which the damper member partially blocks the first flow path for
flow at a second flow rate less than said first flow rate to allow
venting of the cooking appliance while reducing heat loss from the
cooking appliance.
16. A damper system as set forth in claim 15 further comprising an
effluent-removal device in said damper housing.
17. A damper system as set forth in claim 16 wherein said
effluent-removal device is located upstream from said damper
member.
18. A damper system as set forth in claim 16 wherein said damper
member is perforated.
19. A damper system as set forth in claim 16 further comprising a
damper motor for moving said damper member between said open and
closed positions, and a control for operating said damper motor
responsive to operation of said cooking appliance.
20. A damper system as set forth in claim 15 further comprising a
catalyst in said damper housing upstream from said damper member
whereby movement of the damper member to its closed position is
adapted to reduce heat loss from the cooking appliance and
catalyst.
21. An integrated cooking and ventilation system comprising a
cooking appliance, a vent system for venting hot gas and effluents
from said cooking appliance, said vent system comprising at least
one movable venting component and at least one motor for moving the
at least one venting component, and an integrated control system
for controlling operation of said at least one motor and associated
venting component as a function of the operation of the cooking
appliance.
22. A system as set forth in claim 21 wherein said at least one
movable venting component is a variable-speed fan driven by said at
least one motor, said control system being operable to operate said
fan at a first lower speed during a low-vent mode of the cooking
appliance and at a second higher speed during a high-vent mode of
the cooking appliance.
23. A system as set forth in claim 21 wherein said at least one
movable venting component is a damper member movable by said at
least one motor between open and closed positions, said control
system being operable to move said damper member to its closed
position when the cooking apparatus is operating in a low-vent mode
and to its open position when the cooking apparatus is operating in
a high-vent mode.
24. A system as set forth in claim 23 wherein said damper member in
its said open position allows flow along a first flow path at a
first flow rate through the vent system, and wherein said damper
member in its said closed position only partially blocks the first
flow path for flow at a second flow rate less than said first flow
rate but greater than zero to allow venting of the cooking
appliance while also reducing heat loss from the cooking
appliance.
25. A system as set forth in claim 24 further comprising a catalyst
in said first flow path upstream from said damper member whereby
movement of the damper member to its closed position is adapted to
reduce heat loss from the cooking appliance and catalyst.
26. An integrated cooking and ventilation system comprising a
cooking appliance, a vent system for venting hot gas and effluents
from said cooking appliance, and an integrated control system for
controlling operation of said vent system and said cooking
appliance, said integrated control system being responsive to
operation of the cooking appliance to vary flow characteristics of
the vent system.
27. An integrated cooking and ventilation system as set forth in
claim 26 wherein said vent system comprises a damper member movable
between an open position to allow the flow of hot gas and effluents
from the cooking appliance along a flow path at a first flow rate
and a closed position partially blocking the flow path for flow of
hot gas and effluents from the cooking appliance at a second flow
rate less than said first flow rate but greater than zero to allow
venting of the cooking appliance while also reducing heat loss from
the cooking appliance, said control system being operable to move
said damper member to its closed position when the cooking
apparatus is operating in a low-vent mode and to its open position
when the cooking apparatus is operating in a high-vent mode.
28. An integrated cooking and ventilation system as set forth in
claim 27 further comprising a catalyst in said flow path upstream
from said damper member whereby movement of the damper member to
its closed position is adapted to reduce heat loss from the cooking
appliance and catalyst.
29. A method of operating a cooking appliance and vent system for
venting hot gas and effluents from the cooking appliance, said
method comprising operating the cooking appliance, and varying the
flow characteristics of the vent system as a function of the
operation of the cooking appliance.
30. A method as set forth in claim 29 further comprising operating
the cooking appliance in a cycle having different cycle segments,
and varying the flow through the vent system as a function of the
cycle segments.
31. A method as set forth in claim 30 wherein said vent system
comprising at least one movable venting component and at least one
motor for moving the at least one venting component, said method
further comprising controlling said at least one motor to move said
at least one venting component to increase or decrease the flow
through the vent system as a function of the cycle segment.
32. A method as set forth in claim 30 wherein said venting
component is a damper.
33. A method as set forth in claim 30 wherein said venting
component is a fan.
Description
BACKGROUND OF THE INVENTION
[0001] This application is a non-provisional of U.S. Provisional
Patent Application Ser. No. 60/785,745, filed Mar. 24, 2006, the
entirety of which is hereby incorporated by reference.
[0002] This invention relates generally to cooking systems, and
more particularly to improved ventilation and energy management
systems for cooking appliances such as cooking ovens (e.g.,
convection ovens, baking ovens and speed cooking ovens),
rotisseries, broilers, solid fuel ovens, char broilers, and
fryers.
[0003] Cooking appliances used in commercial establishments (e.g.,
institutions, and family, casual, fine-dining, and fast-food
restaurants) generate heat, combustion gases, cooking gases, and
effluents such as grease, moisture and other particulates. Large
overhead exhaust hoods and associated fans are often used to vent
such cooking appliances, but these systems require substantial air
flow and are not energy efficient. Further, substantial amounts of
heat typically escape from the cooking appliance, resulting in
further energy loss. There is a need, therefore, for an improved
ventilation and energy management system for cooking appliances,
particularly in view of increasing utility costs and anticipated
stricter environmental regulations requiring reduced levels of
cooking by-products discharged to atmosphere.
SUMMARY OF THE INVENTION
[0004] Among the several objectives of this invention may be noted
the provision of an improved ventilation and energy management
system for cooking appliances. In different embodiments, the system
has one or more of the following advantages: flexibility and
adaptability for integration with various types of cooking
appliances; capture and disposition of hot gas and effluents in an
energy efficient manner; adaptability to meet different
effluent-removal requirements; integration of the system with the
particulars of the cooking process, foods cooked and cooking
appliance; reduced duct maintenance and cleaning requirements; an
optional damper system for controlling flow through the system to
increase effluent-removal efficiency and effectiveness, and to
provide more efficient energy management; an optional integrated
fan system for generating desired flow throughout the system; an
optional recirculation system for re-circulating flow to improve
effluent removal and energy management throughout the system and/or
cooking appliance; an optional feature for controlling fans and/or
other movable components of the vent system in response to sensing
the presence or certain characteristics of the hot gas and
effluents from the cooking appliance; and an optional embodiment
where there is no need for exhausting hot gas to an atmospheric
flue. It is anticipated that a system of this invention will
contribute substantially to meeting the standards of an energy
efficient or "green" restaurant, a goal which is becoming more and
more important.
[0005] In general, a ventilation and energy management system of
this invention has one or more unique features. In one embodiment,
the system includes a direct exhaust vent adapted to be positioned
adjacent the cooking appliance. The direct exhaust vent comprises a
first direct vent structure having an inlet for receiving said hot
gas and effluents and an outlet communicating with atmosphere. The
first direct vent structure defines a first flow path from the
inlet to the outlet for flow of hot gas and effluents along the
flow path. At least one effluent-removal device is provided in the
first flow path for removing effluents from the hot gas. The direct
exhaust vent also includes an atmospheric flue communicating with
the outlet of the first direct vent structure for venting hot gas
to atmosphere after it has passed through the effluent-removal
device.
[0006] In another embodiment, the vent system comprises an exhaust
canopy for collecting hot gas and effluents from an environment
surrounding the cooking appliance. The exhaust canopy has an
exhaust duct and an exhaust fan for venting hot gas and effluents
collected by the canopy. The system also includes a direct exhaust
vent inside the exhaust canopy. The direct exhaust vent comprises a
first direct vent structure defining a first flow path for
directing hot gas and effluents exiting a cooking chamber of the
cooking appliance, and an atmospheric flue communicating with the
first flow path for venting hot gas to atmosphere.
[0007] In yet another embodiment, the vent system comprises an
exhaust canopy for collecting hot gas and effluents from an
environment surrounding a cooking appliance, and a direct exhaust
vent inside the exhaust canopy. The direct exhaust vent has a first
inlet for receiving hot gas and effluents exiting the cooking
appliance, an outlet, and an atmospheric vent communicating with
the outlet. The system also includes a fan box inside the exhaust
canopy for directing hot gas collected by the exhaust canopy to a
second inlet of the direct exhaust vent communicating with the
atmospheric vent.
[0008] In another embodiment, the vent system is adapted for
retrofit installation in an existing exhaust canopy for venting hot
gas and effluents from a cooking appliance. The vent system
comprises a housing adapted to be secured inside an existing
exhaust canopy, and a direct exhaust vent inside the housing. The
direct exhaust vent has a first inlet for receiving hot gas and
effluents exiting an exhaust area of the cooking appliance, an
outlet, and an atmospheric vent communicating with the outlet. The
system also includes a fan box inside the housing for directing hot
gas collected by the exhaust canopy to a second inlet of the direct
exhaust vent communicating with the atmospheric vent.
[0009] In another embodiment, a vent system of this invention
comprises a first direct vent structure defining a first flow path
for venting hot gas and effluents from a first exhaust area of the
cooking appliance, and a second direct vent structure defining a
second flow path for venting hot gas and effluents from a second
exhaust area of the cooking appliance. At least one atmospheric
flue communicates with the first and second flow paths.
[0010] Another embodiment of this invention is directed to a method
of venting hot gas and effluents from a cooking appliance of the
type having a cooking chamber, a first exhaust area for exhausting
hot gas and effluents from the cooking chamber, and a second
exhaust area through which hot gas and effluents are exhausted from
the cooking appliance into an environment surrounding the cooking
appliance. The method comprises venting hot gas and effluents from
the first exhaust area into a first direct vent structure defining
a first flow path, and venting hot gas and effluents from the
second exhaust area into a second direct vent structure at least
partially defining a second flow path. The method also includes the
step of venting the hot gas flowing along the first and second flow
paths into a common atmospheric flue.
[0011] In another embodiment, the present invention is directed to
a damper system for adjusting flow from an exhaust outlet of a
cooking appliance. The damper system comprises a damper housing
adapted to be connected to the exhaust outlet and defining a flow
path for exhaust from the exhaust outlet. A damper member is
movable in the damper housing between an open position allowing
flow along the flow path at a first flow rate and a closed position
in which the damper member partially blocks the first flow path for
flow at a second flow rate less than said first flow rate but
greater than zero to allow venting of the cooking appliance while
reducing heat loss from the cooking appliance.
[0012] The present invention is also directed to an integrated
cooking and ventilation system. The system comprises a cooking
appliance, and a vent system for venting hot gas and effluents from
the cooking appliance. The vent system includes at least one
movable venting component and at least one motor for moving the at
least one venting component. An integrated control system is
provided for controlling operation of the at least one motor and
associated venting component as a function of the operation of the
appliance.
[0013] In another embodiment, an integrated cooking and ventilation
system of this invention comprises a cooking appliance, a vent
system for venting hot gas and effluents from the cooking
appliance, and an integrated control system for controlling
operation of the vent system and the cooking appliance. The
integrated control system is responsive to operation of the cooking
appliance to vary flow characteristics of the vent system.
[0014] In another embodiment, the present invention is directed to
a method of operating a cooking appliance and vent system for
venting hot gas and effluents from the cooking appliance. The
method comprises operating the cooking appliance, and varying the
flow characteristics of the vent system as a function of the
operation of the cooking appliance.
[0015] Other objectives, advantages and features of this invention
will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a rear elevation of a direct vent system of this
invention for venting cooking gas from a cooking appliance (shown
in phantom);
[0017] FIG. 2 is a side elevation of the direct vent system and
cooking appliance of FIG. 1;
[0018] FIG. 3 is a front elevation of a direct vent system in
combination with a larger exhaust canopy;
[0019] FIG. 4 is a side elevation of FIG. 3;
[0020] FIG. 5 is a top plan view of FIG. 3;
[0021] FIG. 6 is a schematic view of a direct vent system of this
invention inside a larger exhaust canopy with a filtered fan
box;
[0022] FIG. 7 is view similar to FIG. 6 showing another
embodiment;
[0023] FIG. 8 is a top plan view of a vent system which combines a
direct exhaust vent of this invention and a NFPA TYPE I exhaust
hood or canopy;
[0024] FIG. 9 is a front elevation of the system of FIG. 8;
[0025] FIGS. 10 and 11 are views showing additional features of the
system of FIGS. 8 and 9;
[0026] FIG. 12 is a vertical section showing an exemplary
embodiment of a direct vent system of this invention positioned
above a cooking appliance (in phantom);
[0027] FIG. 13 is a top plan view of FIG. 12;
[0028] FIG. 14 is vertical section showing another embodiment of a
direct vent system of this invention positioned above a cooking
appliance (in phantom);
[0029] FIG. 15 is a vertical section showing another embodiment of
a direct vent system of this invention positioned above a cooking
appliance (in phantom);
[0030] FIG. 16 is a vertical section showing another embodiment of
a direct vent system of this invention positioned above a cooking
appliance (in phantom);
[0031] FIG. 17 is a vertical section showing another embodiment of
a direct vent system of this invention positioned above a cooking
appliance (in phantom);
[0032] FIG. 18 is a vertical section showing another embodiment of
a direct vent system of this invention positioned above a cooking
appliance (in phantom);
[0033] FIG. 19 is a perspective of a another embodiment of a direct
vent system of this invention positioned above a cooking
appliance;
[0034] FIG. 20 is a front elevation of the direct vent system of
FIG. 19;
[0035] FIG. 21 is a vertical section in the plane of line 21-21 of
FIG. 20;
[0036] FIG. 22 is a vertical section in the plane of line 22-22 of
FIG. 21;
[0037] FIG. 23 is a vertical section showing another embodiment of
a direct vent system of this invention positioned above a cooking
appliance (in phantom); and
[0038] FIG. 24 is a circuit diagram of an integrated control system
for an energy management system of this invention.
[0039] Corresponding reference number designate corresponding parts
throughout the several views of the drawings.
DEFINITIONS
[0040] As used herein, the following terms have the meanings set
forth below.
[0041] The term "atmospheric flue" means a flue without an air
assist device.
[0042] The term "cooking appliance" means any apparatus which is
used for cooking food and which emits hot gas and effluents during
the cooking process. The appliance may have a single cooking
chamber or multiple cooking chambers arrayed horizontally and/or
vertically.
[0043] The term "hot gas" means heated air or other gas, including
cooking gas and combustion gas.
[0044] The term "effluents" means particulate material entrained in
the hot gas, including grease, moisture and other by-products of
the cooking process.
[0045] The term "effluent-removal device" means one or more
mechanisms for removing effluents from a gas, including catalysts,
filters, precipitators, UV systems, or combinations thereof.
[0046] The term "exhaust area" means any area from which hot gas
(either with or without effluents) exits the cooking appliance,
including dedicated exhaust outlets, doors, other entrances and
exits, apertures, or other openings in the cooking appliance.
[0047] The term "high-vent mode" means a time or portion of a cycle
of operation of a cooking appliance when its venting requirements
are relatively high, as during a cook segment of a cycle when large
amounts of hot gas and effluents requiring ventilation are
generated.
[0048] The term "low-vent mode" means a time or portion of a cycle
of operation of a cooking appliance when venting its requirements
are relatively low, as during a warm-up or stand-by segment of a
cycle, or when the appliance is off. The venting requirements
(e.g., flow rate through the vent) during a low-vent mode are less
than the venting requirements during a "high-vent" mode.
[0049] The term "open" means either fully open or partially
open.
[0050] The term "closed" means a position more closed than the
"open" position.
[0051] The term "variable-speed" as used in connection with a
device (e.g., fan or motor) means that the device can operate at
two or more speeds when it is in operation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] Referring now to the drawings, FIGS. 1 and 2 illustrate a
direct exhaust vent 1 of the present invention for venting a
cooking appliance 3 (shown in phantom lines). The cooking appliance
may be of various types, as noted above. Typically, hot gas and
effluents will exhaust or escape from the cooking appliance at a
number of different locations and in different ways. By way of
example, traditional gas ovens will often have a combustion chamber
exhaust, one or more doors providing access to the cooking chamber
through which hot gas and effluents may escape when the door(s) is
opened, and a cooking chamber exhaust separate from the combustion
chamber exhaust. Electric ovens may not have a separate exhaust for
combustion products. Other types of cooking appliances have cooking
areas which are only partially enclosed, as in the case of fryers,
char-broilers, rotisseries, brick ovens and broilers. For these
types of appliances, hot gas and effluents are exhausted over a
wide, unenclosed area as well as through discrete exhausts or
apertures. In short, hot gas and effluents will exhaust or escape
in different ways from different cooking appliances. As a result,
different appliances will have different ventilation requirements.
As will be described hereinafter, the present invention is
advantageous because it can be tailored to meet a broad range of
such requirements, while at the same time providing for greater
energy efficiency. Further, the required levels of
effluent-removal, air supply and air exhaust can readily be
designed into the direct exhaust vent or surrounding components of
the overall ventilation system, as needed. The focused capture and
specific treatment provided by the direct exhaust vent provides a
more effective and adaptive ventilation system.
[0053] The cooking appliance 3 shown in FIGS. 1 and 2 may be a
convective air oven, for example, having cooking and combustion
chambers (not shown), a door 4 providing access to the cooking
chamber, a first exhaust area 5 at one location on the oven (e.g.,
for exhausting from the cooking chamber), and a second exhaust area
7 at a second location on the oven (e.g., for exhausting from the
combustion chamber). Hot gas and effluents are exhausted from the
exhaust area 5 to the direct exhaust vent 1 and from the exhaust
area 7 via a flue 9 to the direct exhaust vent 1. As will be
described in more detail below, the direct vent 1 may also capture
hot gas and effluents from other exhaust areas.
[0054] The direct exhaust vent 1 can be mounted in different ways.
In FIG. 1, for example, the vent 1 is secured to a surface (e.g.,
ceiling 21) of a building by support rods 23. Other mounting
configurations are possible. For example, the direct exhaust vent
can be mounted on a frame or stand separate from the building
structure. The cooking appliance 3 is typically mounted on a
support 13, which may be a stationary counter, a movable cart, or
other structure for supporting the cooking appliance in a position
below the direct exhaust vent 1.
[0055] If desired, the direct exhaust vent of this invention can be
used in combination with a larger exhaust hood or canopy. FIGS. 3-5
illustrate such a combination in which a direct exhaust vent,
generally designated 121, is mounted inside a larger exhaust canopy
123, and in which both the direct exhaust vent and canopy are
mounted on a frame or stand 125. Alternatively, the direct exhaust
vent and canopy can be secured directly to a surface of the
building in which they are installed, as discussed previously. The
lower inlet end of the exhaust canopy 123 is sized larger than the
lower end of the direct exhaust vent 121 and normally larger than
the footprint of the cooking appliance 3 for collecting any hot gas
and effluents not collected by the direct exhaust vent. By way of
example but not limitation, the open lower end of the exhaust
canopy 123 may have an outline which extends up to six inches or
more beyond opposite sides of the cooking appliance and up to
twelve inches or more beyond the front of the cooking appliance. An
exhaust fan (not shown) draws hot gas up through a main exhaust
duct 131 of the exhaust canopy. One or more filters 135 are
provided for filtering effluents (e.g., grease) from the hot gas.
The volume of flow through the main exhaust duct 131 is preferably
tailored to the size and flow requirements of the cooking appliance
3 and balanced with the flow required for the direct exhaust vent
121.
[0056] In the embodiment of FIGS. 3-5 the stand 125 has back and
sides, a fire extinguisher system, power outlets, gas connection,
fan motor starters and all wiring and interlocks for a complete
system. There is a manual pull station on the stand 125; the gas
valve is pre-piped; the electric shunt trip is pre-wired; and all
interlocks are pre-wired. Nozzles are installed in the exhaust
canopy 123, direct exhaust vent 121 and ductwork, as required. The
stand 125 is preferably free standing and can be movable or secured
in fixed position by fasteners (e.g., floor bolts) or the like. In
any event, the stand preferably incorporates all features to allow
the cooking appliance 3 to be positioned under the exhaust canopy
123, fitted or otherwise connected to the direct exhaust vent 121,
and operated to begin cooking.
[0057] Optionally, the stand 125 may include an air supply duct 141
having an inlet 143 for connection to an outside source of air for
providing additional make-up air to the cooking appliance 3 and
surrounding environment (see FIGS. 3-5). This supply air may be
conditioned, if desired. The air supply duct 141 has an outlet 145
at its lower end covered by removable perforated panels 147 or any
other air direction device. A fan can be provided if make-up air is
necessary. The air supply duct 141 and associated components can be
used even if the stand 125 is not used.
[0058] FIG. 6 shows an embodiment of a direct exhaust vent 201
mounted inside an exhaust canopy 205. The canopy 205 has a filtered
fan box 211 with an exhaust discharge 215 instead of a conventional
exhaust duct and exhaust fan. The direct exhaust vent 201 of this
embodiment is similar to the direct exhaust vent 1 of the first
embodiment except that the exhaust discharge 215 of the filtered
fan box 211 is connected to an inlet 217 in the atmospheric flue
221 of the direct exhaust vent 201. As shown, the filtered fan box
211 has one or more baffles, screen mesh, and/or woven fiberglass
filters 225 (combined as necessary) and a fan 231. The filtered fan
box and components are sized to generate a flow which is as low as
possible but still sufficient to capture any hot gas and effluents
which escape from the front or discharge end of the cooking
appliance 3. Hot gas and effluents escaping through exhaust area 5
are exhausted up the direct exhaust vent 201 through the flue 221.
If necessary or desirable, a small exhaust fan can be used to
generate additional flow up through flue 221.
[0059] FIG. 7 illustrates a direct exhaust vent retrofit unit 301
which may be installed in the shell of an existing exhaust hood or
canopy 303 having an exhaust duct 305. The unit 301 comprises an
optional housing 307 sized to fit inside the existing canopy shell.
In this embodiment, the housing 307 has top and side walls and
contains the various direct exhaust vent components shown in FIG.
6, i.e., a direct exhaust vent 309, a fan box 311, filter 313, fan
315 and associated ductwork 317. The flue 319 of the direct exhaust
vent 309 extends up the existing exhaust duct 305 of the exhaust
canopy 303, although it will be understood that the flue 319 can be
routed in other ways. If used, the housing 307 of the retrofit unit
301 is secured in position under the existing exhaust canopy 303 by
suitable fasteners or other means. In other retrofit installations,
one or more of the fan box 311, filter 313, and fan 315 may be
eliminated.
[0060] FIGS. 8-11 illustrate a vent system 401 which combines a
direct exhaust vent 403 of this invention and a NFPA TYPE I exhaust
hood or canopy 405. In this embodiment the interior of the exhaust
canopy 405 is divided by a partition 411 into a first section A and
a second section B. The two sections A and B are connected by a
main exhaust duct 415 and exhaust fan (not shown). Section A and
the associated flow through this section are configured for
collecting hot gas and effluents from a cooking appliance 419A
positioned below the canopy 405 (FIG. 10). Grease filters 421 are
provided as required. Make-up air may or may not be provided. The
direct exhaust vent 403 is located in section B of the canopy
(FIGS. 9 and 11). Section B may also include one or more grease
filters 435. Most of the hot gas and effluents from the cooking
appliance 419B are directed into the direct exhaust vent 403. The
remaining hot gas and effluents are exhausted through the main
exhaust duct 415. As a result, the air flow requirements are
reduced substantially. The exhaust fan associated with the main
exhaust duct 415 can be operated at different speeds, if desired,
according to whether the cooking appliance is operating in a
high-vent mode or a low-vent mode, resulting in further energy
savings. In another embodiment a second direct exhaust vent may be
added to Section B, and the atmospheric vents may be connected for
one roof penetration. In yet another embodiment, hot gas and
effluents can be directed from Section A, via suitable ducting, to
the direct exhaust vent 403 in Section B for exhaust through the
vent 403.
[0061] FIG. 12 shows an exemplary embodiment of a direct exhaust
vent of this invention, generally designated 501. It comprises a
first direct vent structure 533 defining a first flow path 535, an
optional second direct vent structure 537 at least partially
defining a second air flow path 539, and a flue 541 (atmospheric
vent) communicating with the first and second air flow paths for
exhausting hot gas to atmosphere. The first direct vent structure
533 has a lower inlet end 543 positioned adjacent (e.g., directly
over) the exhaust area 5 of the cooking appliance, and an upper
outlet end 545 in communication with the flue 541. The inlet end
543 of the first direct vent structure 533 is preferably adapted to
be positioned adjacent the exhaust area 5 of the cooking appliance.
In some embodiments, the lower inlet end 543 of the structure may
be configured to fit over, around, in or in close proximity to the
exhaust area 5 of the cooking appliance so that hot gas and
effluents are directed from the cooking appliance upward along the
first flow path 535. In other embodiments, the lower end 543 of the
first direct vent structure may be detachably connected to the
cooking appliance by a suitable attachment mechanism.
Alternatively, the inlet end 543 of the first direct vent structure
533 may be positioned adjacent an exhaust area of the cooking
appliance other than exhaust area 5. Further, while the first and
second direct vent structures 533, 537 illustrated in FIGS. 12 and
13 are centered and symmetrical with respect to the central
vertical axis of the flue 541, it will be understood that
non-centered and asymmetric configurations are possible. For
example, if the exhaust area 5 is at a non-central location on the
top of the appliance 3, the first direct vent structure can be
located directly over such non-central location. In this case, the
first direct vent structure may have a central vertical axis
laterally offset from a central axis of the second direct vent
structure and/or from the central axis of the flue 541.
[0062] In the embodiment of FIG. 12, the first direct vent
structure 533 comprises an upper part 533A which may optionally
house other components of the system (described hereinafter) and a
lower extensible part 533B which is capable of moving up and down
relative to the upper part 533A. Specifically, the lower part 533B
has a sliding telescoping fit with the upper part 533A so that it
may be moved up and down as needed to the desired position with
respect to the exhaust area 5 of the cooking appliance below.
Alternatively, the lower part 533B could be extensible relative to
the upper part 533A in other ways. The lower part 533B may have a
sealing fit or connection with the cooking appliance 3, or it may
have a loose (non-sealing) fit or connection with the cooking
appliance, or it may simply be located adjacent the exhaust area 5
of the cooking appliance. In any case, the lower part 533B should
be positioned and configured such that at least some, and
preferably most if not substantially all of the hot gas and
effluents exhausted from the area 5 of the cooking appliance are
directed up along the first flow path 535 through the first direct
vent structure 533. In some embodiments, the dimension (e.g.,
diameter, length, width) of the lower end 543 of the first direct
vent structure 533 is approximately the same as the dimension
(e.g., diameter, length, width) of the exhaust area 5 of the
cooking appliance. In other embodiments, the dimension of the lower
end of the first direct exhaust vent is no more than one inch
greater, or no more than two inches greater, or no more than three
to six inches greater than the corresponding dimension of the
exhaust area of the cooking appliance. The length of the first
direct vent structure 533 and/or the extent of vertical adjustment
provided by the lower part 533B can vary, depending on the type and
style of cooking appliance to be vented and the elevation at which
the direct exhaust vent system is mounted relative to the cooking
appliance. By way of example, the first direct vent structure can
have a vertical adjustment (i.e., a range of extension) in the
range of 0-18 in., or in the range of 1-12 in., or in the range of
2-8 in., or in the range of 4-6 in.
[0063] Although the first direct vent structure 533 is illustrated
in FIG. 12 as being fabricated from two pieces of sheet metal, it
will be understood that it could be fabricated from any number of
parts and could have other configurations. For example, the
structure 533 could be formed so the upper and lower parts 533A,
533B are formed as a single piece with no vertical adjustment
feature. Also, the cross-sectional shape of the structure can vary
from the rectangular shape shown in FIG. 12A. For example, it may
be circular or have any polygonal shape.
[0064] In the embodiment of FIG. 12, the second direct vent
structure 537 is configured as a small hood having a lower inlet
end 549 and an upper outlet end 551 which communicates with the
atmospheric flue 541 of the direct exhaust vent 501. The second
(outer) direct vent structure 537 surrounds the first (inner)
direct vent structure 533 and is spaced from that structure to
define the second flow path 539 for exhaust of hot gas and
effluents from the environment surrounding the cooking appliance 3.
To capture these cooking by-products efficiently, the lower end 549
of the second direct vent structure 537 is preferably but not
necessarily sized somewhat larger than the overall footprint of the
cooking appliance 3, or at least the zone of the cooking appliance
where this other hot gas and effluents are likely to escape. For
example, the lower end of the second direct vent structure may be
sized to have a footprint which extends a distance of up to three
inches beyond the footprint of the zone either all around the zone
or parts of the zone. Alternatively, this distance may be up to six
inches, or up to 12 inches or even more. In any event, hot gas and
effluents escaping from the cooking appliance 3 at locations other
than through the exhaust area 5 are directed along the second flow
path 539 toward the flue 541 at the upper outlet end 551 of the
second direct vent structure.
[0065] In the embodiment shown in FIG. 13, the second direct vent
structure 537 is rectangular and extends all the way around the
first direct vent structure 533 to define an annular flow path.
However, it will be understood that the second direct vent
structure 537 could have shapes other than rectangular (e.g., other
polygonal shapes or circular). Further, the second direct vent
structure 537 need not extend all the way or even part way around
the first direct vent structure 533. For example, it may extend on
only one, two or three sides of the first direct vent structure
533, so long as a second flow path defined by the second direct
vent structure directs hot gas up through the flue 541, or through
a separate flue, not shown. In one embodiment, the second direct
vent structure could be a channel-shaped structure which overhangs
the door 4 of the cooking appliance 3 for venting cooking
by-products escaping through the door opening. In another
embodiment, the second direct vent structure could be a duct with a
closed cross-sectional shape having a lower inlet end at one side
of the first direct vent structure and an upper outlet end which
communicates with the flue 541.
[0066] A direct exhaust vent of this invention can include more
than two direct vent structures if that is desired or necessary to
meet the ventilation requirements of a particular cooking
installation. For example, a third direct vent structure could be
added to the direct exhaust vent 501 shown in FIG. 12. The third
structure could be a separate flue, for example, similar to the
flue 9 in FIGS. 1 and 2.
[0067] Depending on the type of food being cooked, the cooking
appliance, and the ventilation requirements, the direct exhaust
vent 501 may include an effluent-removal device. One type of such
device is a catalyst. The use of one or more catalysts has
advantages over a conventional grease filter system because a
catalyst generally has lower flow requirements than a grease
filter. That is, to operate effectively, most grease filters
require high-velocity flow through the filter. In contrast, a
catalyst is more efficient at lower flow velocities since the hot
gas and effluents reside in the catalyst for a longer period of
time for more effective treatment by the catalyst. As a result, the
use of a catalyst system can result in substantial savings over a
conventional grease filter system.
[0068] In the embodiment of FIG. 12, a first effluent-removal
device 519A is positioned in the upper part 533A of the first
direct vent structure 533 for treating hot gas flowing along the
first flow path 535, and a second effluent-removal device 519B is
positioned inside the second direct vent structure 537 above the
first direct vent structure 533 for treating hot gas flowing along
the first and second flow paths 535, 539. The removal of effluents
entrained in the hot gas is necessary to keep the direct exhaust
vent 501 free from grease build up and the need for grease filters.
An interlock may be required to prevent operation of the cooking
appliance without effluent-removal device(s) 519A, 519B in place.
Each effluent-removal device 519A, 519B preferably is removable for
cleaning. In some embodiments, the effluent-removal devices may be
similarly sized so that they are interchangeable. In other
embodiments, more or less than two effluent-removal devices can be
used, as needed. For example, in some embodiments, only
effluent-removal device 519A is used, and in other embodiments only
effluent-removal device 519B is used. Further, different types of
effluent-removal devices may be used in combination, depending on
the cooking appliance and type of foods cooked.
[0069] The flow rate requirement of the direct exhaust vent 501,
including the first and second (and any other) direct vent
structures 533, 537, will vary depending on the particular
installation and associated venting requirements. By way of example
but not limitation, when the cooking appliance 3 is operating in a
high-vent mode, the flow requirements of the direct exhaust vent
501 may be in the range of 0 to 220 CFM, or in the range of 30 to
200 CFM, or in the range of 50 to 180 CFM, or in the range of 60 to
150 CFM, or in the range of 70 to 120 CFM. These flow rates are
substantially lower than the flow rates required by conventional
ventilation systems, such as the large exhaust hoods or canopies of
traditional design which often have flow requirements in the range
of 150 to 450 CFM per linear foot of canopy. The result is improved
energy efficiency and reduced operational costs. The direct exhaust
vent 501 will also increase the capture of extraneous hot gas and
effluents from the exhaust areas of the cooking appliance. Quick
capture of the hot gas and effluents at the source reduces heat
radiated into the environment surrounding the cooking
appliance.
[0070] The direct exhaust vent 501 may or may not require a small
air assist fan (either induced or exhaust) for generating addition
flow through the vent, as needed or desired. The need for such a
fan will depend on the particular installation and flow
requirements of the system. In general, however, the use of such a
fan will tend to create more of a vacuum inside the cooking
appliance to inhibit hot gas and effluents from exiting the cooking
appliance except through intended exhaust outlets. The use of such
a fan will also permit the use of a thicker or more flow-resistant
effluent-removal device (e.g., catalyst). An air assist fan can be
used and installed in different ways. One possible embodiment
involves the use of an exhaust fan to pull air through a bypass
duct branching off from the atmospheric flue 541 of the direct
exhaust vent. In this embodiment, a damper is provided in the
atmospheric flue at a location above the branch. When the fan is in
operation, flow is induced up through the bypass duct to
atmosphere. When the fan is no longer needed, the damper is opened
for normal flow through the atmospheric vent to atmosphere. In any
event, each cooking appliance will require a different direct
exhaust vent configuration and control logic, depending on the food
being cooked, the type of cooking appliance, its various modes of
operation, and the vent requirements during such modes of
operation. As an example, an atmospheric vent may be used in one
mode of operation and powered exhaust may be used in a different
mode of operation.
[0071] To use the direct exhaust vent 501, the exhaust area 5 of
the cooking appliance 3 is positioned adjacent (e.g., directly
below) the lower inlet end of the direct exhaust vent. To
facilitate such placement, the second direct vent structure 537 may
be provided with one or more openings extending up from the lower
edge of the structure, to permit passage of any vertical structure
(e.g., short exhaust flue) projecting above the top wall of the
cooking appliance. Each opening has a closure (e.g., a hinged or
sliding door) for closing the opening after the cooking appliance
is moved to its proper position relative to the direct vent
structure 501. The one or more openings also provide ready access
to the first direct vent structure 533 when the cooking appliance
is below the direct exhaust vent 501 in a position where access
might otherwise be limited. After the cooking appliance has been
moved into position, the lower part of the first direct vent
structure is moved up or down or moved in some other manner (e.g.,
swung in a horizontal plane as permitted by a flexible member) as
needed to place the structure in proper position relative to the
exhaust area 5 of the cooking appliance. The ability to move the
first direct vent structure relative to the cooking appliance
facilitates removal of the cooking appliance 3 from the direct
exhaust vent 1 for cleaning. However, it will be understood that
the first direct vent structure could be non-movable. The flue 9
from the second exhaust area 7 of the cooking appliance 3 is also
connected to the atmospheric flue 541. Alternatively, the flue 9
could be connected to the direct exhaust vent at other locations,
such as to the second direct vent structure so that hot gas from
the flue 9 enters the second flow path defined by the second direct
vent structure.
[0072] FIG. 14 illustrates a direct exhaust vent 601 similar to the
direct exhaust vent 501 of the previous embodiment except that a
recirculation system 605 is incorporated as part of the atmospheric
flue 607 of the direct exhaust vent. As shown, a portion of the hot
gas flowing through the flue 607 is directed through this
recirculation system 605, which includes a housing 615, a fan (not
shown) in the housing and, preferably, one or more effluent-removal
devices. Hot gas leaving the housing 615 is directed by means of a
duct 617 back to the second direct vent structure 619 and
re-circulated through an effluent-removal device 621 located above
the first direct vent structure 623. (The effluent-removal device
621 can be used or not used, as necessary for the particular
application.) In one embodiment, the recirculation path in housing
615 has a spiral configuration for flow through multiple
effluent-removal devices (not shown). While the duct 617 of this
embodiment is shown as having an outlet connected to the second
direct vent structure 619 at a location below the effluent-removal
device 621, it will be understood that the outlet of the duct could
be connected at other locations on the direct vent structure.
Further, one or more separate flues from other exhaust areas of the
cooking appliance may connect to the direct exhaust vent 601, as
shown in FIGS. 1 and 2.
[0073] Referring again to FIG. 14, the direct exhaust vent 601 is
provided with a damper system, generally designated 653. The system
653 comprises a damper member 655 mounted inside the upper part
623A of the first direct vent structure 623 below the
effluent-removal device 621. The first direct vent structure 623
also includes a lower part 623B. The damper member 655 is mounted
(e.g., pivoted) by a suitable mechanism to move between a closed
position and an open position in which the plane of the damper
member 655 is generally parallel to the direction of gas flow
through the vent structure. In general, the damper member 655 is
operable to open when the cooking appliance is operating in a
high-vent mode and to close when the cooking appliance is operating
in a low-vent mode. The damper member 655 is configured such that
when it is open, it allows hot gas and effluents to flow at a first
flow rate along the first flow path defined by the first direct
vent structure 623. When the damper member 655 is closed, the rate
of flow through the first direct vent structure is reduced to a
second flow rate less than the first flow rate but preferably not
cut off entirely, thus allowing hot gas and effluents to continue
to vent during periods when the venting requirements of the cooking
appliance are relatively low, but reducing heat loss from the
cooking appliance for greater energy efficiency. By way of example
but not limitation, the damper member 655 in its closed position
may block at least about 66% of the cross sectional area of the
first flow path (leaving about 34% or less of this area open), and
even more preferably at least about 95% of the cross sectional area
of the first flow path (leaving about 5% or less of this area
open). Damper positions will vary based on fuel being used to heat
the apparatus. While FIG. 14 does not illustrate an
effluent-removal device mounted in the first direct vent structure
623 below the damper member 655, it will be understood that an
effluent-removal device could be used at this location. In certain
situations, the use of the damper member 655 can improve the
efficiency of an effluent-removal device installed below the damper
member, particularly a catalyst which operates more effectively at
higher temperatures. In its closed position, the damper member will
retain more heat in the cooking appliance, thus exposing the
catalyst to higher temperatures for more efficient catalytic
operation.
[0074] The damper member 655 can be configured in different ways.
For example, in one embodiment, the damper member 655 is pivotally
mounted on a shaft 657 and, when closed, has an outline which is
only slightly smaller than the outline of the flow path through the
first direct vent structure 623. The damper member 655 is
perforated at 659 to permit some flow when it is in its closed
position, the volume of such flow depending on the size and number
of perforations 659 in the damper member. Alternatively, the damper
member may be formed as a solid (non-perforated) blade or baffle
mounted on a shaft for rotation about an axis transversely offset
from the longitudinal center of the damper member. In this latter
embodiment, the damper member is configured such that when it is in
its closed position, one edge of the damper member contacts or is
immediately adjacent an inner surface of the first direct vent
structure 623 and an opposite edge is spaced a larger distance from
an inner surface of the first direct vent structure to allow a
limited but still substantial volume of flow past the damper
member. Other damper configurations are possible. For example, two
or more damper members may be mounted side by side in the flow path
for pivoting or horizontal sliding movement.
[0075] The damper member(s) 655 is preferably rotated or otherwise
moved between its open and closed positions by at least one motor
(not shown) connected to the shaft 657 by suitable linkage (also
not shown). The damper motor is controlled to open and close the
damper member(s) in an appropriate manner, preferably according to
the operation of the cooking appliance 3 (e.g., whether it is
operating in a low-vent mode or a high-vent mode). To provide a
full range of flow control, the position of the damper member(s)
may be adjustable to any number of positions between fully open and
fully closed. A stepper motor or other suitable drive mechanism can
be used for this purpose.
[0076] The use of the damper system 653 described above is
optional, as noted previously. If a damper system is used, it is
preferably mounted along the flow path to control flow through the
first direct vent structure 623 communicating with the flue
(atmospheric or non-atmospheric).
[0077] The damper system, if used, may be used in combination with
an air assist device (e.g., induced or exhaust fan) to provide
specific flow configurations through the vent system, depending on
the type of cooking appliance used and/or the type of food being
cooked and/or the level of effluents. For example, the air assist
device can be used to provide additional flow through the second
direct vent structure and/or associated ducts (e.g., flue 9 in FIG.
1). At the same time, the damper member(s) can be closed to limit
the amount of heat drawn from the cooking appliance through the
exhaust area 5. The use of the air assist fan and damper system in
this manner might arise in a situation where the environment
surrounding the cooking appliance is particularly odorous as a
result of the food being cooked, for example, or where additional
vacuum is needed to pull combustion gas through the flue 9 of the
direct exhaust vent 1. As noted above, the use of a damper system
may also be beneficial if used in combination with certain types of
effluent-removal devices, such as catalysts. In some embodiments,
the damper can also be used to divert hot gas from the cooking
appliance into a separate duct supplying make-up air or into a duct
for re-circulation back to the cooking appliance (e.g., the cooking
chamber).
[0078] FIG. 15 illustrates an embodiment similar to the one
described above in FIG. 14 and corresponding parts are designated
by the same reference numbers. The main difference is that the
re-circulating duct 617 directs flow back to the cooking appliance
3 instead of back to the direct exhaust vent 601.
[0079] FIG. 16 illustrates an embodiment similar to FIG. 15
(corresponding parts being designated by the same reference
numbers) except that the second direct vent structure is eliminated
and the re-circulating duct 617 directs flow back to the first
direct vent structure 623. Alternatively, the re-circulating duct
617 of FIG. 16 could direct flow back to the cooking appliance, as
in FIG. 15.
[0080] FIG. 17 illustrates another embodiment of a direct exhaust
vent of the present invention, generally designated 701. Direct
exhaust vent 701 is similar in many respects to the direct exhaust
vent 501 described above. Thus, direct exhaust vent 701 has a first
direct vent structure 703 having an upper end 705 connected by
means of a tapered connector 707 to an atmospheric flue 709. The
direct vent structure defines a first flow path 711 which
communicates with the flue 709 for directing hot gas up through the
flue. In this embodiment, there is no second direct vent structure
defining a second flow path to the flue. Optionally, this
embodiment may also include one or more effluent-removal devices
713 and/or a damper system (not shown) comprising one or more
damper members, as previously described. In another embodiment, a
separate flue or flues may connect to the direct exhaust vent 709
as shown in FIGS. 1 and 2.
[0081] FIG. 18 shows another embodiment of a direct exhaust vent
801 of the present invention similar to the embodiment of FIG. 12
except that the lower effluent-removal device 803A is positioned in
or on the cooking appliance 3 rather than in the first direct vent
structure of the direct exhaust vent. By way of example, the device
803A can be mounted in a housing (not shown) attached to the
cooking appliance at the exhaust area 5. Optionally, this
embodiment may eliminate the second direct vent structure if the
cooking appliance does not require it. Also, a damper system (not
shown) of the type described above may be used in this embodiment,
if desired or needed, either in combination with the
effluent-removal device 803A or without an effluent-removal device.
If a damper system is used, the damper member(s) can be mounted on
the first direct vent structure, as previously described.
Alternatively, the damper member(s) can be mounted on the cooking
appliance, such as in the aforementioned housing for the
effluent-removing device 803A, or other structure of the cooking
appliance.
[0082] FIGS. 19-22 show another embodiment of a direct exhaust vent
of the present invention, generally designated 1101. This
embodiment is similar to the embodiment 501 of FIG. 12, and the
description of that system 501 is incorporated into the description
of system 901 to the extent it is not inconsistent. The system 1101
comprises a first direct vent structure 1133 positioned above an
exhaust outlet or flue 5 of the cooking appliance 3, a second
direct vent structure 1137 surrounding the first direct vent
structure 1133, and an atmospheric flue 1141 attached to and
extending up from the second direct vent structure 1137. The first
and second direct vent structures define first and second air flow
paths 1135, 1139, respectively. In this embodiment, the first
(inner) direct vent structure 1133 is suspended in place by
brackets 1159 which attach the first direct vent structure 1133 to
the second direct vent structure 1137. Other means of attachment
may be used.
[0083] In the illustrated embodiment 1101, the first direct vent
structure 1133 comprises an upper part 1133A and a non-extensible
lower part 1133B. However, it will be understood that the lower
part could be extensible as described in regard to previous
embodiments. The lower part 1133B is sized somewhat larger than the
exhaust outlet 5 of the cooking appliance 3. The second (outer)
direct vent structure 1137 is a double-wall structure comprising
inner and outer walls 1137A, 1137B which are spaced apart to
receive insulating material 1161. A door 1163 is hinged to the
front of the second direct vent structure 1137 adjacent the lower
end of the structure. The door 1163 swings up to an open position
to facilitate movement of the cooking appliance 3 to a position
below the direct exhaust vent 1101 in which the exhaust outlet 5 of
the appliance 3 is disposed directly below the first direct vent
structure 1133. The door 1163 then swings down to a closed
position. The door may move between its open and closed positions
in other ways (e.g., by sliding).
[0084] The direct exhaust vent 1101 also includes two
effluent-removal devices, namely, a lower device (e.g., a catalyst)
1167 positioned in the exhaust outlet 5 of the cooking appliance 3
where it is supported by one or more brackets 1169 or other
supporting device, and an upper device (e.g., a catalyst) 1171
positioned above the upper (outlet) end of the first direct vent
structure 1133 where it is supported by one or more brackets 1181
or other suitable supporting device affixed to the second direct
vent structure 1137. An opening 1183 is provided in the second
direct vent structure 1137 to facilitate installation and removal
of the upper effluent-removal device 1171. When the upper device
1171 is in place, a plate 1187 affixed to the device closes the
opening. Suitable fasteners are used to secure the plate 1187 and
catalyst 1171 in place.
[0085] The direct exhaust vent of FIGS. 19-22 also includes a
damper assembly, generally designated 1191. The assembly comprises
a damper housing 1195 at the lower end of the first direct vent
structure 1133 and one or more (two are shown) damper members 1201
mounted in the housing for movement between open and closed
positions. The damper members 1201 are supported on the housing by
shafts 1205, and the shafts are rotated by a suitable mechanism
1209 which may comprise suitable linkage and/or gearing connected
to a drive motor or motors (not shown) mounted on or adjacent the
direct vent structure 1133 or on the appliance 3. In the
illustrated embodiment, the damper assembly 1191 is not attached to
the first direct vent structure 1133. The damper housing 1195
extends down into the exhaust outlet 5 of the appliance 3 to a
position in which the lower end of the housing is adjacent the
lower effluent-removal device 1169. By way of example, the lower
end of the housing may be supported by the same bracket or brackets
1169 supporting the lower effluent-removal device 1167. Gas
exhausted from the cooking appliance 3 flows up through the lower
effluent-removal device 1169, the damper housing 1195, the first
direct vent structure 1133, and the upper effluent-removal device
1171 to the atmospheric flue 1141 of the direct vent system. The
damper assembly 1191 is removable from the outlet of the appliance
3 to permit replacement of the lower effluent-removal device
11169.
[0086] In the embodiment of FIGS. 21 and 22, the damper assembly
1191 includes a collar 1215 surrounding the damper housing 1195 for
capturing additional cooking gas from the cooking appliance 3 and
directing it up to the inner direct vent structure 1133. The collar
1215 is preferably attached to the housing 1195 (as by welding) and
is disposed on or immediately above the top surface of the cooking
appliance 3. The collar 1215 is of suitable shape. By way of
example, in the illustrated embodiment, the collar 1215 is
generally rectangular and has a front wall spaced forward from the
front of the damper housing 1195 to direct cooking gas escaping
from the cooking appliance 3 in this area up to the lower end of
the first direct vent structure 1133. The collar 1215 is configured
such that when the cooking appliance 3 is in place below the direct
exhaust vent 1101, the lower end of the first direct vent structure
1133 is positioned either on or immediately above the upper end of
the collar 1215. The upper end of the collar 1215 has a peripheral
flange 1225 which functions to reinforce the collar and also to
provide a surface which may be contacted by the lower part of the
first direct vent structure 1133, as where the lower part is
extensible.
[0087] As shown in FIGS. 21 and 22, the catalyst 1167 is disposed
in the lower end of the damper housing 1195 below the damper
members 1201. The use of the damper members can improve the
efficiency of the catalyst, particularly a catalyst which operates
more effectively at higher temperatures. In the closed position,
the damper member(s) 1201 will retain more heat in the cooking
appliance 3, thus exposing the catalyst 1167 to higher temperatures
for more efficient catalytic operation. There are advantages to
this design. First, when closed, the damper members 1201 conserve
energy by reducing the air flow through the appliance. Second, when
closed, the damper members retain reduce the escape of heat and
maintain the catalyst at a higher temperature (e.g., about 775
degrees Fahrenheit) at which the catalyst is essentially
self-cleaning, thus eliminating the need for sophisticated controls
to sense the condition of the catalyst. Further, because the
temperature of the catalyst is maintained at a higher level, it
remains ready to incinerate effluents, thereby eliminating any
delay for warm-up before cooking. A third advantage is that the
normal cooking process heat generated by the appliance is
sufficient to keep the catalyst clean so that additional ancillary
devices to generate heat needed to clean the catalyst are not
necessary. This is in contrast to prior art devices as shown, for
example, in PCT International Application No. PCT/US97/10550
(Publication No. WO 97/48479), requiring a separate burner pack or
the like to heat the catalyst to clean it.
[0088] Although not specifically shown in the drawings, it will be
understood that the catalyst 1167 could be located in the exhaust
area of the cooking appliance 3 immediately upstream from (below)
the damper housing 1195 rather than actually in the damper housing
itself, so long as the damper, when closed, functions to reduce the
escape of heat from the appliance and thus maintain the catalyst at
an elevated temperature.
[0089] FIG. 23 shows another embodiment of a direct exhaust vent
901 of the present invention similar to the embodiment of FIG. 12
except that one or more effluent-removal devices 903 are placed in
the atmospheric flue 905 of the vent. A heater 913 (e.g., an
induction coil or some other type of heater) is used to heat the
effluent-removal device(s) to increase the efficiency of the
effluent-removal device(s). Alternatively, the effluent-removal
device 903 and heater 913 could be located in the first direct vent
structure 915 or in the second direct vent structure 917, if a
second direct vent structure is used. If a re-circulation system is
used, a heater and effluent-removal device can be used in the
re-circulation system. A damper system (not shown) of the type
previously described can be used in this embodiment, if necessary
or desired. In the embodiment of FIG. 23, an effluent-removal
device 921 is provided in the first direct vent structure 915.
[0090] If desired, the electronic controls for the cooking
appliance and ventilation system can be integrated to provide an
integrated control and energy management system to achieve more
efficient ventilation and improved energy management. In such an
integrated control system, the control panel on the cooking
appliance 3 or a separate control panel may provide all control
functions for the relevant components of the ventilation system,
including any supply and exhaust fans associated with the direct
exhaust vent, any supply and exhaust fans associated with the
exhaust canopy, if the latter is used, and any damper system. Thus,
for example, when the cooking appliance is operating in a high-vent
mode, one or more of any such fans are operated at a higher speed
and the damper system, if used, is moved to an open position. When
the cooking appliance is operating in a low-vent mode, one or more
of any such fans are operated at a lower or reduced speed
(including off), and the damper system, if used, is moved to a
closed position. Thus, the controls for the cooking appliance may
be used to provide for maximum efficiency and reduced air flow and
heat loss.
[0091] FIG. 24 shows an exemplary integrated control system,
generally designated 1001, for controlling the operation of a
direct exhaust vent system of the present invention, described
above, in coordination with the operation of a cooking appliance 3.
This system includes the combination of a control panel 1007 for
inputting information into the system, and a microprocessor 1013
having inputs and outputs for receiving and sending information
with respect to various components of the appliance and vent
system. These components include, for example, one or more exhaust
fans 1021; one or more air make-up fans 1023; one or more bypass
dampers 1025; one or more induced draft fans 1027; one or more
heaters 1029 for heating respective one or more effluent-removal
devices; one or more filtered fan boxes 1035; one or more appliance
dampers 1037; one or more damper position sensors 1041; one or more
effluent-removal device position sensors 1043 for sensing whether a
respective effluent-removal device is in position; one or more
photo-electric sensors 1047 for sensing the absence or presence of
effluents in the hot gas from the appliance, in response to which
fan speed can be suitably controlled; one or more temperature
sensors 1051 for sensing the temperature at respective one or more
locations in the direct exhaust vent (e.g., above an
effluent-removal device which may tend to overheat under certain
circumstances); one or more sensors for sensing the activation of a
safety system such as a fire extinguisher system 1053 (e.g., a
UL-approved R102 system) associated with the vent system; one or
more appliance position sensors 1057 for sensing whether the
cooking appliance 3 is in proper position relative to the vent
system; and one or more shunt trip breakers 1061 for cutting off
power to the cooking appliance under certain conditions, e.g., in
the event sensor 1053 senses the activation of a safety system, or
in the event the appliance position sensor 1057 senses that the
cooking appliance is not in proper position relative to the vent.
The exhaust fan(s) 1021 and air make-up fan(s) 1023 are driven by
suitable drives 1071 (e.g., a single-speed drive for driving a fan
at only one speed, not including "off", and/or a variable-speed
drive for driving the fan at two or more speeds, not including
"off"); the bypass damper(s) 1025, induced draft fan(s) 1027,
heater(s) 1029, filtered fan box(es) 1035, appliance damper(s)
1037, photo-electric sensor(s) 1047, temperature sensor(s) 1051 and
shunt trip breaker(s) 1061 are associated with relays 1081; and the
damper position sensor(s) 1041, effluent-removal device position
sensor(s) 1043, extinguisher system(s) 1057 and appliance position
sensor(s) 1061 are associated with micro-switches 1091. The drives
1071, relays 1081 and micro-switches 1091 suitably communicate with
microprocessor, as will be understood by the skilled person. Other
control systems may be used, the system in FIG. 24 being only a
schematic illustration of one possible system. The particular
cooking appliance and combination of vent components under the
control of the control system will vary from installation to
installation. In general, however, it will be understood that there
is a communication link between the appliance control and the vent
system control so that components of the vent system (e.g., one or
more dampers and/or fans) are controlled in response to the
operation of the cooking appliance, as when the cooking appliance
is moving through various segments of its operational cycle, such
as the cycle described below.
[0092] An exemplary operational cycle for a cooking appliance is
described below. In this embodiment, the cooking appliance is a
broiler having upper and lower burners for cooking food in a
cooking cavity or chamber. A direct exhaust vent as described above
(e.g., as shown in FIGS. 19-22) is provided for exhausting hot gas
and effluents from the cooking appliance. Each operational cycle of
the broiler in this example includes the following segments:
start-up; idle; cook; and standby. These segments are described
below.
[0093] During the start-up segment, all burners (lower and upper)
are turned on and the broiler cooking cavity is heated to a
predetermined temperature T1 (e.g., 680 degrees F.). The damper of
the vent system 1101 is in its closed position to conserve energy
(i.e., to reduce heat loss.) If an exhaust fan is used, the fan is
turned off. After the temperature in the cavity reaches T1, as
sensed by a suitable temperature sensor, the idle segment
starts.
[0094] During the idle cycle segment, the upper burners are on and
the lower burner cycles to maintain the broiler cavity temperature
at temperature T1. The appliance remains in the idle cycle until
the appliance is used in a cook cycle or is turned off.
[0095] The cook segment is initiated by an operator actuating a
suitable control, such as one of a series of pushbuttons, each of
which may correspond to a particular cooking recipe for a
particular food. During the cook cycle, all burners are initially
on, the upper burners cycle based on time in the cook recipe, and
the lower burner cycles off when the cavity temperature, as sensed
by a suitable sensor, reaches a maximum cooking temperature T2
higher than T1 (e.g., 775 degrees F.). The damper is opened at or
about the start of the cook cycle so that hot gas and effluents
(e.g., smoke) produced by the cooking are vented. If an exhaust fan
is used, the fan is turned on. The cook segment continues according
to the programmed cooking recipe at a suitable temperature or
temperatures for suitable time period or periods. At the end of the
cooking recipe the damper closes to conserve energy and the
appliance enters the idle cycle. If desired, an operator can
initiate a second or next cook cycle following the end of the
preceding cook cycle. However, to conserve energy, if a
predetermined time interval (e.g., two minutes) elapses without
initiation of another cook cycle, the standby segment of the
operational cycle is initiated.
[0096] During the standby cycle segment, the upper burners are
turned off and the lower burner cycles to maintain the broiler
cavity at a predetermined temperature (e.g., T1). The damper is
also moved to its closed position to conserve energy. If an exhaust
fan is used, the fan is turned off. If food product is to be
cooked, an appropriate control (e.g., pushbutton) is actuated to
terminate the standby cycle and initiate the idle segment described
above to prepare the broiler for cooking. At the end of the idle
segment, a cook segment is started by actuating a suitable control,
such as a pushbutton, corresponding to the particular food to be
cooked, as described above.
[0097] To conserve additional energy, it may be desirable in some
situations (e.g., where little or no smoke is generated during the
initial phase of the cook cycle segment) to divide the cook segment
of the cycle described above into two sub-segments, i.e., a first
cook/pre-smoke sub-segment and a second cook/smoke sub-segment.
During the first sub-segment, all burners are on, and the lower
burner cycles off when cavity temperature reaches an appropriate
maximum cooking temperature (e.g., T2). Food product in the broiler
is cooking but is not producing smoke. During this sub-segment, the
damper remains in a closed position to conserve energy. The
cook/pre-smoke sub-segment continues for a predetermined
(programmed) period of time, which may vary depending on the type
of food being cooked, following which the cook/smoke sub-segment is
initiated. During this sub-segment, the damper is opened to exhaust
hot gas and effluents from the cooking appliance. If an exhaust fan
is used, the fan is turned on. As during the previous cook/pre-cook
sub-segment, all burners are on, and the lower burner cycles off
when the cavity temperature reaches the desired maximum cooking
temperature (e.g., T2).
[0098] The number and type of cycle segments and/or sub-segments in
an operational cycle will vary from one cooking appliance to
another. Further, successive operational cycles may vary from one
cycle to the next. By way of example, a first cycle may include
start-up, idle, cook, cook, and standby segments, and a second
cycle may include start-up, idle and cook segments. The present
invention contemplates all such variations. In general, the method
contemplates the basic steps of operating the cooking appliance in
a cycle having different cycle segments, and varying the flow
characteristics of the vent system as a function of the cycle
segment. The integrated control system controlling the vent system
and the cooking appliance operates to vary the flow characteristics
of the vent system (e.g., by opening or closing dampers and/or
changing fan speed) to accommodate the venting requirements of the
different cycle segments.
[0099] In general, a vent system of this invention may be broadly
described as a system for venting a cooking appliance (e.g., 3)
having a first exhaust area (e.g., 5) for exhausting hot gas and
effluents from the cooking appliance. The cooking appliance may
also have a second exhaust area (e.g., exhaust outlet 7, door 4,
relief vents, or other apertures) other than the first exhaust area
through which hot gas and effluents escape. The vent system
generally includes a first direct vent structure (e.g., 533)
defining a first flow path (e.g., 535) for venting substantially
only hot gas and effluents from the first exhaust area (e.g., 5),
and an optional second direct vent structure (e.g., 537) defining a
second flow path (e.g., 539) for venting substantially only hot gas
and effluents from the second exhaust area (e.g., 7). In one
embodiment (e.g., the FIG. 12 embodiment described above), the
second (outer) direct vent structure surrounds the first (inner)
direct vent structure and combines with the first direct vent
structure to define the second flow path. The first and second air
flow paths preferably communicate with a common atmospheric flue
(e.g., 541) for exhausting hot gas to atmosphere. In other
embodiments, the first and second air flow paths can communicate
with separate flues. In still other embodiments, the second direct
vent structure (e.g., 537) can be eliminated entirely, as shown in
FIG. 17. And in yet other embodiments, a third direct vent
structure (e.g., flue 9 in FIGS. 1 and 2) can be added to define a
third flow path to vent hot gas from a different location (e.g.,
the combustion chamber of an oven) through the same atmospheric
flue (e.g., 541) used by the first and/or second direct vent
structures, or through a different flue dedicated to the third flow
path.
[0100] A ventilation and energy management system of this invention
may have one or more of the features described above, or any
combination of such features. These features include a fully
integrated control system for controlling the operation of the
cooking appliance and ventilation system so that the ventilation
requirements of the cooking appliance are met efficiently and in a
way which conserves energy. The ventilation system of this
invention can also be used with conventional hood canopies, either
in an original installation or in a retrofit installation, to
increase ventilation efficiency and to conserve energy. If
necessary or desirable to meet the particular ventilation
requirements of a cooking system, more than one direct exhaust vent
of this invention can be used in parallel. In such a situation, the
vents can exhaust through separate atmospheric flues, or through a
common atmospheric flue. The ventilation system may also include an
optional damper system for controlling flow from the cooking
appliance to achieve energy savings. The damper system can be used
in combination with a direct exhaust vent described herein, or it
can be used separately on the cooking appliance.
[0101] A vent system having one or more of the features described
above will provide one or more advantages, including but not
limited to: flexibility and adaptability for integration with
various types of cooking appliances; the capture and disposition of
hot gas and effluents in an energy efficient manner; adaptability
to meet different effluent-removal requirements; integration of the
vent system with the particulars of the cooking process, foods
cooked and cooking appliance; less maintenance and cleaning of the
vent system components; and a substantial step toward meeting the
standards of an energy efficient or "green" restaurant, a goal
which is becoming more and more important.
[0102] When introducing elements of the present invention or the
preferred embodiments(s) thereof, the articles "a", "an", "the" and
"said" are intended to mean that there are one or more of the
elements. The terms "comprising", "including" and "having" are
intended to be inclusive and mean that there may be additional
elements other than the listed elements.
[0103] In view of the above, it will be seen that the several
objects of the invention are achieved and other advantageous
results attained.
[0104] As various changes could be made in the above constructions,
products, and methods without departing from the scope of the
invention, it is intended that all matter contained in the above
description and shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
* * * * *