U.S. patent application number 11/947924 was filed with the patent office on 2009-03-05 for autonomous ventilation system.
This patent application is currently assigned to Current Energy Controls, LP. Invention is credited to Michael P. Burdett, Daniel Reich.
Application Number | 20090061752 11/947924 |
Document ID | / |
Family ID | 40408216 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090061752 |
Kind Code |
A1 |
Burdett; Michael P. ; et
al. |
March 5, 2009 |
Autonomous Ventilation System
Abstract
An autonomous ventilation system includes a variable-speed
exhaust fan, a controller, an exhaust hood, and an infrared
radiation ("IR") sensor. The exhaust fan removes air contaminants
from an area. The controller is coupled to the exhaust fan and
adjusts the speed of the exhaust fan. The exhaust hood is coupled
to the exhaust fan and directs air contaminants to the exhaust fan.
The IR sensor is coupled to the controller, detects changes in IR
index in a zone below the exhaust hood, and communicates
information relating to detected changes in IR index to the
controller. The controller adjusts the speed of the exhaust fan in
response to information relating to detected changes in IR index.
The autonomous ventilation system also includes an alignment laser
to indicate a point at which the IR sensor is aimed and a
field-of-view ("FOV") indicator to illuminate the zone in which the
IR sensor detects changes in IR index.
Inventors: |
Burdett; Michael P.;
(Tucson, AZ) ; Reich; Daniel; (Tucson,
AZ) |
Correspondence
Address: |
BAKER BOTTS L.L.P.
2001 ROSS AVENUE, SUITE 600
DALLAS
TX
75201-2980
US
|
Assignee: |
Current Energy Controls, LP
Tucson
AZ
|
Family ID: |
40408216 |
Appl. No.: |
11/947924 |
Filed: |
November 30, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60968395 |
Aug 28, 2007 |
|
|
|
Current U.S.
Class: |
454/61 ;
454/341 |
Current CPC
Class: |
F24C 15/20 20130101;
F24C 15/2021 20130101; B08B 15/02 20130101; F24F 11/30
20180101 |
Class at
Publication: |
454/61 ;
454/341 |
International
Class: |
F24C 15/20 20060101
F24C015/20; F24F 7/007 20060101 F24F007/007 |
Claims
1. An autonomous ventilation system comprising: a variable-speed
exhaust fan operable to remove an air contaminant from an area; a
controller coupled to the variable-speed exhaust fan and operable
to adjust the speed of the exhaust fan; an exhaust hood coupled to
the exhaust fan, the exhaust hood operable to direct the air
contaminant to the exhaust fan; and an infrared radiation ("IR")
sensor coupled to the controller, the IR sensor configured to
detect a change in IR index in a zone below the exhaust hood and to
communicate information relating to detected changes in IR index to
the controller, wherein the controller is further operable to
adjust the speed of the fan in response to information relating to
changes in IR index detected by the IR sensor.
2. The ventilation system of claim 1, wherein the exhaust hood is
located above one or more pieces of cooking equipment.
3. The ventilation system of claim 2, wherein the IR sensor
comprises a thermopile sensor.
4. The ventilation system of claim 1, wherein the air contaminant
comprises one or more of smoke, steam, and fumes.
5. The ventilation system of claim 1 further comprising a
variable-speed supply fan coupled to the controller, the
variable-speed supply fan operable to deliver air to the area.
6. The ventilation system of claim 1 further comprising an
alignment laser operable to visibly indicate a point at which the
IR sensor is aimed.
7. The ventilation system of claim 1 further comprising a
field-of-view ("FOV") indicator operable to illuminate the zone
below the exhaust hood in which the IR sensor is operable to detect
a change in IR index.
8. The ventilation system of claim 2, wherein: the IR sensor is
operable to detect a decrease in IR index associated with an
introduction of a food product to the zone below the exhaust hood;
and the controller is operable to adjust the speed of the
variable-speed exhaust fan to a predetermined speed for a
predetermined period of time associated with cooking of the food
product.
9. The ventilation system of claim 2, wherein: the IR sensor is
operable to detect a decrease in IR index associated with an air
contaminant produced by a food product being cooked in the zone
below the exhaust hood; and the controller is operable to adjust
the speed of the variable-speed exhaust fan to a predetermined
speed operable to remove the air contaminant.
10. The ventilation system of claim 1 wherein the controller is
further operable to: monitor an energy level of a piece of
equipment below the exhaust hood; adjust the variable-speed exhaust
fan to a predetermined idle speed when the energy level of the
piece of equipment below the exhaust hood indicates the equipment
has been turned on; and turn the variable-speed exhaust fan off
when the energy level of the piece of equipment below the exhaust
fan indicates the equipment has been turned off.
11. The ventilation system of claim 1 further comprising an eyeball
housing assembly comprising the IR sensor, the eyeball housing
assembly being operable to pivot about a socket to adjust where the
IR sensor is aimed.
12. The ventilation system of claim 11 further comprising a laser
calibration assembly, the laser calibration assembly operable to be
coupled to the eyeball housing assembly and generate a visible
calibration beam to align the IR sensor.
13. A method of ventilating an area comprising: providing a
controller coupled to a variable-speed exhaust fan, the
variable-speed exhaust fan having an associated exhaust hood and is
operable to remove an air contaminant from an area; providing an
infrared radiation ("IR") sensor coupled to the controller; sensing
an IR index change in a zone below the exhaust hood using the IR
sensor; and adjusting the speed of the variable-speed exhaust fan
using the controller based on the IR index change sensed by the IR
sensor in the zone below the exhaust fan.
14. The method of ventilating an area of claim 13, wherein the
exhaust hood is located above one or more pieces of cooking
equipment.
15. The method of ventilating an area of claim 14, wherein: the IR
index change is a decrease associated with an introduction of a
food product to the zone below the exhaust hood; and the speed of
the variable-speed exhaust fan is adjusted to a predetermined speed
for a predetermined period of time associated with cooking of the
food product.
16. The method of ventilating an area of claim 14, wherein: the IR
index change is a decrease associated with an air contaminant
produced by a food product being cooked in the zone below the
exhaust hood; and the speed of the variable-speed exhaust fan is
adjusted to a predetermined speed operable to remove the air
contaminant.
17. The method of ventilating an area of claim 13 further
comprising: monitoring an energy level of a piece of equipment
below the exhaust hood; adjusting the variable-speed exhaust fan to
a predetermined idle speed when the energy level of the piece of
equipment below the exhaust hood indicates the equipment has been
turned on; and turning the variable-speed exhaust fan off when the
energy level of the piece of equipment below the exhaust fan
indicates the equipment has been turned off.
18. The method of ventilating an area of claim 13 further
comprising: controlling a variable-speed supply fan, the
variable-speed supply fan operable to deliver air from an air
supply source to the area; and adjusting the variable-speed supply
fan based on the speed of the variable-speed exhaust fan.
19. The method of ventilating an area of claim 13, wherein the air
contaminant comprises one or more of smoke, steam, and fumes.
20. A sensor assembly comprising: an infrared radiation ("IR")
sensor operable to detect a change in IR index; an alignment laser
operable to visibly indicate a point at which the sensor assembly
is aimed; a field-of-view ("FOV") indicator operable to illuminate
an area where the IR sensor is operable to detect a change in IR
index; and an aperture assembly having one or more adjustable
shunts operable to adjust the size of the area where the IR sensor
is operable to detect a change in IR index.
21. The sensor assembly of claim 20, wherein the IR sensor, the
alignment laser, and the FOV indicator are positioned in a housing
operable to rotate about an axis to allow a user to select either
the IR sensor, alignment laser, or FOV indicator.
22. The sensor assembly of claim 21 wherein the housing comprises a
fixed aperture, the housing further operable to rotate to align the
IR sensor, alignment laser, or FOV indicator with the fixed
aperture.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Application No. 60/968,395 filed
Aug. 28, 2007 entitled "Smart Kitchen Ventilation Hood with
Thermopile Sensor."
TECHNICAL FIELD
[0002] This disclosure relates in general to control systems and
more particularly to an autonomous ventilation system.
BACKGROUND
[0003] Ventilation systems are commonly found in modern
residential, restaurant, and commercial kitchens. Heat, smoke, and
fumes are an ordinary byproduct of cooking many foods and must be
removed in order to protect the health and comfort of those present
in the kitchen and adjacent areas. Ventilation systems provide an
effective way to capture excessive heat, smoke, and fumes generated
in kitchens and ventilate them to the atmosphere where they pose no
threat to health or safety.
[0004] A typical ventilation system consists of an exhaust hood
positioned over pieces of cooking equipment that are known to
produce heat, smoke, or fumes. This exhaust hood is usually
connected via ducts to an exhaust fan and in turn to a vent located
on the outside of the building housing the kitchen. The exhaust fan
is operated in a way to create a flow of air from the exhaust hood
to the outside vent. This creates a suction effect at the exhaust
hood that captures the air and any airborne contaminants around the
hood. Consequently, any heat, smoke, or fumes generated by the
cooking equipment will rise up to the overhead exhaust hood where
it will be captured by the suction and transported out of the
kitchen to the outside vent. There, it will dissipate harmlessly
into the atmosphere.
[0005] Most ventilation systems must be manually activated and
deactivated by the user. In a typical fast-food restaurant, for
example, an employee must manually activate the kitchen ventilation
system early in the day or before any cooking occurs. The system
will then remain active in order to capture any smoke or fumes that
may result from cooking. The system must then be manually
deactivated periodically, at the end of the day, or after all
cooking has ceased. This manual operation of the ventilation system
typically results in the system being active at times when
ventilation is not actually required. This needlessly wastes energy
not only associated with the operation of the ventilation system,
but also due to the ventilation of uncontaminated air supplied to
the kitchen by a heating and cooling system. By operating when no
smoke or fumes are present, the ventilation system will remove
other valuable air that was supplied to heat or cool the kitchen
and thus cause the heating and cooling system to operate longer
than it would have otherwise.
SUMMARY OF THE DISCLOSURE
[0006] The present disclosure provides an autonomous ventilation
system that substantially eliminates or reduces at least some of
the disadvantages and problems associated with previous methods and
systems.
[0007] According to one embodiment, an autonomous ventilation
system includes a variable-speed exhaust fan, a controller, an
exhaust hood, and an infrared radiation ("IR") sensor. The exhaust
fan removes air contaminants from an area. The controller is
coupled to the exhaust fan and adjusts the speed of the exhaust
fan. The exhaust hood is coupled to the exhaust fan and directs air
contaminants to the exhaust fan. The IR sensor is coupled to the
controller, detects changes in IR index in a zone below the exhaust
hood, and communicates information relating to detected changes in
IR index to the controller. The controller adjusts the speed of the
exhaust fan in response to information relating to changes in IR
index detected by the IR sensor. Other embodiments also include an
alignment laser to visibly indicate a point at which the IR sensor
is aimed and a field-of-view ("FOV") indicator to illuminate the
zone below the exhaust hood in which the IR sensor detects changes
in IR index.
[0008] Technical advantages of certain embodiments may include a
reduction in energy consumption, an increase in the comfort of the
ventilated area, and a decrease in noise. Embodiments may eliminate
certain inefficiencies such as needlessly ventilating valuable air
from an area that was supplied by a heating, ventilation, and air
conditioning ("HVAC") system.
[0009] Other technical advantages will be readily apparent to one
skilled in the art from the following figures, descriptions, and
claims. Moreover, while specific advantages have been enumerated
above, various embodiments may include all, some, or none of the
enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present disclosure
and its advantages, reference is now made to the following
description, taken in conjunction with the accompanying drawings,
in which:
[0011] FIG. 1 is a simplified block diagram illustrating a facility
requiring ventilation in accordance with a particular
embodiment;
[0012] FIG. 2 is a simplified block diagram illustrating a
ventilation system in accordance with a particular embodiment;
[0013] FIG. 3 is a simplified block diagram illustrating a
ventilation system in accordance with another particular
embodiment;
[0014] FIG. 4A-4C is an exploded view of an IR sensor assembly in
accordance with a particular embodiment;
[0015] FIG. 5 is an exploded view of an IR sensor assembly in
accordance with a another particular embodiment; and
[0016] FIG. 6 is a method of controlling a ventilation system in
accordance with a particular embodiment.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0017] FIG. 1 depicts a facility 100 where a particular embodiment
may be utilized. Facility 100 may be a restaurant, for example,
that includes a kitchen 102 and at least one adjacent room 104
separated by a wall 106. Wall 106 contains a doorway 108 that
allows access between kitchen 102 and adjacent room 104. Facility
100 also includes an HVAC system 110 that provides conditioned air
to the interior of facility 100 via interior vents 112. Kitchen 102
includes one or more pieces of cooking equipment 114, an exhaust
hood 116, a ceiling supply air vent 118, and a ceiling exhaust vent
124. Examples of cooking equipment 114 include, but are not limited
to, stoves, cooktops, ovens, fryers, and broilers. Exhaust hood 116
is oriented such that a downward-facing opening 120 is operable to
direct an air contaminant 122 associated with the operation of
cooking equipment 114 through ceiling exhaust vent 124 and
ultimately out an exterior exhaust vent 130 via an exhaust duct
132. Air contaminant 122 includes, but is not limited to, smoke,
steam, fumes, and/or heat. Ceiling supply air vent 118 is connected
to a supply air duct 134 and is operable to provide supply air 126.
Supply air 126 may be supplied from HVAC system 110 and may include
conditioned air (i.e., heated or cooled air) or unconditioned air.
Supply air 126 may be supplied in an amount corresponding to the
amount of air removed from kitchen 102 via exhaust hood 116 such
that the air pressure inside kitchen 102 remains relatively
constant.
[0018] Removing air contaminant 122 from kitchen 102 helps ensure
that kitchen 102, as well as adjacent room 104, remains safe,
sufficiently free of air contaminant 122, and at a comfortable
temperature for anyone inside. The volume of air exhausted via
exhaust hood 116 should be carefully regulated to minimize the
quantity of conditioned air (air entering facility 100 through HVAC
system 110) that is vacated from kitchen 102 and facility 100 while
ensuring that enough air is ventilated to prevent buildup of air
contaminant 122. Because a particular piece of cooking equipment
114 may not be in use at all times and thus will not continuously
generate air contaminant 122, it becomes beneficial to vary the
rate at which exhaust hood 116 ventilates air contaminant 122 from
kitchen 102 as well as the rate at which ceiling supply air vent
118 supplies air to kitchen 102 as a means to conserve energy and
increase occupant safety and comfort. The embodiments discussed
below provide a convenient alternative to manually activating a
ventilation system as the level of air contaminants fluctuates.
[0019] While facility 100 has been described in reference to a
restaurant, it should be noted that there are many facilities in
need of such ventilation systems. Such facilities include
manufacturing facilities, industrial facilities, residential
kitchens, and the like. Likewise, embodiments in this disclosure
are described in reference to kitchen 102, but could be utilized in
any facility requiring ventilation.
[0020] FIG. 2 depicts an autonomous ventilation system 200 as would
be located inside kitchen 102 in accordance with a particular
embodiment. Autonomous ventilation system 200 includes exhaust hood
116 with downward-facing opening 120. Exhaust hood 116 is coupled
to ceiling exhaust vent 124 and is positioned above one or more
pieces of cooking equipment 114. Air is drawn up through exhaust
hood 116 via downward-facing opening 120 by an exhaust fan 210.
Exhaust fan 210 may be positioned anywhere that allows it to draw
air up through exhaust hood 116 including, but not limited to,
inside exhaust hood 116 and exhaust duct 132. Autonomous
ventilation system 200 also includes ceiling supply air vent 118
that can supply conditioned or unconditioned air to kitchen 102
from HVAC system 110. Air is supplied to kitchen 102 by a supply
air fan 212 that is located in a position so as to create a flow of
air through supply air duct 134 and ultimately out ceiling supply
air vent 118. Autonomous ventilation system 200 also includes an IR
sensor 214 that can detect IR index (the heat signature given off
by an object) fluctuations in or about a cooking zone 216
associated with cooking equipment 114 beneath exhaust hood 116.
According to a particular embodiment, IR sensor 214 is a thermopile
sensor for remotely sensing infrared radiation changes in cooking
zone 216. IR sensor 214, however, may be any type of IR sensor and
is not limited in scope to a thermopile sensor. IR sensor 214 may
be mounted inside exhaust hood 116, on top of exhaust hood 116, on
a ceiling 218, or in any other position that allows it to detect IR
index fluctuations in cooking zone 216 beneath exhaust hood 116.
Cooking zone 116 may envelop an area adjacent to cooking equipment
114 or any portion of cooking equipment 114.
[0021] Autonomous ventilation system 200 is controlled by a
controller 220. Controller 220 is coupled to IR sensor 214, exhaust
fan 210, supply air fan 212, and/or cooking equipment 114.
Controller 220 has auto-calibration and control logic that may be
heuristically adjusted from observation of the environment, as
discussed below. Controller 220 communicates with IR sensor 214 to
observe the environment and determine IR index fluctuations in or
about cooking zone 216. Controller 220 also communicates with
exhaust fan 210 to control its speed and consequently the rate of
ventilation of autonomous ventilation system 200. In some
embodiments, controller 220 additionally communicates with supply
air fan 212 to control its speed and thus the amount of air that is
re-supplied to kitchen 102. Controller 220 may also be coupled to
cooking equipment 114 in order to determine when it has been turned
on and off.
[0022] In operation, controller 220 automatically adjusts the speed
of exhaust fan 210 and thus the ventilation rate of autonomous
ventilation system 200 based on a schedule and/or certain
conditions sensed by IR sensor 214. These conditions may include
the energy level of cooking equipment 114, the state of IR sensor
214, the introduction of uncooked food into cooking zone 216,
and/or the presence of excessive amounts of air contaminant
122.
[0023] First, controller 220 may turn exhaust fan 210 on and off
and/or adjust its speed based on the energy level of cooking
equipment 114. Controller 220 may observe cooking equipment 114
with IR sensor 214 and determine an average IR index for the
cooking surface or cooking medium when it is not in use. When a
user then activates cooking equipment 114, controller 220 may
detect via IR sensor 214 the increase in the IR index of the
cooking surface or the cooking medium and set the rate of exhaust
fan 210 to an idle rate. This idle rate may be a fixed
predetermined speed or it may be a speed based on the IR index as
measured by IR sensor 214. Conversely, controller 220 may decrease
the speed or completely turn off exhaust fan 210 when it is
determined via IR sensor 214 that cooking equipment 114 has been
turned off. To determine if cooking equipment 114 has been turned
off, controller 220 may determine that the IR index of the cooking
surface or cooking medium of cooking equipment 114 has decreased to
or towards the typical IR index when not in use. In some
embodiments, controller 220 may be additionally or alternatively
coupled to cooking equipment 114 to detect when it has been
activated and deactivated. By automatically controlling the
ventilation rate based on the energy level of cooking equipment
114, autonomous ventilation system 200 alleviates disadvantages of
other ventilation systems such as wasted energy and unnecessary
noise.
[0024] In some embodiments, controller 220 may additionally or
alternatively adjust the speed of exhaust fan 210 based on the
state of IR sensor 214. In this configuration, controller 220
monitors whether sensor 214 has been activated by a user. When a
user activates IR sensor 214, controller 220 will set the speed of
exhaust fan 210 to a predetermined idle rate or a rate based on the
IR index measured by IR sensor 214. In addition, a user may choose
to override IR sensor 214 altogether. By pushing the appropriate
override button, a user may choose to override IR sensor 214 and
manually force controller 220 to increase the speed of exhaust fan
210. This allows the user manual control of autonomous ventilation
system 200 when desired.
[0025] In addition or alternatively, controller 220 of autonomous
ventilation system 200 may set the speed of exhaust fan 210 to a
predetermined normal cooking rate when IR sensor 214 detects a drop
in IR index in all or part of cooking zone 216 due to the
introduction of uncooked or cold food. As examples only, IR sensor
214 may detect a drop in IR index in all or part of cooking zone
216 due to cold and/or uncooked food being placed over an active
burner, cold and/or uncooked food (such as frozen hamburger
patties) being placed at the input to a broiler, or uncooked french
fries being placed into a fryer. As a result of detecting such an
event and setting the speed of exhaust fan 210 to a predetermined
normal cooking rate, autonomous ventilation system 200 will be
operational and will ventilate any airborne contaminant 122 that
may result in the ensuing cooking session.
[0026] Controller 220 may additionally or alternatively set the
speed of exhaust fan 210 to a predetermined flare-up rate when IR
sensor 214 detects a change in IR index in cooking zone 216 due to
a flare-up in cooking. Such changes in IR index may include a
decrease due to the presence of excessive amounts of air
contaminant 122 such as smoke or vapor or it may be an increase due
to the presence of excessive heat and/or flames. Conversely,
controller 220 may decrease the speed or completely turn off
exhaust fan 210 after a predetermined amount of cooking time or
when IR sensor 214 detects an IR index corresponding to a low,
non-cooking, or non flare-up condition. This will additionally
increase the energy efficiency and comfort level of the kitchen
while minimizing unneeded noise.
[0027] The idle, cooking, and flare-up rates of exhaust fan 210 may
be determined in a variety of ways. For example, these rates may be
preset and/or preprogrammed into controller 220 based on the type
of cooking equipment and/or the type of food being cooked under
exhaust hood 116. A user may also determine and/or adjust these
rates heuristically by observing the operation of autonomous
ventilation system 200 in the environment in which it is installed.
Pre-determined times for particular cooking equipment could also be
provided from a manufacturer or standards body. It should also be
noted that even though three distinct rates have been identified,
it is intended that the present disclosure encompass other rates as
well. For example, controller 220 may gradually increase the rate
of exhaust fan 210 over time from a lower rate such as the idle
rate to a higher rate such as the cooking rate. Likewise, it may
gradually decrease the rate of exhaust fan 210 over time from a
higher rate such as the flare-up rate to a lower rate such as the
cooking rate.
[0028] In some embodiments, controller 220 may also automatically
control the speed of supply air fan 212 to provide a desired
pressurization of kitchen 102. For example, it may set the speed of
supply air fan 212 to match the speed of exhaust fan 210. As a
result, the rate at which air is removed and supplied to kitchen
102 is approximately equal and thus the temperature and air
pressure remains relatively constant. Controller 220 may also set
the speed of supply air fan 212 to a speed that is greater than the
speed of exhaust fan 210 to create positive pressure in kitchen
102. This ensures that the environment in kitchen 102 remains safe
and comfortable regardless of how much air is being ventilated
through exhaust hood 116.
[0029] Exhaust fan 210 and supply air fan 212 may be powered by
various types of motors including, but not limited to, AC
single-phase electrical motors, AC three-phase electrical motors,
and DC electrical motors. The speeds of exhaust fan 210 and supply
air fan 212 may be adjusted by controller 220 by modulating the
frequency of the output of a variable frequency drive in the case
of AC single-phase or three-phase electrical motors, by a phase cut
modulation technique in the case of a single-phase motor, or by
changing voltage in case of a DC electrical motor.
[0030] With reference now to FIG. 3, an additional embodiment of an
autonomous ventilation system is provided. In this embodiment, an
autonomous ventilation system 300 is operable to ventilate air
contaminant 122 produced from more than one piece of cooking
equipment 114. Autonomous ventilation system 300 comprises the same
components described above in reference to autonomous ventilation
system 200, but with minor modifications. In this embodiment, more
than one IR sensor 214 and more than one piece of cooking equipment
114 are coupled to controller 220. Each IR sensor 214 can detect IR
index fluctuations in or about a corresponding cooking zone 216
beneath exhaust hood 116. Exhaust hood 116 is positioned above the
more than one piece of cooking equipment 114 and directs air
contaminants 122 to ceiling exhaust vent 124.
[0031] In operation, controller 220 of autonomous ventilation
system 300 adjusts the speed of exhaust fan 210 based on a schedule
or certain conditions sensed by IR sensors 214 in a similar manner
as described above in reference to autonomous ventilation system
200. For example, controller 220 may set the rate of exhaust fan
210 to an appropriate rate when any IR sensor 214 detects a change
in the level of energy of any piece of cooking equipment 114 under
exhaust hood 116. Controller 220 may set the speed of exhaust fan
210 to the default idle rate when it is determined via IR sensors
214 that any piece of cooking equipment 114 under exhaust hood 116
has been activated. Conversely, controller 220 may decrease the
speed or completely turn off exhaust fan 210 when it is determined
via IR sensors 214 that some or all of cooking equipment 114 has
been turned off. In addition, controller 220 of autonomous
ventilation system 300 may set the speed of exhaust fan 210 to a
predetermined cooking rate based on the IR index in all or part of
cooking zones 216 as determined by IR sensors 214. In this
situation, controller 220 first determines the appropriate rate for
each individual piece of cooking equipment 114. Such rates include,
for example, the normal cooking rate and the flare-up rate as
described above in reference to autonomous ventilation system 200.
Controller 220 then sets the speed of exhaust fan 210 to the sum of
the required rates of each of the pieces of cooking equipment 114
under exhaust hood 116 (or any other suitable speed including one
based on the size and shape of exhaust hood 116 or the type of
cooking equipment 114.) Controller 220 may conversely decrease the
speed or completely turn off exhaust fan 210 after a predetermined
amount of cooking time or when IR sensors 214 detect an IR index
corresponding to a low, non-cooking, or non flare-up condition
under exhaust hood 116.
[0032] Modifications, additions, or omissions may be made to
autonomous ventilation system 300 and the described components. As
an example, while FIG. 3 depicts two pieces of cooking equipment
114, two IR sensors 214, and two cooking zones 216, autonomous
ventilation system 300 may be modified to include any number and
combination of these items. Additionally, while certain embodiments
have been described in detail, numerous changes, substitutions,
variations, alterations and modifications may be ascertained by
those skilled in the art. For example, while autonomous ventilation
systems 200 and 300 have been described in reference to kitchen 102
and cooking equipment 114, certain embodiments may be utilized in
other facilities where ventilation is needed. Such facilities
include manufacturing facilities, industrial facilities,
residential kitchens, and the like. It is intended that the present
disclosure encompass all such changes, substitutions, variations,
alterations and modifications as falling within the spirit and
scope of the appended claims.
[0033] FIGS. 4A through 4C depict an IR sensor assembly 400, which
could be utilized as IR sensor 214, discussed above in connection
with FIGS. 2 and 3. FIG. 4A provides a top view of IR sensor
assembly 400, FIG. 4B provides a bottom view of IR sensor assembly
400, and FIG. 4C provides a side view of IR sensor assembly
400.
[0034] IR sensor assembly 400 includes a housing 402, a ball joint
404, a ball joint bracket 406, and a mounting bracket 408. Ball
joint 404 is coupled to mounting bracket 408 and housing 402 is
coupled to ball joint bracket 406. Ball joint 404 fits inside ball
joint bracket 406 and allows coupled housing 402 to rotate freely
about ball joint 404.
[0035] Housing 402 includes a rotating turret 410, aperture shunts
412, an axel pin 414, aperture set screws 416, a fixed aperture
418, and an adjustable aperture 420. Fixed aperture 418 is located
on one side of housing 402 and allows light and infrared radiation
to pass in and out of housing 402. Aperture shunts 412 are affixed
adjacent to fixed aperture 418 with aperture set screws 416.
Aperture set screws 416 may be manually adjusted in a way that
allows aperture shunts 412 to slide and block a portion, none, or
all of the light that exits housing 402 via fixed aperture 418. The
ends of aperture shunts 412 form adjustable aperture 420 whose
shape may be manipulated by adjusting the position of one or more
aperture shunts 412. Aperture shunts 416 may be black or otherwise
dark in color to reduce disturbances in the light emitted from
adjustable aperture 420.
[0036] Rotating turret 410 includes a rotation handle 422, a
retention spring 424, a retention bearing 426, an alignment laser
428, a field-of-view ("FOV") indicator 430, and a thermopile sensor
432. Rotation handle 422 is affixed to rotating turret 410 and
rotating turret 410 is affixed to housing 402 via axel pin 414.
Rotating turret 410 is operable to rotate about axel pin 414 by
grasping and applying force to rotation handle 422. Retention
spring 424 is affixed to rotating turret 410 and is subsequently
coupled to retention bearing 426. Retention spring 424 applies
pressure to retention bearing 426 that is in contact with housing
402. This pressure creates resistance to the movement of rotating
turret 410 and thus ensures rotating turret 410 does not rotate
without sufficient force by the user. Alignment laser 428, FOV
indicator 430, and thermopile sensor 432 are affixed to rotating
turret 410 in such a way that each may be aligned with fixed
aperture 418. When rotating turret 410 is rotated into the
appropriate position, alignment laser 428, FOV indicator 430, and
thermopile sensor 432 may each have a clear line-of-sight out of
housing 402 via fixed aperture 418.
[0037] In operation, IR sensor assembly 400 is mounted with
mounting bracket 408 in a location where it has a clear
line-of-sight to an area to be monitored for IR index fluctuations.
Once mounted in a desired location, housing 402 may be adjusted by
pivoting housing 402 about ball joint 404. This allows three
dimensional adjustments to aim IR sensor assembly 400 at the
desired location. To select one of the attached instruments
including alignment laser 428, FOV indicator 430, and thermopile
sensor 432, the user grasps rotation handle 422 and rotates
rotating turret 410 about axel pin 414 until the desired instrument
is aligned with fixed aperture 418. This allows the selected
instrument to have a clear line-of-sight out of housing 402.
[0038] To ensure IR sensor assembly 400 is aimed at the correct
location to be monitored for IR index fluctuations, the user would
first rotate rotating turret 410 to select FOV indicator 430. FOV
indicator 430 may be any visible light emitting device including,
but not limited to, a bright light LED. Once FOV indicator 430 is
selected and activated, it will shine light out of housing 402 via
fixed aperture 418. The result will be a field of view 434 which is
a pattern of light on an object in the line-of-sight of FOV
indicator 430 in the shape of fixed aperture 418. This corresponds
with the field of view of thermopile sensor 432 when such sensor is
rotated into position in line with aperture 418/420.
[0039] Initially, adjustable aperture 420 is larger in size than
fixed aperture 418 and thus the shape of field of view 434 is
controlled by fixed aperture 418. However, adjustable aperture 420
may be adjusted to overlap fixed aperture 418 in order to adjust
the shape of field of view 434. The shape of adjustable aperture
420 and field of view 434 may be adjusted via aperture shunts 412
so that field of view 434 coincides with the desired area to be
monitored for IR index fluctuations. In one embodiment, IR sensor
assembly 400 is utilized as IR sensor 214 in autonomous ventilation
system 200. Field of view 434 corresponds to cooking zone 216 and
coincides with an area associated with cooking equipment 114
beneath exhaust hood 116. Field of view 434 may envelop any area
associated with cooking equipment 114 including an area adjacent to
cooking equipment 114 where uncooked food products are loaded for
cooking, a portion of the surface of cooking equipment 114, or the
entire surface of cooking equipment 114. To adjust the shape of
field of view 434, one or more aperture set screws 416 are loosened
to allow the associated aperture shunt 416 to slide freely. One or
more aperture shunts 416 are adjusted so that one end overlaps
fixed aperture 418. By overlapping fixed aperture 418, aperture
shunts 412 will block light emitted via fixed aperture 418 and thus
affect and control the shape of field of view 434. Once aperture
shunts 416 are in the desired position and field of view 434 is in
the desired shape, aperture set screws 416 are then tightened to
secure aperture shunts from further movement and set the shape of
adjustable aperture 420.
[0040] Once field of view 434 has been adjusted to match the area
in which IR index fluctuations are to be monitored, the user may
then rotate rotating turret 410 in order to use alignment laser 428
and/or thermopile sensor 432. For example, the user may rotate
rotating turret 410 to align alignment laser 428 with fixed
aperture 418. Alignment laser 428 may be any type of visible laser
including a visible light laser diode. Once activated, alignment
laser 428 will produce a point of light on any object in its
line-of-sight. If IR sensor assembly 400 is aimed at a piece of
equipment that is movable, this point of light produced by
alignment laser 428 may be used to realign the piece of equipment
back to the same position each time after it is moved. To do this,
the user marks on the piece of equipment the location of the point
of light produced by alignment laser 428 when it is in the desired
position. After moving, the user would then reposition the piece of
equipment so that the mark aligns with the point of light produced
by alignment laser 428. This allows the piece of equipment to be
easily realigned to the same position every time and prevents the
user from having to continuously readjust field of view 434.
[0041] In addition, once field of view 434 has been adjusted to
match the area in which IR index fluctuations are to be monitored,
the user may rotate rotating turret 410 to align thermopile sensor
432 with fixed aperture 418 (this may be done regardless of the use
of laser 428 as described above.) Once aligned with fixed aperture
418, thermopile sensor 432 will have the same field of view 434 as
FOV indicator 430. Since thermopile sensor 432 does not emit
visible light, the user would not be able to discern the field of
view of thermopile sensor 432 without first utilizing FOV indicator
430. By utilizing both instruments, the user is able to finely tune
the shape of field of view 434 and precisely select the area in
which to monitor IR index fluctuations with thermopile sensor
432.
[0042] Modifications, additions, or omissions may be made to IR
sensor assembly 400 and the described components. As an example, IR
sensor assembly 400 may be designed to allow one or more of
alignment laser 428, FOV indicator 430, and thermopile sensor 432
to be utilized at the same time. In such an embodiment, for
example, a user may elect to illuminate field of view 434 with FOV
indicator 430 while thermopile sensor 432 is monitoring IR index
fluctuations in field of view 434. Other embodiments of IR sensor
assembly 400 may not include alignment laser 428 or FOV indicator
430. Additionally, while certain embodiments have been described in
detail, numerous changes, substitutions, variations, alterations
and modifications may be ascertained by those skilled in the art,
and it is intended that the present disclosure encompass all such
changes, substitutions, variations, alterations and modifications
as falling within the spirit and scope of the appended claims.
[0043] FIG. 5 depicts an IR sensor assembly 450, which could be
also be utilized as IR sensor 214, discussed above in connection
with FIGS. 2 and 3. IR sensor assembly 450 includes an eyeball
housing assembly 452 and a laser calibration assembly 454.
[0044] Eyeball housing assembly 452 includes a retaining bracket
456, a position-fixing o-ring 458, and a ball housing 464.
Retaining bracket 456 contains mounting holes 462 that allow it to
be attached with fasteners such as screws to any surface. Retaining
bracket 456 also contains a round void that is large enough to
allow ball housing 464 to partially fit through. Position-fixing
o-ring 458 is attached to retaining bracket 456 about the
circumference of the round void and makes contact with ball housing
464 when it is placed into the round void. Retaining bracket 456
and position-fixing o-ring 458 together form a socket in which ball
housing 464 pivots.
[0045] Ball housing 464 contains an aperture 466 and an IR sensor
460. IR sensor 460 is affixed to ball housing 464 on the opposite
side of aperture 466 in such a way that allows it to have a
line-of-sight through ball housing 464 and out aperture 466. IR
sensor 460 receives an IR field 468 through ball housing 464 and
aperture 466. IR sensor 460 detects IR index fluctuations inside IR
field 468. IR field 468 is in the shape of aperture 466 which may
be any shape including round as shown in FIG. 5. In some
embodiments, the shape of aperture 466 is adjustable by a user
similar to how the airflow of an eyeball air vent is adjusted on
many commercial airlines.
[0046] Laser calibration assembly 454 includes a housing 470, an
activation button 472, a spring switch 474, coin cell batteries
476, and a diode laser 478. Housing 470 contains an opening at each
end. Diode laser 478 is enclosed inside housing 470 in such a way
as to allow it to shine a visible calibration beam 480 through the
opening of one end of housing 470. Activation button 472 is also
enclosed inside housing 470 and partially protrudes out of the
opening in housing 470 opposite from calibration beam 480.
Activation button 472 is in the shape of aperture 466 on ball
housing 464 and is slightly smaller to allow it to easily slide
into and out of aperture 466. For example, activation button 472
may be cylindrical in shape to allow it to fit into an aperture 466
that is round as seen in FIG. 5. Activation button 472 is also
slightly smaller than the opening of housing 470 from which it
protrudes. This allows it to move in and out of housing 470 through
the opening. A lip adjacent to one end of activation button 472,
however, prevents the button from sliding completely out of housing
470.
[0047] One or more coin cell batteries 476 are positioned adjacent
to diode laser 478 inside housing 470. Enough coin cell batteries
476 are provided to power diode laser 478, causing it to produce
visible calibration beam 480. Coin cell batteries 476 are
positioned inside housing 470 so that only one terminal (positive
or negative) of coin cell batteries 476 is coupled to diode laser
478. Spring switch 474 is positioned inside housing 470 between the
other (uncoupled) terminal of coin cell batteries 476 and
activation button 472. It is coupled to diode laser 478 on one end
and activation button 472 on the other. A small gap of air exists
between spring switch 474 and the uncoupled terminal of coin cell
batteries 476 when laser calibration assembly is inactive so that
the electrical circuit between coin cell batteries 476 and diode
laser 478 is not complete.
[0048] In operation, eyeball housing assembly 452 is mounted with
retaining bracket 456 in a location where it has a clear
line-of-sight to an area to be monitored for IR index fluctuations.
Once mounted in a desired location, eyeball housing assembly 452
may be adjusted by pivoting ball housing 464. This allows three
dimensional adjustments to aim IR sensor 460 at the desired
location. This is similar in operation to an eyeball air vent that
is typical in most commercial airlines. Ball housing 464 pivots
about the void in retaining bracket 456 and maintains its position
after adjustments due to the pressure applied by position-fixing
o-ring 458.
[0049] Because IR sensor 460 produces IR field 468 that is
invisible to the human eye, it is difficult to reliably determine
exactly where IR sensor assembly 450 is aimed. To alleviate this
problem, a user may utilize laser calibration assembly 454. To do
so, a user first inserts the end of laser calibration assembly 454
containing activation button 472 into aperture 466 of ball housing
464. Activation button 472 will slide into aperture 466 for a
certain distance until it comes into contact with a portion of ball
housing 464 or IR sensor 460 that impedes its movement. At this
point, the user continues to apply pressure to IR sensor assembly
450 in the direction of ball housing 464. This will cause housing
470 to then slide toward ball housing 464 while activation button
472 remains immobile. This causes the end of activation button 472
inside housing 470 to contact spring switch 474 and in turn causes
spring switch 474 to contact the uncoupled terminal of coin cell
batteries 476. This completes the electrical circuit between coin
cell batteries 476 and diode laser 478 and produces visible
calibration beam 480. While still grasping laser calibration
assembly 454, the user may then adjust IR sensor assembly 450 by
pivoting ball housing 464 about retaining bracket 456. Since laser
calibration assembly 454 is still inserted into aperture 466 of
ball housing 464 when the user makes this adjustment, diode laser
478 will be aligned with IR sensor 460. As a result, visible
calibration beam 480 will be produced that is aligned with
invisible IR field 468. The user may then adjust IR sensor assembly
450 by pivoting ball housing 464 until visible calibration beam 480
is in the desired position. Once in the desired position, the user
finally removes laser calibration assembly 454 and allows IR field
468 to be received by IR sensor 460 through aperture 466 from the
desired target.
[0050] With reference now to FIG. 6, an autonomous ventilation
control method 500 is provided. Autonomous ventilation control
method 500 may be implemented, for example, by controller 220
described in reference to autonomous ventilation systems 200 and
300 in FIGS. 2 and 3 above. Autonomous ventilation control method
500 will now be described in reference to controller 220 as
utilized in kitchen 102. It must be noted, however, that autonomous
ventilation control method 500 may be utilized by any controller to
control a ventilation system regardless of location.
[0051] Autonomous ventilation control method 500 begins in step 504
where the energy level of cooking equipment 114 is determined or
where the activation of the equipment is otherwise determined. The
energy level of cooking equipment 114 may be determined by any
suitable technique, including utilizing IR sensor 214 to determine
the IR index of the cooking surface or cooking medium of cooking
equipment 114 or determining the state/settings of equipment
controls through a connection with controller 220. In step 506, a
decision is made based on the energy level determined in step 504.
For example, if the IR index of the cooking surface or cooking
medium of cooking equipment 114 is not greater than the average IR
index when not in use (i.e., the energy level is low or zero), it
is determined that no ventilation is required. As a result, exhaust
fan 210 is turned off if it is not already off and autonomous
ventilation control method 500 proceeds back to step 504. If,
however, the IR index of the cooking surface or cooking medium of
cooking equipment 114 determined in step 504 is greater than the
average IR index when not in use (or if the energy level is
otherwise determined to be above a particular threshold),
autonomous ventilation control method 500 proceeds to step 508
where the speed of exhaust fan 210 is a set to an idle rate. The
idle rate may be, for example, a predetermined rate or a rate based
on the measured IR index.
[0052] Once it is determined in steps 504 and 506 that cooking
equipment 114 has been activated, autonomous ventilation control
method 500 next proceeds to monitor cooking zone 216. In step 512,
the IR index of cooking zone 216 is monitored with IR sensor 214.
In step 514, the IR index (or changes in IR index) of cooking zone
216 is analyzed to determine if uncooked (i.e., cold) food has been
introduced. If it is determined in step 514 that a drop in IR index
has occurred due to uncooked food being introduced into cooking
zone 216, the speed of exhaust fan 210 is adjusted to a
predetermined normal cooking rate in step 516. In particular
embodiments, the speed may be adjusted based on the amount of the
drop in IR index determined in step 514.
[0053] After adjusting the speed of exhaust fan 210 to a
predetermined normal cooking level, autonomous ventilation control
method 500 may next proceed to start a timer in step 518. The
length of the timer in step 518 determines how long exhaust fan 210
remains at the cooking rate. The length of the timer may be based
on the amount of IR index drop caused by the introduction of food
into cooking zone 216. The larger the drop in IR index measured in
step 512, the more uncooked or cold food has been introduced into
cooking zone 216. The length of the timer set in step 518 may also
be a fixed amount of time corresponding to the type of cooking
equipment and/or food being cooked or it may be an amount of time
programmed by a user. Note that in some embodiments, a timer my not
be used at all to determine how long exhaust fan 210 remains at the
cooking rate. In such an embodiment, IR sensor 214 may be used to
determine when cooking is complete and set exhaust fan 210 back to
the idle rate.
[0054] After setting the timer in step 518, autonomous ventilation
control method 500 may next proceed to monitor cooking zone 216 for
flare-ups. A flare-up condition occurs when excessive amounts of
air contaminants 122 such as steam, smoke, or heat are produced by
cooking with cooking equipment 114. To determine if a flare-up
exists, the IR index of cooking zone 216 is measured with IR sensor
214 in step 520. In step 522, the IR index is analyzed to determine
if a change in IR index has occurred due to the presence of
excessive amounts of air contaminants 122. The change in IR index
may include a decrease associated with excessive amounts of smoke,
steam, or vapor or it may be an increase associated with excessive
amounts of heat from flames. If a flare-up condition exists, the
speed of exhaust fan 210 is increased from the normal cooking rate
to a predetermined flare-up rate. If no flare-up condition exists,
the speed of the exhaust fan 210 is maintained at the normal
cooking rate.
[0055] Next, autonomous ventilation control method 500 proceeds to
determine in step 526 if the timer set in step 518 has expired. If
the timer has expired, the speed of exhaust fan 210 is decreased to
the idle rate in step 528 and autonomous ventilation control method
500 proceeds back to step 504 to monitor the energy level of
cooking equipment 114. If the timer has not expired, autonomous
ventilation control method 500 proceeds back to step 520 to monitor
for flare-up conditions. Alternatively, if a timer is not used in a
particular embodiment, IR sensor 214 may be used in step 526 to
determine when cooking is complete and proceed to the next
step.
[0056] While a particular autonomous ventilation control method has
been described, it should be noted that certain steps may be
rearranged, modified, or eliminated where appropriate.
Additionally, while certain embodiments have been described in
detail, numerous changes, substitutions, variations, alterations
and modifications may be ascertained by those skilled in the art,
and it is intended that the present disclosure encompass all such
changes, substitutions, variations, alterations and modifications
as falling within the spirit and scope of the appended claims.
* * * * *