U.S. patent application number 11/724372 was filed with the patent office on 2007-09-20 for water heater with flammable vapor and co sensors.
This patent application is currently assigned to American Water Heater Company, a corporation of the State of Nevada. Invention is credited to Michael A. Garrabrant.
Application Number | 20070215066 11/724372 |
Document ID | / |
Family ID | 38520952 |
Filed Date | 2007-09-20 |
United States Patent
Application |
20070215066 |
Kind Code |
A1 |
Garrabrant; Michael A. |
September 20, 2007 |
Water heater with flammable vapor and co sensors
Abstract
A water heater including a water container, a combustion chamber
adjacent the water container, a burner associated with the
combustion chamber, a flue gas collector located to receive flue
gases generated in the combustion chamber, a CO sensor having at
least an operative portion proximate the flue gas collector, a
flammable vapor sensor having at least an operative portion
positioned proximate a location where combustion air enters the
combustion chamber, and a controller operatively connected to the
CO and flammable vapor sensors and adapted to receive signals
generated by the CO and flammable vapor sensors and responsively
shut off combustion in the combustion chamber.
Inventors: |
Garrabrant; Michael A.;
(Unicoi, TN) |
Correspondence
Address: |
IP GROUP OF DLA PIPER US LLP
ONE LIBERTY PLACE, 1650 MARKET ST, SUITE 4900
PHILADELPHIA
PA
19103
US
|
Assignee: |
American Water Heater Company, a
corporation of the State of Nevada
Atlanta
GA
|
Family ID: |
38520952 |
Appl. No.: |
11/724372 |
Filed: |
March 15, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60784144 |
Mar 20, 2006 |
|
|
|
Current U.S.
Class: |
122/14.1 ;
431/22 |
Current CPC
Class: |
F23M 2900/13003
20130101; F23N 5/242 20130101; F23M 2900/11021 20130101; F24H 1/205
20130101 |
Class at
Publication: |
122/14.1 ;
431/22 |
International
Class: |
F24H 9/20 20060101
F24H009/20; F23N 5/24 20060101 F23N005/24 |
Claims
1. A water heater comprising: a water container; a combustion
chamber adjacent the water container; a burner associated with the
combustion chamber; a flue gas collector located to receive flue
gases generated in the combustion chamber; a CO sensor having at
least an operative portion proximate the flue gas collector; a
flammable vapor sensor having at least an operative portion
positioned proximate a location where combustion air enters the
combustion chamber; and a controller operatively connected to the
CO sensor and the flammable vapor sensor and adapted to receive
signals generated by the CO and flammable vapor sensors and
responsively shut off combustion in the combustion chamber.
2. The water heater of claim 1, wherein the flue gas collector is a
draft hood.
3. The water heater of claim 1, wherein the CO sensor is inside the
flue gas collector.
4. The water heater of claim 1, wherein the controller is a gas
control valve.
5. The water heater of claim 4, wherein the gas control valve
contains a microcontroller.
6. The water heater of claim 5, wherein the microcontroller is
programmable.
7. The water heater of claim 5, wherein the microcontroller is
powered by a grid electrical supply.
8. The water heater of claim 5, wherein the microcontroller is
powered by a thermopile.
9. The water heater of claim 8, wherein the thermopile receives
heat from a pilot burner.
10. The water heater of claim 1, wherein the controller is located
proximate to where the combustion air enters the combustion
chamber.
11. The water heater of claim 1, wherein the flammable vapor sensor
is located on the controller.
12. The water heater of claim 1, wherein the controller shuts off
fuel to the burner.
Description
RELATED APPLICATION
[0001] This patent application claims the benefit of U.S.
Provisional Application No. 60/784,144, filed Mar. 20, 2006. This
earlier provisional application is hereby incorporated by
reference.
TECHNICAL FIELD
[0002] The technology in this disclosure relates to water heaters,
particularly to water heaters that have a flammable vapor sensor
and a CO sensor.
BACKGROUND
[0003] A number of water heaters have been developed that are
flammable vapor ignition resistant (FVIR). Such water heaters are
sold and available on the market today. However, under certain
circumstances with certain types of FVIR water heaters, lint, dirt
or other particles may collect over the course of time, thereby
reducing the amount of combustion air available to the water
heater. This has the potential of causing a number of
disadvantages, including possible production of more than optimal
amounts of CO. This is a result of incomplete combustion that is
brought about by the insufficiency of combustion air. Insufficient
combustion air may also occur in view of insufficient openings into
the enclosed space in which the water heater is located, incorrect
venting, other air-consuming appliances located within close
proximity, vacuum conditions in the area near the water heater due
to the tightness of the structure in which the water heater is
located and the like.
[0004] Some attempted solutions to those problems include utilizing
temperature sensors or switches in and around the combustion
chamber to indirectly determine incomplete combustion.
SUMMARY
[0005] I provide a water heater including a water container, a
combustion chamber adjacent the water container, a burner
associated with the combustion chamber, a flue gas collector
located to receive flue gases generated in the combustion chamber,
a CO sensor having at least an operative portion proximate the flue
gas collector, a flammable vapor sensor having at least an
operative portion positioned proximate a location where combustion
air enters the combustion chamber, and a controller operatively
connected to the CO and flammable vapor sensors and adapted to
receive signals generated by the CO and flammable vapor sensors and
responsively shut off combustion in the combustion chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side elevational view of a water heater,
partially taken in section.
[0007] FIG. 2 is a schematic of a gas control valve and selected
connected water heater components associated with the water heater
of FIG. 1.
[0008] FIG. 3 is a partial sectional view of another water heater,
partially taken in section.
[0009] FIG. 4 is a schematic of a gas control valve and selected
connected water heater components associated with the water heater
of FIG. 3.
DETAILED DESCRIPTION
[0010] It will be appreciated that the following description is
intended to refer to specific aspects of the structure selected for
illustration in the drawings and is not intended to define or limit
this disclosure, other than in the appended claims.
[0011] Water heaters described herein can assist in reducing the
likelihood that flammable vapors outside a water heater will be
ignited by the water heater itself. This may be achieved with a CO
sensor having an operative portion proximate to the water heater
draft hood and a flammable vapor sensor having at least its
operative portion positioned proximate the location where
combustion air enters the combustion chamber. Both the CO sensor
and flammable vapor sensor are connected to a controller which
receives information generated by the CO and flammable vapor
sensors and responsively shuts off combustion in the combustion
chamber, depending on the received information.
[0012] Turning now to the drawings generally and FIGS. 1 and 2 in
particular, a water heater 10 including a water tank/container 12
having a water inlet 14 and a water outlet 16 is shown. A flue 18
extends upwardly through the tank and outwardly from the top of
water heater 10. Tank 12 is surrounded by insulation 20 and a
jacket 21. Such insulation may be made from any number of foam type
insulations well known in the art and/or fiberglass insulation such
as around the lower portion of the water heater. Various
substitutions may be made without varying from the fundamental
spirit of the disclosure.
[0013] A combustion chamber 22 is located below tank 12 and formed
by tank bottom 24, skirt 26 and bottom pan 28. Bottom pan 28 sits
on legs 30. A burner 32 formed from a plenum 68 is positioned in
combustion chamber 22. Burner 32 is also positioned to receive fuel
from fuel line 34, which connects to gas control valve 36, which
connects to a fuel supply line 38 connected to a fuel supply that
is not shown.
[0014] Burner 32 is positioned within combustion chamber 22 and is
a so-called "low NO.sub.x" burner in this instance. It is, however,
possible to utilize other types of burners that combust gas (either
natural gas, propane or the like) or oil or other fuel. Many other
types of burners are known and need not be discussed herein.
[0015] Fuel line 34 connects to and extends through door 44 such
that the end of fuel line 34, which is nozzle 46, is proximate open
end 58 of a venturi 50. Fuel exits nozzle 46 and flows directly
into the exterior end. Although FIG. 1 shows a venturi 50, any
number of fuel/air supply lines may be utilized such as tubes,
pipes, pathways, conduits and other structures capable of
channeling fuel and/or air to burner 32. Burner 32 may be held
above pan 28 by support 53. Pilot fuel line 35 extends between gas
valve 36 and pilot burner 86 (partially shown in FIG. 1).
[0016] A cover 45 also connects to door 44 and in this case serves
several purposes. Cover 45 holds fuel line 34 in a desired position
with respect to the open end 58 of venturi 50 so that fuel is
directed in a desired location through open end 58 and within
venturi 50. Cover 45 provides the desired nozzle to venturi
alignment. Other structures may be used as alternatives. The top of
cover 45 may be solid to prevent dust and other airborne
particulate from entering burner 32. The sides and bottom may be
perforated, enclosed in screen, or louvered to prevent rodents and
large insets from entering and clogging venturi 50. Also,
interchangeable nozzles 46 can be mounted in the front part of
cover 45.
[0017] In operation, burner 32 operates under the fundamental
condition that fuel is supplied to venturi 50 and combustion air is
mixed at the end 58 of venturi 50 and the mixed fuel flows into
plenum 68 and may further be mixed and distributed by some type of
diffuser as desired. The air and fuel mixture is then combusted
along the surface of a screen 33 located on top of plenum 68 in the
usual manner.
[0018] FIGS. 1 and 2 show a pilot burner 86 connected to pilot fuel
supply 35. Pilot burner 86 is mounted on a pilot mounting bracket
(not shown) near screen 33 of burner 32. A power plug 31 connects
to gas control valve 36 to supply power from, for example, a
typical household electrical outlet. A transformer (not shown) can
also be used to convert power supplied from outside to an
appropriate power type/level for gas control valve 36 and/or other
remotely located controllers.
[0019] Gas control valve 36 also connects to a flammable vapor
sensor 80 by way of connection line 82. Flammable vapor sensor 80
is positioned in the vicinity of or proximate to the location where
combustion air enters combustion chamber 22. Although this location
is shown proximate cover 45 and door 44 of water heater 10 in FIG.
1, the location of entry of combustion air into combustion chamber
22 may be altered in accordance with selected design features and
burners utilized. In the case that an additional passageway is
provided to supply combustion air to combustion chamber 22, such as
a conduit having an opening at an upper portion of the water
heater, the flammable vapor sensor 80 may be located outside the
opening (albeit near the upper portion of the water heater), just
inside the opening, anywhere along the conduit or just outside of
the combustion chamber and still be considered in the vicinity of
or "proximate a location where combustion air enters the combustion
chamber."
[0020] Also, combustion chamber 22 may have more than one opening.
For example, an opening covered by a flame trap/flame arrestor (not
shown) such as an air inlet/flame trap of the type as disclosed in
any of U.S. Pat. Nos. 5,797,355; 6,142,106; 6,085,699 and the like
may be used. In such cases, more than one flammable vapor sensor
may be used.
[0021] Thus, the position of sensor(s) 80 is not particularly
limited so long as it is sufficiently close to the opening(s) in
the combustion chamber 22 through which combustion air is drawn to
be effective in accurately measuring/sensing flammable vapors. A
number of flammable vapor sensors are known and may be used in
accordance with water heaters disclosed herein. One particular
example is manufactured by Therm-O-Disc of Mansfield, Ohio.
[0022] A CO detector 94 also connects to gas control valve 36 by
way of a connection line 96. CO sensor 94 may be any type of known
CO sensor. One example is a CO sensor manufactured by Applied
Sensor, Inc. CO sensor 94 in FIG. 1 is located proximate the
location where flue gases exit flue 18 and proceed into draft hood
88. In this particular instance, CO sensor 94 is located exteriorly
of draft hood 88 with at least a portion extending interiorly of
draft hood 88 to be in contact with flue gases exiting the flue 18.
Other locations may be employed so long as CO sensor 84 is located
to effectively detect/sense a selected amount of CO exiting from
flue 18.
[0023] Sensors 80 and 94 have been shown as connected to gas
control valve 36 by way of connection lines 82 and 96,
respectively, which are typically wire connections. However, this
is merely one example of a means for operatively connecting those
sensors to gas control valve 36. Other means may be used such as
optical fiber or wireless transmission, for example. Gas control
valve 36 may also connect to thermister 90 by way of connection
line 92. Thermister 90 senses the temperature within water tank 12
and transmits temperature information to gas control valve 36.
[0024] Referring to FIGS. 3 and 4, an alternate water heater 10 is
shown. Water heater 10 in FIG. 3 contains a different type of
burner 32 than the burner of FIG. 1. It, too, is a conventional
well known burner and its fundamental operation need not be
discussed further herein. Water heater 10 of FIG. 3 also includes a
pilot burner 86 that connects to gas control valve 36 by way of
pilot fuel supply line 35. Thermopile 84 connects to gas control
valve 36 by way of connection line 85.
[0025] The gas control valve 36 shown in FIG. 4 generates power by
means of thermopile 84. Pilot burner 86 supplies heat to thermopile
84, which generates an electrical current such as about 100-about
750 millivolts. This amount of power is sufficient to enable gas
control valve 36 to perform all of its designated tasks. Also, this
arrangement can produce enough power to supply any controller
located in a position remote from gas control valve 36.
[0026] In operation, both water heaters 10 of FIGS. 1 and 3 draw
combustion air into combustion chamber 22 through selected
openings. In so doing, combustion air is drawn past flammable vapor
sensor 80. In the unlikely event that flammable vapors are present
at a concentration or in an amount selected by the manufacturer to
detect such flammable vapors, sensor 80 sends corresponding
information/a signal to gas control valve 36. In response, gas
control valve 36 can typically shut off the supply of fuel 32 (and
pilot burner 86 when present) to assist in avoiding ignition of
flammable vapors outside of water heater 10.
[0027] Similarly, CO sensor 94, located proximate draft hood 88,
can sense the presence of a selected quantity of CO that is
indicative of incomplete combustion associated with water heater 10
for any reason. Thus, CO sensor 94 generates information/a signal
that is transmitted to gas control valve 36. In response, gas
control valve 36 can typically shut off the supply of fuel to
burner 32 (and pilot burner 86 when present) to assist in avoiding
ignition of flammable vapors outside of water heater 10.
[0028] Gas control valve 36 can include a microcontroller that is
capable of collecting the sensor information and taking appropriate
action, including shutting off fuel or engaging other water heater
components (not shown) to shut off the air supply to combustion
chamber 22 or other types of components, for example. The
microcontroller may be integral with gas control valve 36 or
located at an alternative location so long as it is operatively
connected to gas control valve 36. The microcontroller can be
programmable if desired.
[0029] Although this disclosure has been described selected, with
specific forms of a water heater and associated components, it will
be appreciated that a wide variety of equivalents may be
substituted for the specified elements described herein without
departing from the spirit and scope of this disclosure as described
in the appended claims.
* * * * *