U.S. patent application number 15/373223 was filed with the patent office on 2017-03-30 for heating assembly.
The applicant listed for this patent is David Deng. Invention is credited to David Deng.
Application Number | 20170089570 15/373223 |
Document ID | / |
Family ID | 51420293 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170089570 |
Kind Code |
A1 |
Deng; David |
March 30, 2017 |
HEATING ASSEMBLY
Abstract
A heating assembly can be used with one of a first fuel type or
a second fuel type different than the first. The heating assembly
can include a housing have a first actuation member and a second
actuation member. The first and second actuation members can be
positioned within respective first and second fuel hook-ups. The
first and second actuation members can be configured such that
connecting a fuel source to the heater assembly moves one of the
actuation members from a first position to a second position to
control flow through the heating assembly.
Inventors: |
Deng; David; (Diamond Bar,
CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Deng; David |
Diamond Bar |
CA |
US |
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|
Family ID: |
51420293 |
Appl. No.: |
15/373223 |
Filed: |
December 8, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14181535 |
Feb 14, 2014 |
9518732 |
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15373223 |
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61806344 |
Mar 28, 2013 |
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61778072 |
Mar 12, 2013 |
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61773713 |
Mar 6, 2013 |
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61773716 |
Mar 6, 2013 |
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61771795 |
Mar 2, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23D 17/002 20130101;
A47J 37/0727 20130101; A47J 37/0713 20130101; F24C 3/02 20130101;
A47J 37/074 20130101; F24C 1/04 20130101; F23N 1/002 20130101; F23D
2204/10 20130101; F24C 3/08 20130101; F23D 2900/00004 20130101;
A47J 37/07 20130101; F23C 1/08 20130101; F23N 5/242 20130101; F23N
5/102 20130101 |
International
Class: |
F23C 1/08 20060101
F23C001/08; A47J 37/07 20060101 A47J037/07; F24C 3/02 20060101
F24C003/02; F24C 3/08 20060101 F24C003/08; F23D 17/00 20060101
F23D017/00; F23N 1/00 20060101 F23N001/00 |
Claims
1. A heater assembly for use with one of a first fuel type or a
second fuel type different than the first, the heater assembly
comprising: a housing comprising: a first fuel hook-up for
connecting a first fuel type to the heater assembly; a second
hook-up for connecting a second fuel type to the heater assembly; a
first outlet in fluid communication with both the first and second
fuel hook-ups; a first inlet; a second inlet; a second outlet; a
third outlet; and a fourth outlet a first actuation member having
an end located within the first fuel hook-up and having a first
actuation member first position and a second position, the
actuation member configured such that connecting a fuel source to
the heater assembly at the first fuel hook-up moves the actuation
member from the first actuation member first position to the second
position, wherein in the first actuation member first position,
fuel flow through the first fuel hook-up and between the second
inlet and fourth outlet is prevented and in the first actuation
member second position, fuel flow through the first fuel hook-up
and between the second inlet and fourth outlet is permitted; a
second actuation member having an end located within the second
fuel hook-up and having a first position and a second position, the
actuation member configured such that connecting a fuel source to
the heater assembly at the second fuel hook-up moves the actuation
member from the first position to the second position, wherein in
the second actuation member first position, fuel flow through the
second fuel hook-up and between the first inlet and the third
outlet is prevented and in the second actuation member second
position, fuel flow through the second fuel hook-up and between the
first inlet and the third outlet is permitted.
2. The heater assembly of claim 1, wherein in the second actuation
member first position, fuel flow between the first inlet and second
outlet is permitted and in the second actuation member second
position, fuel flow between the first inlet and the second outlet
is prevented.
3. The heater assembly of claim 1, further comprising a first
pressure regulator configured to regulate a fuel flow of the first
fuel type within a first predetermined range.
4. The heater assembly of claim 3, further comprising a second
pressure regulator configured to regulate a fuel flow of the second
fuel type within a second predetermined range different from the
first.
5. The heater assembly of claim 1, further comprising a control
valve, a nozzle, and a pilot or oxygen depletion sensor.
6. The heater assembly of claim 1, further comprising a spring
operatively coupled to the first actuation member to bias the
actuation member towards the first position.
7. The heater assembly of claim 1, wherein the actuation member
comprises a rod configured for linear advancement from the first
position to the second position.
8. The heater assembly of claim 1, wherein each actuation member
comprises at least two separately movable valve members.
9. The heater assembly of claim 8, wherein each actuation member
further comprises a separate movable member positioned in between
two movable valve members.
Description
BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] Certain embodiments disclosed herein relate generally to a
heating apparatus for use in a gas appliance adapted for single or
multiple fuel use. The heating apparatus can be, can be a part of,
and can be used in or with many different appliances, including,
but not limited to: heaters, boilers, dryers, washing machines,
ovens, fireplaces, stoves, water heaters, barbecues, etc.
[0003] Description of the Related Art
[0004] Many varieties of appliances, such as heaters, boilers,
dryers, washing machines, ovens, fireplaces, stoves, and other
heat-producing devices utilize pressurized, combustible fuels. Some
such devices commonly operate with either liquid propane or natural
gas. And some such devices may operate on one or more other fuels.
However, such devices and certain components thereof have various
limitations and disadvantages. Therefore, there exists a constant
need for improvement in appliances and components to be used in
appliances.
SUMMARY
[0005] A heating assembly can be used in a dual fuel heater to mix
air with fuel to be combusted at the burner. For example, the
heating assembly can be configured to be used with one or more of
natural gas, liquid propane, well gas, city gas, and methane. The
heating assembly can be switched between the different fuels
without requiring adjustment of a window or opening for creating
the air fuel mixture. According to some embodiments a heating
assembly can include any number of different components such as a
fuel selector valve, a pressure regulator, a control valve, a
burner nozzle, a burner, a pilot, and/or an oxygen depletion
sensor.
[0006] According to some embodiments, a heater assembly can be
configured to produce a yellow flame. The heater assembly can
comprise a burner, a first nozzle, a second nozzle, a first
conduit, and a second conduit. The first conduit can be positioned
between the first nozzle and the burner, the first conduit
comprising an opening configured to allow air to mix with fuel
injected into the first conduit by the first nozzle. The second
conduit can be positioned between the second nozzle and the burner.
The first nozzle can be configured to inject fuel into the first
conduit near the opening and at a location separate and spaced
apart from where the second nozzle is configured to inject fuel
into the second conduit. In some embodiments, the fuel injected
into the second nozzle does not pass through the first nozzle.
[0007] In some embodiments, the heater assembly can further
comprise one or more of a venturi positioned between the burner and
the first and second nozzles, a control valve configured to control
fuel flow to the burner, and a fuel selector valve having a first
position and a second position, each position configured to direct
a set fuel type through the heater assembly along a set fuel path.
In the first position fuel flow can be directed to the first nozzle
and in the second position fuel flow can be directed to the second
nozzle. In the second position fuel flow may be directed to both
the first nozzle and the second nozzle.
[0008] According to some embodiments, a heating apparatus can
comprise a first fuel input for receiving fuel from a first fuel
source, a second fuel input for receiving fuel from a second fuel
source, a first fuel outlet path, a second fuel outlet path, a
valve body, a transition housing, and a burner. The valve body can
be configured to selectively permit fluid communication between the
first fuel input and the first fuel output path and/or between the
second fuel input and the second fuel outlet path. The transition
housing can define a first inlet, a second inlet and an egress,
said first inlet communicating with a mixing chamber positioned to
receive fuel from the first fuel outlet path and defining one or
more openings through which air can pass in response to fuel flow
through said mixing chamber to mix with fuel received from the
first outlet path and exit through said egress, said second inlet
positioned to receive fuel from the second outlet path and defining
a second chamber configured to receive fuel from said second outlet
path and exit through said egress without flowing across said one
or more openings. The burner can be in fluid communication with
said egress.
[0009] In some embodiments, a heater assembly can be configured for
use with one of a first fuel type or a second fuel type different
than the first. The heater assembly can comprise a housing, a first
actuation member and a second actuation member. The housing can
have a first fuel hook-up for connecting a first fuel type to the
heater assembly, a second hook-up for connecting a second fuel type
to the heater assembly, a first outlet in fluid communication with
both the first and second fuel hook-ups, a first inlet, a second
inlet, a second outlet, a third outlet, and a fourth outlet. The
first actuation member can have an end located within the first
fuel hook-up and having a first actuation member first position and
a second position, the actuation member configured such that
connecting a fuel source to the heater assembly at the first fuel
hook-up moves the actuation member from the first actuation member
first position to the second position. In the first actuation
member first position, fuel flow through the first fuel hook-up and
between the second inlet and fourth outlet is prevented. In the
first actuation member second position, fuel flow through the first
fuel hook-up and between the second inlet and fourth outlet is
permitted. The second actuation member can have an end located
within the second fuel hook-up and having a first position and a
second position, the actuation member configured such that
connecting a fuel source to the heater assembly at the second fuel
hook-up moves the actuation member from the first position to the
second position. In the second actuation member first position,
fuel flow through the second fuel hook-up and between the first
inlet and the third outlet is prevented. In the second actuation
member second position, fuel flow through the second fuel hook-up
and between the first inlet and the third outlet is permitted.
[0010] In some embodiments, the heater assembly may further
comprise a first pressure regulator configured to regulate a fuel
flow of the first fuel type within a first predetermined range and
a second pressure regulator configured to regulate a fuel flow of
the second fuel type within a second predetermined range different
from the first.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features, aspects and advantages are
described below with reference to the drawings, which are intended
to illustrate but not to limit the invention. In the drawings, like
reference characters denote corresponding features consistently
throughout similar embodiments.
[0012] FIG. 1 is a perspective view of an embodiment of a heating
device.
[0013] FIG. 2 is a perspective view of an embodiment of a fuel
delivery system compatible with the heating device of FIG. 1.
[0014] FIG. 3 is a perspective cutaway view of a portion of one
embodiment of a heater configured to operate using either a first
fuel source or a second fuel source.
[0015] FIG. 4 is a partially dissembled perspective view of the
heater of FIG. 3.
[0016] FIGS. 5 and 6 show a pilot assembly in use with a first fuel
and a second fuel respectively.
[0017] FIGS. 7 and 8 show a dual fuel pilot assembly in use with a
first fuel and a second fuel respectively.
[0018] FIG. 9 schematically represents an electric circuit between
the control valve and two thermocouples.
[0019] FIG. 10 is a schematic representation of another embodiment
of heating system.
[0020] FIG. 10A is a schematic representation of another embodiment
of heating system.
[0021] FIG. 11 is a chart showing typical gas pressures of
different fuels.
[0022] FIG. 12 shows a cross-sectional view of a pressure
switch.
[0023] FIG. 13 illustrates a heating unit with a pressure
switch.
[0024] FIG. 14 shows a heater including the heating unit of FIG.
13.
[0025] FIG. 14A shows a schematic detail view of a portion of the
heater of FIG. 14.
[0026] FIG. 15 shows a schematic diagram of the function of the
heater of FIG. 14.
[0027] FIG. 16 shows a schematic diagram of the function of another
embodiment of heater.
[0028] FIGS. 17 and 17A show another embodiment of heating
source.
[0029] FIG. 18 is a cross-section taken along line C-C of FIG.
17A.
[0030] FIG. 19 is a cross-section taken along line B-B of FIG.
17A.
[0031] FIG. 20 is the cross-section of FIG. 18 shown with a
fitting.
[0032] FIG. 21 is the cross-section of FIG. 19 shown with a
fitting.
[0033] FIG. 22 shows another embodiment of a heating source.
[0034] FIG. 23 shows a top view of the heating source of FIG.
22.
[0035] FIG. 24A is a cross-section taken along the line 24A-24A of
FIG. 23.
[0036] FIG. 24B is a cross-section taken along the line 24B-24B of
FIG. 23.
[0037] FIG. 25A show a perspective view partially in cross-section
of another embodiment of pressure switch.
[0038] FIG. 25B is a side cross-sectional view of the pressure
switch of FIG. 25A.
[0039] FIG. 26 shows a heater.
[0040] FIGS. 27A, 28A and 29A show partially dissembled views of
the heater of FIG. 26 illustrating different flow
configurations.
[0041] FIGS. 27B, 28B and 29B respectively show a schematic diagram
of the flow configuration of one of FIGS. 27A, 28A and 29A.
[0042] FIGS. 30 and 31 show perspective views of another embodiment
of heating source.
[0043] FIG. 32 is a side view of the heating source of FIG. 30 in
partial cross-section.
[0044] FIG. 32A is a detail view of the heating source from circle
A in FIG. 32.
[0045] FIG. 33 is a side view of the heating source of FIG. 30.
[0046] FIG. 33A is a top view of the heating source with a partial
cross-section taken along line B-B of FIG. 33.
[0047] FIG. 33B is a detail view of the heating source from the
partial cross-section of FIG. 33A.
DETAILED DESCRIPTION
[0048] Many varieties of appliances, such as heaters, boilers,
dryers, washing machines, ovens, fireplaces, stoves, and other
heat-producing devices utilize pressurized, combustible fuels. For
example, many varieties of space heaters, fireplaces, stoves,
ovens, boilers, fireplace inserts, gas logs, and other
heat-producing devices employ combustible fuels, such as liquid
propane and/or natural gas. These devices generally are designed to
operate with a single fuel type at a specific pressure. For
example, as one having skill in the art would appreciate, some gas
heaters that are configured to be installed on a wall or a floor
operate with natural gas at a pressure in a range from about 3
inches of water column to about 6 inches of water column, while
others operate with liquid propane at a pressure in a range from
about 8 inches of water column to about 12 inches of water
column.
[0049] Although certain embodiments discussed herein are described
in the context of directly vented heating units, such as fireplaces
and fireplace inserts, or vent-free heating systems, it should be
understood that certain features, principles, and/or advantages
described are applicable in a much wider variety of contexts,
including, for example, gas logs, heaters, heating stoves, cooking
stoves, barbecue grills, water heaters, and any flame-producing
and/or heat-producing fluid-fueled unit, including without
limitation units that include a burner of any suitable variety.
[0050] FIG. 1 illustrates an embodiment of a fireplace, fireplace
insert, heat-generating unit, or heating device 10 configured to
operate with a source of combustible fuel. In various embodiments,
the heating device 10 is configured to be installed within a
suitable cavity, such as the firebox of a fireplace or a dedicated
outer casing. The heating device 10 can extend through a wall, in
some embodiments.
[0051] The heating device 10 includes a housing 20. The housing 20
can include metal or some other suitable material for providing
structure to the heating device 10 without melting or otherwise
deforming in a heated environment. The housing 20 can define a
window 220. In some embodiments, the window 220 comprises a sheet
of substantially clear material, such as tempered glass, that is
substantially impervious to heated air but substantially
transmissive to radiant energy.
[0052] The heating device 10 can include a sealed chamber 14. The
sealed chamber 14 can be sealed to the outside with the exception
of the air intake 240 and the exhaust 260. Heated air does not flow
from the sealed chamber to the surroundings; instead air, for
example from in an interior room, can enter an inlet vent into the
housing 20. The air can pass through the housing in a channel
passing over the outside of the sealed chamber 14 and over the
exhaust 260. Heat can be transferred to the air which can then pass
into the interior room through an outlet vent.
[0053] In some embodiments, the heating device 10 includes a grill,
rack, or grate 280. The grate 280 can provide a surface against
which artificial logs may rest, and can resemble similar structures
used in wood-burning fireplaces. In certain embodiments, the
housing 20 defines one or more mounting flanges 300 used to secure
the heating device 10 to a floor and/or one or more walls. The
mounting flanges 300 can include apertures 320 through which
mounting hardware can be advanced. Accordingly, in some
embodiments, the housing 20 can be installed in a relatively fixed
fashion within a building or other structure.
[0054] As shown, the heating device 10 includes a fuel delivery
system 40, which can have portions for accepting fuel from a fuel
source, for directing flow of fuel within the heating device 10,
and for combusting fuel. In the illustrated embodiment, portions of
an embodiment of the fuel delivery system 40 that would be obscured
by the heating device 10 are shown in phantom. Specifically, the
illustrated heating device 10 includes a floor 50 which forms the
bottom of the sealed combustion chamber 14 and the components shown
in phantom are positioned beneath the floor 50.
[0055] With reference to FIG. 2, an example of a fuel delivery
system 40 is shown. The fuel delivery system 40 can include a
regulator 120. The regulator 120 can be configured to selectively
receive a fluid fuel (e.g., propane or natural gas) from a source
at a certain pressure. In certain embodiments, the regulator 120
includes an input port 121 for receiving the fuel. The regulator
120 can define an output port 123 through which fuel exits the
regulator 120. Accordingly, in many embodiments, the regulator 120
is configured to operate in a state in which fuel is received via
the input port 121 and delivered to the output port 123. In certain
embodiments, the regulator 120 is configured to regulate fuel
entering the port 121 such that fuel exiting the output port 123 is
at a relatively steady pressure. The regulator 120 can function in
ways similar to the pressure regulators disclosed in U.S. patent
application Ser. No. 11/443,484, filed May 30, 2006, now U.S. Pat.
No. 7,607,426, the entire contents of which are hereby incorporated
by reference herein and made a part of this specification.
[0056] The output port 123 of the regulator 120 can be coupled with
a source line or channel 125. The source line 125, and any other
fluid line described herein, can comprise piping, tubing, conduit,
or any other suitable structure adapted to direct or channel fuel
along a flow path. In some embodiments, the source line 125 is
coupled with the output port 123 at one end and is coupled with a
control valve 130 at another end. The source line 125 can thus
provide fluid communication between the regulator 120 and the
control valve 130.
[0057] The control valve 130 can be configured to regulate the
amount of fuel delivered to portions of the fuel delivery system
40. Various configurations of the control valve 130 are possible,
including those known in the art as well as those yet to be
devised. In some embodiments, the control valve 130 includes a
millivolt valve. The control valve 130 can comprise a first knob or
dial 131 and a second dial 132. In some embodiments, the first dial
131 can be rotated to adjust the amount of fuel delivered to a
burner 190, and the second dial 132 can be rotated to adjust a
setting of a thermostat. In other embodiments, the control valve
130 comprises a single dial 131.
[0058] In many embodiments, the control valve 130 is coupled with a
burner transport line or channel 124 and a pilot transport or
delivery line 126. The burner transport line 124 can be coupled
with a nozzle assembly 160 which can be further coupled with a
burner delivery line 148. The nozzle assembly 160 can be configured
to direct fuel received from the burner transport line 132 to the
burner delivery line or channel 148.
[0059] The pilot delivery line 126 is coupled with a pilot 180.
Fuel delivered to the pilot 180 can be combusted to form a pilot
flame, which can serve to ignite fuel delivered to the burner 190
and/or serve as a safety control feedback mechanism that can cause
the control valve 130 to shut off delivery of fuel to the fuel
delivery system 40. Additionally, in some embodiments, the pilot
180 is configured to provide power to the control valve 130.
Accordingly, in some embodiments, the pilot 180 is coupled with the
control valve 130 by one or more of a feedback line 182 and a power
line 183.
[0060] The pilot 180 can comprise an igniter or an electrode
configured to ignite fuel delivered to the pilot 180 via the pilot
delivery line 126. Accordingly, the pilot 180 can be coupled with
an igniter line 184, which can be connected to an igniter actuator,
button, or switch 186. In some embodiments, the igniter switch 186
is mounted to the control valve 130. In other embodiments, the
igniter switch 186 is mounted to the housing 20 of the heating
device 10. The pilot 180 can also comprise a thermocouple. Any of
the lines 182, 183, 184 can comprise any suitable medium for
communicating an electrical quantity, such as a voltage or an
electrical current. For example, in some embodiments, one or more
of the lines 182, 183, 184 comprise a metal wire.
[0061] Furthermore, as discussed below, when a pilot light heats
the thermocouple a current is generated in the thermocouple. In
certain embodiments, this current produces a magnetic field within
the control valve 130 that maintains the valve 130 in an open
position. If the pilot light goes out or is disturbed, and the
current flow is reduced or terminated, the magnetic field weakens
or is eliminated, and the valve 130 closes, thereby preventing
passage of fuel.
[0062] The pilot 180 may also be an oxygen depletion sensor (ODS)
180. In various embodiments, the ODS 180 provides a steady pilot
flame that heats the thermocouple unless the oxygen level in the
ambient air drops below a threshold level. In certain embodiments,
the threshold oxygen level is between about 18 percent and about
18.5 percent. In some embodiments, when the oxygen level drops
below the threshold level, the pilot flame moves away from the
thermocouple, the thermocouple cools, and the heat control valve
130 closes, thereby cutting off the fuel supply to the heater 10.
It will be understood that most all references to pilot and pilot
assembly also refer to an ODS.
[0063] The burner delivery line 148 is situated to receive fuel
from the nozzle assembly 160, and can be connected to the burner
190. The burner 190 can comprise any suitable burner, such as, for
example, a ceramic tile burner or a blue flame burner, and is
preferably configured to continuously combust fuel delivered via
the burner delivery line 148.
[0064] The flow of fuel through the fuel delivery system 40, as
shown, will now be described. A fuel is introduced into the fuel
delivery system 40 through the regulator 120 which then proceeds
from the regulator 120 through the source line or channel 125 to
the control valve 130. The control valve 130 can permit a portion
of the fuel to flow into the burner transport line or channel 132,
and can permit another portion of the fuel to flow into the pilot
transport line or channel 126. The fuel flow in the burner
transport line 132 can proceed to the nozzle assembly 160. The
nozzle assembly 160 can direct fuel from the burner transport line
or channel 132 into the burner delivery line or channel 148. In
some embodiments, fuel flows through the pilot delivery line or
channel 126 to the pilot 180, where it is combusted. In some
embodiments, fuel flows through the burner delivery line or channel
148 to the burner 190, where it is combusted.
[0065] An air shutter 150 can also be along the burner delivery
line 148. The air shutter 150 can be used to introduce air into the
flow of fuel prior to combustion at the burner 190. This can create
a mixing chamber 157 where air and fuel is mixed together prior to
passing through the burner delivery line 148 to the burner 190. The
amount of air that is needed to be introduced can depend on the
type of fuel used. For example, propane gas at typical pressures
needs more air than natural gas to produce a flame of the same
size.
[0066] The air shutter 150 can be adjusted by increasing or
decreasing the size of a window 155. The window 155 can be
configured to allow air to pass into and mix with fuel in the
burner delivery line 148.
[0067] FIGS. 3 and 4 show an embodiment of a dual fuel heater 100.
The heater can be made for use with two different fuels, where in a
first setting the heater is set to use the first fuel and in a
second setting the heater is set to use the second fuel. The heater
100 can be configured such that the installer of the gas appliance
can connect the assembly to one of two fuels, such as either a
supply of natural gas (NG) or a supply of propane (LP) and the
assembly will desirably operate in the standard mode (with respect
to efficiency and flame size and color) for either gas. The heater
100 can be, for example, a vent-free infrared heater or a vent-free
blue flame heater. Other configurations are also possible for the
heater 100.
[0068] Though the heater 100 is configured for dual fuel use, the
heater can include many of the same types of components as the
heater 10 as will be understood by review of the below description.
It will be understood that like reference characters or terminology
denote corresponding features, but this does not require that the
components be identical in all aspects.
[0069] The heater 100 can comprise a housing 200. In the
illustrated embodiment, the housing 200 comprises a window 220, one
or more intake vents 240 and one or more outlet vents 260. Heated
air and/or radiant energy can pass through the window 220. Air can
flow into the heater 100 through the one or more intake vents 240
and heated air can flow out of the heater 100 through the outlet
vents 260.
[0070] With reference to FIG. 4, in certain embodiments, the heater
100 includes a regulator 120. The regulator 120 can be coupled with
source line 125. The source line 125 can be coupled with a heater
control valve 130, which, in some embodiments, includes a knob 132.
As illustrated, the heater control valve 130 is coupled to a fuel
supply pipe 124 and an oxygen depletion sensor (ODS) pipe 126, each
of which can be coupled with a fluid flow controller 140. The fluid
flow controller 140 can be coupled with a first nozzle line 141, a
second nozzle line 142, a first ODS line 143, and a second ODS line
144. In some embodiments, the first and the second nozzle lines
141, 142 are coupled with a nozzle 160, and the first and the
second ODS lines 143, 144 are coupled with an ODS 180. In some
embodiments, the ODS comprises a thermocouple 182, which can be
coupled with the heater control valve 130, and an igniter line 184,
which can be coupled with an igniter switch 186. Each of the pipes
125, 124, and 126 and the lines 141-144 can define a fluid
passageway or flow channel through which a fluid can move or
flow.
[0071] In some embodiments, including the illustrated embodiment,
the heater 100 comprises a burner 190. The ODS 180 can be mounted
to the burner 190, as shown. The nozzle 160 can be positioned to
discharge a fluid, which may be a gas, liquid, or combination
thereof into the burner 190. For purposes of brevity, recitation of
the term "gas or liquid" hereafter shall also include the
possibility of a combination of a gas and a liquid. In addition, as
used herein, the term "fluid" is a broad term used in its ordinary
sense, and includes materials or substances capable of fluid flow,
such as gases, liquids, and combinations thereof.
[0072] Where the heater 100 is a dual fuel heater, either a first
or a second fluid is introduced into the heater 100 through the
regulator 120. Still referring to FIG. 4, the first or the second
fluid proceeds from the regulator 120 through the source line 125
to the heater control valve 130. The heater control valve 130 can
permit a portion of the first or the second fluid to flow into the
fuel supply pipe 124 and permit another portion of the first or the
second fluid to flow into the ODS pipe 126. From the heater control
valve 130, the first or the second fluid can proceed to the fluid
flow controller 140. In many embodiments, the fluid flow controller
140 is configured to channel the respective portions of the first
fluid from the fuel supply pipe 124 to the first nozzle line 141
and from the ODS pipe 126 to the first ODS line 143 when the fluid
flow controller 140 is in a first state, and is configured to
channel the respective portions of the second fluid from the fuel
supply pipe 124 to the second nozzle line 142 and from the ODS pipe
126 to the second ODS line 144 when the fluid flow controller 140
is in a second state.
[0073] In certain embodiments, when the fluid flow controller 140
is in the first state, a portion of the first fluid proceeds
through the first nozzle line 141, through the nozzle 160 and is
delivered to the burner 190, and a portion of the first fluid
proceeds through the first ODS line 143 to the ODS 180. Similarly,
when the fluid flow controller 140 is in the second state, a
portion of the second fluid proceeds through the nozzle 160 and
another portion proceeds to the ODS 180. Other configurations are
also possible. The heater 100 and components thereof can be further
understood with reference to U.S. patent application Ser. No.
11/443,484, filed May 30, 2006, now U.S. Pat. No. 7,607,426, the
entire contents of which are hereby incorporated by reference
herein and made a part of this specification.
[0074] With reference now to FIGS. 5-6, a pilot assembly 180 will
now be discussed. The pilot assembly 180 can be used in conjunction
with either of the heaters 10, 100 discussed above, as well as,
with other embodiments of heating devices. Fuel delivered to the
pilot 180 can be combusted to form a pilot light or flame 800. When
the pilot light 800 heats the thermocouple 182 a current is
generated in the thermocouple. This current is used in some heaters
to generate a magnetic field within the control valve 130 to
maintain the valve 130 in an open position.
[0075] In operation, the pilot assembly generally first needs to be
proved before fuel can flow to the burner nozzle 160 and then on to
the burner 190. Proving the pilot is generally the initial step in
turning on the heater. As has been discussed, the pilot 180 has a
thermocouple 182 that generates an electric current when heated to
hold open the control valve 130. If the thermocouple is not hot
enough there won't be enough current generated to keep the control
valve open. Generally speaking, when the control valve is in a
pilot position, the control valve is also being held in an open
position to allow flow to the pilot 180, but not to the burner
nozzle 160. When the control valve is moved from the pilot position
to a heating position, the control valve is no longer held open but
requires the electric current from the thermocouple to hold the
valve open. Thus, if there is not yet enough heat and the control
valve were adjusted from the pilot position to the heating
position, i.e. by turning the knob 132, the control valve will
close and fuel will not be able to flow to the burner. And in fact,
most control valves will not allow the user to rotate the knob, or
change the position of the control to a heating condition, until
after the pilot has been proven.
[0076] Once lit, if the pilot light 800 goes out or is disturbed,
and the current flow is reduced or terminated, the magnetic field
weakens or is eliminated, and the valve 130 closes, thereby
preventing further flow of fuel. So with the control valve in a
heating position, the pilot ensures that if the flame goes out,
uncombusted fuel will not continue to flow into the room or space
where the heating assembly is located. In this way the pilot can
prevent a potential safety hazard, such as an explosion.
[0077] If the pilot assembly is also an oxygen depletion sensor
(ODS) 180, then the ODS can cause the control valve 130 to close
when the oxygen level drops below a certain threshold. For example,
the threshold oxygen level can be between about 18 percent and
about 18.5 percent. As the oxygen level changes the pilot light 800
moves with respect to the thermocouple 182. When the oxygen level
drops below the threshold level, the pilot flame 800 moves away
from the thermocouple 182, the thermocouple 182 cools, and the
control valve 130 closes, thereby cutting off the fuel supply to
the heater 10, 100.
[0078] The illustrated pilot assembly 180 can also be used to shut
off flow through the control valve 130 when an excessive heat
threshold or other condition is met. For example, if the wrong fuel
is connected to the heater 10, 100 depending on the fuel, a large
flame 800B such as that shown in FIG. 6 may be produced. It will be
understood that this wrong fuel could also provide an undesirably
large flame at the burner 190 creating a potential safety
hazard.
[0079] The pilot assembly 180 can be configured to prevent the
heater 10, 100 from starting if the wrong fuel is connected to the
heater, or if an excessive temperature condition is experienced at
the pilot 180. In some embodiments, a temperature sensor, such as
second thermocouple 810 can be used to detect an excessive
temperature condition and/or the connection of the wrong fuel. A
signal can be sent to the control valve 130 or to a printed circuit
board, or the signal from the first thermocouple 182 can be
interrupted, to thereby close the control valve or to activate some
other shut off feature. In some embodiments, this can be done
before fuel is permitted to flow to the burner nozzle 160, or
before the pilot has been fully proven. For example, the heating
assembly can be configured to detect an undesired condition while
the pilot is being proven and before the fuel can flow to the
burner nozzle 160. This can beneficially prevent a potential safety
hazard.
[0080] As one example, if the heater is a natural gas heater the
pilot assembly can be configured for use with natural gas. The
pilot flame 800A shown in FIG. 5 can represent the normal flame
size when the pilot assembly is used with natural gas. As can be
seen, the thermocouple 182 is not only adjacent the flame 800A but
is actually within and surrounded by it. In this condition, the
flame 800A would heat thermocouple 182 to generate an electric
current to hold open the control valve 130. But, it can also be
seen that the flame 800A is spaced away from the second
thermocouple 810. In this condition the flame 800A would not
provide sufficient heating to the second thermocouple to exceed the
set threshold.
[0081] Thus, in this condition, the first thermocouple 182 can be
heated sufficiently to prove the pilot, thereafter allowing flow to
the burner nozzle when the heater is changed from the pilot
position to a heating position. But the second thermocouple is not
heated sufficient to generate a closing signal to the control
valve, or to interrupt the current from the first thermocouple 182.
The first thermocouple can be spaced a first distance from the
nozzle. The second thermocouple can be spaced a second distance
from the nozzle. Preferably, the second distance is greater than
the first distance, but in some embodiments the distances may be
the same, of the second distance may be less than the first
distance.
[0082] In FIG. 6 it can be seen that large flame 800B contacts and
surrounds both the first and second thermocouples 182, 810. Where
the pilot assembly 180 is configured for use with natural gas, this
can be the condition when liquid propane is passed into the pilot
assembly. The sensed temperature at the second thermocouple can
exceed the set threshold to cause the control valve to close as
will be described in more detail below.
[0083] As shown, the pilot assembly 180 comprises a first
thermocouple 182, a nozzle 801, and an electrode 808, and a second
thermocouple 810. It will be understood that other temperature
sensors and devices could be used instead of, or in addition to,
one or both of the thermocouples, such as a thermopile. The pilot
assembly 180 can include a frame 820 for positioning the
constituent parts of the pilot assembly. The nozzle 801 can include
an injector 811 to be coupled with the line 143 (see FIGS. 1-4), an
air inlet 821, and an outlet 803.
[0084] In many embodiments, the injector is a standard injector as
are known in the art, such as an injector that can be utilized with
liquid propane or natural gas. Thus, the injector can have an
internal orifice sized for a particular fuel. The nozzle 801 is
directed towards the electrode 808 to ignite the fuel and towards
the thermocouple 182 such that a stable flame 800A exiting the
nozzle 801 will heat the thermocouple 182.
[0085] A gas or a liquid can flow from the line 143 through the
injector 811 to the outlet 803 and toward the thermocouple 182. The
fluid flows near the air inlet 821 drawing in air for mixing with
the fluid. In some embodiments, a user can activate the electrode
by depressing the igniter switch 186 (see FIGS. 2 and 4). The
electrode can comprise any suitable device for creating a spark to
ignite a combustible fuel. In some embodiments, the electrode is a
piezoelectric igniter.
[0086] With reference now to FIGS. 7-8, a dual fuel pilot assembly
180' will be discussed. As previously mentioned, the pilot assembly
180' can also be an oxygen depletion sensor. The pilot assembly
180' can function is a manner substantially similar to the pilot
assembly 180. The primary difference being that the dual fuel pilot
assembly 180' has a second nozzle 802. The first nozzle 801 can be
configured for use with a first fuel, such as natural gas, and the
second nozzle 802 can be configured for use with a second fuel,
such as liquid propane. As shown, the pilot assembly 180' also
includes a second electrode 809. It will be understood that some
embodiments may only have a single electrode.
[0087] Similar to the first nozzle, the second nozzle can include
an injector 812, an air inlet 822, and an outlet 804. In some
embodiments, the first nozzle 801 and the second nozzle 802 are
directed toward the thermocouple such that a stable flame exiting
either of the nozzles 801, 802 will heat the thermocouple 182. In
certain embodiments, the first nozzle 801 and the second nozzle 802
are directed to different sides of the thermocouple 182. In some
embodiments, the first nozzle 801 and the second nozzle 802 are
directed to opposite sides of the thermocouple 182. In some
embodiments, the first nozzle 801 is spaced closer to the
thermocouple than is the second nozzle 802.
[0088] In some embodiments, the first nozzle 801 comprises a first
air inlet 821 at a base thereof and the second nozzle 802 comprises
a second air inlet 822 at a base thereof. In various embodiments,
the first air inlet 821 is larger or smaller than the second air
inlet 822. In many embodiments, the first and second injectors 811,
812 are also located at a base of the nozzles 801, 802. In certain
embodiments, a gas or a liquid flows from the first line 143
through the first injector 811, through the first nozzle 801, and
toward the thermocouple 182. In other embodiments, a gas or a
liquid flows from the second line 144 through the second injector
812, through the second nozzle 802, and toward the thermocouple
182. In either case, the fluid flows near the first or second air
inlets 821, 822, thus drawing in air for mixing with the fluid. In
certain embodiments, the first injector 811 introduces a fluid into
the first nozzle 801 at a first flow rate, and the second injector
812 introduces a fluid into the second nozzle 802 at a second flow
rate. In various embodiments, the first flow rate is greater than
or less than the second flow rate.
[0089] In some embodiments, the first electrode 808 is positioned
at an approximately equal distance from an output end of the first
nozzle 801 and an output end of the second nozzle 802. In some
embodiments, a single electrode is used to ignite fuel exiting
either the first nozzle 801 or the second nozzle 802. In other
embodiments, a first electrode 808 is positioned closer to the
first nozzle 801 than to the second nozzle 802 and the second
electrode 809 is positioned nearer to the second nozzle 802 than to
the first nozzle 801.
[0090] With reference back to any of FIGS. 5-8, certain embodiments
of an electrical control system will be described. As shown in
FIGS. 5-8 the thermocouples are electrically connected. Wires 813
and 815 are connected to the first thermocouple 182 and wires 817
and 819 are connected to the second thermocouple. The wires 813 and
817 represent the positive wire connected to the anode of the
thermocouple and wires 815 and 819 represent the negative wire
connected to the cathode of the thermocouple. It can be seen that
the second thermocouple is electrically connected to the first
thermocouple with opposite wires or in reverse polarity. In other
words, the positive wire 813 of the first thermocouple 182 is
connected to the negative wire 819 of the second thermocouple 810.
Also the negative wire 815 of the first thermocouple 182 is
connected to the positive wire 817 of the second thermocouple 810.
In this way, when the second thermocouple is heated, the current
from the first thermocouple can be effectively cancelled out or
interrupted by generating a current that flows in the opposite
direction. Thus, when the wrong fuel is connected to the heater, or
to the wrong connection of the heater, the second thermocouple can
detect the excessive temperature and prevent the pilot from
proving.
[0091] In some embodiments, a pilot can comprise a first
thermocouple, a second thermocouple and a nozzle pointing at both
thermocouples. The pilot can be configured to direct a flame at
only the first thermocouple during normal operation and at both
thermocouples when an incorrect fuel is directed through the pilot.
In some embodiments, the thermocouples can be electrically
connected in reverse polarity. In some embodiments, the pilot can
include a second nozzle. The second nozzle can be pointed at only
the first thermocouple. In other embodiments, the second nozzle can
be pointed at a third thermocouple and the position of the second
nozzle and third thermocouple can be independent from the position
of the other nozzle and thermocouples.
[0092] Looking now to FIG. 9, a schematic diagram is shown of the
control valve 130 and the two thermocouples 182 and 810. The
illustrated control valve 130 includes a solenoid that can hold the
valve in an open position when an electric current is generated by
the first thermocouple 182.
[0093] The first thermocouple can generate an electric potential E1
and has an internal resistance r1. The second thermocouple can
generate an electric potential E2 and has an internal resistance
r2. The solenoid has an internal resistance R. In the illustrated
embodiment, when the correct gas is connected to the heating
system, only the first thermocouple generates an electric potential
E1. Thus the current I generated equals:
I=E1(r1+r2)/(R(r1+r2)+r1r2) (1)
[0094] And when the wrong gas is connected such that a larger flame
800B is generated, the current I equals:
I=((E1-E2)(r1+r2))/(R(r1+r2)+r1r2) (2)
[0095] The second thermocouple generates a reverse potential which
can cause the potential to drop. This will reduce the current and
in some embodiments may effectively cancel out the potential from
the first thermocouple. The solenoid needs a rated current to
operate, but as the second thermocouple causes a potential drop the
solenoid can close. This can prevent a potential safety issue
and/or the wrong fuel from flowing through the system.
[0096] A thermocouple can include one or more an anode and a
cathode. The anode can be the negative terminal on the thermocouple
and the cathode can be the positive terminal.
[0097] A safety pilot can comprise a first pilot nozzle having an
outlet, a first thermocouple and a second thermocouple. The first
thermocouple can be positioned a first distance from said outlet of
said first pilot nozzle, said first thermocouple comprising a first
anode and a first cathode and configured to generate voltage in
response to heat from said first pilot nozzle. The second
thermocouple can be positioned a second distance from said outlet
of said first pilot nozzle, said second thermocouple comprising a
second anode and a second cathode and configured to generate
voltage in response to heat from said first pilot nozzle.
[0098] In some embodiments, the thermocouples can be electrically
connected in reverse polarity. The second cathode can be in
electrical contact with the first anode, and the second anode can
be in electrical contact with the first cathode. In some
embodiments, a wire leading from the positive terminal of the first
thermocouple can be connected to the negative terminal of the
second thermocouple. And a wire leading from the negative terminal
of the first thermocouple can be connected to the positive terminal
of the second thermocouple. A single set of wires may then be used
to connect the pilot to a control valve or other electrically
responsive valve.
[0099] With the thermocouples electrically connected in reverse
polarity and when heated by the pilot, two separate currents can be
generated which can have the effect of reducing the generated
current and/or effectively cancelling each other out as has been
explained above. But, when only one thermocouple is heated by the
pilot, a usable current can be generated.
[0100] In some embodiments, the cathode of the first thermocouple
is in electrical contact with the anode of the second thermocouple
and the anode of the first thermocouple is in electrical contact
with the cathode of the second thermocouple. Thus, when a single
thermocouple is heated in response to heat from said the pilot
nozzle a first current is generated by the safety pilot and when
both the first and the second thermocouples are heated in response
to heat from the pilot nozzle, two currents are generated which
combine to generate a second current that is less than the first
current.
[0101] A heating assembly can include a pilot and an electrically
responsive valve in electrical communication with a first
thermocouple and a second thermocouple of the pilot. The
electrically responsive valve can direct fuel flow to a burner
through a burner nozzle. (1) The valve can maintain a closed
position when an insufficient signal is generated by the first
thermocouple and no significant signal is generated by the second
thermocouple. (2) The valve can maintain an open position in
response to a first signal level from said first thermocouple when
no or insufficient signal is generated by said second thermocouple.
(3) The valve can close in response to the first signal level from
the first thermocouple and a sufficient signal level from the
second thermocouple or from simply a sufficient signal level from
the second thermocouple. If the electrically responsive valve is a
control valve that directs fuel to both the burner and the pilot,
it will be understood, that the electrically responsive valve may
also direct fuel to the pilot light apart from the actions of the
valve controlling the flow of fuel to the burner and the burner
nozzle.
[0102] Many different types of temperature sensors can be used to
detect an excessive temperature condition and/or the connection of
the wrong fuel. For example, in many embodiments a thermopile could
be used in place of one or more of the thermocouples discussed
herein. The signal generated could be sent to the control valve
130, but could also be sent to a printed circuit board. In
addition, one or more shut off features can be included in the
system instead of, or in addition to the control valve.
[0103] FIG. 10 is a schematic representation of another embodiment
of heating system. In the illustrated heating system basic
components of the heating system are shown including a regulator
120, a control valve 130, a nozzle assembly 160, a burner 190, and
a pilot assembly 180. The heating system and components can
function in a similar manner to those previously described and can
be a single fuel or a dual fuel system. Thus, for example fuel can
flow from the regulator 120 to the control valve. The control valve
130 can provide fuel to both the nozzle assembly 160 and to the
pilot assembly 180. The nozzle assembly 160 can direct fuel to the
burner.
[0104] The heating system of FIG. 10 also includes a safety feature
to prevent the heating system from starting if the wrong fuel is
connected to the heating system under certain circumstances. In
some embodiments, a pressure sensor 60 can be used to detect an
incorrect fluid pressure entering the system. The incorrect fluid
pressure can be indicative of a wrong type of fuel connected to the
heating system. In some embodiments, a signal from the pressure
switch 60 can be sent to the control valve 130, or the signal from
the thermocouple 182 can be interrupted, to thereby close the
control valve. In some embodiments, this can be done before fuel is
permitted to flow to the burner nozzle 160, or before the pilot has
been fully proven. For example, the heating assembly can be
configured to detect an undesired condition while the pilot is
being proven and before the fuel can flow to the burner nozzle 160.
This can beneficially prevent a potential safety hazard.
[0105] Different fuels are generally run at different pressures.
FIG. 11 shows four different fuels: methane, city gas, natural gas
and liquid propane; and a typical pressure range of each particular
fuel. The typical pressure range can mean the typical pressure
range of the fuel as provided by a container, a gas main, a gas
pipe, etc. for consumer use, such as the gas provided to an
appliance. Thus, natural gas is generally provided to a home gas
oven within the range of 4 to 7 inches of water column. The natural
gas can be provided to the oven through piping connected to a gas
main. As another example, propane may be provided to a barbeque
grill from a propane tank with the range of 10 to 14 inches of
water column. The delivery pressure of any fuel may be further
regulated to provide a more certain pressure range or may be
unregulated. For example, the barbeque grill may have a pressure
regulator so that the fuel is delivered to the burner within the
range of 10 to 12 inches of water column rather than within the
range of 10 to 14 inches of water column.
[0106] As shown in the chart, city gas can be a combination of one
or more different gases. As an example, city gas can be the gas
typically provided to houses and apartments in China, and certain
other countries. At times, and from certain sources, the
combination of gases in city gas can be different at any one given
instant as compared to the next.
[0107] Because each fuel has a typical range of pressures that it
is delivered at, these ranges can advantageously be used in a
heating assembly to ensure that the proper gas is connected to the
proper inlet. In particular, a pressure sensor can be used to
determine the pressure of the gas before, or as it enters the
regulator. If the pressure is not within the typical range or is
greatly outside of the typical range of the desired fuel, the
control valve can be triggered to close, preventing the incorrect
fuel from flowing to the burner nozzle 160 and to the burner 190.
In some embodiments, the pressure sensor could be set to a
threshold pressure level above the typical pressure range, for
example, about 0.5, 1, 1.5 or 2 inches of water column above or
below the typical pressure range. In a preferred embodiment, the
pressure sensor is set at a threshold level above the typical
pressure range.
[0108] One embodiment of such a system is represented in FIG. 10. A
pressure switch 60 can be fluidly connected to an inlet on or in
fluid communication with the pressure regulator 120. The pressure
switch 60 can be electrically connected to one or more of the
control valve 130, the pilot assembly 180, and the igniter. As
shown, the pressure switch 60 is electrically connected to both the
control valve 130 and the pilot assembly 180. The pressure switch
60 can be a normally closed switch and can be electrically
positioned between the thermocouple 182 and the control valve 180.
Thus, if the pressure switch is opened the circuit between the
thermocouple and the control valve will be opened and current from
the thermocouple will be prevented from reaching the control valve
as the circuit will be an open circuit. Other configurations of the
system can also be used.
[0109] In another embodiment as shown in FIG. 10A, the pressure
switch 60 can be electrically connected to the igniter 808. The
pressure switch 60 can be a normally closed switch and can be
electrically positioned between the switch 186 for the igniter and
the igniter 808 itself, such as a piezoelectric igniter. Thus, if
the pressure switch is opened the circuit between the igniter
switch and the igniter will be opened and current from the igniter
switch will be prevented from reaching the igniter as the circuit
will be an open circuit. Thus, if the pressure is too high, which
may indicate the wrong fuel is connected to the heater, the pilot
assembly 180 cannot be ignited with the igniter 808.
[0110] In some embodiment, two pressure switches can be used per
inlet. One pressure switch can be set at a low level below the
typical pressure range for the desired fuel and the other can be
set at a high level above the typical pressure range for the
desired fuel. The pressure regulator can be set based on the
desired fuel. Thus, if the heating assembly is a dual fuel heating
assembly, the heating assembly may have two inlets and four
pressure switches, two on each inlet. Similarly, if the heating
assembly is a single fuel heating assembly, the heating assembly
may have one inlet and one or two pressure switches. In another
embodiment, the heating assembly can be a dual fuel heating
assembly with a single inlet and it may include one or more
pressure switches.
[0111] In another embodiment, a dual fuel heating assembly can have
two inlets and only one pressure switch. The pressure switch can be
connected to the inlet for the lower pressure fuel and can be set
at a level above the typical pressure range for that fuel. In this
way, the heating assembly can prevent the higher pressure fuel from
being connected to the inlet for the lower pressure fuel. As an
example, the pressure switch 60 can be used with a natural gas
inlet and set to 7.5 inches of water column. The second inlet can
be used with liquid propane which is delivered at a higher pressure
than natural gas. Propane would also produce a higher flame if
introduced through into the system that has been set for natural
gas. Thus, the pressure switch can beneficially prevent a safety
hazard from occurring.
[0112] FIG. 12 shows a cross-sectional view of one embodiment of a
pressure switch 60. The pressure switch 60 has a housing 62 having
an inlet 68 to receive fluid as indicated by the arrow and to be
able to respond to certain pressures. As shown, the pressure switch
60 is a normally closed pressure switch. The pressure switch 60 can
be set to open when a greater than desired pressure encounters a
valve member 58, such as the illustrated diaphragm 58. A spring 64
and screw 66 can be used to set and adjust the pressure required to
move the diaphragm 58. A cap 72 can cover the screw 66. In
addition, a contact member 56 can move with the diaphragm. The
contact member 56 can contact two electrical connection members 52,
54 which can be electrically connected to a printed circuit board,
the igniter 808, igniter switch 186, the control valve 130 and/or
the thermocouple 182, among other features.
[0113] As has been discussed previously, under normal operation a
flame at the pilot 180 heats the thermocouple 182 to generate a
current to maintain the control valve in an open position. The
pressure switch 60 can be set to open this circuit and prevent the
current from reaching the control valve when the switch 60 has been
advanced, if it is a normally closed pressure switch. In another
embodiment, the pressure switch 60 can be normally open switch so
that the switch will only be closed when a minimum pressure is
present at the inlet. The system can operate in a similar manner
with an igniter, a printed circuit board, or with other features of
the heater assembly.
[0114] The pressure switch 60 positioned at the inlet can allow the
system to provide a safety check before the pilot has been proven
and before fuel begins to follow to the burner nozzle 160 and the
burner 190. As the pressure switch can respond immediately based on
the delivery pressure of the fuel.
[0115] In some embodiments, a pressure switch is configured such
that if a fuel is connected to the first gas hook-up that has a
delivery pressure either above or below a predetermined threshold
pressure, the fuel will act on the pressure switch to move a
movable contact member from one of a first or second position to
the other position. This will open or close a circuit as the case
may be, such that the pilot light cannot be proven to thereby
prevent fuel from flowing to the burner.
[0116] A pilot light may comprise a thermocouple electrically
coupled to one of a first and a second electrical contact of the
pressure switch and to the control valve. The heater assembly can
be configured so that the movable contact member of the pressure
switch is in the second disengaged position when the delivery
pressure is above the predetermined threshold pressure to create an
open circuit between the thermocouple and the control valve such
that the control valve cannot flow fuel to the burner.
[0117] In some embodiments, an igniter may be electrically coupled
to one of the first and second electrical contacts. The heater
assembly can be configured so that the movable contact member of
the pressure switch is in the second disengaged position when the
delivery pressure is above the predetermined threshold pressure to
create an open circuit between the igniter and one of the first and
second electrical contacts such that the fuel cannot be
ignited.
[0118] In some embodiments, a pressure switch can communicate with
a fuel hook-up. When the fuel has a pressure below a threshold
pressure, the pressure switch can permit a temperature sensor to
electrically connect with a control valve. When the fuel is above
the threshold pressure, the pressure switch can prevent the
temperature sensor from electrically connecting with the control
valve.
[0119] A pressure switch can comprise a housing having an inlet and
defining an internal chamber. The pressure switch can also include
a spring, a diaphragm, first and second electrical contacts, and a
movable contact member. The diaphragm can be connected to the
spring and positioned within the internal chamber such that fluid
entering the inlet acts on the diaphragm. The movable contact
member can be connected to the diaphragm such that movement of the
diaphragm can cause the movable contact member to movably engage
and disengage the first and second electrical contacts, the
diaphragm and spring configured to the movable contact member
between engaged and disengaged positions at a set fluid pressure.
In some embodiments, the movable contact member is biased to the
engaged position.
[0120] Some embodiments of heater assembly can comprise a
thermocouple and a pressure switch. The pressure switch can
comprise a valve member movable at a predetermined threshold
pressure, first and second electrical contacts, and a movable
contact member. The movable contact member can be mechanically
connected to the valve member and movable therewith. The movable
contact member can be configured for electrical connection to the
first and second electrical contacts when in a first engaged
position and have a second disengaged position configured to create
an open circuit. The thermocouple can be electrically coupled to
one of the first and second electrical contacts, wherein the heater
assembly is configured so that the movable contact member of the
pressure switch is in the second disengaged position at a set fluid
pressure of fuel in fluid communication with the valve member to
create an open circuit with the thermocouple.
[0121] Turning now to FIG. 13, a heating unit 70 including a
pressure switch 60 is shown. The heating unit 70 combines certain
features of a pressure regulator 120 and a fluid flow controller
140 for use with a dual fuel heating assembly. The heating unit 70
is functionally similar to the heating units described in U.S.
provisional application No. 61/748,071 filed Dec. 31, 2012, the
entire contents of which are incorporated by reference herein. For
example, in many aspects, the heating unit 70 is similar to that
described with reference to FIGS. 22-28 in U.S. provisional
application No. 61/748,071.
[0122] The heating unit 70 is shown with a pressure switch 60 in
fluid communication with one of the inputs 15 of the heating unit
70. The pressure switch 60 can function in a manner as described
above.
[0123] FIG. 14 shows a heater including the heating unit of FIG. 13
having the pressure switch 60. FIG. 15 shows a schematic diagram of
the function of the heater of FIG. 14. FIG. 16 shows a schematic
diagram of the function of another embodiment of heater that is
similar to those described in U.S. provisional application No.
61/748,071 filed Dec. 31, 2012 and incorporated by reference
herein.
[0124] In some embodiments, the heating unit 70 can be a fuel
selector valve. The fuel selector valve 70 can receive a first fuel
or a second fuel. In some embodiments, the first fuel may be liquid
propane gas (LP). In some embodiments, the second fuel may be
natural gas (NG). The fuel selector valve 70 includes a fuel source
connection 12 and a fuel source connection 15. The fuel selector
valve 70 can receive LP at fuel source connection 12. The fuel
selector valve 70 can receive NG at fuel source connection 15.
[0125] In some embodiments, the fuel selector valve 70 can direct
fuel to a control valve 130. The control valve can include at least
one of a manual valve, a thermostat valve, an AC solenoid, a DC
solenoid and a flame adjustment motor. The control valve 130 can
direct fuel back to the fuel selector valve 70 and/or to one or
more nozzle assemblies 160. In some embodiments the one or more
nozzle assemblies 160 can be part of the fuel selector valve 70.
The nozzle assembly 160 can be similar the various embodiments that
described in U.S. patent application Ser. No. 13/310,664 filed Dec.
2, 2011 and published as U.S. 2012/0255536, the entire contents of
which are incorporated by reference herein and are to be considered
a part of the specification. FIGS. 23-24B, 28A-34B, 39A-44B, and
their accompanying descriptions are but some examples of nozzle
assemblies from U.S. 2012/0255536.
[0126] A window or opening 155 can be positioned at the nozzle
assembly 160. An opening 155 can be used to introduce air into the
flow of fuel prior to combustion. The amount of air that is needed
to be introduced depends on the type of fuel used. For example,
propane gas needs more air than natural gas to produce a flame of
the same size as will be discussed in more detail below. In some
embodiments, the heating assembly can be switched between the
different fuels without requiring adjustment of a window or opening
for creating the air fuel mixture. Some embodiments can also
include an air shutter assembly around the opening 155. An air
shutter can be used to adjust the size of the window. This may be
done to accommodate for differences in fuel quality and/or
pressure. In some embodiments, this adjustment can be done once for
the system as a whole, but it may not be required to further adjust
the air shutter if the heater assembly is switched between
different fuels.
[0127] The fuel selector valve 70 can also direct fuel to an oxygen
depletion sensor (ODS) 180. In some embodiments, the fuel selector
valve 70 can be coupled with ODS lines 143 and 144. As shown, the
ODS 180 has a thermocouple 182 coupled to the control valve 130,
and an igniter line 184 coupled with an igniter, such as an
electrode. In some embodiments, the ODS 180 can be mounted to the
main burner 190.
[0128] Referring now to FIGS. 17-17A, another embodiment of a fuel
selector valve 70 will be described. The illustrated fuel selector
valve is similar to that shown in FIGS. 13-14. The fuel selector
valve of FIGS. 13-14 is also shown with a pressure sensitive switch
and can also include one addition input and output for receiving
fuel from the control valve and for directing fuel to a nozzle
160.
[0129] The fuel selector valve 70 as illustrated in FIGS. 17-17A
includes two pressure regulators 16, one for each different fuel
type for a dual fuel heater. Each of the pressure regulators can
have a spring loaded valve connected to a diaphragm. The fluid
pressure acting on the diaphragm can move the valve allowing more
or less fluid to flow through the pressure regulator depending on
the orientation of the valve with respect to a valve seat which are
generally positioned within the flow passage through the pressure
regulator.
[0130] Among other features, the heating assembly can be used to
select between two different fuels and to set certain parameters,
such as one or more flow paths, and/or a setting on one or more
pressure regulators based on the desired and selected fuel. The
heating assembly 100 can have a first mode configured to direct a
flow of a first fuel (such as LP) in a first path through the
heating assembly 100 and a second mode configured to direct a flow
of a second fuel (such as NG) in a second path through the heating
assembly.
[0131] The fuel selector valve 70 can be used to select between two
different fuels and to set certain parameters, such as one or more
flow paths, and/or a setting on one or more pressure regulators
based on the desired and selected fuel. The fuel selector valve 70
can have a first mode configured to direct a flow of a first fuel
(such as LPG) on a first path through the fuel selector valve 70
and a second mode configured to direct a flow of a second fuel
(such as NG) on a second path through the fuel selector valve 70.
The fuel selector valve 70 can also include one or more actuation
members. In some embodiments, the fuel selector valve 70 can be
configured such that inlets of the valve are only open when they
are connected to a source of fuel, as described in more detail
below.
[0132] FIG. 17 illustrates an external view of a fuel selector
valve 70 that can have a first inlet 12 and a second inlet 15. Both
inlets can have an actuation member with an end that can at least
partially enter the inlet and close or substantially close the
inlet. For example, as illustrated in FIG. 18, the first inlet 12
can have a first actuation member 22 with an end that blocks the
inlet. Similarly, the second inlet 15 can have a second actuation
member 24 with an end that blocks the inlet.
[0133] As described with respect to various embodiments above, the
actuation members can have sealing sections 34, 36 that can seat
against respective ledges to close or substantially close their
respective inlets 12, 14. Thus, the first actuation member 22 can
have a first position in which the sealing section 34 of the first
actuation member seats against the first ledge. Similarly, the
second actuation member 24 can have a first position in which the
sealing section 36 of the second actuation member seats against the
second ledge. Each actuation member preferably has a biasing
member, such as a spring 32 that biases the actuation member toward
the first position.
[0134] As described in various embodiments above, when a fitting
for a source of fuel connects to one of the inlets, it can move the
actuation member into a second position that allows fluid to flow
through the inlet. FIG. 20 illustrates a fitting 30 of a source of
fuel connected to the first inlet 12. Each of the inlets is shown
fluidly connected to a pressure regulator 16 and to the outlet
18.
[0135] As with some pressure regulators described above, the
pressure settings of each pressure regulator 16 can be
independently adjusted by tensioning of a screw or other device
that allows for flow control of the fuel at a predetermined
pressure or pressure range (which can correspond to a height of a
spring) and selectively maintains an orifice open so that the fuel
can flow through a spring-loaded valve or valve assembly of the
pressure regulator. If the pressure exceeds a threshold pressure, a
plunger seat can be pushed towards a seal ring to seal off the
orifice, thereby closing the pressure regulator. In some
embodiments, a fuel selector valve 70 can include two inlets with
respective inlet valves as well as dedicated pressure regulators
that can direct fluid flow to an outlet. Other embodiments may have
additional features.
[0136] The fuel selector valve can provide additional control of a
fluid flow through an additional valve system. The fuel selector
valve can both direct fluid to the control valve 130 and receive a
flow of fluid from the control valve. As shown, the control valve
130 directs the fluid flow for the oxygen depletion sensor (ODS) to
the fuel selector valve. It will be understood that other
embodiments can receive both the ODS fluid flow, as well as the
nozzle fluid flow, or just the fluid flow for the nozzle. In
addition, the fuel selector valve can direct fluid flow to other
components in addition to and/or instead of the control valve
130.
[0137] As best seen in FIG. 21, the actuators 22, 24 can each be
operatively coupled to a valve member 112, 114 that can open the
flow path to either the second outlet 96 or the third outlet 98 114
can be. Thus, fluid received at the third inlet 94 can be
discharged to either the second outlet 96 or the third outlet 98.
In this way, the fuel selector valve can direct fuel to desired
location, such as a burner nozzle or ODS nozzle specific for a
particular type of fuel.
[0138] The actuation members 22, 24 are shown as have three
separate movable members. For example, actuation member 22 has a
first valve 26, a moveable member 102 and a second valve 112. This
second valve 112 of actuation member 22 is also the third valve of
the system. Actuation member 24 is shown with a first valve 28, a
moveable member 104 and a second valve 114. In the overall system,
these valves are also called the second valve 28 and the fourth
valve 112. One benefit of having two or more independently movable
members is that having two or more separate members can allow each
member to properly seat to the respective valve to prevent leakage;
though it will be understood that one, two, or more members could
be used. It can also be seen that a number of springs 32 and
O-rings, 106 can be used to bias the members to their initial
positions and to prevent leakage.
[0139] In some embodiments, a fuel selector valve 70 similar to
that described with respect to FIGS. 17-21 and described further
below with respect to FIGS. 22-24B can have a single pressure
regulator, or no pressure regulators. In addition, in some
embodiments, the fuel selector valve 70 can have separate outlets
fluidly connected to each inlet and/or fuel hook-up.
[0140] Each of the fuel selector valves described herein can be
used with a pilot light or oxygen depletion sensor, a nozzle, and a
burner to form part of a heater or other gas appliance. The
different configurations of valves and controls such as by the
actuation members can allow the fuel selector valve to be used in
different types of systems. For example, the fuel selector valve
can be used in a dual fuel heater system with separate ODS and
nozzles for each fuel. The fuel selector valve can also be used
with nozzles and ODS that are pressure sensitive so that can be
only one nozzle, one ODS, or one line leading to the various
components from the fuel selector valve.
[0141] According to some embodiments, a heater assembly can be used
with one of a first fuel type or a second fuel type different than
the first. The heater assembly can include a pressure regulator
having a first position and a second position and a housing having
first and second fuel hook-ups. The first fuel hook-up can be used
for connecting the first fuel type to the heater assembly and the
second hook-up can be used for connecting the second fuel type to
the heater assembly. An actuation member can be positioned such
that one end is located within the second fuel hook-up. The
actuation member can have a first position and a second position,
such that connecting a fuel source to the heater assembly at the
second fuel hook-up moves the actuation member from the first
position to the second position. This can cause the pressure
regulator to move from its first position to its second position.
As has been discussed, the pressure regulator in the second
position can be configured to regulate a fuel flow of the second
fuel type within a predetermined range.
[0142] The heater assembly may also include one or more of a second
pressure regulator, a second actuation member, and one or more arms
extending between the respective actuation member and pressure
regulator. The one or more arms can be configured to establish a
compressible height of a pressure regulator spring within the
pressure regulator.
[0143] A heater assembly can be used with one of a first fuel type
or a second fuel type different than the first. The heater assembly
can include at least one pressure regulator and a housing. The
housing can comprise a first fuel hook-up for connecting the first
fuel type to the heater assembly, and a second fuel hook-up for
connecting the second fuel type to the heater assembly. The housing
can also include a first inlet, a first outlet, a second outlet
configured with an open position and a closed position, and a first
valve configured to open and close the second outlet. A first
actuation member having an end located within the second fuel
hook-up and having a first position and a second position can be
configured such that connecting a fuel source to the heater
assembly at the second fuel hook-up moves the actuation member from
the first position to the second position which causes the first
valve to open the second outlet, the second outlet being in fluid
communication with the second fuel hook-up.
[0144] The first actuation member can be further configured such
that connecting the fuel source to the heater assembly at the
second fuel hook-up moves the first actuation member from the first
position to the second position which causes the at least one
pressure regulator to move from a first position to a second
position, wherein the at least one pressure regulator in the second
position is configured to regulate a fuel flow of the second fuel
type within a predetermined range.
[0145] The at least one pressure regulator can comprises first and
second pressure regulators, the first pressure regulator being in
fluid communication with the first fuel hook-up and the second
pressure regulator being in fluid communication with the second
fuel hook-up.
[0146] Similarly, the first valve can be configured to open and
close both the first and second outlets or there can be a second
valve configured to open and close the first outlet. The housing
may include addition, inlets, outlets and valves. Also a second
actuation member may be used and positioned within the first fuel
hook-up.
[0147] In certain embodiments, the heater assembly is configured to
accept and channel liquid propane when in a first operational
configuration and to accept and channel natural gas when in a
second operational configuration. In other embodiments, the heater
assembly is configured to channel one or more different fuels when
in either the first or second operational configuration.
[0148] The fuel selector valves 70 of FIGS. 17-21 can be used in
the system shown in FIG. 16. Returning to FIGS. 13 and 14, a fuel
selector valve 70 (also shown in FIGS. 22-24B) can be used in the
system shown in FIG. 15. It can be seen that one of the main
differences between FIG. 15 and FIG. 16 is how the fuel travels
from the control valve to the burner. In FIG. 16, fuel can travel
from the control valve to a pressure sensitive nozzle which can
control how the fuel is injected to the burner, i.e. the pathway
through the nozzle to the burner.
[0149] In FIG. 15, the control valve directs some of the flow
directly to the burner through a nozzle and some of the flow is
returned to the fuel selector valve 70. This second flow may be
directed to the burner by a second nozzle dependent upon which fuel
inlet is connected to a fuel source. In this way, some of the flow
to the burner travels the second path when the natural gas
connection is made. But, the direct flow to the burner is
independent of whether liquid propane or natural gas is connected.
From this it will be understood that the fuel selector valve of
FIGS. 13-14 includes one additional input and an output for
receiving fuel from the control valve and for directing fuel to a
nozzle, as well as an internal valve to open and close this
passageway.
[0150] FIG. 22 illustrates an external perspective view of a fuel
selector valve 70 that can have an additional input and output and
can be used in the system shown in FIG. 15, although it can also be
used in the system shown in FIG. 16. Like valves described above,
valve 70 of FIG. 22 can have a first fuel source connection or
inlet 12 and a second fuel source connection or inlet 15. In some
embodiments, the first inlet 12 can be configured to connect to a
fitting for a first fuel (such as LP), and the second inlet 15 can
be configured to connect to a fitting for a second fuel (such as
NG). Both inlets can have an actuation member with an end that can
at least partially enter the inlet and close or substantially close
the inlet. For example, as illustrated in FIG. 18, the first inlet
12 can have a first actuation member 22 with an end that blocks the
inlet. Similarly, the second inlet 15 can have a second actuation
member 24 with an end that blocks the inlet. FIG. 18 is a
cross-section of the valve illustrated in FIG. 17, but is similar
in all relevant respects to the valve of FIG. 22 if considered to
be viewed from the line D-D of FIG. 17A.
[0151] As described with respect to various embodiments above, the
actuation members can have sealing sections 34, 36 that can seat
against respective ledges to close or substantially close their
respective inlets 12, 14. Thus, the first actuation member 22 can
have a first position in which the sealing section 34 of the first
actuation member seats against the first ledge. Similarly, the
second actuation member 24 can have a first position in which the
sealing section 36 of the second actuation member seats against the
second ledge. Each actuation member preferably has a biasing
member, such as a spring 32 that biases the actuation member toward
the first position.
[0152] As described in various embodiments above, when a fitting
for a source of fuel connects to one of the inlets, it can move the
actuation member into a second position that allows fluid to flow
through the inlet. FIG. 20 illustrates a fitting 30 of a source of
fuel connected to the first inlet 12. Each of the inlets is shown
fluidly connected to a pressure regulator 16 and to the outlet 18.
FIG. 20 shows the same view as FIG. 18.
[0153] As with some pressure regulators described above, the
pressure settings of each pressure regulator 16 can be
independently adjusted by tensioning of a screw or other device
that allows for flow control of the fuel at a predetermined
pressure or pressure range (which can correspond to a height of a
spring) and selectively maintains an orifice open so that the fuel
can flow through a spring-loaded valve or valve assembly of the
pressure regulator. If the pressure exceeds a threshold pressure, a
plunger seat can be pushed towards a seal ring to seal off the
orifice, thereby closing the pressure regulator. In some
embodiments, a fuel selector valve 70 can include two inlets with
respective inlet valves as well as dedicated pressure regulators
that can direct fluid flow to an outlet. Other embodiments may have
additional features.
[0154] The fuel selector valve can provide additional control of a
fluid flow through additional valve systems, as described further
below. The fuel selector valve can both direct fluid to the control
valve 130 and receive a flow or flows of fluid from the control
valve. In some embodiments the control valve 130 directs the fluid
flow for the oxygen depletion sensor (ODS) to the fuel selector
valve. In some embodiments, the fuel selector valve can receive
both the ODS fluid flow as well as a portion of the nozzle fluid
flow. In some embodiments, the fuel selector valve can receive just
the fluid flow for the nozzle from the control valve. In addition,
the fuel selector valve can direct fluid flow to other components
in addition to and/or instead of the control valve 130. For
example, in some embodiments the fuel selector valve can
selectively direct fluid flow to a nozzle. In some embodiments, the
fuel selector valve can direct fluid flow toward an ODS.
[0155] With reference to FIG. 22, the fuel selector valve can have
a variety of connections allowing for use in the system shown in
FIG. 15 and in various other embodiments of systems described
herein. In additional to the first inlet 12 and second inlet 15,
the fuel selector valve can have a third inlet 94 and a fourth
inlet 95, each of which can fluidly connect to the control valve.
The fuel selector valve can also have a first outlet 18, which can
fluidly connect to the pressure regulators 16 and the control
valve, a second outlet 96 and third outlet 98, which can fluidly
connect to an ODS, and a fourth outlet 97, which can fluidly
connect to a nozzle.
[0156] As best seen in FIGS. 24A and 24B, which illustrate the
cross sections of the fuel selector valve 70 identified in FIG. 23,
the actuators 22, 24 can each be operatively coupled to a valve
member 112, 114 that can adjust flow paths through the selector
valve. For example, as illustrated in FIG. 24A, the valve member
112 can selectively allow a flow of fluid that enters through the
fourth inlet 95 from the control valve to pass through the fourth
outlet 97 to the nozzle. In some embodiments, the valve member 112
can have a first position configured to allow a second fuel (such
as NG) to exit the fourth outlet 97 and a second position
configured to block or substantially block a first fuel (such as
LP) from exiting the fourth outlet 97. The valve member 112 can be
biased toward the first position. In some embodiments, connecting a
fitting to the first inlet 12 can move the valve member 112 to the
second position. Because the second inlet 15 can be configured to
receive fittings for the second fuel (such as NG), when the second
inlet receives the second fuel the valve member 112 can be in the
first position.
[0157] Similarly, as illustrated in FIG. 21B, the valve member 114
can direct a fluid flow path from the control valve through the
third inlet 94 to either the second outlet 96 or the third outlet
98. In some embodiments, the second outlet can fluidly connect to
an ODS pilot for the first fuel (such as LP). In some embodiments,
the third outlet can fluidly connect to an ODS pilot for the second
fuel (such as NG). In some embodiments, the valve member 114 can be
configured to be biased toward a first position that allows fluid
that enters through the third inlet 94 to flow through the second
outlet 96, and that blocks or substantially blocks fluid flow
through the third outlet 98. In some embodiments, connecting a
fitting to the second inlet 15 can move the valve member to a
second position that allows fluid that enters through the third
inlet 94 to flow through the third outlet 98, and that blocks or
substantially blocks fluid flow through the second outlet 96.
Because the first inlet can be configured to receive fittings for
the first fuel (such as LP), when the first inlet receives the
first fuel the valve member 114 can be in the first position.
[0158] As above, in some embodiments, an actuation member 22, 24
may have multiple separate movable members. For example, actuation
member 22 is shown with three separate movable members: a first
valve 26, a moveable member 102, and a second valve 112. This
second valve 112 of actuation member 22 is also the third valve of
the system. As a further example, actuation member 24 is shown with
two separate movable members: a first valve 28 and a second valve
114. In the overall system, these valves are also called the second
valve 28 and the fourth valve 114. One benefit of having two or
more independently movable members is that having two or more
separate members can allow each member to properly seat to the
respective valve to prevent leakage; though it will be understood
that one, two, or more members could be used for either the first
actuation member or the second actuation member. It can also be
seen that a number of springs 32 and O-rings 106 can be used to
bias the members to their initial positions and to prevent leakage.
Additionally, different sealing systems can be used. For example,
the fourth valve 114 can move relative to and seal against O-rings
106 to close or substantially close the valve. The third valve 112
can have a sealing section 116 that seats against a respective
ledge to close or substantially close the valve.
[0159] Returning now to FIG. 14, in certain embodiments, a control
valve 130 and/or a heating unit 70, such as a fuel selector valve,
can be positioned to be in fluid communication with the burner 190.
The heating unit 70 and/or control valve 130 can be coupled to the
burner 190 in any suitable manner. As has been discussed, various
pipes or lines (including 124, 124A, 124B) can be used to direct
fuel flow to a nozzle 160 which is then directed to the burner 190.
A burner delivery line 148 can be used to direct fuel flow from the
nozzle(s) to the burner 190. The burner delivery line 148 can be
part of, or separate from, the actual burner 190 and may not be
used in all embodiments. Thus, it will be understood that features
of the burner delivery line can also be features of the burner.
[0160] In some embodiments, the burner delivery line 148 defines an
opening 145A, 145B at a first end thereof through which one or more
of the nozzles 160A, 160B can extend (FIG. 14A). In other
embodiments, the nozzles are not located within the burner delivery
line 148 but are positioned to direct fuel into the burner delivery
line 148. The nozzle(s) can direct fuel to the venturi 146A, 146B
or the throat of the burner, which as shown is constricted to act
like a built-in venturi, and then into the burner itself.
[0161] In some embodiments, such as that shown in FIG. 14, the
burner delivery line 148 defines an air intake, aperture, opening,
or window 155 through which air can flow to mix with fuel dispensed
by the nozzle 160A. An opening 155 can be used to introduce air
into the flow of fuel prior to combustion. The amount of air that
is needed to be introduced depends on the type of fuel used. For
example, propane gas at typical pressures needs more air than
natural gas to produce a flame of the same size. In some
embodiments, the window 155 is adjustably sized. For example, in
some embodiments, a cover as part of an air shutter can be
positioned over the window 155 to adjust the amount of air that can
enter the burner delivery line 148 through the window. The area or
volume inside of the burner delivery line 148 at the window 155
defines a mixing chamber where air and fuel can be mixed.
[0162] Referring now to FIG. 14A, a schematic cross-section view of
a portion of the heater is shown. As shown, in some embodiments, a
burner 190 or burner delivery line 148 can have two separate inlets
145A, 145B. The inlets can be separate and can remain divided along
a portion of the length of the burner or burner delivery line. For
example, the burner delivery line 148 can be divided from the
inlets 145A, 145B until after the venturi 146A, 146B. In some
embodiments, the end of the separation may determine the end of the
venturi. In some embodiments, the first inlet 145A can be part of a
first conduit, and the second inlet 145B can be part of a second
conduit. The first and second conduits can connect to then form a
single conduit, or can both connect to a third conduit. These
conduits can all be part of the burner or burner delivery line.
[0163] As shown, a window 155 can be positioned between the inlet
145A and the venturi 146A. It can also be seen that the other side
does not have a window. In some embodiments, the burner delivery
line 148 can be divided starting from the inlets 145A, 145B until
after the window 155, or until after a set distance from the
window. A first fuel that requires more air (compared to a second
fuel) can be injected into the burner delivery line 148 through
nozzle 160A to pass by the window. The second fuel, that does not
require as much air, can be injected into the burner delivery line
148 through nozzle 160B. In some embodiments, a fuel that does not
require as much air can be injected into the burner through both
nozzles 160A, 160B. Injecting a fuel into both nozzles will result
in a less air rich fuel. It will be understood that the various
factors can be considered to obtain the desired air fuel mixture,
including, but not limited to, nozzle orifice size, window size,
position of the nozzle with respect to the window, position of the
second nozzle with respect to the window, etc.
[0164] As shown, the burner delivery line can be used in a dual
fuel heater without requiring an air shutter, or adjustments to the
window size. This can reduce costs and also prevent user error
associated with adjusting an air shutter.
[0165] As fuel passes the window 155 it will pull air into the
mixing chamber of the burner delivery line 148. As the nozzle 160B
does not have a window positioned close to the nozzle, an air/fuel
mixture will still be created at injection, but it will generally
not be as air rich as it would if it were positioned next to a
window.
[0166] In some embodiments, the first inlet 145A can be positioned
a set distance away from the second inlet 145B. For example, the
set distance can be equal to or greater than the size of the window
155. In some embodiments, the distance from the end of the window
to the venturi can be substantially the same as the distance from
the second inlet to the venturi.
[0167] It will be understood that though the inlets are shown
positioned next to each other, in some embodiments the two inlets
can be more clearly separated, or even completely separated, such
as having one inlet at one end of the burner, and the other at an
opposite end or different part of the burner. In addition, though
the illustration shows one inlet with a window 155 and one without,
in other embodiments, both inlets can have a window, but one window
can be substantially larger than the other, such as 2, 3, 4, or 5
times the size of the first smaller window. It will also be
understood that the window can be any of a number of different
sizes, shapes, and configurations, and may be one or more
windows.
[0168] Referring to FIGS. 14 and 15, operation of the illustrated
heater will be described according to certain embodiments. A user
can connect one of two fuels, such as either natural gas or propane
to the heater. Each fuel hook-up can be set for a certain fuel
type. Connecting the fuel source to the fuel selector valve 70 can
automatically set the fuel selector valve to a position configured
for the particular gas as has been described. If propane is
connected to the natural gas inlet, the pressure sensor 60 can
detect this pressure difference and prevent the control valve from
opening thereby preventing fluid flow to the burner.
[0169] With the proper gas is connected and once the pilot has been
proven, the system can be changed to a heating configuration where
fuel can flow from the control valve to the burner. The control
valve 130 can then control the flow to the pilot (or ODS) 180 and
to the burner 190.
[0170] In the illustrated embodiment, the control valve 130 returns
the pilot fuel flow to the fuel selector valve 70. The setting of
the fuel selector valve 70, based on which fuel hook-up is used,
then determines which pilot nozzle receives the pilot fuel
flow.
[0171] In the illustrated embodiment, the control valve 130 returns
some of the burner fuel flow to the fuel selector valve 70 and some
is directed at the burner nozzle 160A. The setting of the fuel
selector valve 70, based on which fuel hook-up is used, then
determines whether burner nozzle 160B also receives the burner fuel
flow. If the natural gas fuel hook-up is used and natural gas is
flowing in the heater, an internal valve in the fuel selector valve
70 will be open to allow fuel flow to burner nozzle 160B. If the
propane fuel hook-up is used and propane gas is flowing in the
heater, an internal valve in the fuel selector valve 70 will be
closed to prevent fuel flow to burner nozzle 160B. But, with
propane, as with natural gas, fuel can flow from the control valve
130 to the burner nozzle 160A.
[0172] It can be seen that one of the main differences between FIG.
15 and FIG. 16 is how the fuel travels from the control valve to
the burner. In FIG. 16, fuel can travel from the control valve to a
pressure sensitive nozzle which can control how the fuel is
injected to the burner, i.e. the pathway through the nozzle to the
burner.
[0173] In FIG. 15, the control valve directs some of the flow
directly to the burner through a nozzle and some of the flow is
returned to the fuel selector valve 70. This second flow may be
directed to the burner by a second nozzle dependent upon which fuel
inlet is connected to a fuel source. In this way, some of the flow
to the burner travels the second path when the natural gas
connection is made. But, the direct flow to the burner is
independent of whether liquid propane or natural gas is connected.
From this it will be understood that the fuel selector valve of
FIGS. 13-14 includes one addition input and an output for receiving
fuel from the control valve and for directing fuel to a nozzle, as
well as an internal valve to open and close this passageway.
[0174] Turning now to FIGS. 25A-25B, another embodiment of a
pressure switch 60 is illustrated. The pressure switch 60 has a
housing 62 having an inlet 68 to receive fluid to be able to
respond to certain pressures. As shown, the pressure switch 60 is a
normally open pressure switch. The pressure switch 60 can be set to
close when a greater than desired pressure encounters a valve
member 58, such as the illustrated diaphragm 58. A spring 64 can be
used to determine the pressure required to move the diaphragm
58.
[0175] As can be seen, in this pressure switch, rather than control
an electrical connection, the valve member can control a flow path
through the pressure switch between an inlet 61 and an outlet 63. A
valve stem 65 on the valve member 58 can engage a valve seat 67 on
the housing 62 to close the flow path when the pressure of the
fluid entering inlet 68 is at or above a set threshold pressure.
The inlet 68 may also be considered a pressure chamber. Other types
and styles of valve members can also be used. For example, the
diaphragm 58 alone can be used to close the flow path. In addition,
in other embodiments, the pressure switch 60 can be a normally
closed pressure switch that is opened when the pressure in the
inlet or pressure chamber 68 is at or above a set threshold
pressure.
[0176] The pressure switch 60 with flow path control can be used to
control one or more flows of fuel within a heating assembly. For
example, the pressure switch 60 can be in fluid communication with
an inlet on the heating assembly such that the pressure at the
pressure chamber 68 is the delivery pressure of the fluid. As
different types of fuels are generally provided within
distinguishable pressure ranges, as has been discussed, the
pressure switch can be used to distinguish between different types
of fuel. The pressure switch may be used as a safety feature,
similar to other pressure switches and devices discussed herein,
but may also serve other or additional purposes, such as
determining one or more flow paths through the heating
assembly.
[0177] FIGS. 26-29B show an example of a heater 110 having a
pressure switch 60 with flow path control. The heater 110 of FIG.
26 is very similar to the heater shown in FIG. 14. Looking now at
FIG. 27A, the heater 110 is shown in a partially dissembled view.
The illustrated heating source 70 of the heater 110 is the same as
that shown and described with respect to FIGS. 22-24B and FIG. 14.
Thus, the primary difference between the heater 110 and the heater
shown in FIG. 14 is the use of a different pressure switch. In the
embodiment of FIGS. 26-29B, the pressure switch 60 provides flow
path control to the pilot or ODS 180 based on the delivery pressure
of the fuel at one of the inlets.
[0178] FIGS. 27A, 28A and 29A are partially dissembled views of the
heater of FIG. 26 illustrating different flow configurations and
FIGS. 27B, 28B and 29B respectively show a schematic diagram of the
flow configuration of one of FIGS. 27A, 28A and 29A. FIGS. 27A-B
show the flow paths through the heater when a natural gas (NG)
supply is connected to the natural gas input 15. It will be
understood that the illustrated NG and liquid propane (LPG) inputs
and supplies are simply examples of fuels that can be used with the
heater.
[0179] As shown, when NG is connected to the NG inlet 15, the
pressure chamber 68 of the pressure switch 60 is in communication
with the fuel as it is delivered to the heater. Thus, the delivery
pressure of the gas determines the position of the internal valve
member 58. The valve can be configured such that NG delivered
within a standard or typical pressure range does not move the valve
member so that the flow path between the inlet 61 and the outlet 63
is open and fuel can flow through the flow path. The NG ODS or
pilot line 144 has been divided into two segments 144A and 144B
with the pressure switch 60 in-between. In this position, the
pressure switch 60 can determine whether NG fuel can flow to the
pilot or ODS 180. As will be described in more detail below, when
an incorrect fuel is connected to the NG inlet with a higher
delivery pressure, the pressure switch can prevent this gas from
flowing to the pilot 180. Thus, the pilot cannot be proven and fuel
cannot flow to the burner.
[0180] Though the schematic diagram has been drawn slightly
differently from FIG. 15, the other flow paths through the heater
and between the control valve 130, heating source 70, ODS 180, and
nozzle(s) 160 are the same as those previously described.
[0181] FIGS. 28A-B show an LP fuel source connected to the LP inlet
12. The LP inlet 12 is not in communication with the pressure
switch 60, thus, the delivery pressure does not control any of the
flow paths through the heater.
[0182] FIGS. 29A-B show an LP fuel source connected to the NG inlet
15. As shown, when LP is connected to the NG inlet 15, the pressure
chamber 68 of the pressure switch 60 is in communication with the
fuel as it is delivered to the heater. Thus, the delivery pressure
of the gas determines the position of the internal valve member 58.
The valve can be configured such that LP delivered within a
standard or typical pressure range moves the valve member so that
the flow path between the inlet 61 and the outlet 63 is closed and
fuel cannot flow through the flow path. The NG ODS or pilot line
144 has been divided into two segments 144A and 144B with the
pressure switch 60 in-between. In this position, the pressure
switch 60 can determine whether fuel can flow to the pilot or ODS
180. As LP is the incorrect fuel in this instance, because it in is
connected to the incorrect NG inlet and it has a higher delivery
pressure than NG, the pressure switch can prevent LP from flowing
to the pilot 180 in this situation. Thus, the pilot cannot be
proven and LP fuel cannot flow to the burner through incorrect flow
paths. Thus, a user can be prevented from causing a safety hazard
that may result if the wrong fuel where connected to the wrong
inlet or fuel hook-up of the heater.
[0183] Though the pressure switch 60 is shown configured to control
flow through one of the ODS lines, it will be understood that the
pressure switch 60 could also be positioned in other locations to
control other flows. For example, the pressure switch could be used
to control flow to the burner, positioned for example at a point
along the NG gas line 124B. In this way, the pressure switch could
allow the heater to still be used when LP is connected to the NG
inlet, but would only allow flow to the LP burner nozzle.
[0184] In another embodiment, the pressure switch 60 can be used on
a dual fuel heater with a single inlet, such as with a changeable
pressure regulator to a two position pressure regulator. The
pressure switch can include a rocker valve, instead of the on/off
valve and can be used to determine the flow path to the pilot or
ODS. Thus, the pressure switch can have two alternate outlets
instead of a single outlet 63. One outlet can direct fuel to a
first pilot, first pilot nozzle, or first orifice and the second
outlet can direct fuel to a second pilot, second pilot nozzle, or
second orifice. For example the first nozzle pilot can be
configured for NG and the second for LP.
[0185] In addition, the pressure switch 60 with flow control could
be used on a single fuel heater, such as an NG heater. The pressure
switch may be positioned along a flow path directed towards the
pilot, ODS, burner, or control valve, among other features.
[0186] Moving now to FIGS. 30-33B an embodiment of a heating source
70 is shown that incorporates a pressure switch 60 with flow
control into the housing of the heating source. The heating source
can function in a manner similar to those previously described. For
example, the heating source of FIGS. 30-33B can be the same as that
described with respect to FIGS. 22-24B with the addition of the
pressure switch 60. Of course it will be understood that the
pressure switch 60 can also be used with and/or integrated into
other heating sources as well. In addition, other types of pressure
switches may be integrated into the heating source, for example, a
pressure switch with electronic control can be integrated into the
heating source.
[0187] Thus, in some embodiments a fuel source can connect to
either inlet 12 or inlet 15. Selecting the inlet can determine
which pressure regulator 16 will be used as well as selecting
certain flow paths through the heating source 70. From the pressure
regulator, the fuel can exit at outlet 18 to the control valve 130.
The control valve 130 can direct a flow of fuel for the pilot or
ODS to the inlet 94 and a flow of fuel for the burner to the inlet
95. Depending on whether the inlet 12 or the inlet 15 is selected
can determine whether fuel will flow to the burner from outlet 97.
Also, depending on whether the inlet 12 or the inlet 15 is selected
can determine whether the pilot flow will exit outlet 96 or 98.
[0188] If the inlet 15 has been selected, then the delivery
pressure of the fuel and the pressure switch 60 can also determine
whether fuel can flow to the pilot. Looking now at FIGS. 32-33B,
the details of the pressure switch can be seen. In FIG. 32A the
inlet 68 can be seen that allows fluid communication between fuel
at the inlet 15 and the valve 58 of the pressure switch. If the
delivery pressure exceeds a predetermined threshold pressure, the
valve 58 can be moved from a first position to a second position.
In the illustrated embodiment, this can close the flow path between
inlet 61 and outlet 63 as best seen in FIG. 33B. Inlet 61 of the
pressure switch 60 can be connected to the inlet 94 of the heating
source 70 and outlet 63 of the pressure switch 60 can be connected
to the outlet 98 of the heating source 70. A separate valve can be
used to determine whether the inlet 94 is open to the outlet 96 or
the outlet 98 as has been described with respect to previous
embodiments.
[0189] According to some embodiments, a heater assembly can
comprise a burner, a pilot light, a gas hook-up, a control valve
and a pressure switch. The control valve can be configured to
receive a flow of fuel from the gas hook-up and to selectively
direct fuel to the pilot light and the burner. The pressure switch
can be in fluid communication with the gas hook-up and be movable
at a predetermined threshold pressure from a first position to a
second position. The pressure switch can be further configured such
that if a fuel is connected to the gas hook-up that has a delivery
pressure either above or below the predetermined threshold
pressure, the fuel will act on the pressure switch to move it from
the first position to the second position.
[0190] The movement from the first position to the second position
results in a change in the heater assembly. This change can be a
safety feature, such as to prevent the wrong fuel from flowing
through the heater assembly through the wrong flow paths, but may
also provide a control mechanism, such as determining a flow path
through the heater assembly. In some embodiments, the movement of
the pressure switch prevents that the pilot light from being proven
to thereby prevent the fuel from flowing to the burner. This may be
a result of a change in the electrical system or a change in the
flow of fuel through the system.
[0191] In some embodiments, the pressure switch can comprise a
valve member, first and second electrical contacts, and a movable
contact member mechanically connected to the valve member and
movable therewith. The movable contact member can be configured for
electrical connection to the first and second electrical contacts
when in a first engaged position and having a second disengaged
position configured to create an open circuit. The electrical
contacts can be used with a thermocouple, igniter, printed circuit
board, and/or control valve, among other features. For example, in
some embodiments, the movable contact member of the pressure switch
is in the second disengaged position when the delivery pressure is
above a predetermined threshold pressure to create an open circuit
between the thermocouple and the control valve such that the
control valve cannot flow fuel to the burner.
[0192] In some embodiments, the pressure switch can be used to
control whether an electric signal can flow to the igniter. In
still other embodiments, the pressure switch comprises a valve
member positioned within a flow channel and movement of the
pressure switch either opens or closes the flow channel. The
pressure switch can allow or prevent flow to the pilot or to the
burner in some embodiments.
[0193] According to some embodiments, a heater assembly can
comprise a pilot light, a burner, a first gas hook-up, a control
valve configured to receive a flow of fuel from the first gas
hook-up and to selectively direct fuel to the pilot light and the
burner, and a pressure switch in fluid communication with the first
gas hook-up. The pressure switch can comprise a valve member
movable at a predetermined threshold pressure, first and second
electrical contacts, and a movable contact member mechanically
connected to the valve member and movable therewith. The movable
contact member can be configured for electrical connection to the
first and second electrical contacts when in a first engaged
position and have a second disengaged position configured to create
an open circuit. The pressure switch can be configured such that if
a fuel is connected to the first gas hook-up that has a delivery
pressure either above the predetermined threshold pressure in one
situation, or below the predetermined threshold pressure in another
situation, the fuel will act on the pressure switch to move the
movable contact member from one of the first or second positions to
the other position such that the pilot light cannot be proven to
thereby prevent the fuel from flowing to the burner.
[0194] The contact member can contact two electrical connection
members which can be electrically connected to a printed circuit
board, igniter, igniter switch, control valve and/or thermocouple,
among other features.
[0195] In some embodiments, a heater assembly can comprise a
housing comprising: a first gas hook-up, a first pressure
regulator, a first flow path extending between the first gas
hook-up and the pressure regulator, a second flow path, and a
pressure switch in fluid communication with the first gas hook-up
upstream from the first pressure regulator. The pressure switch can
be movable from a first position to a second position when a
delivery pressure of a fuel at the first gas hook-up is within a
predetermined delivery pressure range. The pressure switch can be
configured such that if the fuel connected to the first gas hook-up
has a delivery pressure within the predetermined delivery pressure
range, the fuel will act on the pressure switch to move it from the
first position to the second position which movement opens or
closes the second flow path through the housing.
[0196] Although this invention has been disclosed in the context of
certain preferred embodiments and examples, it will be understood
by those skilled in the art that the present invention extends
beyond the specifically disclosed embodiments to other alternative
embodiments and/or uses of the invention and obvious modifications
and equivalents thereof. In addition, while a number of variations
of the invention have been shown and described in detail, other
modifications, which are within the scope of this invention, will
be readily apparent to those of skill in the art based upon this
disclosure. It is also contemplated that various combinations or
sub-combinations of the specific features and aspects of the
embodiments may be made and still fall within the scope of the
invention. Accordingly, it should be understood that various
features and aspects of the disclosed embodiments can be combined
with or substituted for one another in order to form varying modes
of the disclosed invention. Thus, it is intended that the scope of
the present invention herein disclosed should not be limited by the
particular disclosed embodiments described above, but should be
determined only by a fair reading of the claims that follow.
[0197] Similarly, this method of disclosure, is not to be
interpreted as reflecting an intention that any claim require more
features than are expressly recited in that claim. Rather, as the
following claims reflect, inventive aspects lie in a combination of
fewer than all features of any single foregoing disclosed
embodiment. Thus, the claims following the Detailed Description are
hereby expressly incorporated into this Detailed Description, with
each claim standing on its own as a separate embodiment.
* * * * *