U.S. patent application number 13/337466 was filed with the patent office on 2012-04-19 for thermocouple shutoff for portable heater.
This patent application is currently assigned to ENERCO GROUP, INC.. Invention is credited to Brian S. Vandrak.
Application Number | 20120094244 13/337466 |
Document ID | / |
Family ID | 43605641 |
Filed Date | 2012-04-19 |
United States Patent
Application |
20120094244 |
Kind Code |
A1 |
Vandrak; Brian S. |
April 19, 2012 |
THERMOCOUPLE SHUTOFF FOR PORTABLE HEATER
Abstract
Provided is an assembly comprising a combustion-powered heater,
a target component, and a transducer operatively engaged with said
target component. A combustion-powered heater may comprise a
combustion site adapted to power said heater. A target component
may be engaged with the combustion site. A transducer may be
adapted to measure the temperature of the target component and
adapted to shut-down said combustion-powered heater in response to
a temperature measurement of less than a temperature limit.
Inventors: |
Vandrak; Brian S.; (Highland
Heights, OH) |
Assignee: |
ENERCO GROUP, INC.
Cleveland
OH
|
Family ID: |
43605641 |
Appl. No.: |
13/337466 |
Filed: |
December 27, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12544433 |
Aug 20, 2009 |
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13337466 |
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Current U.S.
Class: |
432/1 ;
126/85R |
Current CPC
Class: |
F23N 5/10 20130101; F24H
3/006 20130101; F24H 9/2085 20130101; F24H 2240/00 20130101; F23N
5/24 20130101 |
Class at
Publication: |
432/1 ;
126/85.R |
International
Class: |
F24C 3/00 20060101
F24C003/00 |
Claims
1. An assembly comprising: a combustion-powered heater comprising a
combustion site adapted to power said heater; a target component
engaged with said combustion site; and a transducer operatively
engaged with said target component, said transducer, adapted to
measure the temperature of the target component, and adapted to
shut-down said combustion-powered heater in response to a
temperature measurement of less than a temperature limit.
2. The assembly of claim 1, wherein said heater is portable.
3. The assembly of claim 2, wherein said heater is adapted to
consume oxygen from air and propane fuel.
4. The assembly of claim 3, wherein said target component comprises
a burner output modifier.
5. The assembly of claim 4, wherein said operative engagement of
the transducer with said burner output modifier comprises embedding
said transducer within said burner output modifier.
6. The assembly of claim 5, wherein said burner output modifier
comprises a radiant surface.
7. The assembly of claim 6, wherein said transducer comprises at
least one thermocouple.
8. The assembly of claim 7, wherein said adaptation to shut-down
said combustion-powered heater is an adaptation wherein said
thermocouple ceases holding open a normally-closed valve.
9. The assembly of claim 8, wherein the temperature of the radiant
surface is adapted to be less than the temperature limit during
operation of the heater in an atmosphere comprising less than 18%
oxygen by volume.
10. A method of selectively shutting off a combustion-powered
portable heater, comprising: providing a combustion-powered heater,
said heater comprising a combustion site adapted to power said
heater when in operation; engaging a target component with said
combustion site in such a manner that said combustion site heats
said target component when in operation; and operatively engaging a
transducer with said target component, said transducer, adapted to
measure the temperature of the target component, and adapted to
shut-down said combustion-powered heater in response to a
temperature measurement of less than a temperature limit.
11. The method of claim 10, wherein said heater is portable.
12. The method of claim 11, wherein said heater is adapted to
consume oxygen from air and propane fuel.
13. The method of claim 12, wherein said target component comprises
a burner output modifier.
14. The method of claim 13, wherein said operatively engaging a
transducer with said burner output modifier comprises embedding
said transducer within said burner output modifier.
15. The method of claim 14, wherein said burner output modifier
comprises a radiant surface.
16. The method of claim 15, wherein said transducer comprises at
least one thermocouple.
17. The method of claim 16, wherein said adaptation to shut-down
said combustion-powered heater is an adaptation wherein said
thermocouple ceases holding open a normally-closed valve.
18. The method of claim 17, wherein said thermocouple ceases
holding open a normally-closed valve during operation of said
heater in an atmosphere comprising less than 18% oxygen by
volume.
19. An assembly comprising: a portable, combustion-powered heater
comprising a combustion site adapted to power said heater, said
heater adapted to consume oxygen from air and propane fuel; a
radiant surface engaged with said combustion site; and at least one
thermocouple embedded within said radiant surface, said at least
one thermocouple, adapted to measure the temperature of the radiant
surface, and adapted to cease holding open a normally-closed valve
to shut-down said combustion-powered heater in response to a
temperature measurement of less than a temperature limit.
20. The assembly of claim 19, wherein the temperature of the
radiant surface is adapted to be less than the temperature limit
during operation of the heater in an atmosphere comprising less
than 18% oxygen by volume.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/544,433, filed Aug. 20, 2009. The following
application is incorporated by reference, in its entirety:
International Application No. PCT/US2007/007426, filed Mar. 26,
2007, titled "Gas-Fired Portable Unvented Infrared Heater", which
PCT application claimed priority to U.S. Provisional Application
No. 60/743,757, filed Mar. 24, 2006.
TECHNICAL FIELD
[0002] Provided is a device for shut-off of a portable heater. More
particularly, provided is device to shut down a portable heater in
response to certain atmospheric conditions.
BACKGROUND
[0003] Combustion-powered heaters combust reactants to yield heat
and reaction products. Combustion-powered heaters consume a fuel
and an oxidant and react the fuel and oxidant to yield heat and one
or more combustion products. Some combustion-powered heaters modify
the composition of the local atmosphere by uptake of one or more
reactants from the local atmosphere or release of one or more
combustion products into the local atmosphere or both.
[0004] In some combustion-powered heaters, the combustion process
consumes oxygen from the local atmosphere as a combustion reactant.
The consumption of oxygen by a combustion-powered heater can modify
the composition of the local atmosphere by reducing the local
oxygen amounts. In some amounts, reduced local oxygen may be
undesirable. It remains desirable to develop technology to detect
and address atmospheric conditions such as undesirable amounts of
local oxygen.
[0005] Some combustion-powered heaters release of one or more
combustion products into the local atmosphere. The combustion
products may comprise, but are not limited to, carbon dioxide,
carbon monoxide, and nitrogen oxides. The release of combustion
products can modify the composition of the local atmosphere by
increasing the amounts of combustion products therein. In some
amounts, the presence of one or more combustion products may be
undesirable. It remains desirable to develop technology to detect
and address atmospheric conditions such as undesirable amounts of
combustion products in the local atmosphere.
SUMMARY
[0006] Provided is an assembly comprising a combustion-powered
heater, a target component, and a transducer operatively engaged
with said target component. A combustion-powered heater may
comprise a combustion site adapted to power said heater. A target
component may be engaged with the combustion site. A transducer may
be adapted to measure the temperature of the target component and
adapted to shut-down said combustion-powered heater in response to
a temperature measurement of less than a temperature limit.
[0007] Further provided is a method of selectively shutting off a
combustion-powered portable heater. The method may comprise
providing a combustion-powered heater. The heater may comprise a
combustion site adapted to power said heater when in operation. The
method may further comprise engaging a target component with said
combustion site in such a manner that said combustion site heats
said target component when in operation. The method may further
comprise operatively engaging a transducer with said target
component. The transducer may be adapted to measure the temperature
of the target component, and adapted to shut-down said
combustion-powered heater in response to a temperature measurement
of less than a temperature limit.
[0008] Further provided is an assembly comprising a portable,
combustion-powered heater, a radiant surface, and at least one
thermocouple. The heater may comprise a combustion site adapted to
power said heater. The heater may be adapted to consume oxygen from
air and propane fuel. The radiant surface may be engaged with the
combustion site. The thermocouple may be embedded within the
radiant surface. The thermocouple may be adapted to measure the
temperature of the radiant surface. The thermocouple may be adapted
to cease holding open a normally-closed valve to shut-down said
combustion-powered heater in response to a temperature measurement
of less than a temperature limit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present subject matter may take physical form in certain
parts and arrangement of parts, embodiments of which will be
described in detail in this specification and illustrated in the
accompanying drawings which form a part hereof, and wherein:
[0010] FIG. 1 is a perspective cross-sectional view of one
embodiment of a heater assembly;
[0011] FIG. 2 is a longitudinal cross-sectional view of one
embodiment of a heater assembly;
[0012] FIG. 3 is sectional view of one embodiment of a heater
assembly;
[0013] FIG. 4 is detail view of one embodiment of a transducer in a
heater assembly.
DETAILED DESCRIPTION
[0014] Reference will be made to the drawings, FIGS. 1-4, wherein
the showings are only for purposes of illustrating certain
embodiments of a thermocouple shutoff for portable heater, and not
for purposes of limiting the same. Specific characteristics
relating to the embodiments disclosed herein are not to be
considered as limiting, unless the claims expressly state
otherwise.
[0015] Portable heaters may be combustion-powered.
Combustion-powered portable heaters 100 are adapted to react fuel,
and an oxidant at a combustion site. A combustion site may be any
region adapted for conducting a combustion reaction. Without
limitation, a combustion site may comprise a burner, or a catalytic
surface.
[0016] A burner is a device adapted to generate a flame by
combustion. In operation, a burner accepts a fuel and an oxidant,
combusts the fuel and the oxidant, and outputs heat and a
combustion product.
[0017] In some embodiments, a burner may be operatively associated
with components adapted to modify the output from the burner.
Without limitation, a burner output modifier may be adapted to
affect the efficiency of the heater, may be adapted to affect the
rate of heat output, may be adapted to separate a flow of heat from
a flow of combustion products, or may be adapted to focus or
disperse a flow of heat. Without limitation, a burner output
modifier may include a heat reflector, a heat concentrator, a heat
diffuser, a chimney, a heat exchanger, a regenerator, or a radiant
surface.
[0018] In some embodiments, a burner may produce a naked flame
exposed to the environment. Without limitation, a heater comprising
a burner adapted to produce a naked flame exposed to the
environment will be referred to herein as a blue flame heater
unless otherwise noted. In some embodiments a burner may be
operatively engaged with a radiant surface adapted to shield the
flame from the environment. Without limitation, a radiant heater is
one embodiment of heater comprising a burner operatively engaged
with a radiant surface adapted to shield the flame from the
environment.
[0019] A catalytic surface is a combustion site adapted so that a
fuel and an oxidant may react thereupon in catalyzed reaction to
yield heat and a combustion product. Without limitation, the
material of the catalytic surface may act as a catalyst in a
catalyzed combustion reaction at the combustion site. Without
limitation, a catalyst in a combustion reaction may catalyze the
combustion reaction by speeding up the reaction, slowing down the
reaction, lowering the ignition energy needed to initiate the
combustion reaction, promoting more complete combustion, promoting
cleaner combustion, reducing or eliminating certain combustion
products, or increasing operating efficiency.
[0020] Without limitation, some catalytic surfaces comprise a
catalyst supported by a substrate. In certain embodiments a
catalyst may comprise ruthenium, rhodium, palladium, osmium,
iridium, platinum, and mixtures thereof. Substrates may comprise a
glass fiber, a porous metal, a ceramic, or a mixture thereof.
[0021] Without limitation, some fuels that a combustion site may
react comprise, methane, ethane, propane, butane, pentane, other
alkanes, alkenes, alkynes, kerosene, LP gas, wood gas, other gas
mixtures, oil, hydrogen, or mixtures thereof. Without limitation,
some oxidants that a combustion site may react comprise oxygen, gas
mixtures comprising oxygen, nitrous oxide, or mixtures thereof.
Without limitation, air is a gas mixture comprising oxygen that may
be used as an oxidant.
[0022] FIG. 1 shows a combustion-powered portable heater 100.
Without limitation, the cross-sectional view also shows a device 80
adapted to shut off a combustion-powered portable heater 100.
[0023] FIG. 2 shows a combustion-powered portable heater 100.
Without limitations, the cross-sectional view also shows a device
80 adapted to shut off a combustion-powered portable heater
100.
[0024] FIG. 3 shows a combustion-powered heater 10. Without
limitation, the sectional view shows a fuel control valve 20
adapted to selectively permit fuel flow to a combustion site 40.
During operation of heater 10, air flows into heater 10 from the
atmosphere 90. In the non-limiting embodiment showing in FIG. 3,
the heater 10 comprises intake apertures 80 to admit air into the
heater 10. During operation, air and fuel undergo a combustion
reaction at combustion site 40 to produce heat and combustion
products. The non-limiting embodiment of a combustion site 40 shown
in FIG. 3 is a burner 41. By contrast, in other non-limiting
embodiments, combustion site 40 may comprise a catalytic surface.
Burner 41 comprises an inlet (not shown) for accepting air. The
non-limiting embodiment shown in FIGS. 3 and 4 also comprises a
burner output modifier 60. Without limitation, burner output
modifier 60 comprises a radiant surface 61. Without limitation, the
combustion-powered heater 10 shown in FIGS. 3 and 4 also comprises
a transducer 50 in engagement with a component of heater 10. The
transducer 50 is adapted to detect the temperature of components
with which it is engaged. In the non-limiting embodiment shown in
FIG. 3, the transducer 50 comprises at least one thermocouple 51,
engaged with, and adapted to detect the temperature of, radiant
surface 61.
[0025] In certain embodiments, the composition of the atmosphere
can substantially affect the combustion reaction during operation.
"Good air" is a description of air quality. Good air is air from an
atmosphere that has not been modified to contain an defined reduced
oxygen content or to contain a defined amount of combustion
products. The defined reduced oxygen content and the defined amount
of combustion products are quantities that may be determined based
on engineering judgment. In certain embodiments, during operations
in good air, the combustion reaction may be substantially complete.
In certain embodiments, during operations in good air, the
combustion reaction will produce heat at some rate for a given fuel
consumption rate. "Bad air" is another description of air quality.
Bad air is air from an atmosphere that has been modified to contain
a defined reduced oxygen content or to contain a defined amount of
combustion products. In certain embodiments, during operations in
bad air, the combustion reaction may be substantially incomplete.
In certain embodiments, during operations in bad air the combustion
reaction will produce heat at some rate for a given fuel
consumption rate; wherein said rate of heat production in bad air
is substantially less than the rate of heat production in good air
for the same fuel consumption rate.
[0026] In some embodiments, because of predictable differences
between the rate of heat produced by combustion in good air and the
amount of heat produced by combustion in bad air, a transducer 50
sensitive to temperature may be used to detect changes in
combustion related to changes local air quality and, thereby, used
as a detector of atmospheric quality in terms of good air versus
bad air. Such temperature detection may be performed by sensing of
the temperature at the combustion site, or by sensing temperature
of materials or components engaged with the combustion site 40.
That is, a transducer 50 may be used to discriminate between heater
operations within good air and burner or heater operations within
bad air by measuring the temperature of heater components heated by
heat produced at a combustion site 40.
[0027] Without limitation a transducer 50 may be electrical or
mechanical. A transducer 50 may comprise at least one thermocouple
51, a thermoelectric material, a thermostat, a bi-metallic strip,
or a pyrometer.
[0028] In some embodiments, and without limitation, operating
temperature data of components or materials of the heater 10, can
be used to determine air quality. In certain embodiments, operating
temperature data of components other than those components in a
combustion site 40 can be used to determine air quality. In some
embodiments, a transducer 50 is used to take operating temperature
data of components of the heater 10 or to acquire a signal
representative of operating temperature data of components of the
heater 10. Components of the heater 10 from which a transducer 50
is used to take operating temperature data or to acquire a signal
representative of operating temperature data are target components
62. Target components 62 may include a burner output modifier 60, a
radiant surface 61, or any other component of the heater 10 or
material within the heater 10 other than a combustion site 40, a
burner 41, a catalytic surface (not shown), or a flame (not
shown).
[0029] In certain embodiments, operation of a combustion-powered
heater 10 in good air may result in an operating temperature of
target components or materials 62 at or above some predetermined
temperature. Without limitation, in certain embodiments, operation
of a combustion-powered heater in bad air may result in an
operating temperature of the target components or materials 62
below some predetermined temperature.
[0030] In certain embodiments, a transducer 50 comprises at least
one thermocouple 51. During operation in good air, the combustion
site 40 produces heat sufficient to heat a target component or
material 62 to a temperature high enough to produce an output
signal consistent with good air from at least one thermocouple 51.
During operation in bad air, the combustion site 40 does not
produce heat sufficient to heat a target component or material 62
to a temperature high enough to produce an output signal consistent
with good air from at least one thermocouple 51.
[0031] In certain embodiments, failure of at least one transducer
50 or thermocouple 51 to produce an output signal consistent with
good air will trigger an alarm or will trigger actions to stop
operations at combustion site 40 or heater 10. In certain
embodiments, actions to stop operations at combustion site 40
includes shut off of the valve 20 to interrupt fuel flow necessary
to continuing operations at combustion site 40.
[0032] In certain embodiments, the heat from combustion site 40 may
affect objects and materials in contact engaged with combustion
site 40. In certain embodiments, heat from combustion site 40 will
propagate through components and materials from areas proximate to
or in contact with combustion site 40 to areas more distal from
combustion site 40.
EXPERIMENT
[0033] As shown in TABLE 1, nine experiments were performed on
heater embodiments similar to those shown in FIGS. 3-4. In each
experiment at least one thermocouple 51 was engaged with, and
provided a potential substantially proportionate to the temperature
of, a radiant surface 61. In each experiment, the cut-off potential
in the thermocouple in millivolts was established as "TC mV @
Cut-Off". A potential in the thermocouple of the cut-off potential
or less would fail to hold open a fuel control valve 20 and would
allow the fuel control valve 20 to close, thereby cutting off fuel
to the combustion site 40 and shutting down the heater 10. In each
experiment the heater 10 was started and the initial potential in
the thermocouple 51 in millivolts was recorded as "Starting
Thermocouple (mV)". The heater 10 was then isolated from the
greater atmosphere by sealing it in a small, substantially
air-tight, enclosure with a small amount of air. In each
experiment, the percentage of oxygen in the air in the enclosure
was monitored. Over time, the percentage of oxygen in the air in
the enclosure diminished. Over time, the potential in the
thermocouple 51 in millivolts diminished. In each experiment, the
heater 10 was allowed to operate until the potential in the
thermocouple 51 in millivolts diminished to the cut-off potential
and the heater 10 shut down. In each experiment, the percentage of
oxygen in the air in the enclosure when the heater 10 shut down was
recorded as "% O2 Cut-Off".
[0034] Without wishing to be bound to any particular theory, the
data in TABLE 1 is consistent with the conclusion that heat
produced at a combustion site 40 is a function of the air quality
of the atmosphere 90. The operating temperature data of the
components of the heater 10 with which thermocouple 51 was engaged
produced an output potential consistent with the components
dropping in temperature as the air quality in the enclosure
decreased. The data is consistent with a finding that the potential
in thermocouple 51 is a function of air quality. The results of the
experiments are shown in TABLE 1 below.
TABLE-US-00001 TABLE 1 Starting Test Thermocouple % O2 TC mV @
Number (mV) Cut-Off Cut-Off 1 20.0 17.88 7.50 2 20.0 17.89 8.00 3
21.0 17.85 8.00 4 20.0 18.00 7.00 5 20.0 17.82 7.50 6 20.0 17.89
7.50 7 20.5 17.99 7.00 8 20.5 17.89 7.00 9 20.0 18.00 8.00
[0035] While the thermocouple shutoff for a portable heater has
been described above in connection with the certain embodiments, it
is to be understood that other embodiments may be used or
modifications and additions may be made to the described
embodiments for performing the same function of the thermocouple
shutoff for a portable heater without deviating therefrom. Further,
the thermocouple shutoff for a portable heater may include
embodiments disclosed but not described in exacting detail.
Further, all embodiments disclosed are not necessarily in the
alternative, as various embodiments may be combined to provide the
desired characteristics. Variations can be made by one having
ordinary skill in the art without departing from the spirit and
scope of the thermocouple shutoff for a portable heater. Therefore,
the thermocouple shutoff for a portable heater should not be
limited to any single embodiment, but rather construed in breadth
and scope in accordance with the recitation of the attached
claims.
* * * * *