U.S. patent application number 13/556494 was filed with the patent office on 2013-01-10 for forced air heater including on-board source of electric energy.
This patent application is currently assigned to ENERCO GROUP, INC.. Invention is credited to Jeff Bush, Nathan Noble, Brian S. Vandrak.
Application Number | 20130008423 13/556494 |
Document ID | / |
Family ID | 47437886 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130008423 |
Kind Code |
A1 |
Noble; Nathan ; et
al. |
January 10, 2013 |
FORCED AIR HEATER INCLUDING ON-BOARD SOURCE OF ELECTRIC ENERGY
Abstract
A forced-air heater having a self-contained on-board
electric-power supply, a fuel tank, a support, a housing, a
combustion chamber, and a motorized fan. The self-contained
on-board electric-power supply may have a generator, a photovoltaic
component, or some combination thereof. The fuel tank may be
adapted to store a first fuel. The combustion chamber may be
adapted to generate heat by combusting the first fuel with air. The
motorized fan may be adapted to draw in ambient air through an air
intake and force the air into the combustion chamber.
Inventors: |
Noble; Nathan; (Morgantown,
KY) ; Vandrak; Brian S.; (Highland Heights, OH)
; Bush; Jeff; (Chagrin Falls, OH) |
Assignee: |
ENERCO GROUP, INC.
Cleveland
OH
|
Family ID: |
47437886 |
Appl. No.: |
13/556494 |
Filed: |
July 24, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13182713 |
Jul 14, 2011 |
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13556494 |
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11954704 |
Dec 12, 2007 |
8068724 |
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13182713 |
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60874427 |
Dec 12, 2006 |
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Current U.S.
Class: |
126/116C ;
126/99A; 432/222; 432/29 |
Current CPC
Class: |
F24H 2240/09 20130101;
Y02B 30/00 20130101; F24H 9/0094 20130101; Y02B 30/28 20130101;
F24H 9/2085 20130101; F24H 3/0488 20130101 |
Class at
Publication: |
126/116.C ;
126/99.A; 432/222; 432/29 |
International
Class: |
F24H 3/04 20060101
F24H003/04; F24H 9/20 20060101 F24H009/20 |
Claims
1. A forced-air heater comprising: a self-contained on-board
electric-power supply comprising, a generator, a photovoltaic
component, or some combination thereof; a fuel tank adapted to
store a first fuel; a support; a housing; a combustion chamber
adapted to generate heat by combusting the first fuel with air; and
a motorized fan adapted to operate to, draw in ambient air through
an air intake, and force the air into the combustion chamber.
2. The forced-air heater of claim 1, wherein said self-contained
on-board electric-power supply comprises a photovoltaic
component.
3. The forced-air heater of claim 2, further comprising a
battery.
4. The forced-air heater of claim 3, wherein the battery is a
lithium ion battery or a sealed lead-acid battery.
5. The forced-air heater of claim 1, wherein said self-contained
on-board electric-power supply comprises a generator.
6. The forced-air heater of claim 5, further comprising an engine
operationally engaged with the generator.
7. The forced-air heater of claim 6, wherein the engine is an
external combustion engine.
8. The forced-air heater of claim 7, wherein the engine is adapted
to generate work from the heat.
9. The forced-air heater of claim 6, wherein the engine is an
internal combustion engine.
10. The forced-air heater of claim 9, wherein the engine is adapted
to generate work from combustion of a second fuel.
11. The forced-air heater of claim 10, wherein said second fuel is
a fuel oil, kerosene, gasoline, propane, natural gas, or
alcohol.
12. The forced-air heater of claim 11, wherein said second fuel is
a different fuel from said first fuel.
13. The forced-air heater of claim 10, wherein said second fuel is
a fuel oil, kerosene, gasoline, or alcohol.
14. The forced-air heater of claim 13, wherein said second fuel is
the same fuel as said first fuel.
15. A method for producing heat, comprising providing a forced-air
heater, said forced-air heater comprising: a self-contained
on-board electric-power supply comprising, a generator, a
photovoltaic component, or some combination thereof; a fuel tank
adapted to store a first fuel; a support; a housing; a combustion
chamber adapted to generate heat by combusting the first fuel with
air, a motorized fan adapted to operate to, draw in ambient air
through an air intake, and force the air into the combustion
chamber; generating electric power from said self-contained
on-board electric-power supply; and directing a majority of said
generated electric power to an electric load component or external
electric load accessory other than a resistive heating element.
16. The method of claim 15, wherein said self-contained on-board
electric-power supply comprises a photovoltaic component.
17. The method of claim 15, wherein said self-contained on-board
electric-power supply comprises a generator.
18. The method of claim 17, further comprising an engine
operationally engaged with the generator.
19. The method of claim 18, wherein the engine is an internal
combustion engine adapted to generate work from combustion of a
second fuel different fuel from said first fuel.
20. A forced-air heater comprising: a self-contained on-board
electric-power supply comprising a generator; a fuel tank adapted
to store a first fuel, said first fuel comprising fuel oil,
kerosene, gasoline, or alcohol; a support; a housing; a battery
comprising a lithium ion battery, or a sealed lead-acid battery; an
engine operationally engaged with the generator, said engine being
an internal combustion engine adapted to generate work from
combustion of a second fuel other than the first fuel; a combustion
chamber adapted to generate heat by combusting the first fuel with
air; a motorized fan adapted to operate to, draw in ambient air
through an air intake, and force air into the combustion chamber.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S.
application Ser. No. 13/182,713, filed Jul. 14, 2011, which claims
the benefit of and is a continuation of U.S. application Ser. No.
11/954,704, filed Dec. 12, 2007, which has issued as U.S. Pat. No.
8,068,724, and which claims the benefit of U.S. Provisional
Application No. 60/874,427, filed Dec. 12, 2006. All of the subject
matter disclosed by U.S. Ser. No. 60/874,427 is hereby incorporated
by reference into this application. All of the subject matter
disclosed by U.S. Ser. No. 11/954,704 is hereby incorporated by
reference into this application. All of the subject matter
disclosed by U.S. Ser. No. 13/182,713 is hereby incorporated by
reference into this application.
BACKGROUND
[0002] This matter relates generally to portable forced-air
heaters, and more particularly to portable forced-air heaters that
derive at least a portion of their electric energy required for
operation of the heaters, or an accessory thereof, from an on board
source.
[0003] Fuel-fired portable heaters such as forced-air heaters find
use in multiple environments. The heater typically includes a
cylindrical housing with a combustion chamber disposed coaxially
therein. A combustible liquid fuel from a fuel tank is atomized and
mixed with air inside the combustion chamber where it is combusted,
resulting in the generation of a flame. During combustion of the
air/fuel mixture a fan blade is rotated by an electric motor to
draw ambient air into the heater to be heated by the combustion of
the air/fuel mixture. The heated air is expelled out of the heater
by the continuous influx of air caused by the fan.
[0004] Traditionally, forced-air heaters have required a source of
electric energy to energize the motor that rotates the fan blade
and optionally to operate an ignition source that triggers
combustion of the air/fuel mixture. The fan is often a heavy-duty,
high output fan that consumes significant amounts of electric
energy during operation thereof, and operation of the igniter
consumes even more electric energy. The demand for electric energy
created by operation of the fan and other electric components of
forced-air heaters has required such heaters to be plugged into a
conventional wall outlet supplying alternating current ("AC")
electric energy generated by a public utility. In remote
environments a lengthy extension cord can establish a conductive
pathway for the electric energy between a wall outlet and the
location of the forced-air heater. However, at locations where a
new structure is being built a conventional wall outlet is
typically not available, requiring the use of a portable generator
to supply the electric energy until utility-generated electric
energy becomes available.
[0005] As previously mentioned, forced-air heaters are often
utilized to provide heat to new construction environments for
significant periods of time that can extend well into the night.
After dusk, illumination of the environment in the vicinity of the
forced-air heater is required to enable workers to view their
worksite and avoid potentially hazardous conditions. Assuming that
a conventional wall outlet is available, an extension cord can be
used to conduct electric energy from the wall outlet to an on-site
light stand. However, the light stand adds to the equipment that
must be transported to a jobsite, and a conventional wall outlet is
usually not available during the initial stages of a new
construction.
[0006] Even in instances when a conventional wall outlet is
available, there are normally a limited number of electric devices
that can be powered by the outlet at any given time. Using adaptors
to increase the number of available outlets into which an
electrical device can be plugged can lead to excessive currents
being drawn through an extension cord or other adaptor. Thus, there
are a limited number of electrical devices that can be
simultaneously powered on a new construction jobsite at any given
time. This limitation is even greater when a wall outlet supplying
utility-generated electricity is unavailable.
[0007] Forced-air heaters are also relatively bulky, and occupy a
significant amount of storage space while not in use. Attempts to
store such a heater in an alternative orientation other than its
intended operational orientation in which the heater is designed to
be fired in order to conserve storage space results in the liquid
fuel leaking out of the heater. And although the fuel can be
drained from the heater before storing it in an alternative
orientation to minimize the leakage of fuel, such an option is time
consuming, and is impractical for temporary storage on a daily
basis.
[0008] Accordingly, there remains a need in the art for a forced
air heater that is operational in a remote environment in the
absence of a conventional wall outlet or other external supply of
electric energy.
SUMMARY
[0009] Provided is a forced-air heater having a self-contained
on-board electric-power supply, a fuel tank, a support, a housing,
a combustion chamber, and a motorized fan. The self-contained
on-board electric-power supply may have a generator, a photovoltaic
component, or some combination thereof. The fuel tank may be
adapted to store a first fuel. The combustion chamber may be
adapted to generate heat by combusting the first fuel with air. The
motorized fan may be adapted to draw in ambient air through an air
intake and force the air into the combustion chamber.
[0010] Also provided is a method for producing heat including
providing a forced-air heater, generating electric power from the
self-contained on-board electric-power supply, and directing a
majority of the generated electric power to an electric load
component or external electric load accessory other than a
resistive heating element. The forced-air heater may have a
self-contained on-board electric-power supply, a fuel tank adapted
to store a first fuel, a support, a housing, a combustion chamber
adapted to generate heat by combusting the first fuel with air, and
a motorized fan adapted to operate to draw in ambient air through
an air intake, and force the air into the combustion chamber.
[0011] Also provided is a forced-air heater having a self-contained
on-board electric-power supply having a generator, a fuel tank
adapted to store a first fuel, said first fuel comprising fuel oil,
kerosene, gasoline, or alcohol, a support, a housing, a battery
having a lithium ion battery or a sealed lead-acid battery, an
engine operationally engaged with the generator, a combustion
chamber adapted to generate heat by combusting the first fuel with
air, and a motorized fan adapted to operate to draw in ambient air
through an air intake and force air into the combustion chamber.
The engine may be an internal combustion engine adapted to generate
work from combustion of a second fuel other than the first
fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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:
[0013] FIG. 1 is a perspective view of a forced-air heater
including an outlet and a light exposed to an exterior of the
forced-air heater in accordance with an embodiment of the present
subject matter;
[0014] FIG. 2 is a perspective view of a forced-air heater
including an outlet and a light exposed to an exterior of the
forced-air heater in accordance with an embodiment of the present
subject matter;
[0015] FIG. 3 is a cutaway view of a forced-air heater in
accordance with an embodiment of the present subject matter;
[0016] FIG. 3A is a cutaway view of a forced-air heater in
accordance with an embodiment of the present subject matter;
[0017] FIG. 3B is a cutaway view of a forced-air heater in
accordance with an embodiment of the present subject matter;
[0018] FIG. 4 is a cutaway view of a battery that can optionally be
utilized as a power source for a forced-air heater in accordance
with the present subject matter;
[0019] FIG. 5 is a view of a forced-air heater in an orientation in
which it is to be fired according to an embodiment of the present
subject matter;
[0020] FIG. 6 is a view of a forced-air heater in an orientation in
which it can optionally be transported with minimal leakage of a
liquid fuel from the heater's fuel tank according to an embodiment
of the present subject matter;
[0021] FIG. 7 is a view of a forced-air heater in a
substantially-vertical orientation in which it can optionally be
stored with minimal leakage of a liquid fuel from the heater's fuel
tank according to an embodiment of the present subject matter;
and
[0022] FIG. 8 is a cutaway view of a fuel management system that
can optionally be provided to a forced-air heater according to an
embodiment of the present subject matter.
DETAILED DESCRIPTION
[0023] Certain terminology is used herein for convenience only and
is not to be taken as a limitation on the present subject matter.
Relative language used herein is best understood with reference to
the drawings, in which like numerals are used to identify like or
similar items. Further, in the drawings, certain features may be
shown in somewhat schematic form.
[0024] FIGS. 1 and 2 show illustrative embodiments of a forced-air
heater 1, which generally includes a fuel tank 3, a support 5, a
housing including upper and lower housing portions 8, 7,
respectively, and a combustion chamber 10 including an inner
cylinder (not shown) and an outer cylinder 12. Alternate
embodiments include a housing formed as a singular, generally
cylindrical shell. A semi-spherical shaped baffle 13 is provided
adjacent to a discharge end 2 of the combustion chamber 10 and an
intake guard 14 is provided adjacent to an air intake end 19 port
of the forced-air heater 1.
[0025] The fuel tank 3 can optionally be formed as a singular
molded unit or from two opposing rectangular trays arranged with
their openings facing each other. For embodiments including a fuel
tank 3 formed from two opposing trays, the trays are joined
together by seam welding or otherwise coupling flanges 3a extending
around the perimeter of the fuel tank 3. A removable filler cap 4
covers a fueling aperture (not shown) formed in a surface of the
fuel tank 3 through which a liquid fuel 20 (FIG. 3) such as diesel
fuel oil, another suitable grade fuel oil, kerosene, gasoline,
alcohol, or the like may be added. The liquid fuel is atomized and
combined with air or other oxygen source in the combustion chamber
10, where it is combusted to generate the thermal energy for
heating air being forced through the forced-air heater 1.
[0026] The combustion chamber 10 includes a cavity defined by a
generally cylindrical shell 12. An annular space 71 (FIG. 3) is
left between an outer surface of the shell 12 and the housing to
reduce the amount of heat that is transferred therebetween from the
amount of heat that would be so transferred if the outer surface of
the shell 12 contacted the housing. The combustion chamber 10 is
secured to the housing by a plurality of brackets disposed about
the periphery of the combustion chamber's input and output. The
brackets are secured by screws or the like to the shell 12 and to
locations of the housing. One or more brackets are also provided to
couple the baffle 13 to the shell 12 defining the combustion
chamber 10.
[0027] A light 38 can optionally be coupled to the heater 1 to
illuminate an environment within the vicinity of the heater 1. The
light 38 can be any conventional electric light including, but not
limited to a fluorescent light, incandescent light, high-intensity
light emitting diode ("LED"), and the like. A clear, translucent,
colored, or slightly opaque protective shroud or lens can
optionally be provided to protect the light 38 from being damaged
by other objects near the heater 1. Further, operation of the light
38 can be controlled by the operator with a switch 42 independent
of the operation of the other components of the forced-air heater 1
and the combustion of fuel from the fuel tank 3. The switch 42 can
be any type of operator input device, such as a multi-position
switch, one or more push button switches (as shown in FIGS. 1 and
2), and the like. In FIGS. 1 and 2, the switch 42 includes an ON
pushbutton switch 42a and an OFF pushbutton switch 42b, which turn
the light 38 on and off, respectively. According to alternate
embodiments, the switch 42 can optionally offer a plurality of
intensity settings, such as low, medium and high, or can be
controlled with an infinitely adjustable dimmer switch to control
the intensity of the light 42.
[0028] A heater control panel 46 is operatively coupled to the
heater 1 to allow the operator to control heating of the ambient
environment by the heater 1. The control panel 46 in the
illustrative embodiments shown in FIGS. 1 and 2 include a
thermostat interface 48 and an ignition switch 52. The thermostat
interface 48 can be rotated about a central axis to a desired
temperature to which the operator wishes to heat the ambient
environment of the heater 1. The thermostat interface 48 can be
infinitely adjusted between high and low temperature limits, or can
be rotated to one or more predetermined temperature settings such
as LOW, MEDIUM and HIGH. The temperature selected with the
thermostat interface 48 can govern operation of an electric motor
15 discussed below, ignition of an air/fuel mixture, the supply of
fuel to the combustion chamber 10, the ratio of air to fuel
provided to the combustion chamber 10, an igniter 56 discussed
below with reference to FIG. 3, or any combination thereof. As is
known in the art, a thermostat operatively coupled to the
thermostat interface 48 controls activation, deactivation, and
operation of any of these components to maintain the temperature
within the ambient environment of the heater 1 at approximately the
temperature selected with the thermostat interface 48.
[0029] The support 5 is secured to or otherwise formed adjacent to
the top surface of the fuel tank 3 by spot welding, brazing, or the
like, and supports the heater's housing. The support 5 includes at
least one adjustable panel 6 that can be adjusted by an operator to
gain access into an interior chamber 21 defined by the support 5.
The adjustable panel 6 can be secured to the support 5 by any type
of fastener that permits adjustment of the adjustable panel 6 to
allow access into the interior chamber 21. Examples of such
fasteners include a hinge, locking screw, latch, and the like. The
interior chamber can house components of the forced-air heater 1,
such as a self-contained, on-board power supply 24 (FIG. 3),
control and ignition circuitry, electrical wiring, air and fuel
hoses, and the like. Each of such components can be serviced,
replaced or accessed through the aperture in the support 5
concealed by the adjustable panel 6 is removable to provide
convenient access to the components housed in the compartment for
servicing and replacement.
[0030] The self-contained, on-board power supply 24 can be any type
of portable energy source that can supply electric energy, at least
temporarily, when utility-generated electric energy is unavailable.
Examples of suitable on-board power supplies 24 include, but are
not limited to, a battery, a thermoelectric component, a generator,
a fuel cell, a photovoltaic component, an ultracapacitor, some
combination thereof, and the like.
[0031] In embodiments in which the power supply 24 comprises a
battery, the battery may comprise a zinc-carbon battery, a
zinc-chloride battery, an alkaline battery, a nickel oxyhydroxide
battery, a lithium battery, a mercury oxide battery, a zinc-air
battery, a silver-oxide battery, a nickel-cadmium battery, a
lead-acid battery, a nickel-metal hydride battery, a nickel-zinc
battery, a lithium ion battery, or some combination thereof. In
certain embodiments, a battery may be sealed, such as, without
limitation, a sealed lead-acid battery.
[0032] An example of a suitable battery is the lithium secondary
cell battery (also called a lithium ion battery), a cutaway view of
which is shown schematically in FIG. 4. Details of such a battery
are disclosed in United States Patent Publication No. US
2005/0233219, published on Oct. 20, 2005, which is incorporated in
its entirety herein by reference. Another example of a suitable
battery 24 is described in detail in United States Publication No.
US 2005/0233220, published on Oct. 20, 2005, which is also
incorporated in its entirety herein by reference. This, or
batteries with similar performance characteristics may be utilized
to supply electric energy, at least temporarily, to one or more
electric components of the forced-air heater 1.
[0033] The aforementioned lithium ion examples of a suitable
battery that can be used as the power source 24 of the present
subject matter include a high-capacity lithium-containing positive
electrode in electronic contact with a positive electrode current
collector. A high-capacity negative electrode is in electronic
contact with a negative electrode collector. The positive and
negative collectors are in electrical contact with separate
external circuits. A separator is positioned in ionic contact
between with the cathode (positive terminal) and the anode
(negative terminal), and an electrolyte is in ionic contact with
the positive and negative electrodes. The slow discharge rates of
the battery allow for extended shelf-life and extended use
characteristics.
[0034] The total and relative area specific impedances for the
positive and negative electrodes of such exemplary batteries 24 are
such that the negative electrode potential is above the potential
of metallic lithium during charging at greater than or equal to 4C
(4 times the rated capacity of the battery per hour). The current
capacity per unit area of the positive and negative electrodes each
are at least 3 mA-h/cm2 and the total area specific impedance for
the cell is less than about 20 .OMEGA.-cm2. The ratio of the area
specific impedances of the positive electrode to the negative
electrode is at least about ten.
[0035] Also, for the lithium ion batteries 24 discussed in the
examples above, the area specific impedance of the total cell is
localized predominantly at the positive electrode. The charge
capacity per unit area of the positive and negative electrodes each
are preferably at least 0.75 mA-h/cm2, more preferably at least 1.0
mA-h/cm2, and most preferably at least 1.5 mA-h/cm2. The total area
specific impedance for the cell is less than about 16 .OMEGA.-cm2,
preferably less than about 14 .OMEGA.-cm2, and more preferably less
than about 12 .OMEGA.-cm2, more preferably less than about 10
.OMEGA.-cm2, and most preferably less than or equal to about 3
.OMEGA.-cm2. The negative electrode has an area specific impedance
of less than or equal to about 2.5 .OMEGA.-cm2, more preferably
less than or equal to about 2.0 .OMEGA.-cm2, and most preferably
less than or equal to about 1.5 .OMEGA.-cm2.
[0036] Examples of suitable materials for the positive electrode
include a lithium transition metal phosphate including one or more
of vanadium, chromium, manganese, iron, cobalt, and nickel.
Examples of suitable negative electrode materials include carbon,
such as graphitic carbon. The carbon is selected from the group
consisting of graphite, spheroidal graphite, mesocarbon microbeads
and carbon fibers.
[0037] Embodiments of the battery 24 can optionally include a
battery element having an elongated cathode and an elongated anode,
which are separated by two layers of an elongated microporous
separator which are tightly wound together and placed in a battery
can. An example of a typical spiral electrode secondary cell is
shown in FIG. 4, the details of which are discussed in U.S. Patent
Publication 2005/0233219 and U.S. Pat. No. 6,277,522, both of which
are incorporated in their entirety herein by reference. The
secondary cell 200 includes a double layer of anode material 220
coated onto both sides of an anode collector 240, a separator 260
and a double layer of cathode material 280 coated onto both sides
of cathode collector 300 that have been stacked in this order and
wound to make a spiral form. The spirally wound cell is inserted
into a battery can 320 and insulating plates 340 are disposed at
upper and lower surfaces of the spirally wound cell. A cathode lead
360 from anode collector 300 provides electrical contact with the
cover. An anode lead 380 is connected to the battery can 320. An
electrolytic solution is also added to the can.
[0038] FIG. 3 is a cutaway view of a forced-air heater 1 in
accordance with one embodiment of the present subject matter.
Adjacent to the intake end 19 of the forced-air heater 1, a motor
15 is supported by means of a bracket 32 that extends between the
lower and upper housing portions 7, 8. A drive shaft 16 extends
from and is rotationally driven by the motor 15. An end of the
drive shaft 16 is coupled to fan blades 18, which draw ambient air
in the direction of arrows 34 through the air intake end 19 of the
forced-air heater 1. The fan blades 18 force air into the
combustion chamber 10, where it is mixed with the atomized fuel
injected into the combustion chamber 10 through the nozzle 36 and
the mixture is combusted. The intake guard 14 at the intake port
prevents large objects, which can damage the fan blades 18 or block
the air passages, from entering the forced-air heater 1.
[0039] The battery or other type of power supply 24 can supply
electric energy, at least temporarily, to operate an electric load
component of the heater 1 while the heater 1 is generating thermal
energy for heating its ambient environment 35. An electric load
component may comprise a resistive heating element, a component
other than a resistive heating element such as, without limitation,
a light 38, a motor 15, a control unit 62, a rectifier 58, a fuel
pump (not shown), an inverter 66, a battery, an ultracapacitor, and
igniter 56 or ignition circuitry, or some combination thereof.
Electric energy can be supplied by the power source 24 to a control
unit 62 or other electric load component via an electrical
conductor 64 disposed within the internal chamber 21 of the support
5. The control unit 62 is operatively coupled to the operator
interface devices provided to the heater 1 such as the switch 42,
control panel 46, any other operator input device, or any
combination thereof to carry out control commands input by an
operator. The control unit 62 may include useful electrical and
electronic hardware, software, or a combination thereof chosen with
sound engineering judgment to respond to commands input by an
operator via one or more operator interface devices provided to the
heater 1.
[0040] The heater 1 can be equipped with a rectifier 58 that
converts alternating current ("AC") electric energy from an
external source conducted via a plug 28 into direct current ("DC")
electric energy. The rectifier 58 may be operatively coupled to the
power supply 24 and the control unit 62 to distribute DC electric
energy as needed for proper operation of the heater 1. DC electric
energy can be selectively supplied by the rectifier 58 to the
control unit 62, to recharge the battery or other power source 24,
or simultaneously to the control unit 62 and the power source 24
when electric energy from an external source such as a conventional
wall outlet or external generator is available. Thus, when AC
electric energy is available from an external source, the AC
electric energy may be rectified by the rectifier 58 into DC
electric energy. In certain embodiments, if a power source 24 is
chargable and is charged to a degree that is less than a
predetermined lower limit, such as 90%, the rectifier may be
adapted to automatically (i.e., without operator intervention)
supply DC electric energy for charging the power source 24 until a
predetermined cutoff condition is met. Simultaneously, the
rectifier 58 can supply DC electric energy to the control unit 62
during operation of the heater 1. In turn, the control unit 62
selectively establishes conductive pathways between one or more
electric load components, such as an igniter 56, light 38, fuel
pump (not shown), and motor 15 for example, to energize the
appropriate component(s) in response to control commands input by
the operator via switch, 42, control panel 46 and the like.
[0041] As used herein, unless otherwise noted, a thermoelectric
component may refer to a thermoelectric cell, a thermopile, a
Peltier cell, or any other device adapted to produce electrical
energy from thermal energy. As shown in FIG. 3A, a thermoelectric
component 32 may be engaged with the heater 1 in such a way to
expose part of the thermoelectric component 32 to a heat source 33
and part of the thermoelectric generator 32 to a cold sink 35. As
shown in FIG. 3A, heat source 33 may be heater 1, and cold sink 35
may be the environment surrounding the heater 1. Thermoelectric
component 32 may be utilized to supply electric energy, at least
temporarily, to one or more electric load components of the
forced-air heater 1. Thermoelectric component 32 may be utilized to
supply electric energy for the same purposes and in a similar way
to the above-described battery or other type of power supply 24.
Thermoelectric component 32 may be utilized to supply electric
energy, in addition to or in substitution for electric energy from
a battery, generator 43, photovoltaic component 39 or other type of
power supply 24. As shown in FIG. 3A, an electrical conductor 64
may electrically connect thermoelectric component 32 to control
unit 62. In certain other embodiments, thermoelectric component 32
may be in direct electrical engagement with other components of
heater 1. Other means for electrically connecting thermoelectric
component 32 to heater 1 selected with good engineering judgment
may also be acceptable.
[0042] As used herein, unless otherwise noted, a photovoltaic
component may refer to a photovoltaic cell, a photovoltaic system,
or any other device adapted to converts the energy of light
directly into electricity by the photovoltaic effect. As shown in
FIG. 2, a photovoltaic component 39 may be engaged with the heater
1 in such a way to expose part of the photovoltaic component 39 to
light 49. As shown in FIG. 2, light 49 may be light, such as
without limitation, sunlight, from the environment surrounding the
heater 1. Photovoltaic component 39 may be utilized to supply
electric energy, at least temporarily, to one or more electric load
components of the forced-air heater 1. Photovoltaic component 39
may be utilized to supply electric energy for the same purposes and
in a similar way to the above-described battery or other type of
power supply 24. Photovoltaic component 39 may be utilized to
supply electric energy, in addition to or in substitution for
electric energy from a battery, generator 43, thermoelectric
component 32, or other type of power supply 24. An electrical
conductor 64 may electrically connect photovoltaic component 39 to
control unit 62. In certain other embodiments, photovoltaic
component 39 may be in direct electrical engagement with other
components of heater 1. Other means for electrically connecting
photovoltaic component 39 to heater 1 selected with good
engineering judgment may also be acceptable.
[0043] As used herein, unless otherwise noted, a generator, may
refer to a DC generator, an AC generator, an alternator, a dynamo,
or any other device adapted to produce electrical energy from
mechanical work. As shown in FIG. 3B, a generator 43 may be engaged
with the heater 1 in such a way to receive mechanical work,
directly or indirectly, from a source of mechanical work, such as,
without limitation, an engine 44 and to output electrical energy to
the heater 1. As shown in FIG. 3B, mechanical work may be input to
the generator 43 by an input shaft 47 in the form of shaft work.
Other means for supplying mechanical work to the generator 43
selected with good engineering judgment may also be acceptable.
Generator 43 may be utilized to supply electric energy, at least
temporarily, to one or more electric load components of the
forced-air heater 1. Generator 43 may be utilized to supply
electric energy for the same purposes and in a similar way to the
above-described battery or other type of power supply 24. Generator
43 may be utilized to supply electric energy, in addition to or in
substitution for electric energy from a battery, thermoelectric
component 32, photovoltaic component 39, or other type of power
supply 24. Electrical energy may be output to the heater 1 via an
electrical conductor 64. As shown in FIG. 3B, an electrical
conductor 64 may electrically connect generator 43 to control unit
62. In certain other embodiments, generator 43 may be in direct
electrical engagement with other components of heater 1. Other
means for electrically connecting generator 43 to heater 1 selected
with good engineering judgment may also be acceptable.
[0044] As noted above, and as shown in FIG. 3B, a generator 43 may
be operationally engaged with an engine 44 so that the engine 44
may supply, directly or indirectly, mechanical work to the
generator 43. In FIG. 3B, the engagement of engine 44 to generator
43 to transmit mechanical work thereto is by input shaft 47. In
certain other embodiments, the engagement of engine 44 to transmit
mechanical work to generator 43 may be made indirectly through a
clutch, a transmission, or other components selected with good
engineering judgment. Engine 44 may be an internal combustion
engine or an external combustion engine. The nature of the
engagement between an engine 44 and heater 1 may be by any means
selected with good engineering judgment.
[0045] In embodiments in which engine 44 is an internal combustion
engine it may be adapted to generate work from the combustion of
any of a large variety of fuels, including, but not limited to,
diesel fuel oil, another suitable grade fuel oil, kerosene,
gasoline, propane, natural gas, alcohol, or the like. In certain
embodiments, engine 44 may be adapted to use the same fuel 20 as
heater 1 and may be supplied with fuel from fuel tank 3. In certain
embodiments, engine 44 may be adapted to use a fuel supplied from a
one pound, or twenty pound, or other size propane bottle.
[0046] In embodiments in which engine 44 is an external combustion
engine it may be a Stirling engine, an Ericsson engine or any other
kind of external combustion engine. In embodiments in which engine
44 is an external combustion engine it may be adapted to generate
work from heat generated by heater 1. In order to receive
sufficient heat from heater 1 to generate a desired amount of work,
an external combustion engine may be engaged proximate to the
combustion chamber 10, or proximate to the shell 12, or proximate
to the baffle 13.
[0047] Certain embodiments of the present subject matter utilize
the air forced into the combustion chamber 10 by the fan blades 18
to draw fuel from the fuel tank 3 into the combustion chamber 10.
According to these embodiments, the air is directed passed the
nozzle 36, thereby creating a vacuum force that draws the fuel from
the fuel tank 3 and directs it into the combustion chamber 10.
[0048] When AC electric energy from an external source is
unavailable, the rectifier 58 can conduct DC electric energy from
the power source 24 via a conductive pathway 64 to the control unit
62. Since rectification of the DC electric energy from the power
source 24 is not needed if DC electric energy is demanded, the
rectifier 58 can merely establish the conductive pathway 64 leading
to the control unit. In response to a control command input by the
operator, the control unit 62 can selectively establish and break
conductive pathways corresponding to the control command to
activate and deactivate the appropriate electric component(s) of
the heater 1.
[0049] While in some embodiments, motor 15 is adapted to be
energized by DC electric energy, in certain embodiments, the heater
1 can optionally include a motor 15 or other electric load
component that is adapted to be energized by AC electric energy.
For such embodiments, if the power source 24 is a battery,
thermoelectric component 32, generator 43 or other source of
electric energy adapted to provide DC electric energy, the heater 1
can further include an inverter 66 to convert the DC electric
energy into AC electric energy to be utilized by the motor 15 or
other component. When an external source of AC electric energy such
as a wall outlet or generator is available, the rectifier 58 can
conduct the AC electric energy via a conductive pathway to the
control unit 62 without rectifying it into DC electric energy.
Thus, the AC electric energy conducted by the plug 28 from the
external source is conducted to the control unit 62 as AC electric
energy for use in energizing one or more AC electric load
components corresponding to a control command input by the operator
via switch 42, control panel 46, and the like. Additionally, if an
external source of AC electric energy is available, the rectifier
58 can simultaneously rectify the AC electric energy into DC
electric energy for charging the battery or other such power source
24. In certain embodiments, electrical energy provided from a
thermoelectric component 32 or a generator 43, may be used for
charging a battery or other power source 24.
[0050] If the heater 1 includes one or more electric load
components to be energized with AC electric energy and such
electric energy is not available from an external source of AC
electric energy, an inverter 66 may convert DC electric energy from
the power source 24 into AC electric energy. This inverted AC
electric energy is conducted by a conductive pathway 68 to the
control unit 62, which establishes one or more conductive pathways
to the component(s) to be energized with AC electric energy
corresponding to the control command input via switch 42, control
panel 46, and the like.
[0051] The embodiment of the heater 1 shown in FIGS. 1 and 2
further includes an optional electric energy outlet 81 into which
external electric load accessories such as radios, clocks, power
tools and the like can be plugged. The outlet 81 includes one or
more female receptacles 83 that can receive conventional two-prong
electric power cord plugs. Accordingly, each receptacle 83 includes
at least two apertures 85 into which the prongs of the plug
provided to the external electric load accessory are inserted to
establish an electrical connection between the heater 1 and the
external electric load accessory.
[0052] The outlet 81 can act as a source of AC electric energy to
energize an external electric load accessory when a conventional
wall outlet or generator is not available. The outlet 81 can also
act as an extension of a conventional wall outlet or generator when
such an external source of AC electric energy is available.
[0053] When an external source of AC electric energy is
unavailable, the inverter 66 may convert DC electric energy from
the power source 24 into AC electric energy. The AC electric energy
output by the inverter 66 can be in the form of a sinusoid having a
peak in the form of a with a peak voltage of about 170 volts and a
frequency of about 60 Hz, similar to the AC electric energy sourced
by a conventional wall outlet. However, it should be noted that the
AC electric energy output by the inverter 66 can deviate from a
perfect sinusoid, and in fact, can take on the shape of a square
wave, triangular waveform, and any other waveform shape suitable
for energizing an external electric load accessory. Due to the
large power output capacity of a battery, such as the lithium ion
battery described above, some of which can output up to 3000 Watts,
the external electric load accessory can be energized by AC
electric energy converted from DC electric energy supplied by the
battery or other power source 24.
[0054] When an external source of AC electric energy is available
to the heater 1, the rectifier 58 can conduct the AC electric from
the external source to the control unit 62. The control unit 62 is
operatively connected to the one or more electrical outlets 81 to
establish a conductive path there between. Thus, in addition to
controlling the flow of any AC electric energy required to energize
one or more components of the heater 1, the control unit 62 can
also direct the AC electric energy to the outlet 81. Even when the
heater 1 is not combusting the air/fuel mixture to deliver thermal
energy to the ambient environment of the heater 1, the outlet 81
can still be utilized by an external electric load accessory. This
is true regardless of whether the AC electric energy is converted
from DC electric energy from the power source 24 or supplied from a
conventional wall outlet, generator or the like through the
heater's plug 28.
[0055] The control unit 62 may operate in conjunction with a power
source 24 a rectifier 58, an inverter 66, other power conditioning
equipment, or a combination thereof, to accept, condition, process,
convert, store and/or use electrical energy from an external source
of AC electric energy that deviates substantially from the AC
electric energy conventionally provided in the United States. For
example, and without limitation, in some world regions, it is
common for AC electrical energy to be provided at 220v and/or 50
Hz. The heater 1 may be adapted to accept AC electrical energy
having any voltage within a range of voltages, and having any
frequency within a range of frequencies. For example and without
limitation, the heater 1 may be adapted to accept AC electrical
energy having a voltage ranging from 0 to 240 volts, and/or a
frequency ranging from 50 to 60 Hz.
[0056] The outlet 81 may be any of the conventional outlet
varieties commonly used in the United States, or may be any other
type of outlet, such as, without limitation, a conventional 12v DC
outlet, or any of the conventional outlet varieties commonly used
in Japan, Europe, Great Britain, China, Israel, India, or
elsewhere. Control unit 62 may operate in conjunction with a power
source 24 a rectifier 58, an inverter 66, other power conditioning
equipment, or a combination thereof, to output to outlet 81
electrical energy that is DC or that is AC electric energy. In
certain embodiments, the properties of the electric energy output
to outlet 81 may be selectable by a operator such that a operator
may select DC electrical energy, or AC electrical energy having any
voltage within a range of voltages, and having any frequency within
a range of frequencies. For example and without limitation, the
heater 1 may be adapted to output to outlet 81 AC electrical energy
having a voltage ranging from 0 to 240 volts, and/or a frequency
ranging from 50 to 60 Hz.
[0057] Thus, the power source 24 provided to the heater 1 can
selectively supply electric energy, AC, DC, or any combination
thereof to one or more of the following electric load components of
the heater 1: an igniter such as a hot surface igniter, spark
igniter, and the like; a fan; a blower; one or more electric
outlets 81; one or more lights 38; a thermostat; and any
combination thereof. Further, the power source 24 can supply this
electric energy simultaneously while combustion of the combustible
fuel is taking place, or in the absence of the combustion of the
combustible fuel. Electric energy supplied by the power source 24
can be supplied at least temporarily in the absence of an external
source of electric energy, simultaneously with the supply of
electric energy from an external source, or as a backup power
supply.
[0058] An alternate embodiment of a forced-air heater 110 according
to the present subject matter is shown in FIG. 5. The embodiment in
FIG. 5, in combination with one or more of the features discussed
above, can optionally further include a chassis that facilitates
mobility of the heater 110, and the ability to be stored in a
substantially-vertical orientation with only minimal, if any,
leakage of the liquid fuel from the fuel tank 114. One or more
wheels 124 can optionally be provided to facilitate transportation
of the forced-air heater 110. Each wheel 124 can include a rim 126
provided with a rubberized exterior coating 128 about its exterior
periphery. According to an embodiment of the forced-air heater 110,
the fuel tank 114 includes a generally-cylindrical passage formed
in the housing through which an axle extends to support the wheels
124. Each wheel 124 can also optionally be positioned within a
wheel well 130 formed in the fuel tank 114. The wheel wells 130
allow the wheels 124 to be recessed inwardly toward the center of a
fuel tank 114 thereby giving the forced-air 110 a
generally-streamlined configuration.
[0059] A frame 132 fabricated from an arrangement of tubes or rods
made from a metal or other suitably-strong material for supporting
the weight of a fully fueled forced-air heater 110 forms a cage
that at least partially encases the heating conduit 112 and fuel
tank 114. The frame 132 includes a proximate end 134 and a distal
end 136 separated by longitudinally extending members 138. A cross
member 140 can serve as a handle at the proximate end 134, allowing
the operator to grasp the forced-air heater 110 and maneuver it as
desired. A member 138' can extend longitudinally along each side of
the forced-air heater 110 adjacent to the fuel tank 114 and
externally of the wheels 124. In this arrangement, the member 138'
allows for simplified installation of the wheels 124 and the frame
132, and also protects the wheels 124 from impacting nearby objects
while the forced-air heater 110 is being maneuvered.
[0060] FIG. 6 illustrates transportation of the forced-air heater
110 in a somewhat vertical orientation according to an embodiment
of the present subject matter. The orientation of the forced-air
heater 110 shown in FIG. 6 is but one of the possible orientations
in which the forced-air heater 110 can be oriented without leaking
significant amounts of liquid fuel from the fuel tank 114. This
orientation is an example of what is meant herein by references to
an orientation other than the orientation in which the forced-air
heater 110 is intended to be fired, which is the orientation shown
in FIG. 5.
[0061] FIG. 7 illustrates an embodiment of a forced-air heater 110
in a substantially-vertical storage orientation. When not in use,
the forced-air heater 110 can be stood on the distal end 136 of the
frame 132. The tubing made from a metal or other strong material
that forms the distal end 136 of the frame 132 is patterned to give
the distal end 136 a suitably-wide footprint that can maintain the
forced-air heater 110 in the substantially vertical orientation
shown in FIG. 3. The footprint of the distal end 136 can optionally
be large enough to maintain the substantially-vertical orientation
of the forced-air heater 110 even when minor forces are imparted on
the forced-air heater 110 above the distal end 136 with reference
to FIG. 7.
[0062] While the forced-air heater 110 is in the
substantially-vertical storage orientation, a rain shield 142 is
positioned to interfere with the entry of falling objects or other
debris into the heating conduit 112. The rain shield 142 can be a
planar sheet of metal or other rigid material that extends between
the cross member 140 that serves as the handle and a second cross
member 144. With the rain shield 142 positioned as shown in FIG. 7,
it interferes with the entry of falling objects into the end of the
heating conduit 112 in which air is drawn from the ambient
environment.
[0063] The forced-air heater 110 has been described thus far and
illustrated in the drawings as optionally including a rain shield
142 adjacent to the ambient air intake end of the heating conduit
112. However, it is to be noted that the present subject matter is
not limited solely to such an arrangement. Instead, the present
subject matter also encompasses a forced-air heater 110 that can be
stored in a substantially-vertical orientation such that the
discharge end of the heating conduit 112 from which heated air is
forced is aimed upwardly, and the ambient air intake end is aimed
toward the ground. Of course, the fuel-management system of the
present subject matter described below will be adapted
accordingly.
[0064] FIG. 8 is a cross-section view of an embodiment of a fuel
tank 114, which forms a portion of the combustion heater's
fuel-management system. The fuel tank 114 includes one or more
cavities 146 that alternately accommodates liquid fuel and an air
gap that is shifted when the forced-air heater 110 is transitioned
from its firing orientation (shown in FIG. 5) to its
substantially-vertical storage orientation (shown in FIG. 7), and
vice versa. A fuel outlet 154 is provided adjacent to the lowermost
portion of the fuel tank 114 while the forced-air heater 110 is in
its horizontal firing position. Positioning the fuel outlet 154 in
this manner allows approximately all of the fuel to be removed from
the fuel tank 14 during operation of the forced-air heater 110.
[0065] A hose 158 is connected between the fuel outlet 154 and a
nozzle 160 through which the fuel is metered into the combustion
chamber 120. The hose 158 can be fabricated from any material that
will resist damage and degradation from exposure to the particular
fuel used to fire the forced-air heater 110. Examples of the types
of fuels the hose 158 will transport include, but are not limited
to, diesel fuel oil, another suitable grade fuel oil, kerosene,
gasoline, alcohol, or the like.
[0066] The hose 158 includes an arcuate portion 162, which is also
referred to herein as a return curve 162. The return curve 162 is
positioned on the forced-air heater 110 such that the return curve
162 is oriented similar to a "U" while the forced-air heater 110 is
in its substantially-vertical storage orientation, with both arms
aimed upwardly in a direction generally opposing the acceleration
of gravity.
[0067] The location of the fuel inlet 148 through which liquid fuel
can be inserted into the fuel tank 114 limits the amount of fuel
that can be placed in the fuel tank 114. With the forced-air heater
110 in its firing orientation, the lowest point of the fuel inlet
148 marks the upper fuel level limit 150. Thus, the air gap 152a is
disposed above the upper fuel level limit 50 and the liquid fuel in
the fuel tank 14. When the forced-air heater 110 is transitioned to
the substantially-vertical storage orientation shown in FIG. 3, the
fuel in the fuel tank 114 shifts to position an air gap 152b
adjacent to the fuel outlet 154. An example of a suitable size for
the air gaps 152a, 152b is about 0.4 gallons with the fuel tank 114
at its maximum capacity, but air gaps 152a, 152b of any size is
within the scope of the present subject matter.
[0068] The shifting of the fuel in the fuel tank 14 when the
forced-air heater 110 is transitioned from the intended firing
orientation to the substantially-vertical storage orientation
creates a vacuum at the fuel outlet 154. The vacuum results in the
siphoning of fuel from the hose 158 back into the fuel tank 114
instead of allowing the fuel to leak from the nozzle 160.
Additionally, most, if not all of the remaining fuel not siphoned
back into the fuel tank 114 is allowed to pool in the return curve
162 in the hose 158 instead of draining from the nozzle 160. This
further minimizes leakage of the fuel from the forced-air heater
110.
[0069] Although much of the description above focuses on portable
forced-air heaters, fixed heating installations such as furnaces
are also within the scope of the present subject matter.
[0070] Illustrative embodiments have been described, hereinabove.
It will be apparent to those skilled in the art that the above
devices and methods may incorporate changes and modifications
without departing from the general scope of this subject matter. It
is intended to include all such modifications and alterations in so
far as they come within the scope of the appended claims.
* * * * *