U.S. patent number 3,623,470 [Application Number 05/015,794] was granted by the patent office on 1971-11-30 for gas fireplace.
This patent grant is currently assigned to Temco, Inc.. Invention is credited to Murray O. Wilhoite.
United States Patent |
3,623,470 |
Wilhoite |
November 30, 1971 |
GAS FIREPLACE
Abstract
A wall-mounted, gas-fired fireplace unit includes a decorative
simulated-log gas burner and a gas-fired, room-heating unit
disposed behind the logs within a common decorative cabinet. Room
air passes in heat exchange relationship with the exterior of the
heating unit, while hot combustion products from the log burner are
directly vented to avoid heating room air. A manually operable
control system permits the log burner and heating unit to be used
separately or together.
Inventors: |
Wilhoite; Murray O. (Nashville,
TN) |
Assignee: |
Temco, Inc. (Nashville,
TN)
|
Family
ID: |
21773684 |
Appl.
No.: |
05/015,794 |
Filed: |
March 2, 1970 |
Current U.S.
Class: |
126/503; 126/90R;
126/92R; 126/116B; 126/512 |
Current CPC
Class: |
F24C
3/122 (20130101); F24C 3/10 (20130101); F24C
1/14 (20130101) |
Current International
Class: |
F24C
3/12 (20060101); F24C 3/00 (20060101); F24C
1/14 (20060101); F24C 3/10 (20060101); F24C
1/00 (20060101); F24c 003/00 () |
Field of
Search: |
;126/127,128,129,121,120,116,116B,110,86,89,90,92,92C |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Myhre; Charles J.
Claims
What is claimed is:
1. A gas-fired fireplace comprising:
a simulated-log structure including a first gas burner;
a flue conduit extending from an open lower end above said first
burner upwardly to an open upper end;
a heating unit disposed behind said simulated-log structure and
including a vertically elongated combustion chamber of greater
height than said structure, said combustion chamber being formed by
spaced-apart front and rear walls joined together along their edges
and a second gas burner disposed within the lower part of said
combustion chamber, said combustion chamber having a combustion gas
outlet aperture at its upper end; an upwardly extending main vent
conduit having a lower end common to both said flue conduit and
said combustion gas outlet;
wall means surrounding said flue and at least that portion of said
combustion chamber which is above said simulated-log structure and
defining with said combustion chamber a space for heating room air,
said wall means being provided with at least one room air inlet
aperture at an elevation near the lower end of said combustion
chamber and with at least one heated air outlet aperture at an
elevation near the upper end of said combustion chamber; and
manually operated gas supply means for selectively supplying gas to
said first and second burners.
2. A gas-fired fireplace comprising:
wall means defining an open-front hearth box having an upwardly
extending flue conduit;
a gas-fired heating unit disposed behind said hearth box in spaced
relation to the rear wall of said hearth box, said heating unit
including a vertically disposed combustion chamber formed by
spaced-apart front and rear walls joined together along their
edges, said combustion chamber having a combustion gas outlet at
its upper end and said front wall having an aperture opening into
the rear of said hearth box;
a first gas burner disposed within said combustion chamber at the
location of said aperture;
simulated-log burner means including a second gas burner disposed
within said hearth box and closely adjacent said first burner;
gas supply and control means for said first and second burners
including a single pilot burner disposed in a position to light
both burners.
3. A gas-fired fireplace as in claim 2 wherein said second gas
burner is constructed with a plurality of relatively large upwardly
facing gas ports each of which is fitted with a gas distribution
plug which effects a tall flame during operation, said fireplace
further including an integral ceramic structure simulating a
plurality of logs piled one on the other, said ceramic structure
overlying said ports and having a plurality of spaced-apart
relatively large openings extending upwardly therethrough at
locations between the simulated logs, said openings permitting the
tall flames from said gas distribution plugs to project above the
upper surfaces of said integral ceramic structure.
4. A gas-fired fireplace as in claim 2 wherein said gas supply and
control means includes:
a main gas inlet conduit, a first gas feed line for delivering gas
to said first burner, a manually adjustable thermostatically
controlled valve connected between said inlet conduit and said
first gas feed line, a second gas feed line for delivering gas to
said second burner connected between said main gas inlet and said
thermostatically controlled valve so as to bypass the latter, and a
manual off-on valve connected into said second gas feed line
whereby said first and second burners may be operated together or
separately.
5. A gas-fired fireplace comprising:
a simulated-log gas burner;
wall means defining an open-front hearth box surrounding the top,
bottom and sides of said simulated-log gas burner;
a flue conduit extending upwardly from the top of said hearth box
and having an open upper end;
a gas-fired heating unit disposed behind said hearth box, said unit
including a combustion chamber adapted to heat room air by
heat-exchange between the exterior surfaces of said combustion
chamber and room air, said combustion chamber being provided with
an upwardly extending combustion gas outlet tube having an open
upper end;
a draft hood disposed above said hearth box to receive combustion
products from said flue conduit and from said combustion gas outlet
tube, said draft hood being defined by front, side, rear and top
walls which form a space into which the open upper ends of said
flue conduit and said outlet tube project; and
a main flue conduit extending upwardly from the top of said draft
hood for carrying off all combustion products.
6. A gas-fired fireplace as in claim 5 including a downdraft baffle
located within said draft hood in overlying and spaced relation to
the upper ends of said flue conduit and said outlet tube, the
bottom of said draft hood being open and unobstructed at a location
forward of said flue conduit.
7. A gas-fired fireplace as in claim 6 including a cabinet
surrounding said flue conduit, draft hood and combustion gas outlet
tube and defining with said combustion chamber a space for heating
room air, said cabinet being provided with at least one room air
inlet aperture near the lower end of said combustion chamber and
with at least one heated room air outlet aperture at a higher
elevation at the level of said draft hood.
8. A gas-fired fireplace comprising:
a room-heating unit including a first gas burner located in a
combustion chamber which is adapted for heating room air;
a decorative simulated-log structure disposed in front of said
heating unit and including a second gas burner;
a gas supply and control system adapted for manually operating said
first and second burners separately or together, said simulated-log
structure, heating unit and supply and control system being
disposed within decorative cabinet means having a hearth opening
which exposes said simulated-log structure;
said gas supply and control system including a main gas inlet
conduit, a first gas feed line for delivering gas to said first
burner, a valve connected between said inlet conduit and said first
gas feed line, temperature-responsive manually adjustable control
means operatively connected to said valve for opening and closing
said valve at preselected low and high room temperatures,
respectively, a second gas feed line for delivering gas to said
second burner connected between said main gas inlet and said valve
so as to bypass the latter, and a manual off-on valve connected
into said second gas feed line.
Description
This invention relates to a combination fireplace and fluid fuel
heater and in particular to an improved structure which includes
both a decorative simulated-log gas burner and a gas-fired heating
unit adapted to heat room air.
A gas fireplace typically includes a simulated-log structure and an
associated gas burner for producing a flame which in combination
with the log structure gives the appearance of burning logs. In
some constructions the heat generated by the burning gas is
utilized to warm the room air by indirect heat exchange between the
combustion products and the room air. In other constructions
products can be vented without any appreciable heat exchange with
room air. Sometimes an additional gas-fired heating unit is
employed in conjunction with the simulated-log burner. So far as is
known, all of these known structures suffer from a lack of
versatility in that little or no control can be exerted separately
over the heating and decorative functions of the devices. As a
result, these known devices have the disadvantage of tending to
overheat the room when used during warm weather or in mild
climates.
It is therefore one object of the present invention to provide a
combination gas-operated fireplace and heater unit in which a
decorative simulated-log burner and a gas space heater can be
operated separately or together. In the preferred embodiment,
rather than using a conventional gas control unit for each of the
two burners, there is provided a special simplified control unit
which achieves separate control of the burners with a minimum of
parts.
A further object of the invention is to provide a combination
gas-fired fireplace and heater having an improved internal
arrangement of its major parts, particularly the relative positions
of the simulated-log burner and the heating unit and the
construction of the parts which achieve venting of the combustion
products. In particular, there is provided a special draft hood
which receives combustion products separately from the
simulated-log burner and from the heating unit and channels them
into a common main flue.
A further object of the invention is the provision of a special
simulated-log structure and burner combination which produces a
particularly pleasing decorative effect during operation. In the
preferred construction the simulated-log structure is an integral
ceramic structure having the form of a plurality of logs stacked
one on the other with spaced apart openings therebetween to permit
flames from the underlying burner to project above the upper
surface of the integral log structure.
The invention will be further understood from the following
detailed description of an illustrative embodiment taken with the
drawings in which:
FIG. 1 is a front elevational view, partly broken away, of a
fireplace construction embodying the principles of the present
invention;
FIG. 2 is a sectional view taken on the line 2-2 of FIG. 1;
FIG. 3 is a fragmentary perspective view of the burners and the
control system therefor;
FIG. 3A is a schematic sectional view of the main control valve of
FIG. 3, and
FIG. 4 is a vertical transverse sectional view through the
simulated-log structure.
Referring to FIGS. 1 and 2 there is shown a gas fireplace
construction which includes among its major components a decorative
simulated-log structure 10 disposed within an open-front hearth box
12 and an upright gas heater unit 14 disposed behind the hearth box
12. An external cabinet 16, open at the front of the hearth box 12,
surrounds the internal parts as is conventional in the art. In the
illustrated embodiment the fireplace is adapted to be mounted on a
wall 17 of a room, and the cabinet is comprised of front and
sidewalls 18 and 20 and suitable wall mounting plates such as shown
at 22 and rear heat shields such as shown at 24 and 26. The lower
portion of the cabinet below the hearth box 12 and heater unit 14
houses a gas supply and control system 28 illustrated schematically
in FIG. 2 and more in detail in FIG. 3.
The hearth box 12 includes a rear wall 30, spaced-apart sidewalls
32 and 34 and a top wall 36 from the central portion of which there
extends an upwardly and rearwardly inclined flue conduit 38 having
an open upper end 40. In the illustrated embodiment the flue
conduit 38 is defined between a sheet of metal 42 extending
upwardly from the top wall 36 of the hearth box 12 and a relatively
narrow sheet metal channel 44 having flanged edges secured to the
front face of the sheet 42. The upper end of the flue conduit 38 is
restricted in cross section as by means of an angle piece 46 in
order to achieve proper draft characteristics. The front of the
hearth box is sealed with a glass panel 47.
The heating unit 14 includes a combustion chamber which may be of
the now conventional construction which includes spaced-apart front
and rear walls 50 and 52 secured together along their edges 54 to
define a space through which combustion products travel in indirect
heat exchange with the room air in contact with exterior surfaces
of the walls 50 and 52. The upper end of the rear wall 52 is
provided with a centrally located hole 56 through which combustion
products pass into a suitable outlet structure 58 having an
upwardly directed open-ended discharge tube 60. The end of the tube
60 is restricted in cross section as by a lip 62 in order to
achieve proper draft characteristics. The entire combustion chamber
is supported within the cabinet 16 in any suitable manner as by a
floor-supported bracket 63 or the like located in the lower portion
of the cabinet.
The combustion chamber is in communication with the hearth box 12
through a centrally located opening 64 in the lower part of the
front wall 50 of the combustion chamber and a complementary opening
in the rear wall 30 of the hearth box 12, there being provided for
this purpose a suitable tubular connection 68. Two gas burner tubes
70 and 72 are disposed at the elevation of the openings 64 and 68,
the forward burner 70 being located within the hearth box 12 below
the simulated-log structure 10 and the rear burner 72 being located
in the combustion chamber. In the interest of simplicity and
economy of construction, a single pilot burner 74 is disposed
between the burners and for igniting both the burners. Combustion
air from the room reaches the burners by entering through louvers
76 in the cabinet sidewalls near the lower ends thereof and then
passing upwardly through an opening 78 in the bottom wall of the
hearth box 12 and past a sheet metal radiation shield 80.
Combustion products from the burners 70 and 72 are vented to the
outside of the building through a common main flue pipe 82 which
may extend upwardly through the roof or upwardly and then
horizontally through the wall 17. The combustion products from the
inclined flue conduit 38 and from the discharge tube 60 from the
combustion chamber enter the lower end of the lower end of the main
flue pipe 82 by way of a common draft hood 84 which neutralizes
downdrafts likely to be caused by ambient wind conditions while
ensuring proper operating updraft during operation.
In the illustrated construction the draft hood 84 is a generally
boxlike sheet metal structure of lesser width than the combustion
chamber and defined by a rear wall 86, two laterally spaced-apart
sidewalls one of which is shown at 88, a partial bottom wall 92 and
an inclined front wall 94 extending downwardly a substantial
distance below the bottom wall 92. The front wall 94 is spaced away
from the parts 42 and 44 which form the flue conduit 38 so as to
define a relief opening 90 of substantial cross section. The relief
opening 90 functions in the event of a blocked main flue to carry
combustion products out of the draft hood 84. The upper end of the
flue conduit 38 projects a short distance into the draft hood at a
location directly in front of the partial bottom wall 92, and the
upper end of the discharge tube 60 projects through the partial
bottom wall 92. An L-shaped upwardly and rearwardly inclined
antidowndraft baffle 96 is disposed above the upper ends of the
flue conduit 38 and the tube 60, and the flow paths for combustion
products are shown by the arrows in FIG. 2.
The top wall of the draft hood 84 is provided with an upwardly
extending discharge pipe 98 which is telescoped into the lower end
of the main flue 82. At this location the fireplace cabinet 16 is
provided with an internal top wall structure. In the illustrated
embodiment the wall structure is defined by two vertically
spaced-apart horizontal plates 100 and 102 which are suitably
apertured to allow passage of the main vent therethrough. In order
to minimize heating of room air by operation of the simulated-log
burner, the upper plate is provided with a layer of thermal
insulation 104, and the inner surface of the front wall 20 of the
cabinet 16 is also covered with thermal insulation 106. On the
other hand, room air is intended to be heated by the heating unit
14, and to this end the cabinet sidewalls 18 are interrupted at the
location of the hearth box, as shown at 108 in FIG. 1, to allow
entry of room air. Louvers 110 in the sidewalls at the location of
the draft hood allow passage of warmed air back into the room. A
flexible traversing firescreen 112 is mounted in front of the glass
plate 47 and around the interrupted sides of the cabinet 16. A
vertical metal plate 114 with louvers 116 therein is disposed at
each side of the space to cover the internal parts from view while
permitting entry of room air.
FIG. 3 illustrates the two burners 70 and 72, arranged parallel to
each other, and the control system by means of which the burners
may be used together or separately. The fireplace burner 70
includes an elongated hollow cast iron body 118 and an integral
venturi-type gas and air inlet structure 120 which merges with a
hollow projection 122 on the body 118. The upper surface of the
body 118 is provided with a plurality of spaced-apart ports each of
which is fitted with a tip 124 designed to produce a tall,
irregular or flickering flame. In the illustrated embodiment the
tips are ceramic disks perforated with a plurality of radial slots
126. The spacing between the tips 124 is irregular, and some of the
tips are offset with respect to others in order to conform
generally to the pattern of holes in the ceramic log structure 10.
A pilot light 128 is disposed adjacent the outer end of the
projection 122, and a series of small ignition ports 130 is
provided in the projection 122 in order to carry the initial flame
to the tips 124. Additional ignition ports 130 are provided between
some of the tips 124 where the spacing is too great to permit flame
propagation between tip 124 and its neighbor.
The heating unit burner 72 is a separate structure although it is
physically connected to the projection 122 of the fireplace burner
70 as by suitable brackets (not shown). The burner 72 may be of any
conventional design which is compatible with the dimensions of the
heating unit 14 (FIG. 2) in which it is employed. The pilot light
128 is arranged so that it will light both the burner 72 and the
ignition ports 122 of the burner 70.
The control system for burners 70 and 72 includes thermostatic and
manual valving which permit operation of the burners together or
separately by means of two manually rotatable control knobs 132 and
134 mounted at some convenient location on the exterior of the
cabinet 16. The knob 132 controls a conventional off-on valve 136
which supplies gas to the venturi mixer 120 of the burner 70
through an extension 137, there being provided a rigid connecting
rod 138 between the knob and the valve. Gas flow to the burner 72
is by way of a line 139 and is controlled by a conventional
adjustable thermostatic valve located within a main control valve
140, the arrangement including a conventional thermostatic element
142 and the usual tubes 144,146. Rotation of the knob 134 to a
desired temperature setting has the effect of opening the valve
when the room temperature drops to a predetermined temperature and
closing the valve when room temperature reaches a predetermined
higher temperature. Adjusting the knob 134 to, for example, a
setting of 40.degree. F. has the practical effect of turning off
the heating unit 14.
The main control valve 140 may be of conventional construction with
one important exception, and in the interest of simplicity the
major parts of the valve 140 are illustrated schematically in FIG.
3A. Valves of this kind are conventionally constructed of two basic
valve components 140a and 140b, one of which embodies a safety
feature in the form of a shutoff valve 150 which cuts off the gas
flow in the event that the pilot light 128 becomes extinguished.
The other component 140b includes the previously mentioned
adjustable thermostatic valve, illustrated in FIG. 3A at 152.
Conventionally, the safety valve 150 is constructed in such a
manner that it is held open by the electric current generated by a
thermocouple 156 disposed to receive heat from the flame of the
pilot light 128. If the pilot light 128 becomes extinguished, the
valve 150 closes, and no gas can flow to the thermostatic valve
152.
In the illustrated construction the valve component 140a is
provided with a first outlet 149 for the burner 72 and a second
outlet 151 for the burner 70. However, the gas passing through the
safety valve 150 passes first into a chamber 153 in the valve
component 140b. Gas from the chamber 153 can pass to the outlet 149
only when the thermostatic valve 152 is open, while gas is always
available to the outlet 151 by means of a bypass hole 155 drilled
through a wall 157 within the body of the valve component 140b.
Ordinarily the component 140b is manufactured with a single
operational gas outlet, such as the outlet 149. However, it is
customary for the component to have one or more nonoperating, dead
end outlets facing in various directions so that a conveniently
located outlet may be selected for making the desired connection,
it being only necessary to drill a hole between the downstream side
of the valve 152 and the appropriate outlet. According to the
present invention, however, two outlets are employed, and one of
them bypasses the valve 152. By this arrangement one safety valve
150 serves both burners 70 and 72, while at the same time the
fireplace burner 70 can be operated independently of the
thermostatic valve 152.
The heat output of the burner 70 is considerably less than the
output of the burner 72. For example, a burner of 20,000 Btu has
been found to provide the necessary decorative flame, and actual
heat to the room may be only 10,000 Btu due to the intentionally
inefficient construction of the vent conduit 38. On the other hand
the burner 72 may be designed to produce 35,000 Btu, 75 percent of
which will be transferred to the room air by the walls 50 and 52 of
the combustion chamber.
FIG. 4 illustrates the construction of the simulated-log structure
10 and its relationship to the burner 70. The structure 10 is an
integral refractory ceramic structure simulating four logs piled
one on another and having a plurality of relatively large
horizontally elongated openings 160 extending vertically through
the structure at randomly spaced-apart locations between simulated
logs. The openings 160 correspond to the naturally occurring spaces
between piled logs resulting from the irregular diameters of the
logs or the presence of protrusions on the logs. In practice, the
openings 160 will be horizontally spaced apart in both a
longitudinal and transverse direction with respect to the axes of
the logs, and will conform generally to the pattern of tips 124 on
the burner 70. This arrangement, in operation, permits the tall
flickering flames to project upwardly through the openings and
above the upper surfaces of the ceramic structure 10.
* * * * *