Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to heating systems that burn
gas and particularly to closed circuit systems of this type
having special arrangements for heating a liquid to be eireu-
lated.
The invention contemplates a highly efficient gas
burner energized system wherein a heating liquid is passed
through heating and holding coils disposed in special heat
exchange relationship with one or more gas burners whereby
heat derived by conduction and radiation from the burners and
by passage of the flue gases through the holding coil prior to
exhaust is cumulatively utilized to heat the liquid, and this
is a major objeet of the invention.
The invention further contemplates passing the liquid
so heated through a closed circuit ineluding a heat collector
coil assembly disposed to selectively impart heat to space to
be heated, together with associated controls for preheating
the liquid in the circuit to a desired temperature and auto-
matically acitvating components of the system to perform their
sequential functions, and this is a further object of the
invention.
More detailed objects of the invention include
insulated heating compartment construction embodying special
arrangements of serially connected heating and holding coils
relative to the burner or burners, and an associated perforated
eompartment wall strueture whereby flue gases from the burners
may be drawn in heat exehange relation through at least the
holding coil before exhaust through the perforated walls.
Further objects of the iDvention will appear in con-
nection with the appended elaims and the annexed drawings.
The present invention provides a heating system
having communicating means leading to space to be heated com-
C prising means defining a closed compartment with at least one
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gas burner assembly disposed in the compartment, said burner
assembly having a high heat conducting and radiating flue gas
discharge wall facing the interior of said compartment said
wall containing multiple perforations, a heating coil in said
compartment at least in closely adjacent radiant heat exchange
with said wall and extending planar to and substantially the
length of said wall, a holding coil in said compartment posi-
tioned separate from an inwardly of said heating coil and con-
nected at one end to one end of said heating coil, a heat col-
lector coil disposed in an enclosure in said space to be heatedconnected to said communicating means, means for forcing air
to be heated over said heat collector ooil into said ducting,
a heating liquid supply conduit connecting the other end of
said holding coil to one end of said heat collector coil, a
heating liquid return conduit connecting the other end of said
heat collector coil to the other end of said heating coil,
thus providing a closed circuit between and including said -
coils containing a heating liquid, a motor driven pump in said
supply line adapted when actuated to force liquid from said
holding coil toward said heat conduit, means responsive to a
drop in the temperature in said heat collector coil below a
predetermined lower value for energizing said burner and
actuating the pump to circulate heating fluid through said
circuit and for stopping such circulation and inactivating
the burner when that temperature raises to a predetermined
higher value, said heating and holding coils being subject to
direct heating from said burner and there being means at said
compartment for ~orcing hot flue gases from said burner through
said holding coil before exhaust.
In another embodiment, the heating system comprises
means defining a closed compartment, at least one gas burner
assembly disposed in said compartment, said burner assembly
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having a high heat conducting and radiating flue gas discharge
wall facing the interior of said compartment, said wall con-
taining multiple perforations, a heating coil in said compart-
ment at least in closely adjacent radiant heat exchange with
said wall and extending planar to and substantially the length
of said wall, a holding coil in said compartment positioned
separate from and inwardly of said heating coil and connected
at one end to one end of said heating coil, said heating and
holding coils being subject to direct heating from said burner,
a heating liquid outlet conduit connected to the other end of
said holding coil, a heating liquid inlet conduit connected to
the other end of said heating coil, pump means for forcing
liquid from said holding coil through said liquid outlet con-
duit, and means for forcing hot flue gas from said burner through
said holding coil.
In drawings which illustrate the embodiments of the
invention,
Fig, 1 is a diagrammatic view illustrating the heating
- system of the invention according to a preferred embodiment;
and
Fig, 2 is a partly diagrammatic view showing preferred
physical relationships of the parts of the heat generating
portion of the system.
Referring now to the drawings, the illustrated system
shown in Fig. 1 comprises two burner assemblies 11 and 12 dis-
posed in a compartment 13 at opposite sides of a holding coil
14, with heating coils 15 and 16 serially connected to the
holding coil and disposed between the respective burners and
the holding coil.
In a preferred structure such as shown in Fig. 2,
holding coil 14 is composed of copper or other suitable metal
tubing carrying thin heat conductive fins; and the respective
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burner assemblies are gas burners having hign heat conductive
perforated ceramic walls 17 and 18 facing into the compartment,
with heating coils 15 and 16 being sinuous lengths of copper
or like metal tubing preferably mounted directly on the per-
forated burner walls or immediately adjacent thereto.
As shown, adjacent ends of heating coils 15 and 16
are connected to one end of the holding coil 14, The other end
of holding coil 14 is connected to a heating liquid supply line
19 connected through a motor driven pump 21 to one end of a
heat collector coil 22, The other ends of heating coils 15 and
16 are connected to a heating liquid return line 24 connected
to the other end of the heat collector coil, The heating liquid
may be water or any other liquid capable of being heated with-
out deterioration of the system components,
The foregoing coils and lines constitute a closed
circuit (can be a closed circuit of an open circuit with expan-
sion tank mounted outside combustion chamber on hot line l9)
that is filled with a heating liquid, The volumetric capacity
of holding coil 14 is preferably about equal to that of collec-
tor coil 22,
An aquastat or equivalent heat sensitive device 25in the circuit in ~r adjacent heat collector coil 22 is con-
nected to a control device 20 for simultaneous actuation or
deactivation of pump 21 and the burners, as will appear~
Heat collector coil 22 as shown may be disposed in
an enclosure 26 in the building containing a motor driven fan
27 and connected to the conventional hot air ducting 28 leading
; to the space or spaces to be heated, A thermostat 29 in that
space is connected to selectively operate the fan to force air
through the heat collector coil as will appear,
Preferably lines 19 and 24 are heavily covered with
heat insulation where they extend between compartment 13 and
. enclosure 26, That is true whether the compartment 13 is
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located outside the building as shown, or within the same
building which is an important phase of the invention that
decreases the extent of heat insulation required for compart-
ment 13.
The disposition and heating of the heating and holding
coils is a very important phase of the invention, As disclosed
above the heating coils 15 and 16 may be in direct heat con-
ductive contact or at least in closely adjacent radiant heat
exchange with the cer~mic walls 17 and 18 of the burners, both
the heating coils and holding coil 14-being exposed to direct
radiant heat from the perforated burner walls.
Additionally it will be noted that the inner top wall
31, inner bottom wall 32 and the inner front and rear walls 33
; (rear wall only shown in Fig. 1) that partly bound the compart-
ment 13 are perforated stainless steel or other rigid metal
j~ plates. The compartment inner side walls 35 and 36 on which
burner assemblies 11 and 12 are mounted are preferably imper-
forate stainless steel plates. The outer top wall 37, outer
bottom wall 38 and outer front and rear walls (not shown) are
also imperforate stainless steel plates. All of these imper-
forate plates are joined at their edges so that the outer walls
define a complete outer jacket enclosure that is imperforate
except for flue gas outlet 39, combustion air ~nlets such as
the louvers indicated at 41 and 42, arrangements for introduc-
ing the gas conduits to gas burners 43 and 44 and electrical
wires for spark discharge igniters 45 and 46 of the burners.
Fig. 1 shows an exhaust fan assembly 50, which when
idle closes and seals off flue outlet 39, and the motor of
fan 50 is suitably connected to operate the fan to withdraw
flue gas only when the gas burners are energized. When fan
50 rotates the products of combustion including the flue gas
are pulled into compartment 13 through the perforations in
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burner walls 17 and 18 and circu]ated through the compartment
in heat exchange relation with the finned holding coil 14
before being drawn out through the perforated metal walls
around the compartment. Preferably a layer 51 of asbestos
or like heat insulation, lines all of the imperforate plates
and there is a small space between that layer and the adjacent
perforated plates providing passage so that the flue gas drawn
through the perforated plates travels through that passage to
exit at 39.
As shown in chain lines in Fig. 1 the entire compart-
ment structure is disposed in a heavily insulated enclosure,
and may be located externally of the building wall W. Alter-
natively it may be disposed internally of the building wherein
; the collector coil is mounted In either event the liquid
heating portion of the system is essentially a separate u~it
capable of being factory made and shipped to a point of use
; for installation in coaction with existing ducting in a building.
The term coil is meant to include substantially all
passage forming structures for equivalently circulating the
heating liquid. While a two burner system is specifically
; disclosed, the invention contemplates a system using one burner
and one heating coil associated with the holding coil.
The foregoing structure and mode of operation has
been found to be unexpectedly efficient. In an existing
system a building containing about 5400 square feet of floor
space has been heated successfully in the rigorous climate of
South Dakota. The heating liquid was preheated to about
180F and the pump and burners were activated, when the tempera-
ture reached about 145 at the collector coil and cut off when
the temperature in there again reached about 180.
The remarkable efficiency of about at least 35 to 50
per cent more efficiency for a properly installed and operated
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system is claimed.
The invention may be embodied in other specific
forms without departing from the spirit or essential character-
istics thereof. The present embodiments are therefore to be
considered in all respects as illustrative and not restrictive,
- the scope of the invention being indicated by the appended
claims rather than by the foregoing description, and all
changes which come within the meaning and range of equivalency
of the claims are therefore intended to be embraced therein.
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