Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates generally to space and
water heating units, and more particularly to the advantageous
use of a radiant burner or reactor, of the type operated by a
gas-air mixture, to provide heat and hot water requirements.
To raise the interior of a dwelling to a comfortable
temperature, it isthe practice to operate burners on a gas-air
mixture as a source of heat, and to pass the air entering the
dwelling in heat exchange with the burners, all as is noted ir.
U.~. patent 4,261,326. The efficiency of this prior art system
is determined primarily by the ~fficiency of the "gas burners",
which is not particularly noteworthy. Using the same fuel,
namely a gas-air mixture, but not in a combustion process involving
an "open" flame of a burner or the like, it has been found possible
to greatly increase the efficiency of heat exchange to the air
delivered for heating purposes, as well as satisfying the hot
water needs thereof,and providing many other noteworthy benefits.
Broadly, it is an object of the present invention to
provide an efficiently operating gas space heater overcoming the
foregoing and other shortcomings of the prior art. Specifically,
it is an objec~ to avoid the inefficiency of a gas-fed burner
having an open flame as the heat source, and instead use a
gas-fueled radiant heater, as exemplified by the heater of U.S.
patent 3,217,7Gl. To achieve this improvement, the heater is
first used to heat water which then heats the air, and despite
this two-stage heat exchange the efficiency of the within space
heater is still a noteworthy improvement over space heaters
using open flame burners.
A gas space heating unit for a dwelling or the like
demonstrating objects and advantages of the present invention
includes three major components consisting of the referred-to
radiant burner in the specific form of a cylindrically shaped gas
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combustion device, an air blower, and a closed conduit loop
for flowing water for heat exchange therethrGugh Added to the
foregoing is a first coiled length segment in said closed loop
conduit disposed in encircling relation about the cylindrical
gas combustion device for transferring the heat thereof to the
flowing water. A second coiled length segment in said conduit
is located downstream of the first coiled segment and is
disposed in the path of air issuing from the air blower. In
this way, there is heat transfer from the previously heated water to
lo the air exiting from the blower incident to the air entering into
the dwelling space~
The above brief description, as well as further obiects,
features and advantages of the present invention, will be more
fully appreciated by reference to the following detailed
description of a presently preferred, but nonetheless illustrative
embodiment in accordance with the present invention, when taken
in conjunction with the accompanying drawings, wherein:
Fig. 1 is a diagrammatic side elevational view of an
improved gas space heating unit according to the present inven-
tion; and
Fig. 2 is a partial plan view of the air heating portion
of the unit of Fig. 1.
PRIOR ART
It is already well known, as exemplified by U.S. patent
3,217,701, issued on November 16, 1965, for "Radiant Hea~er",
and which patent is herewith incorporated by reference in its
entirety, that an optimum source of heat that can be used in
heat exchange with a flowing fluid, such as water or the like,
to heat a dwelling house or other structure is a so-called combustion
element which is described in detail and illustrated in the re-
ferred-to patent. More particularly, as noted in column 1,
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lines 9-20 of said referred-to patent, there is considerable
patent literature which discloses techniques for manufacture and
use of a porous combustion element. Thus, subsequently in said
referred-to patent, as at column 4, lines 7-15, it is noted that
an optimum source of heat consists of said porous combustion
element that in practice is operated by a combustible gas which
is forced under pressure through the porous wall of said element.
As a result, the outer surface of the element will sustain a
combustion reaction at or adjacent the outer peripheral surface
layer thereof, such as will cause the outer surface layer to
incandesce.
Also no~ed in said U.S. patent 3,217,701, as at
column 4, lines 63-67, is that in the operation of the referred-
to combustion-operated combustion element, that there is an
output therefrom in the form of hot exhaust gases possessing
suitable energy in the form of convection heat, and also in the
form of direct heat radiation radiating from the incandescent
outer surface layer of the combustion element.
INVENTIVE COMB _ ATION
With the above understanding, it is the inventive
contribution hereof to provide a highly efficient gas-fuel space
heating unit using the combustion element of the referred-to
U.S. patent 3,217,701. More particularly, ant referring to
Fig. 1, the combustion element of U.S. patent 3,217,701 is used
in the within inventive combination and is designated 10 and will
be understood to be in communication with a source of combustible
gas-air, as denoted by the arrow 12 which is forced under pres4ure
into the combu~tion element 10 and through the porosity of its
wall construction so that it radiates radially therefrom as noted
by the arrows individually and collectively designated 14.
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As understood and as described in detail in the referred-
to U.S. patent 3,217,701, the operation of the combustion element
10 contemplates igniting of the combustion gases 12 with the
result that at, or near, the periphery of the surface of the
element 10, there is the referred-to combustion reaction that is
manifested by incandescence. As a result, the radially flowing
exhaust gases 14 are at an elevated temperature with which it is
highly desirable to effectuate a heat transfer to any fluid in
the vicinity. Additionally, the heat generated by the incandescing
lo surface of the device 10 is an effective radiation heat source
for any heat transfer to fluid and/or heat exchange surface in
the vicinity.
In accordance with the present invention, there is
therefore provided a closed conduit loop, generally designated
16, through which water is circulated by a pump 18. In the
direction of the flow induced by the pump 18, namely, direc~ion
20, the closed loop 16 has a first coil length segment, generally
designated 22, which consists of helical coils, individually
and collectively designated 24,which, as clearly illustrated in
Fig. 1, are arranged juxtaposed to each other, as at the point of
contact individually and collectively designated 26, and are in
superposed relation along the longitudinal axis of the cylindric-
ally shaped combustion device 10. As a result, the water that
is circulated through the coil 22 is in heat exchange for the
entire length of the combustion device lO as it flows through the
helical coils 24 of which the coil 22 is composed.
More particularly, the hot gas that emanates from reactor
10 passes through and around all of the helical turns 24 of
the coil 22. These hot gases transfer their remaining heat by
convection and are in contact with the coil 22 due to a tur~ulent
flow pattern that is essentially a helical movement caused by
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the shape of the coil 22 and the extended surface affixed to
it. A plug 100 located centrally at the bottom of the coil 22
contributes to the turbulent flow and Eorces the combustion
gases to flow around the remaining bottom turns 24 of the coil
22, thus extracting an optimum amount of heat therefrom.
The cooled combustion gas products and condensate exit the coil
chamber 48 through a sealed gas vent conduit 50. It has been
found-in practice that no secondary heat exchanger is necessary
to condense the flue products to obtain a high heat exchange
efficiency
The water which exits from the heat exchange coil 22, as
through the exiting length segment 28, will be understood to
flow through an open valve 30 and then along an undulating path,
provided by a second encountered heat exchange coil 32, the
undulating pattern of which is best illustrated in Fig. 2.
The purpose of flowing the previously heated water through
the heat exchange coil 32 will soon be explained, but first it
is to be noted that said water returns through a return conduit
33 to the inlet of the pump 18 for recirculation. Situated
beneath the heat exchange coil 32 is an air blower 34 of conven-
tional construction and a well understood operational mode ~n
which cool air 36 from the dwelling or the like, is drawn into
the blower 34 and driven, under pressure, out of the exit end 38
thereof, as in the direction 40. In accordance with the present
invention, si~uated in the path of the exiting air 40 is the
second heat exchange coil 32. As a result, the exiting air 40 is
passed in heat exchange with the previously heated water
circulating through the heat exchange coil 32, with the result
that the temperature of the air is elevated and exits as heated
air, exemplified by the arrows 42, from the exit opening 44 of a
housing 46 which encloses the individual components of the
combination structure previously described.
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For completeness' sal<e it is noted that externaily
disposed about the heat exchange coil 22 is an insulated sealed
jacket 48 which by confining the hot exhaust gases to the
proximity of the coil 22, enhances the heat exchange which occurs
between combustion device 10 and the water circulating through
coil 22. Further, and in conjunction with the above, the gas/air
supply 12 for the burner 10 is provided by the blower 101.
More particularly, blower 101 obtains air for combustion
from a sealed conduit 104 in communication with the outdoors.
The gas for combustion is supplied via a sealed conduit 103
from a source that is also outdoors through a combination
pressure regulator and shutoff valve 102.
As already noted, the cooled spent combustion exhaust
products and condensate are directed through the sealed conduit
50. The exit end of said conduit 50 i5 also discharged out-
doors, as at 105, and thus the within heating unit is one that
is completely sealed and rendered safe from leaking any noxious
or toxic gases into the living space serviced by said heating
unit.
In addition to functioning as the heat source for air
being circulated throughout a dwelling or the like, combustion
device lO also effectively serves as a heat source for hot water
service of the dwelling. To this end, there is a second closed
loop of conduit, generally designated 52, formed by a length
segment 54 starting just upstream of the valve 30 and itself
including a check valve 56. The return of the closed loop 52 is
provided by a conduit length segment 58, and connected between tne
two length segments, namely 54 and 58, is a heat exchange coil 60
which it will be understood is immersed in hot water 62 for the
dwelling which is stored in a tank 64. Water volume 62 is
replenished by cold water through an inlet 66 and i9 withdrawn
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under pressure through an outlet 68. Assuming that valve 56
is open, the previously heated water exiting from the coil 22,
or at least a portion thereof, is diverted through the length
segment 54 and through the heat exchange coil 60 before it returns
to the pump 18 through the return conduit 58. While circulating
through the heat exchange coil 60, the heated water is effective
in elevating the temperature of the water 62 in the tank 64,
and in this manner provides hot water service for the dwelling or
the like which is operatively associated with the combination
heater lO and blower 34, previously described.
In summary, combustion element 10 is thus effective in
supplying the needs for heated air and heated water in a compact,
efficiently operating combination of components as hereinbefore
described~
A latitude of modification, change and substitution is
intended in the foregoing disclosure, and in some instances,
some features of the invention will be employed without a
corresponding use of other features. Accordingly, it is ap-
propriate that the appended claims be considered broadly and in
a manner consistent with the spirit and scope of the invention
herein.
