Note: Descriptions are shown in the official language in which they were submitted.
79
The present invention is directed to a novel heat
exchanger which forms an improvement of the "Heat-Augmentecd
Heat Exchanger" disclosed in applicant's corresponding
Canadian Applicatlon Serial Nos. 341,640 and 419,942
Eiled on December 11, 1979 and January 20, 1983, respectively.
In the latter-noted applications, a heat exchanger
is disclosed in which an outdoor coil is subjected to heat
other than ambient air by, for example, a gas burner. This
heat is absorbed by the heat exchange medium (Freon) passing
through the coils of the heat exchanger, which is an "A-
coil", and heat thus absorbed generally drives the heat
exchange medium from its liquid to its vapor phase witll the
]atter being utilized for indoor heating purposes. While
the latter system is extremely efficient, it has been
rendered more so by the present invention.
In keeping with the present invention, an upper end
portion of the "A-coil" is closed by heat insulating
material and, therefore, virtually all of the heat which
rises within an interior chamber of the "A-coil" Elows
upwardly and outwardly through the inclividual coils of the
"A-coil", and virtually none of the heat escapes unused or
unabsorbed through the top of the "A-coil". In the latter
manner, virtually all of the heat generated by the gas
burners or the equivalents thereof (resistance heaters,
steam generators, etc.) is totally absorbed, thus increasing
the efficiency of the overall heat exchanger.
In further accordance with this invention, means
in the form of a small fan is provided in an area above the
"A-coil", and control means are provided for initiating
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the ro-tation of -the fan generally simul-taneously with the
ignition of the gas burner such that a slight draft or
draw is effected in the interior chamber of the ~A-coil"
to prevent oxygen depletion internally of the ~'A-coil"
from in effec-t s-tifling the flames of the gas heater and
alterna-tively to preclude down-draf-ting of oxygen-depleted
air (carbon dioxide) which would otherwise -tend to
extinguish -the flames of the gas burner. Stated another
way, the interior chamber of the "A-coil" is at atmospheric
temperature and pressure and, therefore, there is sufficient
air/oxygen for initial combustion. However, under certain
conditions, once combustion occurs, -the air/oxygen within
the interior chamber of the "A-coil" can become quickly
depleted if, for example, the ambient air is relatively cold
and the natural convection currents of the hot flames can
not force -the colder air rapidly outwardly from -the
interior of the "A-coil". Under such condi-tions, combustion
gasses which are depleted of oxygen will progressively and
rapidly collect in the interior of the "A-coil" and -thus
quickly extinguish the flames of the gas burner shortly after
being begun or ignited. I'hus, by star-ting the fan at about
the time the burner is ignited, a negative pressure is
created within -the in-terior chamber of the "A-coil" thereby
drawing -the air and/or gasses of combus-tion from -the in-terior
chamber of the "A-coil" through the coils thereof and
outwardly of the "A-coil" to assure continued burning of the
gas flame.
Still another object of -this invention is -to provide
within the "A-coil" and between the gas burner and the upper
insulating means or cover a generally upwardly opening
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V-shaped baffle which is designed to direct the flames or
heat from -the burners in an outward direction -toward the
coils of the ~A-coil~ again assuring tha-t the heat is
absorbed in as efficient and as maximized a manner as is
possible .
In fur-ther accordance with -this invention, the
baffle just described is preferably formed of a pair of
plates seated within a -trough for support spanning a
lower por-tion of -the "A-coil~' within the interior thereof,
and a suitable spring or springs are inserted wi-thin and
be-tween -the baffle plates to hold the same in posi-tion
wi-thin the interior chamber of the "A-coil".
With the above and other objects in view tha-t
will hereinafter appear, the nature of the invention will
be more clearly unders-tood by reference to the following
detailed description, the appended claims and the several
views illustrated in the accompanying drawings.
IN THE DRAWINGS:
FIGURE 1 is a fragmentary perspective view of
a novel heat exchanger constructed in accordance wi-th
this invention, and illus-trates a fan atop a housing for
insulating means associa-ted wi-th an "A coil".
FIGURE 2 is a cross-sectional view taken generally
along line 2-2 of Figure 1, and illustrates a pair of
baffle plates within an in-terior chamber of the "A-coil"
and a gas burner therebeneath.
FIGURE 3 is a sectional view taken generally along
line 3-3 of Figure 2, and illustrates details of the
insulating means, -the baffle plates and the springs
associated therewith.
FIGURE 4 is an exploded perspective view of an
upper portion of the "A-coil", a suppor-t for particulate
insulating ma-terial and two sheets of insulating ma-terial.
Reference is now made to -the drawings in which
a novel hea-t exchanyer constructed in accordance with
-this invention is generally designated by -the reference
numera]. 10 and includes as par-t thereof a conventional
housing 11 closed by a cover 12, -though the la-t-ter is
spaced somewhat above an uppermos-t peripheral edge
portion 13 of the housing 11 to permit circulation be-tween
an interior 14 of the housing 11 and the exterior thereof.
The interior 14 of the housing 11 includes a generally
horizontal partition of support 15 having a generally
rectangular opening 16 with the parti-tion 15 supporting
a generally shallow condensate collec-ting reservoir or
pan 17 having an upwardly directed, generally rectangular
wall 18 defining a generally rectangular opening 20. Sup-
por-ted in a conventional manner contiguous -the opening 20 is
a natural gas burner 21 which defines means for introducing
heat into an interior chamber 22 of coil means 23 which is
an "A-coil" having a pair of generally upwardly converging
legs 24, 25, each of which includes conventional coils 26
through which a heat exchange medium, such as Freon, is
circulated in a conventional manner be-tween one or more
inlets which are simply schematically illus-tra-ted by headed
arrows 27 and one or more outlets which are similarly
schematically illustrated by headed arrows 28. Na-tural gas
is introduced into the burner 21 through a conventional
control mechanism 30 (Figure 3) which includes a valve
for the gas and an elec-trical igniter, bo-th of which are
con-trolled from a suitable con-tro]. box (not shown) over
leads 31, 32 such -that upon -the energization of the control
means 30, the valve is open, gas enters -the burner 21 and
-is ign:ited by -the elec-tric ignition device -to create -the
:~lames F resulting in upwardly rising heat, as is
ind:icated by the unnumbered headed arrows in Figures 1 and
2. The hea-t is, of course, absorbed by the heat exchange
medium -travelling generally upwardly in the coils 26, -thus
changing the phase of the normally liquid refrigerant or
heat exchange medium as it enters the inle-ts 27 to its
vapor phase as it exits the coils 26 -through -the outlets 28
for subsequent u-tilization to heat a house, office or
similar building by simply connecting the outlets 2$ and
the inlets 27 in a conventional series connection to a
compressor (not shown), an expansion valve (also not shown),
and an indoor coil (not shown) in the usual and well known
"heat pump" system. As thus far described, the heat
exchanger 10 corresponds generally -to that set for-th in
the latter-noted applications and for further details
in regard to the specifics thereof, reference may be had
to the latter applica-tions.
In order to realize op-timum output from -the
coil means 23, i-t is necessary -to absorb as much as -the
heat by the heat exchange medium and the coils 26 as is
generated by the flames F and in order to do so, -the
present invention includes first means generally designa-ted
by the reference numeral 40 for closing an upper end
por-tion (unnumbered) of the interior chamber 22 of -the
"A-coil" 23 to prevent heat generated by the flames F
from flowing -therethrough, whereby essentially all of -the
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heat introduced into the interior chamber 22 is absorbed
during its passage therethrough ancl to the exterior of the
"A-coil" 23 through the spaced coils or coil portions 26 in
the manner indicated by the unnumbered headed arrows.
Furthermore, the present invention also includes further
means designated by the reference numeral 50 for directing
the heat during its upward passage through the interior
chamber 22 in generally an upward and outward direction
whereby the heat passes along and through the spaced coil or
coil portions 26 and, thus, is readily absorbed by the heat
exchange medium therein.
Associated with both of the means 40 and 50 are
also means 60 in the form of a fan for creating negative
pressure within the interior chamber 22 of the "A-coil" 23
or, stated otherwise, for creating a slight draft or upward
draw such that substantially simultaneously with the
ignition of the gas to create the Elames F by the control
means 30 over the leads 31, 32, the fan 60 is likewise
energized over the same leads 31, 32. This creation of the
negative pressure within the interior chamber 22 assures
that combustion gases, such as carbon dioxide, do not
accumulate within the interior chamber 22 which might
otherwise extinguish the flames F shotly after the same have
been begun.
The specific construction of the means 40
includes a generally U-shaped wire or mesh basket 41
(Figure 4) which includes a bottom wall 42, a pair of
side walls 43, 44~ and respective oppositely outwardly
directed supporting flanges 45, 46. The screen 41 fits
snugly within an upper opening 0 (Figure 4) of the
"A-coil" 23 and is suspended therein by -the flanges 45, 46
resting atop the "A-coil" 23, as is most readily apparen-t
from Figure 2 of the drawings. The interior of the screen
41 is filled wi-th loose or pulverulent heat insulating
materia:L or insulating which is generally designated by
the reference nurneral 47. A sheet 48 of insulating
material is -then placed atop -the pulverulent insulating
material 47, again as is most readily apparent from
Figures 2 and 4 of the drawings. Finally, a relatively
larger sheet 49 of the heat insulating material 49 seats
atop -the sheet of insulating material 48 and also spans
the overall upper peripheral ou-tline of -the "A-coil" 23.
By virtue of the heat insulating material 47, 48 and 49
of the closing means 40, all of the hea-t generated within
the interior chamber 22 of the "A-coil" must necessarily
exit the chamber 22 by passing through the coils 26 of
the legs 24 and 25 thereby maximi~ing the absorption
of the heat by the hea-t exchange medium within the coils 26.
Axially opposite ends of the "A-coil" 23 are
closed by end plates 51, 52 and spanning the distance
therebetween and connected thereto is a generally upwardly
opening V-shaped bar 53 having legs 54, 55 at each end.
The legs 54, 55 are suitably secured to the side plates 51,
52 in the manner mos-t readily apparent from Figures 2 and
3 of the drawings. The means 50 include a pair of
generally rectangular baffle plates 56, 57 each having
lower terminal end portions (unnumbered) received wi-thin
and supported upon the V-shaped bar 53 (Figures 2 and 3).
Upper end portions (unnumbered) of the baffle plates 56, 57
are bent a-t an angle -to correspond -to the inner surfaces of
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the legs 24, 25 of the "A-coil" 23. A pair of metallic
springs 5~, 59 of a generally V-shaped configura-tion are
inser-ted in a downward direction between -the pla-tes 56,
57 and the natural resiliency of -the springs 58, 59 urge
the p:Lates 56, 57 ou-twardly such -that the upper end
portions of -the baffle plates 56, 57 are in in-timate
engagement wi-th the inner surfaces of the legs 24, 25 of
the "A-coil" 23. Thus, as the heat rises along the paths
indicated by the unnumbered headed arrows in Figure 2, the
baffle pla-tes 56, 57 direct the hea-t generally upwardly
and outwardly such tha-t the same moves through the
coils 26 and is, of course, to-tally absorbed by the
heat exchange medium in -the coils 26. Fur-thermore, -the
baffle plates 56, 57 are made of metal, and they,
themselves, become heated by -the heat from -the flames F
and, of course, also radiate this heat outwardly toward
the legs 24, 25 of the "A-coil" 23. Furthermore, the
upper end portions (unnumbered) of the baffle plates 56, 57
transfer the heat through conduc-tion since -they con-tac-t
the inner surfaces of the legs 24, 25. Thus, -the baffle
plates 56, 57 are effective -to not only direc-t the heat
rising from the flames F toward the coils 26, but also
direc-t heat there-through by both convection and
conduction curren-ts.
The draft creating means or negative air pressure
creating means 60 simply includes, as was here-tofore
noted, a fan whose blade 61 is fixed -to a shaf-t 62 in
a conventional manner and -the same is driven by an elec-tric
motor 63 connected to the control circui-t (no-t shown) of -the
overall heat exchanger 10 such that the same leads 31, 32
also energize the burner 21. The means 60 is supported ln
a conventional manner by a me-tallic housing 64 having
flanges 65 which are bolted or otherwise connected -to
a shallow metallic inver-ted U-shaped cover 66 which houses
the sheet 49 of hea-t insula-ting material. Flanges 67
of the cover 66 also partially overlap exterior surfaces
of -the upper end portions of the legs 24, 25 of the "A-coil"
23. Thus, as the burner 21 is ignited, the fan blade 61
rotates and causes an upward circulation of air which, in
effect, draws the hea-t upwardly along the same paths
indicated by the unnumbered headed arrows in Figures 1 and
2, thus assuring that the flames F will no-t be abruptly
extinguished due to oxygen depl.etion within the interior
22 of the "A-coil" 23.
Although only a preferred embodiment of the
invention has been specifically illustrated and described
herein, it is to be unders-tood that minor variations may
be made in the apparatus without departing from the spirit
and scope of the invention, as defined in the appended
claims.
