Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention appertains in general to new
and novel improvements in gas-fired heating plants, such as
warm-air furnaces, boilers and the like, and particularly
relates to a new and novel system for venting such heating
plants.
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2. State of the Art:
Known venting systems function to carry of the fumes
or products of combustion, which contain carbon monoxide, from
the flue opening in a gas-fired heating plant to the chimney
flue. The venting systems incorporate a back-draft diverter
which is built adjacent to the combustion chamber of the heating
plant and disposed within the jacket of the heating plant and
which functions to prevent a back draft from blowing out the
pilot light in the combustion chamber.
In such conventional vented installations, the gravity
of the heat in the top of the combustion chamber allows the
heated air to rise out through the chimney flue and to be re-
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placed through the fresh air inlet by cool air, thus cooling off
the combustion chamber. Such venting systems permit a consider-
able loss of heat which escapes up through the chimney flue.
Draft hoods or regulators have been used to prevent
the occurrence of down drafts through the chimney into the
combustion chamber of the heating plant. But such draft hoods
or regulators also tend to reduce the temperature within the
combustion chamber for the heat within the combustion chamber
is drawn off or allowed to escape through the chimney flue and,
consequently, more combustion of fuel is re~uired to raise the
temperature within the combustion chamber.
None of the known venting systems deals with the
dual problem of conservation of fuel while realizing a safe
installation and operation in warm-air furnaces and gas-fired
boilers. In conventional methods of venting a gas-fired heating
plant, the gravity of the heat in the top of the combustion
chamber always permits the heat to rise out of the chimney flue
and be replaced in the fresh air inlet at the main burners by
cold air. This cools off the combustion chamber.
Furthermore, internal baffle means are utilized only
as back-draft dlverters and none of these serve to form a heat
lock within the combustion chamber so as to hold high temperature
heat wi n the combustion char~er until be heat exchanger gives
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the heat off for use. ~;
~ In addition, none of the venting systems reduce the~
¦ flue vent pipe temperature. And overheated vent pipes cause
l most, lf not all, flue fires. Also, known venting systems do
; not take into account flue stoppages which block up the chimney
flue.
Further, previous fuel saving venting systems do not
A..meet the~standards set hy the American National Standards
Institute For Fire Protection and the American Gas Association ;
and are not adaptable for use in the limited furnace space
usually found in modern home installations.
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SUM~RY OF THE INVENTION ~¦
An important object of the present invention is to
provide a venting system for a gas-fired heating plant whereby ¦
considerable savings in gas consumption can be realized, back-
drafts to the pilot light can be prevented, flue pipe temperature
can be reduced and dangers fraught with flue stoppages can be
eliminated. ; ;
A further important object of the present invention
is to provide an improved economical, simple but highly effective ~;
venting system for a gas-fired heating plant, which system will
serve to divert back drafts and to lock-in the heat inside the
combustion chamber of the heating plant. ~ -:
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A further important object of the present invention
is to provide an improved venting system that can be used with
modern warm-air furnaces having factory :installed internal
diverters or gas-fired boilers having factory installed draft
hoods and that can meet the safety standards set by government
regulatory agencies and trade associations. .-
Another object of the present invention is to provide
an improved venting system that cools the...~mes...emana~ing from -
the combustion chamber of a gas-fired heating plant so as to
reduce the temperature of the vent pipe and thereby prevent flue ;~:.
fires and to provide an improved safety arrangement which will
respond to higher than no.rmal temperatures of the fumes, such .:
as occurring in the instance of blocked flues, to shut off the . ;
main burners for the heating plant. ;
Generally considered, the present invention provides
in combination with a gas-fired heating plant, a venting system ~.
for the combustion chamber thereof which includes horizontally
disposed pipings extending straight out from the flue outlet of
the heating plant and the chimney ~lue and which are inter- .
connected and intercommunicated by the upper portion of an . . .
elongate diverter box that is vertically oriented alongside . -~.
and disposed exteriorly of the heating plant and has a vertical
baffle dividing the~upper portion into a flue outlet section and
a chimney flue section with such sections being provided with
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temperature indicators. The bottom of the elongate diverter box
is completely open or is provided with a substantial opening for
the ingress o~ cold atmospheric air into the diverter box. The
gases coming into the diverter box at its upper end portion from
the heating plant flue outlet arrive on one side of the baffle
and the cold air establishes a cold air pressure head within the
flue outlet section below the inlet of the piping from the flue
outle~ of the heating plant to establish a heat lock and prevent
the flow of heated air from the combustion chamber of the heating -`
plant. The cold air also acts in the chimney flue section to
prevent down drafts from the chimney flue attempting to pass
down through the chimney ~lue section from reaching the com-
bustion chamber of the heating plant. ii
A safety limit switch is housed in the lower end of i
the flue outlet section of the diverter box and is intended to
be activated by a rise in temperature of the fumes so as to act
through the thermostat circuit and close the gas valve to shut
off the flow of gas to the burner of the heating plant. A
barrier plate is positioned across the lower end of the diverter
ox in front of the safety switch to prevent any cold down draft - -
li from F into contact therewith and neutrali~ing its operation.¦
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BRIEF DESCRIPTION OF TEIE DR~WING
Figure 1 is a front elevational view of a gas-fired
heating plant, such as a typical warm-air furnace, equipped with
a venting system in accordance with the present invention.
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Figure 2 is a side elevational view of the furnace ~ '
and venting system'of''~ig'ur'é'~''l'and-is taken onrthe lines 2-2 ~
of Fig. 1. -
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Figure 3 is a perspective view of the venting system,
per se, shown apart from the furnace.
10 ~ Figure 4 is a fragmentary vertical sectional view taken
~ on line 4 4 of Figure 3.
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¦ DESCRI PTION OF THE PREFERRED EMBODIMENT -
I Referring now more particularly to the accompanying
¦ drawing, and initially to Fig. 3, the venting system 10 includes
an elongate substantially rectangular diverter box 12 which is
fabricated from 24 gauge galvinized iron or other sheet metal.
The diverter box in use, as shown in Figs. 1 and 2, is arranged
vertically and attached by suitable means to the outside casing ;~
14 of a warm-air furnace 16 or other type of gas-fired heating
plant.
The diverter box is composed of opposing vertical ~`
side walls 18 and 20 and opposing vertical end walls 22 and 24.
The top of the box is open and closed off by a removable lid or
cover 26 having side and end flanges that fit over the upper
edges of the side and end walls of the box and to which they
are releasabiy fastened by metal screws Z8. The bottom 30 of
the bottom is completely open or it may be somewhat closed and
formed with a substantial opening for the ingress into the box
of atmospheric air.
Maving reference to Figs. 1 and 2, the warm-air
furnace 16 is of modern conventional construction and includes ;
a jacket 32 containing a burner compartment, composed of the -
, pilot and main burners, a heat exchanger, a blower compartment
and suitable openings in the jacket for supply ducts 34 and
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¦ return ducts. The furnace has a factory installed, built-in
draft diverter 36 shown in dotted lines in Figs. 1 and 2. The
factory diverter 36 has an open bottom and flue outlets open
thereinto. Usually, there is a flue outlet for each main burner
3~3 so, if there are the usual three burners 38, then there are
three flue outlets, as exemplarily shown in Fig. 1.
The first step that is taken in the installation
.~. of the venting system_10 of the present invention is to seal
off tight the open bottom of the factory diverter 38 so that
it becomes a collection box. Then, the diverter box 12 of the
resent invention is attached to the outside of the furnace
jacket 32, as shown in Figs. 1 and 2. The open bottom diverter
ox 12 is vertically positioned so that its open bottom 30 is
at the same elevation as the factory diverter 36. It is important
that the diverter box 12 be positioned so that it has its open
ottom 30 lying in a horizontal plane above or, at least, in the
ame plane in which the bottom of the factory diverter lies. This
is important so that sufficient oxygen enters the diverter box
2 through the open bottom. The proper amount of entering oxygen
will keep the carbon monoxide in the fumes from getting dirty and
ill create the heat lock in the combustion chamber with the fumes
eing clean and the fumes in the diverter box becominy cooler and
lowing out to the chimney flue, which is thereby cool. Thus,
the generated heat is retained inside the combustion chamber of
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the furnace until the heat. exchanger gives o~f the heat through ..
the warm air supply duct to the rooms in the building.
As can be seen, the diverter box 12 is provided in
the upper end portions of its side and end walls with potential
openings 40 in the form of scribe or score lines 42 that indicate
where the actual openings (preferably circular) should be cut
on the job. The openings are made to accommodate the installed
ends of horizontally disposed pipes 44 a~d ~6 - The-pipe 46 ex~ - .
tends straight out from the box to the chimney flue (not shown)
while the pipe 44 extends straight into the box from the vertical .
pipe section 48 connected to the top of the furnace. The pipe ~:~
44 is attached to the vertical flue outlet pipe section 48 by an .
elbow 50. The pipes 44 and 46 are so attached to the opposing ..
end walls 22 and 24 of the diverter box, as shown, or the side ..
. walls 18 and 20, as can be appreciated, in a way so that they
are substantially coplanar and enter the upper portion of the ..
diverter box in an opposing manner. . ..
The opposing openings 42 for the opposing pipes 44
and 46, whether in the side walls or in the end walls as shown :
in Fig. 3, are separated by a baffle plate 52. The plate 52 is ~
: ¦ formed from asbestos or other heat resistant material and is ..
: positioned vertically in the diverter box 12, in the manner :
shown in Fig. 3. The baffle plate extends between the side
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walls in the instance of the pipes 44 and 46 coming into the end
wall~, as sho~ in Fig. 3. It has its side edges suitably
secured to the inner surface of the side walls centrally of the
box or midway betw~en the end walls. The upper end of the baffle
plate is in gas tight engagement of the lid or cover 26 while the -
side edges thereof are in gas tight engagement of the side walls.
The lower free end of the baffle plate terminates above the open
bottom 30 but the baffle plate extends more than hal:E the vertical,
extent of the diverter box or approximately three quarters of the
vertical extent.
The baffle plate divides the diverter box 12 into a
combustion flue section 5~ and a chimney flue section 56'with the
combustion flue section 54 being communicated with the pipe 44
and receiving therefrom the combustion gases from the combustion
chamber of the furnace while the section 56'is in communication
with the chimney flue pipe 46.
The sections 54 and 56'are provided in their upper
portions just below the pipes 44 and 46 with thermostatic means
in the form of feeler tubes 56 mounted in the walls of the diverte
box and extending into the interior of the sections. The tubes ar
disposed within the sections so that they are passed over by the
¦hot combustion gases as they enter the box and the cooler gases
as they leave the box for passage through the pipe 46 to the ;
chimney flue (not shown~. The tubes have outer e~ds provided ~
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l with indicating dials 58 which are located on the outside of the ~-
¦ walls and give temperature readings to an observer.
; I The combustion end section 54 of the diverter box 12
' ¦ is provided with a safety spill switch 6~ which is tied into one
¦ leg of the conventional thermostat for the heating plant and
which is activated to shut off the thermostat circuit which
controls the gas flow to the main burner through the gas valve.
The thermostat works through,a h,igh~limit cont~ol,,,,a,~afety-pilot
I switch and then to the gas valve. When the gas valve is open, '
10 ¦ gas flows to the main burner where it is ignited by the pilot. ,
The safety switch operates under the high temperature -,
o~ ~umes or combustion products to prevent lethal carbon monoxide
fumes ~rom entering the building should the chimney flue be
l blocked. To protect the switch from being disinfluenced by
i l cold air drafts, a shield or barrier plate 62 is arranged trans-
versely between the side walls 18 and 20 at the open bo,ttom 30
¦ and transversely in between the openings 40 in the end walls.
The shield is disposed below and spaced vertically from the lower
~ree end of the baffle plate 52. The shield keeps cold air from
~ contacting the safety switch and preventing it from functioning. ,,
¦ As shown in Figs. 3 and 4, the safety switch 60 is -,,
~ mounted one one leg 64 of a U-shaped member 66 which is removably
I l fitted over the top edge of the barrier plate 62 that also serves
I as a br ce member for the side walls of the diverter box 12,
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The member 66 preferably is a resilient clip. The leg 64 is
positioned on the side of the plate 62 facing the combustion
flue section 54 of the diverter box 12 and has a lateral flange
68 which is normal to the diverter box and on which the switch
60 is fixedly superimposed.
When installed, as shown in Fig. 1 and 2, the
elongate diverter box 12 has its bottom located just above or,
at least, in the horizontal plane in which the factory box 36
lies so that the open bottom is positioned well above the base
~f the furnace. The box has its upper end portion located so
that the pipes 44 and 46 come straight thereinto. Thus, there
is a minimum of piping coming into and going out of the upper
end of the diverter box 12 and such piping comes straight into
and straight out of the box and lies in substantially the same
horizontal plane.
Of course, while the preferred form of this invention
has been described herein and shown in the attached drawing, it
is to be understood that such is merely exemplary in nature and
the sc of the invention is defined by the appended claims.
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