Note: Descriptions are shown in the official language in which they were submitted.
CA 02538822 2006-03-08
CONDUIT DRAIN
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drain for a gas
conduit and more particularly, to a drain for removing
liquid condensation in a vertical, exhaust gas conduit.
BACKGROUND
Furnaces, hot water heaters and other heating
appliances in residential and commercial applications
often require conduits to exhaust gas to the exterior of
a structure. Air may be drawn from within the structure
or air from the exterior of the structure may be drawn
through an intake conduit and supplied to the furnace or
appliances. In a
furnace application, the air may be
mixed with a fuel and ignited. Heat may be drawn from
the combustion process by way of a heat exchanger and
supplied to various parts of the building to heat the
interior. The by-products of the combustion process are
expelled from the structure by an exhaust conduit.
Appliances may use the combustion process to provide
mechanical energy or heat energy for residential and
commercial applications.
Similar to the furnace
application, the by-products of the combustion are
expelled from the structure by an exhaust conduit.
The combustion process may involve the use of a fuel
that has significant moisture content. When
the
combustion by-products (moisture and the gas) are
exhausted through the exhaust conduit, the gas begins to
cool and the moisture condenses within the air and
collects on the inner walls of the conduit. As
the
liquid moisture collects, gravity pulls the droplets of
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moisture down the walls of the conduit and may cause
puddles to form at low points or elbows in the conduit.
Traditionally the exhaust conduit is made from
rolled or extruded metal or other materials (including
plastic) and shaped into cylindrical piping. The
temperature differential between the gas and the walls of
the conduit results in the condensation of the moisture
in the exhaust air. The condensed moisture is corrosive
to metal, which leads to corrosion of the exhaust
conduit. Over an extended period of time, the corrosion
may cause leaks and failure of the conduit to properly
exhaust gases to the exterior of the structure.
To aid in the removal of the moisture at elbows,
holes have been provided at the bottom point on an elbow
to allow the liquid moisture to leak from the conduit.
However, the moisture still collects on the interior
walls of the conduit and still may run the length of the
conduit before exiting the conduit. For example, a two-
story building with an exhaust conduit running to the
roof of the building will have moisture collect at the
top portion of the exhaust conduit. The
collected
moisture will run the entire length of the conduit and
corrode the walls of the conduit until it reaches an
elbow or tee in the basement of the building. In
addition, the design of the building may not require an
elbow in the exhaust conduit. A
builder may have to
provide unnecessary additional turns to provide an elbow
or turn so that a drain can be provided in the exhaust
conduit.
Therefore, what is needed is a drain for
removing liquid condensation in a vertical, exhaust gas
conduit.
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SUMMARY
The present invention is a novel device, system, and method of
manufacture for a conduit drain. An exemplary embodiment, according to the
present
invention, is a conduit having walls for directing the flow of air in a
substantially vertical
direction wherein condensation from the air collects on the walls. The conduit
may have
a collection interior rim extending from the walls of the conduit inward and
in a
substantially vertical direction. The collection interior rim may provide a
condensation
collection channel between the walls of the conduit. The conduit may also have
a drain
port exiting through the conduit walls and located within the condensation
collection
channel.
In an alternative embodiment, the exemplary conduit drain may have a
drain port valve. The drain port valve allows liquids to pass and prevents the
passage of
gas. In another embodiment the conduit drain may have an outer conduit portion
with
cylindrical walls adapted to receive an inner exhaust conduit portion. The
inner conduit
portion may have a fitted portion producing a frictional fit with the walls of
the outer
exhaust conduit and a collection lip portion having a diameter smaller than
the fitting
portion and tapering inward to produce the collection lip. In yet another
embodiment, a
washer may be fitted between the outer conduit portion and the inner conduit
portion and
located around the fitting portion of the outer conduit portion.
It is important to note that the present invention is not intended to be
limited to a device, system, or method which must satisfy one or more of any
stated
objects or features of the invention. It is also important to note that the
present invention
is not limited to the exemplary embodiments described herein. Modifications
and
substitutions by one of ordinary skill in the art are considered to be within
the scope of
the present invention, which is not to be limited except by the following
claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will be
better understood by reading the following detailed description, taken
together with the
drawings wherein:
FIG. 1 is a side view of a vertical exhaust gas conduit with a conduit drain
system 100
according to an exemplary embodiment of the present invention.
FIG. 2 is a side profile view of the conduit drain 104 according to a first
exemplary
embodiment of the present invention.
FIG. 3 is a side profile view of the conduit drain 301 according to a second
exemplary
embodiment of the present invention.
FIG. 4A is a side profile view of the conduit drain 401 according to a third
exemplary
embodiment of the present invention.
FIG. 4B is a top profile view of the conduit drain 401 according to the third
exemplary
embodiment of the present invention.
DETAILED DESCRIPTION
The present invention features a vertical exhaust gas conduit drain 104,
FIG. 1, for use in an exhaust gas conduit system 100 according to an exemplary
embodiment of the present invention. A vertical exhaust gas conduit 102 runs
from the
furnace or appliance 106 located in the interior of a building 108, to the
exterior of the
building 108. Air is drawn from the interior or exterior of the building 108
and mixed
with fuel in the furnace or appliance 106. The heated air and combustion by-
products exit
the furnace or appliance 106 through the exhaust conduit 102 and pass through
the
conduit drain 104. As the air travels further along the exhaust conduit 102,
the air cools
and moisture collects on the walls of the exhaust conduit 102. The air exits
the exhaust
conduit through a cap 110 on the top of the exhaust conduit 102, and mixes
with the air at
the exterior of the building 108.
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The moisture that collects on the interior walls of the exhaust conduit 102
flows down the walls and into the conduit drain 104. The conduit drain 104
collects the
liquid from the walls of the exhaust conduit 102 and drains the liquid into a
drain pipe
112. The drain pipe 112 may also have a drain trap 114. The drain trap 114 may
prevent
unwanted components from exiting the drain pipe 112, for example, combustion
by-
product gases.
The exhaust conduit 102 according to the first exemplary embodiment
couples to the conduit drain 104, FIG. 2, at a coupling proximate an upper
region 103 of
the outer conduit portion 214. The lower region 202 of the outer conduit
portion 214 can
be coupled to an exhaust conduit 102 or a gas appliance 106 and can use a
variety of
devices and methods to couple the conduit drain 104 to an exhaust conduit 102
or a gas
appliance 106, for example, but not limited to, a friction fit type coupling,
a crimped type
coupling or adhesive type fitting. The conduit drain 104 may couple to the
exhaust
conduit 102 at an upper coupling 204. The upper region coupling 204 may be of
similar
construction to the lower region coupling 202. The exhaust gas is drawn
through the
exhaust conduit 102 and exits to the exterior of the building. As moisture
from the
exhaust gas collects on the interior walls of the exhaust conduit 102 (due to
the
temperature differential between the exhaust gas and the walls of the
conduit), the
moisture flows down the walls of the exhaust conduit 102 and collects in a
collection lip
206 in the conduit drain 104. A drain channel 208 is produced around the inner
circumference of the conduit drain 104 between the inner wall 203 of the outer
conduit
portion 214 and the collection lip 206. The moisture collects within the drain
or
collection channel 208 and is drawn off into a drain port 210 that is coupled
to a drain
pipe 112 (as shown in FIG. 1).
The conduit drain 104 may be made from two pieces of conduit. An inner
portion 212 and an outer portion 214 are coupled together to produce the
conduit drain
104. The collection lip 206 may be crimped into a top edge or upper region 201
of the
CA 02538822 2013-04-11
inner conduit portion 212. The inner portion 212 may be inserted into the
outer portion
214 and coupled together in an engagement area or region 222 in the middle
region 217
of the outer conduit portion 214 to produce the conduit drain 104. Examples of
couplings
may include, but are not limited to, a friction fit type coupling, a crimped
type coupling
or adhesives. The collection lip may also be made from a ring having a lip or
flare, or the
like.
Exhaust gas travels through a center region of the conduit drain 102. The
collection lip 206 extends inward towards the center of the conduit drain 104.
Liquid
moisture may travel around the circumference of the conduit drain 104 and exit
through
the drain port 210. A ratcheting type bracket may be mounted around the outer
circumference of the drain conduit 104 in order to provide a friction fit
coupling to the
exhaust conduit 102. The conduit drain 104 is not limited to a cylindrical
shape. A variety
of other shaped conduits may be used and are within the scope of the
invention. The
conduit drain 104 is also not limited to an exhaust conduit. The conduit drain
104 may be
implemented in a variety of other conduits and venting devices.
The conduit drain 104 may have a recessed ring portion 216 in and around
the circumference of the inner portion 212. Within the recessed ring portion
216, a
washer 220 may be inserted to allow the inner portion 212 to provide an
airtight and
watertight connection between the outer portion 214 and inner portion 212. An
additional
recess stop 218 may be provided around the circumference of the inner portion
212. The
recess stop 218 may provide a stopping point when the inner portion 212 is
inserted into
the outer portion 214. During assembly, the inner portion 212 may be inserted
into the
outer portion 214. The inner portion 212 may be pressed upward within the
outer portion
214 until the bottom 215 of the outer portion 214 rests against the ridge
produced by the
recess stop 218. An outer surface of the inner conduit portion 212 may be
welded to an
inner surface of the outer conduit portion 214, thereby forming a welded
region of the
inner and outer conduits as shown for example, at 222.
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The outer portion 214 and inner portion 212 may be manufactured by
shaping or extruding material into the cylindrical conduit or other shaped
conduit. A
drain port 210 may be provided through the wall of the outer portion 214. The
inner
portion 212 may be provided with a smaller diameter than the diameter of the
outer
portion 214. The inner portion 212 may be divided into a fitted portion 213
and the
collection lip 206. The collection lip 206 may be produced by tapering the top
edge of the
inner portion 212. As previously discussed, a recessed ring portion 216 may be
provided
between the fitted portion 213 and the collection lip 206.
The conduit drain 104 may be assembled by inserting the whole inner
portion 212 into the outer portion 214. As previously discussed, the inner
portion 212
may be pressed against the recess stop 218. According to the first exemplary
assembly, a
fitting may be provided on the top and bottom of the outer portion 214 for
connecting the
conduit drain 104 to a run of conduit 102. The conduit drain 104 may also be
assembled
by allowing the inner portion 212 to extend from the outer portion 214.
According to this
exemplary assembly, a fitting may be provided at the top of the outer portion
214 and at
the bottom of the inner portion 212. A variety of fittings may be used to
connect the
conduit drain 104 to a run of conduit 102.
Referring to FIG. 3, the exhaust conduit 102 couples to the conduit drain
301 of the second exemplary embodiment at a lower coupling 302 and an upper
coupling
304. The lower coupling 302 and upper coupling 304 may be of similar
construction and
design to the respective components of the first exemplary embodiment.
Moisture from
the exhaust gas collects in a collection lip 306 in the conduit drain 301. A
drain channel
308 is produced around the inner circumference of the conduit drain 301 by the
collection
lip 306, as previously described with regard to the first exemplary
embodiment.
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According to the second embodiment, the collection lip 306 extends a
greater distance vertically through the conduit drain 301. The moisture
collects within the
drain channel 308 and is drawn off into a drain port 310 that is coupled to a
drain pipe
112 (as shown in FIG. 1). The increased length of the collection lip 306 may
reduce
negative pressure due to the flow of exhaust gas and allows for greater
collection of
moisture. The increased length may also reduce the ability for the condensed
moisture to
re-evaporate back into the exhaust gas.
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Referring to FIGS. 4A and 4B, the exhaust
conduit 102 couples to the conduit drain 401 of the third
exemplary embodiment at a lower coupling 402 and an upper
coupling 404. The lower coupling 402 and upper coupling
404 may be of similar construction and design to the
respective components of the first and second exemplary
embodiments. Moisture from the exhaust gas collects in a
collection lip 406 in the conduit drain 401. A
drain
channel 408 is produced around the inner circumference of
the conduit drain 401 by the collection lip 406, as
previously described with regard to the first exemplary
embodiment.
According to the third embodiment, the conduit
drain 401 may have a check valve 420 that prevents the
flow of air backwards through the exhaust conduit 102.
The check valve 420 may be positioned at a location prior
to the collection lip 406. The
check valve 420 may
include a valve plate 422. The valve plate 422 rotatably
couples at hinge points 424 to the conduit drain 401. A
valve plate stopper 426 prevents the valve plate 422 from
rotating and holds the valve plate 422 in a closed
position perpendicular to the flow of air. The
hinge
points 424 allow the valve plate 422 to rotate to an open
position located between perpendicular and parallel to
the flow of air.
When exhaust air pushes on a bottom surface of
the valve plate 422, the valve plate 422 rotates to an
open position and allows the exhaust air to flow. When a
back draft or other source of pressure pulls air in the
wrong direction or there is a lack of pressure on the
bottom surface of the valve plate 422, the valve plate
422 rotates to a closed position resting against the
valve plate stopper 426. The
closed position prevents
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the flow of air in the wrong direction of the exhaust
conduit 102.
The check valve 420 may be positioned within
the conduit drain 401 to provide efficient installation.
The check valve 420 may also be efficiently manufactured
in combination with the conduit drain 401. The
hinge
points 424 and the valve plate stopper 426 may be
constructed, for example, by attaching additional
material to the conduit drain 401 by weld, rivet, or
other coupling device. The
hinge points 424 and the
valve plate stopper 426 may also be produced from the
walls of the conduit by forming or bending the walls.
The valve plate 422 may be inserted providing an
efficient construction of both a moisture drain and a
check valve to the exhaust conduit 104.
Other modifications and substitutions by one of
ordinary skill in the art are also considered to be
within the scope of the present invention.
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