Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CONTINUOUS FLOW MULTI STAGE GAS CONTACT WATER HEATER
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to water heaters in general and in particular to
a
water heater having heat recovery and exhaust cleaning.
= 2. Description of Related Art
Many industries and locations require heated water for a wide variety of
processes and application. For such uses, water heaters are commonly
utilized which require a heat source to heat the water. Due to issues of
availability and logistics, combustion of coal or hydrocarbons is a common
heat source. Such heat sources require an air input and exhaust to maintain
the combustion for heating. Disadvantageously, such exhaust is frequently a
source of a reduction in efficiency of the heater due to the elevated
temperature of the exhaust gas escaping through the exhaust port.
Additionally, an additional difficulty with conventional gas fired water
heaters
is that the exhaust gasses produced by such combustion sources have a
significant amount of pollutants.
SUMMARY OF THE INVENTION
According to a first embodiment of the present invention there is disclosed an
assembly for heating water in a gas-fired water heater having an exhaust
pipe. The apparatus comprises at least one water distribution manifold sized
to be located in the exhaust pipe of the water heater in fluidic communication
with a water supply and having a plurality of ports therein to distributed
water
therethrough and at least one permeable layer supported below the at least
one water distribution manifold.
The permeable layer may comprise a plurality of bodies of expanded metal.
The permeable layer may be supported by a water distribution manifold
located thereunder. The permeable layer may be supported by a support
grate located thereunder.
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The water distribution manifold may comprise at least one pipe. The water
distribution manifold may comprise a plurality of pipes distributed across the
exhaust pipe.
According to a further embodiment of the present invention there is disclosed
an
apparatus for heating water comprising a tank formed by a tank wall and
having a water inlet and a water outlet and a water collection pan in a bottom
portion thereof and a burner located through a wall of the tank so as to
position a flame originating therefrom above a surface of water located in the
collection pan. The apparatus further includes an exhaust pipe extending
from the tank, at least one water distribution manifold sized to be located in
the exhaust pipe of the water heater in fluidic communication with a water
supply and having a plurality of ports therein to distributed water
therethrough
and at least one permeable layer supported below the at least one water
distribution manifold.
The water inlet may be located at a first end of the tank. The water inlet may
distribute water through a jacket surrounding the tank to a second end of the
tank. The water may be deposited from the jacket to the collection pan at the
second end of the tank.
The distribution manifold may be in fluidic communication with the second end
of the tank to as to pass water from the second end of the tank through the
exhaust. The permeable layer may comprise a plurality of bodies of
expanded metal. The permeable layer may be supported by a water
distribution manifold located thereunder. The permeable layer may be
supported by a support grate located thereunder.
The water distribution manifold may comprise at least one pipe. The water
distribution manifold may comprise a plurality of pipes distributed across the
exhaust pipe. The apparatus may further comprise a plurality of distribution
manifolds each having an associated permeable bodies located thereunder.
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Other aspects and features of the present invention will become apparent to
those ordinarily skilled in the art upon review of the following description
of
specific embodiments of the invention in conjunction with the accompanying
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate embodiments of the invention wherein similar
characters of reference denote corresponding parts in each view,
Figure 1 is a perspective view of an apparatus for heating water according
to a first embodiment of the present invention.
Figure 2 is a cross sectional view of the apparatus of
Figure 1 as taken
along the line 2-2.
Figure 3 is a cross sectional view of the Apparatus of
Figure 1 as taken
= 15 along the line 3-3 of Figure 2.
Figure 4 is a detailed perspective view of one of the
permeable bodies.
Figure 5 is a top plan view of the distribution manifold
according to a first
embodiment of the present invention.
Figure 6 is a top plan view of the distribution manifold
according to a further
embodiment of the present invention.
Figure 7 is a perspective view of a permeable body for
use in the exhaust
flume of the apparatus of Figure 1.
DETAILED DESCRIPTION
= 25 Referring to Figure 1, an apparatus for heating water
according to a first
embodiment of the invention is shown generally at 10. The apparatus
comprises a water tank 12 extending between first and second ends, 14 and
16, respectively and having a burner assembly 18 at the first end 14 thereof
and an exhaust flume 20 at the second end 16. The burner assembly 18 may
be of any conventional type and may burn any known fuel type. The burner
assembly extends into the interior of the tank as will be described below so
as
to provide the heat of combustion produced by the burner assembly to the
water contained within the tank interior.
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As illustrated, the tank 12 may have a substantially circular cross-section,
although it will be appreciated that other cross-section shapes may be useful
as well, such as, by way of non-limiting example, square, oval, rectangular,
= 5 octagonal or irregular. The tank 12 includes first and
second end walls, 22
and 24, respectively defining the first and second ends and cylindrical outer
wall 26 extending therebetween. The burner assembly 18 passes through the
first end wall 22, and the exhaust flume 20 extends substantially vertically
from a top portion of the outer wall 26. The outer wall also includes an
expanded section 28 containing an intermediate collection pan as will be more
fully described below extending around the base of the exhaust flume.
The first end wall 22 of the tank includes at least one water inlet 32 and at
least one water outlet 34 extending therethrough. As illustrated, more than
one inlet or outlet may be provided to balance the water flow through the
heater as desired by a user. The water inlets 32 are sized to provide the
desired water flow into the heater. By way of non-limiting example, two water
inlets 32 may be utilized and selected to have a nominal diameter of between
3 and 6 inches (76 and 152 mm) although other diameters and quantities may
be useful as well. Also by way of non-limiting example, one water outlet 34
may be utilized and selected to have a nominal diameter of between 4 and 8
inches (102 and 203 mm) although other diameters and quantities may be
useful as well.
Turning now to Figures 2 through 4, cross-sectional views of the tank is
shown. The tank includes an inlet distribution chamber 36 located proximate
to the first end 14 behind the first end wall 22. An intermediate wall 38 may
be utilized to separate the distribution chamber 36 from an interior 40 of the
tank 12. As shown in Figures 3 and 4, the tank 12 includes plurality of water
channels 42 extending the length of the tank proximate to the outer wall 26.
The water channels 42 are in fluidic communication with the inlet distribution
= chamber 36 such that water introduced into the inlet distribution chamber
36
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is distributed into each of the water channels 42 along a flow path generally
indicated at 44.
As illustrated in Figure 3, the water channels 42 may be formed between the
outer wall 26 and an inner wall 46 with dividing walls 48 extending
therebetween to separate the water channels 42 from each other. It will be
appreciated that a common inner wall 46 may be utilized with separate
dividing walls 48. Optionally, each water channel 42 may be formed from a
= separate inner wall which extends to the outer wall 26 or to adjacent
inner
walls. The water channels 42 extend around the circumference of the tank 12
so as to completely surround and encase the flame produced by the burner
with at least some water which is to be heated. The separation of each water
channel from each other along paths longitudinally extending along the tank
12 ensures that flow path of water in each channel 42 flows from the first end
of the tank 12 to the second end 16 and further ensures that none of the water
channels has stagnant water contained therein which may be susceptible to
overheating or boiling. The inner wall 46 and divider walls 48 may be secured
to each other and to the outer wall 26 by any commonly known means, such
as, by way of non-limiting example, welding, adhesives, fasteners or the like.
With further reference to Figure 2, the water exits each of the water channels
at a free distal end. As set out above, the tank 12 further includes an
intermediate collection pan 50 extending substantially horizontally across the
interior 40 of the tank 12 below the exhaust flume 20. The intermediate
collection pan 50 further has an end wall 52 extending from an end of the
intermediate collection pan 50 to the outer wall 26 of the tank thereby
separating and defining an intermediate tank 54 around the exhaust flume 20
from the interior 40 of the tank 12. For the water channels 42 which are
= located above the intermediate collection pan 50, such water channels 42
terminate at the end wall 52 such that the water transferred by such water
channels 42 is into the intermediate tank 54 in a direction generally
indicated
at 55. For the water channels 42 which are located below the intermediate
collection pan 50, such channels will terminate proximate to the second end
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wall 24 so as to discharge the water transported by such water channels 42
into the interior 40 of the tank.
The intermediate tank 54 further includes transfer pipes 58 having top and
bottom open ends, 60 and 62 extending through the intermediate collection
= pan 50. The top end 60 is located at a height within the intermediate
tank 54
such that water contained within the intermediate tank 54 will flow into the
transfer pipes 58 when the water level reaches a predetermined height. The
bottom end 62 of the transfer pipe 58 discharge into the interior 40 of the
tank
12. In such a way when the water in the intermediate tank reaches a
predetermined level, it is discharged down into the interior 40 of the tank in
a
direction generally indicated at 63. Furthermore, the water level within the
intermediate tank 54 is maintained at that predetermined level so as to ensure
heat within the exhaust flume is recovered.
With reference to Figure 2, as set out above, the transfer pipes 58 and the
water channels 42 located below the intermediate tank 54 each discharge into
the tank interior 40. As set out above the burner extends into the tank
interior
so as to produce an open flame within the tank interior. As illustrated, the
burner assembly 8 extends through both of the first end wall and the
intermediate wall 38 so as to separate the flame produced by the burner
assembly from the water within the water distribution manifold 36. The water
that is discharged from the transfer pipes 58 and the water channels 42 is
contained within the tank interior 40 with free top surface below the open
flame produced by the burner assembly 8. In such a way the water within the
tank interior 40 will be heated by the flame. Optionally, the tank may include
one or more baffles 64 extending thereacross so as to slow and control the
flow of water within the tank interior from the second end 16 to the first end
14
of the tank. The baffles may also include one or more bore 66 therethrough to
further control the flow of water as is commonly known. As illustrated in
Figure 2, a clean out port 68 may be provided through the second end wall 24
of the tank 12 which is covered by a sealed plate 70 so as to permit an
operator to clean out the tank interior 40 during maintenance.
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As illustrated in Figures 2 and 4, the exhaust flume 20 comprises a tubular
member having a central passage 80 therethrough extending into the interior
40 of the tank 12. Although the central passage 80 is illustrated as having a
substantially circular cross-section, it will be appreciated that other shapes
will
be useful as well, such as, by way of non-limiting example, square,
triangular,
oval, rectangular, octagonal or irregular.
= As illustrated in Figures 2 and 4, the exhaust flume 20 includes a
plurality of
water distribution manifolds 90, a plurality of support grates 94 and a
plurality
of water permeable layers 92. Each water permeable layer is supported on a
support grate with a water distribution manifold 90 located thereabove. In
operation, exhaust gasses from the burner assembly 18 pass through the
exhaust flume 20 and transfer heat contained therein to the water permeable
layer. During such use, the water distribution manifolds distributes water
across the water permeable layer 92. In such a manner, water is carried by
and runs across the water permeable layer so as to transfer heat that is
absorbed by the water permeable layer to the water. The heated water is
then permitted to flow down the exhaust flume 20 to be collected in the
interior
40 of the tank. It will be appreciated that such heated water increases the
efficiency of the apparatus 10 as it reduces the amount of heat which is
permitted to escape out the exhaust flume. Additionally, the water running
over and passing through the water permeable layer will provide some
measure of absorption of any combustion gasses, such as 002, NO2,
particles and other pollutants. The absorption of such pollutants reduces the
amount of such gasses and particles which are permitted to escape the
heater into the atmosphere.
With reference to Figure 5, the manifolds 90 may comprise a plurality of pipes
arranged to extend across the exhaust flume 20. In particular, with reference
to Figure 5, the manifold may include an inlet pipe 110 and an outer ring 112
sized to extend around the interior of the central passage 80 proximate to the
wall thereof. One or more secondary rings 114 may be arranged inside the
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outer ring 112 coplanar with the outer ring. Additionally, one or more inner
pipes 116 may extend through the interior of the inner ring 114. The inner
and outer rings 112, 114 and inner pipes 116 may be distributed across the
central passage 80 so as to substantially evenly cover the central passage.
Optionally, the manifold may have an outer ring 112 and a serpentine inner
pipe 116 extending through the interior thereof as illustrated in Figure 6.
The
inner and outer rings 112, 114 and inner pipes 116 are connected to each
other by connection pipes as illustrated to be in fluidic communication with
each other and with the inlet pipe. The inner and outer rings 112, 114 and
inner pipes 116 each include a plurality of holes or nozzles 118 extending
therethrough. The nozzles 118 permit water supplied from the inlet pipe 110
to be dispensed from the manifold and are oriented in a downward direction.
The nozzles may have a diameter selected to dispense water from the
manifold 90 at a desired rate according to known methods. The manifold 90
may be formed of any suitable heat resistant material, such as, by way of non-
limiting example, steel, stainless steel and copper and may be formed as a
unitary member or may optionally be formed of individual elements connected
together by welding, brazing, soldering, threading or the like.
The permeable layer 92 may be formed of any suitable permeable material
able to pass air and water therethrough while providing a surface to retain
water to come into contact with the exhaust gasses. In particular, the
permeable layer 92 may be formed of a plurality of permeable bodies 100.
With reference to Figure 7, the permeable bodies 100 may be formed of a
sheet of metal extending between first and second ends, 102 and 104,
respectively and having a plurality of slits cut thereinto to form a plurality
of
ribbons between the first and second ends 102 and 104. Thereafter the
plurality of ribbons may be bent or otherwise formed out of the plane of the
sheet to form a plurality of loops 106. The permeable body 100 thus formed
will therefore provide a greater surface area than the sheet alone while also
providing many flow paths around and through the permeable bodies 100 so
as to ensure exhaust flowing therethrough will contact each area of the
permeable body 100 to transfer heat to the block and the water contained
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thereon. The permeable bodies 100 may be formed of any suitable heat
stable material, such as, by way of non-limiting example, stainless steel,
aluminium or copper. The permeable blocks may also have a thickness
selected to provide adequate heat transfer between the water and the exhaust
gas, such as, by way of non-limiting example, between 10 and 36 gauge
although other thicknesses may be useful as well. With reference to Figures
2 and 4, the support grates 92 may be of any suitable permeable grill type,
and may be secured or otherwise supported within the exhaust flume 20 by
welding, adhesives, support pins, rods, fasteners or the like. The material
and
thickness of the support grates 92 should be selected to provide adequate
support for the permeable blocks located thereon. The apparatus 10 may be
provided with one or more sets of manifolds 90, permeable bodies 92 and
support grates 94. As illustrated in Figure 2 and 4, 4 and 3, respectively
sets
of manifolds 90, permeable bodies 92 and support grates 94 may be utilized
although it will be appreciated that other quantities may be used as well.
In operation, water is pumped into the inlet pipes 32 by pumps (not shown) in
a direction generally indicated at 33 which then flows through the
distribution
chamber 36 into the individual water channels 42 which then flow into the tank
interior 40 as set out above. The burner assembly 18 provides a flame above
the water level in the tank interior 40 so as to heat the water therein as
well as
the water in the water channels 42. The exhaust gas from the burner
assembly then flows up the exhaust flume 20 through the permeable bodies
100 thereby transferring heat thereto. Water may then be pumped by external
pumps (not shown) into the inlet pipes 110 of the manifolds to be dispensed
through the nozzles 118 which will thereafter fall onto the permeable bodies
100 below. The water flowing past the permeable bodies will collect the heat
contained within the permeable bodies as well as capture some of the
pollutants in the exhaust gasses. Thereafter the water will fall into the tank
interior 40 to combined with the water flowing through the water channels 42.
The water within the tank interior 40 will then be removed therefrom through
the water outlet 34 in a direction generally indicated at 35 for the use
desired
by a user. Furthermore, the exhaust gas will be permitted to flow away from
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the heater in a direction generally indicated at 81 through any other exhaust
stacks or the like as are commonly known.
While specific embodiments of the invention have been described and
illustrated, such embodiments should be considered illustrative of the
invention only and not as limiting the invention as construed in accordance
with the accompanying claims.
