U.S. patent application number 12/395894 was filed with the patent office on 2010-09-02 for condensing boiler and water heater.
This patent application is currently assigned to Laars Heating Systems Company. Invention is credited to Joshua Roberts, Scott Rowe.
Application Number | 20100221675 12/395894 |
Document ID | / |
Family ID | 42667299 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100221675 |
Kind Code |
A1 |
Rowe; Scott ; et
al. |
September 2, 2010 |
CONDENSING BOILER AND WATER HEATER
Abstract
A boiler and method of operating a boiler are disclosed. The
boiler generally includes a housing defining an enclosed region and
a plurality of heat exchange conduits at least partially positioned
within the enclosed region of the housing and arranged into an
interior column and an exterior column. A baffle is at least
partially positioned within the enclosed region of the housing and
positioned between the interior column and the exterior column of
heat exchange conduits. The baffle and the housing together define
a constricted region. The heat exchange conduits of the exterior
column are positioned within the constricted region. The
constricted region defines a path for directing the flow of
products of combustion adjacent the heat exchange conduits of the
exterior column thereby facilitating the exchange of heat between
the products of combustion and water within the heat exchange
conduit of the exterior column.
Inventors: |
Rowe; Scott; (Dover, NH)
; Roberts; Joshua; (Barrington, NH) |
Correspondence
Address: |
RATNERPRESTIA
P.O. BOX 980
VALLEY FORGE
PA
19482
US
|
Assignee: |
Laars Heating Systems
Company
Rochester
NH
|
Family ID: |
42667299 |
Appl. No.: |
12/395894 |
Filed: |
March 2, 2009 |
Current U.S.
Class: |
432/29 ;
122/13.3; 122/235.17 |
Current CPC
Class: |
Y02E 20/14 20130101;
Y02B 30/106 20130101; F24H 8/00 20130101; F24H 1/40 20130101; Y02B
30/00 20130101; Y02B 30/102 20130101; F22D 1/06 20130101; F24H
8/006 20130101 |
Class at
Publication: |
432/29 ;
122/13.3; 122/235.17 |
International
Class: |
F24H 1/00 20060101
F24H001/00; F24H 9/12 20060101 F24H009/12; F22B 37/10 20060101
F22B037/10 |
Claims
1. A boiler comprising: a housing defining an enclosed region; a
plurality of heat exchange conduits at least partially positioned
within the enclosed region of the housing, each heat exchange
conduit having a first end spaced apart from a second end thereof
and a water passageway defined between said first end and said
second end, said plurality of heat exchange conduits being arranged
into an interior column and an exterior column, each column
including at least one heat exchange conduit; a burner positioned
to deliver products of combustion into the enclosed region of the
housing for heat exchange with water contained within said
plurality of heat exchange conduits; and a baffle at least
partially positioned within said enclosed region of said housing
and positioned between the interior column and the exterior column
of said heat exchange conduits, said baffle and said housing
together defining a constricted region and said at least one heat
exchange conduit of said exterior column being positioned within
said constricted region; said constricted region being configured
to direct the flow of products of combustion adjacent said at least
one heat exchange conduit of said exterior column thereby
facilitating an exchange of heat between the products of combustion
and water within said at least one heat exchange conduit of said
exterior column.
2. The boiler of claim 1, wherein a cross-sectional area of said
constricted region is sized to increase the velocity of the
products of combustion flowing therethrough.
3. The boiler of claim 1, wherein each heat exchange conduit is
substantially "U" shaped, and said first end and said second end of
each heat exchange conduit are positioned to face in substantially
the same direction.
4. The boiler of claim 3, said first ends and said second ends of
said plurality of heat exchange conduits being arranged on a common
plane.
5. The boiler of claim 1, wherein said at least one heat exchange
conduit of said exterior column is positioned outwardly from said
at least one heat exchange conduit of said interior column.
6. The boiler of claim 1, said burner being positioned to deliver
the products of combustion into a region circumscribed by the at
least one heat exchange conduit of said interior column.
7. The boiler of claim 1 further comprising an inlet conduit
coupled to introduce water into said first end of said at least one
heat exchange conduit of said exterior column.
8. The boiler of claim 7 further comprising a bypass conduit
coupled to direct at least a portion of water within said inlet
conduit into said second end of said at least one heat exchange
conduit of said interior column or the first end or the second end
of said at least one heat exchange conduit of said exterior
column.
9. The boiler of claim 8, wherein said bypass conduit and said
inlet conduit are positioned at least partially outside of said
enclosed region of said housing.
10. The boiler of claim 1 further comprising an outlet conduit
being positioned to receive water from either the first end or the
second end of said at least one heat exchange conduit of said
interior column.
11. The boiler of claim 1 further comprising an exhaust outlet
positioned in flow communication with said constricted region for
exhausting said products of combustion from said enclosed region of
said housing.
12. A boiler comprising: a housing defining an enclosed region; a
plurality of heat exchange conduits at least partially positioned
within said enclosed region, each heat exchange conduit having a
first end spaced apart from a second end thereof and a water
passageway defined between said first end and said second end, said
plurality of heat exchange conduits being arranged into an interior
column and an exterior column, each column including at least one
heat exchange conduit; an inlet conduit coupled to introduce water
into said first end of said at least one heat exchange conduit of
said exterior column; an outlet conduit positioned to deliver water
from either said first end or said second end of said at least one
heat exchange conduit of said interior column; and a bypass conduit
coupled to direct at least a portion of the water from said inlet
conduit into either said first end or said second end of said at
least one heat exchange conduit of said interior column or said
exterior column, wherein said inlet conduit, said outlet conduit
and said bypass conduit are positioned at least partially outside
of said enclosed region of said housing.
13. The boiler of claim 12 further comprising an adjustable
restriction positioned on the bypass conduit for selectively
directing at least a portion of the water from said inlet conduit
into either said first end or said second end of said at least one
heat exchange conduit of said interior column or said exterior
column.
14. The boiler of claim 12, wherein said interior column includes a
plurality of heat exchange conduits and the exterior column
includes a plurality of heat exchange conduits.
15. The boiler of claim 14 further comprising a header
communicating with said first ends of said interior column of heat
exchange conduits and said first ends of said exterior column of
said heat exchange conduits, wherein said inlet conduit is
positioned to deliver water into said first header.
16. The boiler of claim 15 further comprising a partition within
said header positioned to isolate one or more of said first ends of
said interior column of said heat exchange conduits from one or
more of said first ends of said exterior column of said heat
exchange conduits.
17. The boiler of claim 15 wherein the header is configured to
direct water from said first end of at least one heat exchange
conduit of said interior column to the first end of at least one
adjacent heat exchange conduit of said interior column.
18. The boiler of claim 15 wherein the header is configured to
direct water from the first end of at least one heat exchange
conduit of said exterior column to the first end of at least one
adjacent heat exchange conduit of said exterior column.
19. The boiler of claim 14 further comprising a header
communicating with said second ends of said interior column of said
heat exchange conduits and said second ends of said exterior column
of said heat exchange conduits, wherein said outlet conduit is
positioned to receive water from said header, and wherein said
bypass conduit is coupled to deliver water into said header.
20. The boiler of claim 19 further comprising a partition within
said header positioned to direct water from said second end of at
least one heat exchange conduit of said exterior column into said
second end of at least one heat exchange conduit of said interior
column.
21. The boiler of claim 19 wherein the header is configured to
direct water from the second end of at least one heat exchange
conduit of said interior column to the second end of at least one
adjacent heat exchange conduit of said interior column.
22. The boiler of claim 19 wherein the header is configured to
direct water from the second end of at least one heat exchange
conduit of said exterior column to the second end of at least one
adjacent heat exchange conduit of said exterior column.
23. The boiler of claim 13, said adjustable restriction comprising
a valve.
24. A method of operating a boiler including a heat exchanger
positioned at least partially within an enclosed region of a boiler
housing, said method comprising the steps of: introducing water
into a first conduit of the heat exchanger; transferring water from
the first conduit to a second conduit of the heat exchanger,
wherein exterior surfaces of the first conduit and the second
conduit are physically separated by a baffle; delivering products
of combustion into the enclosed region of the boiler housing for
heat exchange with water contained within the second conduit; and
directing the products of combustion into a constricted region of
the boiler housing defined between the baffle and the boiler
housing for heat exchange with water contained within the first
conduit.
25. The method of claim 24, wherein the introducing step comprises
introducing water into the first conduit through an inlet conduit
at least partially positioned outside of the boiler housing.
26. The method of claim 25, wherein the introducing step further
comprises directing at least a portion of the water from the inlet
conduit into the second conduit.
27. The method of claim 24 further comprising the step of
exhausting the products of combustion through an exhaust outlet
positioned in flow communication with the constricted region.
28. A method of operating a boiler including a heat exchanger
positioned at least partially within an enclosed region of a boiler
housing, said method comprising the steps of: introducing water
through an inlet conduit into an end of at least one heat exchange
conduit in an exterior column of heat exchange conduits; delivering
water through an outlet conduit from an end of at least one heat
exchange conduit in an interior column of heat exchange conduits;
and directing at least a portion of the water through a bypass
conduit from the inlet conduit into an end of at least one heat
exchange conduit in the interior or exterior column of heat
exchange conduits.
29. The method of claim 28 wherein the directing step comprises
adjusting an adjustable restriction positioned on the bypass
conduit to selectively direct at least a portion of the water
through the bypass conduit.
30. The method of claim 28 wherein the directing step comprises
directing at least a portion of the water into a header that is
positioned in fluid communication with the end of the at least one
heat exchange conduit in the interior or exterior column of heat
exchange conduits.
31. The method of claim 30 wherein the directing step further
comprises delivering the portion of water from the header into the
end of the at least one heat exchange conduit in the interior or
exterior column of heat exchange conduits.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a hydronic boiler or water
heater and a method of operating the same.
BACKGROUND OF THE INVENTION
[0002] Hydronic boilers operate by way of heating water (or any
other fluid) to a preset temperature and circulating the water
throughout a building or a home typically by way of radiators,
baseboard heaters, and so forth. Hydronic boilers typically include
a burner for introducing hot combustion gases into a housing of the
boiler, and a heat exchanger including hollow tube members fitted
within the boiler housing. Water is circulated through the hollow
tube members of the heat exchanger for heat exchange with the hot
combustion gases introduced into the boiler housing.
[0003] Hydronic boilers may also be referred to as condensing
boilers when they are configured to condense the water vapor in the
combustion gases to capture the latent heat of vaporization of the
water produced during the combustion process. When water vapor
condenses to a liquid phase onto a surface of the tube members,
latent energy is released as sensible heat onto the surface of the
tube members.
[0004] There is a need to further refine boilers to improve at
least one of their performance, efficiency, cost and reliability.
Furthermore, there is a need for such a boiler which also provides
for easy cleaning of the interior of the hollow tube members of the
heat exchanger.
SUMMARY OF THE INVENTION
[0005] In one exemplary aspect, a boiler is provided. The boiler
comprises a housing defining an enclosed region and a plurality of
heat exchange conduits at least partially positioned within the
enclosed region of the housing. Each heat exchange conduit has a
first end spaced apart from a second end thereof and a water
passageway defined between the first end and the second end. The
plurality of heat exchange conduits are arranged into an interior
column and an exterior column, wherein each column includes at
least one heat exchange conduit. A burner is positioned to deliver
products of combustion into the enclosed region of the housing for
heat exchange with water contained within the plurality of heat
exchange conduits. A baffle is at least partially positioned within
the enclosed region of the housing and positioned between the
interior column and the exterior column of the heat exchange
conduits. The baffle and the housing together define a constricted
region and the at least one heat exchange conduit of the exterior
column is positioned within the constricted region. The constricted
region being configured to direct the flow of products of
combustion adjacent the at least one heat exchange conduit of the
exterior column thereby facilitating the exchange of heat between
the products of combustion and water within the at least one heat
exchange conduit of the exterior column.
[0006] In another exemplary aspect, an inlet conduit coupled to
introduce water into the first end of the at least one heat
exchange conduit of the exterior column. An outlet conduit is
positioned to deliver water from either the first end or the second
end of the at least one heat exchange conduit of the interior
column. A bypass conduit is coupled to direct at least a portion of
the water from the inlet conduit into either the first end or the
second end of the at least one heat exchange conduit of the
interior column or the exterior column, wherein the inlet conduit,
outlet conduit and the bypass conduit are positioned at least
partially outside of the enclosed region.
[0007] In yet another exemplary aspect, a method of operating a
boiler is provided. The method comprises the step of introducing
water into a first conduit of a heat exchanger of a boiler. Water
is transferred from the first conduit to a second conduit of the
heat exchanger, wherein the exterior surfaces of the first conduit
and the second conduit are physically separated by a baffle.
Products of combustion are delivered into an enclosed region of the
boiler housing for heat exchange with water contained within the
second conduit. The products of combustion are directed into a
constricted region of the boiler housing defined between the baffle
and the boiler housing for heat exchange with water contained
within the first conduit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is best understood from the following detailed
description when read in connection with the accompanying drawings.
It is emphasized that, according to common practice, the various
features of the drawings are not to scale. On the On the contrary,
the dimensions of the various features are arbitrarily expanded or
reduced for clarity. Included in the drawings are the following
figures:
[0009] FIG. 1 is a perspective view of an embodiment of a boiler
including a heat exchanger.
[0010] FIG. 2 is a perspective view of the heat exchanger of the
boiler of FIG. 1, wherein headers of the heat exchanger are shown
exploded to reveal the exposed ends of the heat exchange conduits
of the heat exchanger.
[0011] FIG. 3 is an exploded view of the heat exchanger of FIG.
2.
[0012] FIG. 4 depicts a top plan view of the heat exchanger of FIG.
2.
[0013] FIG. 5 is a front elevation view of the heat exchanger of
FIG. 2 with the front surface of the headers removed to reveal the
water flow paths.
[0014] FIG. 6 is a cross-sectional view of the boiler of FIG. 2
taken along the lines 6-6.
[0015] FIG. 7 is an exploded view of another exemplary embodiment
of a heat exchanger of a boiler.
[0016] FIG. 8 is a cross-sectional perspective view of the heat
exchanger of FIG. 7.
[0017] FIG. 9 is a front elevation view of the heat exchanger of
FIG. 7 with the front surface of the headers removed to reveal the
water flow paths.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Although the invention is illustrated and described herein
with reference to specific embodiments, the invention is not
intended to be limited to the details shown. Rather, various
modifications may be made to the illustrated embodiments within the
scope and range of equivalents of the claims and without departing
from the invention. Also, the embodiments selected for illustration
in the figures are not shown to scale and are not limited to the
proportions shown.
[0019] Referring generally to the figures and according to one
exemplary aspect of the invention, a boiler 10 is provided. The
boiler 10 comprises a housing 12 defining an enclosed region and a
plurality of heat exchange conduits 30, 130 and 32, 132 at least
partially positioned within the enclosed region of the housing 12.
Each heat exchange conduit 30, 130 and 32, 132 has a first end 30a
and 32a, respectively, spaced apart from a second end 30b and 32b,
respectively, thereof and a water passageway defined between the
first end 30a and 32a and the second end 30b and 32b. The plurality
of heat exchange conduits 30, 130 and 32, 132 are arranged into an
interior column C1 and an exterior column C2, wherein each column
includes at least one heat exchange conduit. A burner 20 is
positioned to deliver products of combustion into the enclosed
region of the housing 12 for heat exchange with water contained
within the plurality of heat exchange conduits 30, 130 and 32, 132.
A baffle 31, 131 is at least partially positioned within the
enclosed region of the housing 12 and positioned between the
interior column C1 and the exterior column C2 of the heat exchange
conduits 30, 130 and 32, 132. The baffle 31, 131 and the housing 12
together define a constricted region `C` and the at least one heat
exchange conduit 32, 132 of the exterior column C2 is positioned
within the constricted region `C.` The constricted region `C.` The
constricted region `C` defines a path for directing the flow of
products of combustion adjacent the at least one heat exchange
conduit 32, 132 of the exterior column C2 thereby facilitating the
exchange of heat between the products of combustion and water
within the at least one heat exchange conduit 32 of the exterior
column C2.
[0020] In another exemplary aspect, an inlet conduit 16 is
configured to introduce water into the first end of the at least
one heat exchange conduit 32, 132 of the exterior column C2. An
outlet conduit 18 is positioned to deliver water from either the
first end 30a or the second end 30b of the at least one heat
exchange conduit 30, 130 of the interior column C1. A bypass
conduit 26 is coupled to direct at least a portion of the water
from the inlet conduit 16 into either the first end 30a, 32a or the
second end 30b, 32b of the at least one heat exchange conduit 30,
130 or 32, 132 of the interior column C1 or the exterior column C2,
wherein the inlet conduit 16, outlet conduit 18 and the bypass
conduit 26 are positioned at least partially outside of the
enclosed region of the housing 12.
[0021] In yet another exemplary aspect, a method of operating a
boiler 10 is provided. The method comprises the step of introducing
water into a first conduit 32, 132 of a heat exchanger 14, 114 of a
boiler 10. Water is transferred from the first conduit 32, 132 to a
second conduit 30, 130 of the heat exchanger 14, 114, wherein the
exterior surfaces of the first conduit 32, 132 and the second
conduit 30, 130 are physically separated by a baffle 31, 131.
Products of combustion are delivered into an enclosed region of the
boiler housing 12 for heat exchange with water contained within the
second conduit 30, 130. The products of combustion are directed
into a constricted region `C` of the boiler housing 12 defined
between the baffle 31, 131 and baffle 31, 131 and the boiler
housing 12 for heat exchange with water contained within the first
conduit 32, 132.
[0022] Referring now to FIG. 1, an exemplary embodiment of a boiler
is designated by the numeral "10." The boiler 10 generally includes
a housing 12, a heat exchanger 14 (not entirely shown) contained
within the housing 12, an inlet conduit 16 for delivering water (or
other suitable liquid) into the heat exchanger, and an outlet
conduit 18 for removing water (or other suitable liquid) from the
heat exchanger 14.
[0023] The housing 12 of the boiler 10 generally includes a top
cover 17, three walls 19 (right side wall shown; left side wall and
rear wall not shown), a front panel 36, and a lower panel 57 (see
FIG. 6) for encapsulating the heat exchanger 14. The walls of the
housing 12 define an interior region of the housing 12. The heat
exchanger 14 includes a series of conduits (not shown in FIG. 1)
containing water (or any other suitable liquid) and a fuel-fired
burner 20 for introducing products of combustion into the interior
of the housing 12. Details of an exemplary burner 20 are described
in U.S. Pat. No. 6,644,393, which is incorporated by reference
herein in its entirety. The top cover 17, three walls 19, the front
panel 36, and the lower panel 57 enclose the sides of the boiler
housing 12 to limit or prevent products of combustion from
inadvertently escaping.
[0024] In use, a supply of unheated or heated water (or any other
suitable liquid) is delivered into the boiler 10 through the inlet
conduit 16. The inlet conduit 16 includes an outlet port 24 for
delivering water into one side of the heat exchanger 14. A bypass
conduit 26 is fluidly coupled to a bypass port 22 of the inlet
conduit 16. The bypass conduit 26 is configured to deliver water
into the opposite side of the heat heat exchanger 14. Optionally,
the bypass conduit 26 can be configured to deliver water into an
inner conduit on the same side of the heat exchanger 14.
[0025] A valve 28 is mounted to the bypass conduit 26 for
selectively permitting water to flow through the bypass conduit 26.
In the open position of the valve 28, water is permitted to flow
through the bypass conduit 26, and in a closed position of the
valve 28, water is restricted from flowing through the bypass
conduit 26. The purpose of the valve 28 and the bypass conduit 26
will be described in greater detail with respect to FIG. 5. Valve
28 is optionally a conventional shut-off valve. Alternatively,
valve 28 can be a restricted orifice, a pressure regulating valve,
or any other adjustable restriction.
[0026] FIGS. 2 and 3 depict a perspective and an exploded view,
respectively, of the heat exchanger 14 of FIG. 1. The heat
exchanger 14 generally includes a plurality of heat exchange
conduits 30 and 32 for carrying water (or other suitable liquid), a
baffle 31 positioned between the conduits 30 and 32 defining a flow
path for products of combustion, a front panel 36, two header
mounting plates 42 and 44 mounted to the front panel 36, and two
headers 48 and 50 mounted to the header mounting plates 42 and 44,
respectively.
[0027] The heat exchanger 14 may be referred to as a "two-pass"
heat exchanger. More particularly, at least a portion of the water
delivered through the inlet conduit 16 makes a first pass through
the secondary heat exchange conduits 32 and is preheated by the
products of combustion passing over the secondary heat exchange
conduits 32. By way of example, about 20% to about 25% of the
thermal energy of the products of combustion is transferred to the
water within the secondary heat exchange conduits 32. The preheated
water then makes a second pass through the primary heat exchange
conduits 30 and is heated by the products of combustion passing
over the primary heat exchange conduits 30. By way of example,
about 75% to about 80% of the thermal energy of the products of
combustion is transferred to the water within the heat exchange
conduits 30.
[0028] The heat exchanger includes ten primary heat exchange
conduits 30(1) through 30(10) (referred to collectively as conduits
30) and ten secondary heat exchange conduits 32(1) through 32(10)
(referred to collectively as conduits 32). Alternatively, the heat
exchanger includes eight primary heat exchange conduits and eight
secondary heat exchange conduits. Additionally, smaller and larger
numbers of conduits are contemplated as well, depending on the size
or capacity of the system. Also, the number of primary and
secondary conduits can be the same (as illustrated) or their
numbers may be different. For example, there may be a larger number
of primary or secondary conduits as compared to secondary and
primary conduits, respectively.
[0029] Each conduit 30 and 32 includes a first end portion 30a and
32a, respectively, spaced apart from a second end portion 30b and
32b, respectively. A hollow liquid passageway having a circular
cross-section is defined between the first end portion 30a and 32a
and the second end portion 30b and 32b of each conduit 30 and 32,
respectively. The cross-sectional shape of the liquid passageway
may vary without departing from the scope or spirit of the
invention. Although not shown, each conduit 30 and 32 may include
heat sink fins extending from or forming part of its exterior
surface (see FIG. 8, for example). The heat sink fins increase the
heat transfer between the liquid distributed through the liquid
passageway and the products of combustion delivered into the
housing 12 by the burner 20.
[0030] The conduits 30 and 32 are arranged into two vertical
columns C1 and C2. In assembled form, the exterior column C2 of
conduits 32 surrounds or extends about the interior column C1 of
conduits 30. According to the exemplary embodiment illustrated
herein, each column C1 and C2 includes ten conduits 30 and 32,
respectively. The heat exchanger 14 may include any number of
conduits 30 and 32, and is thereby not limited to a specific number
of conduits 30 and 32. The conduits 30 and 32 of each column C1 and
C2, respectively, may optionally be fastened together by a weld,
clamp, bracket, mechanical fastener, strap, or any other fastening
means known to those skilled in the art.
[0031] The baffle 31 is positioned to extend between the columns C1
and C2 of conduits 30 and 32, respectively. The column C1 of
conduits 30 are positioned within the baffle 31, whereas the column
C2 of conduits 32 are positioned outside of the baffle 31. In this
exemplary embodiment, the baffle 31 includes a single "U" shaped
wall 40 positioned to extend between the columns C1 and C2 of "U"
shaped conduits 30 and 32, respectively. As will be described with
reference to FIG. 6, the wall 40 of the baffle is configured to
direct the products of combustion through the heat exchanger 14
along a pre-determined path.
[0032] The baffle 31 includes a floor surface 49 for limiting or
preventing inadvertent escape of combustion products through the
lower end of the heat exchanger 14. Opposite the floor surface 49,
the top end of the baffle 31 is exposed for inducing the flow of
combustion products over the wall 40 of the baffle 31 as described
in greater detail with reference to FIG. 6. Although not shown, the
floor surface 49 of the baffle 31 or other surface of the housing
may include a condensate outlet port, or other provisions, to
facilitate the draining of condensation formed on the interior
surfaces of of the baffle 31 and the exterior surfaces of the
conduits 30. A drain, tube or pipe (not shown) may be coupled to
the condensate outlet port for removing the condensate from the
boiler 10.
[0033] The front panel 36 is mounted to the baffle 31 by a swaging
operation. Alternatively, the front panel 36 may be mounted to the
baffle 31 by a series of fasteners (not shown). An aperture 43 is
defined in the center of the front panel 36 for accommodating the
burner 20 (see FIG. 1). Although not shown, the circular aperture
43 may have a square shape or any other shape for accommodating the
burner 20, depending on the shape or size of the burner selected
for use in the boiler 10. The burner 20 is configured to introduce
products of combustion into the interior region of the boiler
housing 12. A mounting flange 45, which surrounds the aperture 43,
is provided for mounting the burner 20 to the front panel 36. A
series of holes (not shown), studs or fasteners may be positioned
or defined on the mounting flange 45 for mounting the burner 20
onto the front panel 36.
[0034] Two header mounting plates 42 and 44 are mounted to the
front panel 36 by a series of fasteners. Two headers 48 and 50 are
mounted to the header mounting plates 42 and 44, respectively, by a
series of fasteners (not shown) or any other means for fastening
known to those skilled in the art. The headers 48 and 50 conceal
the exposed ends of the conduits 30 and 32. Although not shown, a
compressible, elastomeric gasket may be positioned at the interface
between each header 48 and 50 and its respective header mounting
plate 42 and 44, respectively, for limiting leakage of water.
[0035] The first header 48 includes a inlet opening 52 for coupling
with the outlet port 24 of the inlet conduit 16. The second header
50 includes a secondary inlet opening 54 for coupling with the an
outlet port 27 of the bypass conduit 26. The second header 50
further includes an outlet opening 56 for coupling with the outlet
conduit 18 and providing a passageway for removing heated water
from the conduits 30 and 32 of the heat exchanger 14.
[0036] In assembled form, the conduits 30 are coupled (either
directly or indirectly) to the front plate 36 of the housing 12 and
both header mounting plates 42 and 44. According to one exemplary
method of assembling heat exchanger 14, the first end portion 30a
of each conduit 30 is sequentially positioned through a respective
aperture 34(III) defined on a flange of the front plate 36 and a
respective aperture 38(III) defined on the header mounting plate
42. Similarly, the second end portion 30b of each conduit 30 is
sequentially positioned through a respective aperture 34(II)
defined on the front plate 36 and a respective aperture 38(II)
defined on the header mounting plate 44.
[0037] The conduits 32 are coupled (either directly or indirectly)
to the baffle 31, the front plate 36, and both header mounting
plates 42 and 44. More particularly, the first end portion 32a of
each conduit 32 is sequentially positioned through a respective
aperture 39(II) defined on a flange of the baffle 31, a respective
aperture 34(IV) defined on the front plate 36, and a respective
aperture 38(IV) defined on the header mounting plate 42. Similarly,
the second end portion 32b of each conduit 32 is sequentially
positioned through a respective aperture 39(I) defined on the
flange of the baffle 31, a respective aperture 34(I) defined on the
front plate 36, and a respective aperture 38(I) defined on the
header mounting plate 44.
[0038] According to one aspect of the invention and as best shown
in FIG. 3, the wall thickness of each conduit end portion 30a, 30b,
32a and 32b is optionally less than the wall thickness of the
remaining segment of each conduit. A shoulder 30c and 32c is
optionally formed at the interface between the thin-walled end
portion and the remaining segment of the conduits 30 and 32,
respectively. In assembly, the shoulder is positioned to abut the
rear face (not shown) of the front plate 36. Alternatively, and as
an alternative to shoulders 30c and 32c, fins attached to the
conduit ends or end portions abut the rear face of the front plate
36. The end portions 30a, 30b, 32a and 32b of the conduits 30 and
32 are each positioned to extend through the front panel 36 of the
heat exchanger. The end portions 30a and 32a of the conduits 30 and
32, respectively, are thereafter swaged over the header mounting
plate 42. Similarly, the end portions 30b and 32b of the conduits
30 and 32, respectively, are swaged over the header mounting plate
44.
[0039] Swaging the end portions 30a, 30b, 32a and 32b, as shown,
captivates the conduits 30 and 32 to the baffle 31, the front plate
36, and both header mounting plates 42 and 44. Additionally, the
end portions 30a, 30b, 32a and 32b of the conduits are swaged for
accomplishing a liquid-tight seal between the header mounting plate
42 and 44 and the swaged end portions 30a, 30b, 32a and 32b. As
shown in FIG. 2, to enhance the sealing properties at that
interface, a gasket 55 is optionally positioned between the front
surface of the header mounting plate 42 or 44 and each swaged
conduit end portion. The gasket 55 may take the form of an
elastomeric o-ring as shown or any other sealing means known to
those skilled in the art.
[0040] A lower refractory panel 47 is positioned between the bottom
conduit 30(10) and the floor 49 of the baffle 31. Similarly, a top
support panel 51 is positioned between the top conduit 30(1) and
the top cover 17 of the housing 12. The upper support panel 51 and
the lower refractory panel 47, respectively, are optionally mounted
to the conduits by a series of straps 53 (two shown) for added
structural support. It should be understood that a variety of ways
exist for mounting the upper and lower panels 51 and 47 to the
conduits 30.
[0041] FIG. 4 depicts a top plan view of the heat exchanger 14 of
FIG. 1. The overall shape of each conduit 30 and 32 is
substantially "U"-shaped. It should be understood that the geometry
of the conduits 30 and 32 may differ from the "U"-shape illustrated
herein without departing from the scope and spirit of the
invention. The plurality of conduits 30 and 32 are arranged
side-by-side into an interior column C1 and an exterior column C2,
respectively. The columns C1 and C2 are optionally stacked
coaxially, i.e., the arcuate portion of the conduits 30 of column
C1 optionally share the same axis "A" with the arcuate portion of
the conduits 32 of column C2. Aligning the axes "A" of columns C1
and C2 maintains a substantially constant horizontal spacing "S"
between the columns C1 and C2 of conduits 30 and 32, respectively,
to accommodate the baffle 31 between the columns C1 and C2.
[0042] The exterior column C2 of conduits 32 is positioned
outwardly from the interior column C1 of conduits 30. It follows
that the horizontal distance between the first end portion 32a and
the second end portion 32b of each conduit 32 is greater than the
horizontal distance between the first end portion 30a and the
second end portion 30b of each conduit 30. The baffle 31 is
positioned between the columns C1 and C2 of conduits 30 and 32,
respectively. The baffle 31 is substantially "U"-shaped for for
mounting between the "U"-shaped columns C1 and C2. It should be
understood that the shape of the baffle 31 may depart from that
shown to conform to the shape of the conduits 30 and 32.
[0043] FIG. 5 depicts a front elevation view of the heat exchanger
14 of FIG. 2 illustrating the front surfaces of the headers 48 and
50, respectively, in phantom to reveal the exposed ends of the
conduits 30 and 32. The headers 48 and 50 are configured to direct
the water into and out of the heat exchanger 14, as well as to
direct water through the individual conduits 30 and 32 of the heat
exchanger 14. The headers 48 and 50 include a series of interior
partitions 60 and 62, respectively, for isolating the water flow
into respective channels Z1 through Z8. The channels Z1 through Z8
are defined by the partitions 60 and 62 of the headers 48 and 50,
respectively. The partitions 60 of the header 48 delineate four
channels within the header 48, i.e., channels Z1, Z3, Z5 and Z7.
The partitions 62 of the header 50 delineate four channels within
the header 50, i.e., channels Z2, Z4, Z6 and Z8.
[0044] The partitions 60 and 62 are positioned to retain water in a
respective channel. Each partition 60 and 62 is a solid wall that
extends the entire width "W" of the header 48 and 50 (see FIG. 2),
respectively. Although not shown, an elastomeric gasket may be
positioned at the interface between each partition 60 and 62 and
the header mounting plate 42 and 44. The elastomeric gasket is
provided to maintain the water within a particular channel and to
limit the water from inadvertently entering an adjacent
channel.
[0045] The purpose of the headers 48 and 50, the partitions 60 and
62 and the channels Z1 through Z8 are best described with reference
to the operation of the heat exchanger 14. According to one
exemplary use of this invention, water is first introduced into the
inlet conduit 16 (see FIG. 1). A portion of the water flows through
the outlet port 24 of the inlet conduit 16, through the inlet
opening 52 of the first header 48, and into channel Z1.
[0046] Upon entering the channel Z1, the water fills the channel Z1
and flows into the first end of conduits 32(1) and 32(2). In FIG.
5, the exposed ends of every conduit 30 and 32 includes a symbol
designating water flow. The symbol `*` denotes that water is
entering the end of a conduit, whereas the symbol `.cndot.` denotes
that water is exiting from the end of a conduit. The water travels
through conduits 32(1) and 32(2) and exits into channel Z2 of the
second header 50. The water then fills the channel Z2 and flows
into the second end of conduits 32(3) and 32(4). The water travels
through conduits 32(3) and 32(4) and exits into channel Z3 of the
first header 48. The water fills the channel Z3 and flows into the
first end of conduits 32(5) and 32(6). The water travels through
conduits 32(5) and 32(6) and exits into channel Z4 of the second
header 50. The water fills the channel Z4 and flows into the second
end of conduits 32(7) and 32(8). The water travels through conduits
32(7) and 32(8) and exits into channel Z5 of the first header 48.
The water fills the channel Z5 and flows into the first end of
conduits 32(9) and 32(10). The water travels through conduits 32(9)
and 32(10) and exits into channel Z6 of the second header 50.
[0047] Water is also introduced into the channel Z6 through the
bypass opening 54 of the second header 50. By way of non-limiting
example, about approximately 20% of the water introduced into the
heat exchanger 14 flows into the inlet opening 52 of the first
header 48, and the remaining portion of the water flows into the
bypass opening 54 of the second header 50. A lower proportion of
the water is introduced through through the inlet opening 52 in an
effort to reduce the pressure drop through the exterior column of
conduits 32. The relative proportions of water flow, however, may
be altered through adjustment of the valve 28 provided on the
bypass conduit 26.
[0048] Both sources of water, either alone or in combination, fill
the channel Z6 and flow into the second end of conduits 30(6),
30(7), 30(8), 30(9) and 30(10). The water then travels through
conduits 30(6), 30(7), 30(8), 30(9) and 30(10) and exits into
channel Z7 of the first header 48. The water fills the channel Z7
and flows into the first end of conduits 30(1), 30(2), 30(3), 30(4)
and 30(5). The channel Z7 includes the first ends of the entire
interior column C1 of conduits 30. The water then travels through
conduits 30(1), 30(2), 30(3), 30(4) and 30(5) and exits into
channel Z8 of the second header 50. The water fills the channel Z8
of the second header 50 and flows into the outlet opening 56
provided in the second header 50. The water is ultimately carried
away by the outlet conduit 18 that is coupled to the outlet opening
56 of the second header 50.
[0049] Those skilled in the art will recognize that various ways
exist to direct the flow of water through the conduits 30 and 32
without departing from the scope or spirit of the invention, and
the invention is not limited to any particular flow path.
[0050] FIG. 6 is a cross-sectional view of the boiler of FIG. 1
taken along the lines 6-6. As best shown in FIG. 6, the heat
exchanger 14 of FIGS. 2-4 is positioned between the top panel 17
and the lower panel 57 of the boiler housing 12. A partition 72
extends between the top panel 17 and the lower panel 57 of the
boiler housing 12 and is positioned outwardly from the outer column
of conduits 32. The partition 72 is a "U" shaped wall having
substantially the same radius of curvature as the wall 40 of the
baffle 31. A gap "C" of substantially constant width is defined
radially between the baffle wall 40 and the partition 72. The gap
"C" is referred to hereinafter as constricted region "C", the
significance of which will be explained in greater detail later.
According to this exemplary embodiment, the partition 72 is a
component of the boiler housing 12. Alternatively, the partition 72
may be a component of the heat exchanger 14. As another
alternative, the side walls 19 (see FIG. 1) of the boiler housing
12 may form the partition.
[0051] The flow of combustion products along a defined flow
passageway is depicted by a series of arrows labeled `1` through
`6` in FIG. 6. Products of combustion are first introduced into the
interior region of the boiler housing 12 by the burner 20 (not
shown in this figure). The products of combustion initially expand
to fill the interior portion 70 of the housing that is
circumscribed by the interior column of conduits 30, as indicated
by the eight horizontal arrows labeled `1.` Heat from the products
of combustion is transferred to the water within the conduits 30
through convective and radiant heat transfer. By way of example,
about 75% to about 80% of the thermal energy of the products of
combustion is transferred to the water within the conduits 30.
[0052] The products of combustion are then induced to flow between
gaps (not shown) provided between the exterior surfaces of adjacent
conduits 30. These gaps are optionally defined by fins formed on
the conduits 30. The gaps may also be provided by spaces defined
between the conduits 30. The products of combustion are then urged
or forced to flow in an upward direction and along the opposite
surface of the conduits 30 as indicated by the vertical arrows
labeled `2.` The products of combustion are then induced to flow
through the gap "G" provided between the top cover 17 of the
housing 12 and the top edge of the wall 40 of the baffle 31, as
baffle 31, as indicated by the horizontal arrows labeled `3.`
[0053] The products of combustion are then induced to flow through
the constricted region "C" defined between the baffle wall 40 and
the partition 72 of the boiler housing 12, as indicated by the
vertical arrows labeled `4.` The conduits 32 are positioned within
the constricted region "C." Heat from the products of combustion is
transferred to the water within the conduits 32 through convective
heat transfer. By way of example, about 20% to about 25% of the
thermal energy of the products of combustion is transferred to the
water within the conduits 32. The purpose of the constricted region
"C" will be described in greater detail later.
[0054] After passing through the constricted region "C," the
products of combustion collect in an exhaust chamber 74 positioned
beneath the heat exchanger 14, as indicated by the horizontal
arrows labeled `5.` The exhaust chamber 74 is bounded by the lower
panel 57 of the boiler housing 12, the lower portion of the
partition 72 and the floor 49 of the baffle 31. The products of
combustion are then drawn through an exhaust opening 76 provided in
the lower panel 57 of the boiler housing 12, as indicated by the
vertical arrow labeled `6.` The exhaust opening 76 is positioned
proximal to and in flow communication with the constricted region
"C." Although not shown, an exhaust conduit may be coupled to the
exhaust opening 76 for removing the products of combustion from the
boiler 10.
[0055] As indicated previously, the products of combustion are
induced to flow through the constricted region "C" defined between
the baffle wall 40 and the partition 72 of the boiler housing 12,
as indicated by the vertical arrows labeled `4.` Both the total
volume and cross-sectional area of the constricted region "C" is
significantly less than the total volume and cross-sectional area
of the interior portion 70 of the housing 12 circumscribed by the
interior column of conduits 30, as depicted by the cross-sectional
view of FIG. 6. According to one embodiment of the invention the
total cross-sectional area of the constricted region "C" is about
152 square-inches, for example. In contrast, the total
cross-sectional area of the interior portion 70 of the housing 12
is about 849 square-inches, for example.
[0056] Upon entering the constricted region "C," the velocity of
the combustion products substantially increases as a result of the
reduced cross-sectional area of the constricted region "C." By way
of example, the velocity of the products of combustion in the
interior portion 70 of the housing 12 is about 1.1 feet/second and
the velocity of the products of combustion in the constricted
region "C" is about 6.4 feet/second. The high-velocity products of
combustion within the constricted region "C" results in a greater
heat exchange between the products of combustion and the water
within the exterior column of conduits 32. By way of example, about
20% to about 25% of the thermal energy of the products of
combustion is transferred to the water within the conduits 32.
[0057] The products of combustion flowing through the constricted
region "C" release sufficient heat to cause the water vapor in the
products of combustion to condense on the outer surfaces of the
conduits 32. As background, condensate is introduced through
combustion as a byproduct of the combustion reaction, and hot
combustion gases therefore contain relatively large quantities of
moisture. When the hot combustion gas is cooled, the temperature of
the gas drops. As this occurs, the amount of moisture that the gas
can hold decreases and at some distance from the combustion source,
the water condenses on any surface that is below the dew point of
the gas mixture. The dew point is the temperature to which a given
parcel of air must be cooled, at constant barometric pressure, for
water vapor to condense into water. Hydronic boilers are tailored
to condense the water vapor in the combustion gases to capture the
latent heat of vaporization of the water produced during the
combustion process. When the water vapor condenses to a liquid
phase onto a surface of the conduits 32, latent energy is released
as sensible heat onto the surface of the conduits 32, thereby
transferring heat to the water within the conduits 32.
[0058] Condensate is typically acidic, with pH values often in the
range of between about 2 to 5. The formation of increased amounts
of such acidic condensate, even in relatively small quantities, can
accelerate the corrosion of heat exchange tubing, increase
oxidation and scale formation, reduce heat exchange efficiency and
contribute to failure of the boiler. To limit or prevent corrosion
in the presence of water, the conduits 30 and 32 are optionally
formed from stainless steel, aluminum or coated copper; the header
mounting plates 42 and 44 are optionally composed of carbon steel;
and the front panel 36 is optionally composed of stainless steel.
The headers 48 and 50 are optionally composed of carbon steel. The
interior of the headers 48 and 50 and the conduits 30 and 32, or
any other component of the boiler 10 in the presence of water, may
be lined with glass for safely distributing potable water. It
should be understood by those skilled in the art that the
individual components of the boiler 10 may be formed from a variety
of materials without departing from the spirit or scope of the
invention.
[0059] The heat exchanger 14 confers several benefits over
conventional heat exchangers. First, the heat exchanger 14 can
withstand a greater quantity of condensate without exhibiting
corrosion because the conduits 30 and 32 are formed from a material
that resists corrosion in the presence of water. Accordingly,
because introducing lower inlet water temperatures into a heat
exchanger results in greater quantities of condensate and the
conduits 30 and 32 are formed from a corrosion resistant material,
water may be introduced into the heat exchanger 14 at a lower
temperature. For example, water may be introduced into the heat
exchanger 14 at 40.degree. F., as compared with conventional
boilers which are designed to receive water pre-heated or heated to
a temperature of at least 130.degree. F. Because the heat exchanger
14 can efficiently process low-temperature water, the incoming
water does not have to be pre-heated, thereby resulting in a
significant energy savings.
[0060] Second, increasing the velocity of the combustion products
passing over the conduits 32 maximizes the heat exchange
therebetween, thereby resulting in a better utilization of the heat
exchange material as compared with heat exchangers of conventional
boilers. Accordingly, less heat exchange material (i.e., fewer or
smaller conduits 32) is required to achieve the same level of heat
exchange efficiency observed in conventional boilers, thereby
resulting in a significant material cost savings.
[0061] Third, the heat exchanger 14 is configured for the efficient
removal of condensate from the interior of the housing 12. Although
not shown, the lower panel 57 and the floor surface 49 of the
baffle 31 may include a condensate outlet port, or other
provisions, to facilitate the draining of condensation formed on
the interior surfaces of the heat exchanger 14. A drain, tube or
pipe (not shown) may be coupled to the condensate outlet port for
removing the condensate from the boiler 10. Furthermore, the
high-velocity products of combustion flowing through the
constricted region "C" urge the condensate formed on the conduits
32 in a direction towards the aforementioned condensate removal
provisions provided in the lower panel 57.
[0062] Fourth, by virtue of the unique design of the heat exchanger
14, the boiler can be configured to operate at about 93% efficiency
to about 97% efficiency, as compared with traditional hydronic
boilers which operate at 90% efficiency. One measurement of the
efficiency of a boiler is the annual fuel utilization efficiency
(AFUE). AFUE is the ratio of heat output of the boiler compared to
the total energy consumed by a boiler. An AFUE of 90%, for example,
indicates that 90% of the energy in the fuel becomes heat for the
installation and the other 10% escapes through outlet piping.
[0063] Referring back to FIG. 5, many of the serviceable components
of the heat exchanger 14 are conveniently located on the front
panel 36 of the heat exchanger 14. The headers 48 and 50 are
removable for line-of-sight access to the interior surfaces of the
conduits 30 and 32 for cleaning and/or maintenance. Upon removal of
the headers 48 and 50, the interior surfaces of the conduits 30 and
32, the headers 48 and 50, and the header mounting plates 42 and 44
may be cleaned and serviced. Additionally, the burner 20 is
conveniently positioned on the front panel 36 of the heat exchanger
14 for removal and servicing.
[0064] By positioning the burner 20, the ends of the conduits 30
and 32, and the headers 48 and 50 on the front panel 36, multiple
boilers 10 may be positioned side-by-side in an installation to
save valuable floor space.
[0065] FIGS. 7-9 depict another exemplary embodiment of a heat
exchanger 114 of a boiler. This embodiment is similar to the heat
exchanger embodiment illustrated in FIG. 4 with various exceptions,
as described hereinafter.
[0066] As best shown in FIG. 7, the heat exchanger 114 generally
includes a plurality of heat exchange conduits 130 and 132 for
carrying water (or other suitable liquid), a baffle 131 positioned
between the conduits 130 and 132 defining a flow path for products
of combustion, two header mounting plates 142 and 144 mounted to
the front panel 136, and two headers 148 and 150 mounted to the
header mounting plates 142 and 144, respectively.
[0067] Unlike the baffle 31 of FIG. 3, the baffle of FIG. 7 is
divided into two separate components, i.e., baffle 131 and mounting
plate 191. The mounting plate 191 includes apertures 139(1) and
139(2) for receiving the ends of the conduits 130, whereas the
baffle 31 of FIG. 3 includes apertures 39(1) and 39(2) for
receiving the ends of the conduits 30.
[0068] The heat exchanger 114 of FIGS. 7-9 includes an interior
column C1 of eight conduits 130 and an exterior column C2 of eight
conduits 132, as opposed to ten conduits. Accordingly, the water
flow path through the heat exchanger 114 of FIG. 7 is different
from the water flow path through the heat exchanger 14 of FIG. 3,
as described in greater detail with respect to FIG. 9. Moreover,
unlike the headers 48 and 50 of FIG. 3, the header 148 of FIG. 7
includes an inlet opening 152, a bypass opening 154, and an outlet
opening 156.
[0069] Each conduit 130 and 132 includes heat-sink fins 197
longitudinally spaced along its entire length to maximize heat
transfer between the products of combustion and the fluid within
the conduits 130 and 132.
[0070] Unlike the heat exchanger of FIG. 4, the heat exchanger 114
includes a series of baffles 190 to maximize heat transfer between
the products of combustion and the fluid within the conduits 130
and 132. As best shown in FIG. 8, baffles 190 are positioned on the
exterior surface of conduits 130 between adjacent conduits 130. The
baffles 190 optionally extend along the entire height and the
entire exterior perimeter of the conduits 130.
[0071] Each baffle 190 includes a "U" or "V" shaped portion which
is sized to fit between the revolved surface of adjacent conduits
130, as best shown in FIG. 8. One or more spring clips 192 are
mounted to each baffle 190. In assembled form, the spring clips 192
are compressed between the conduits 130 and the wall of the baffle
131, such that the baffles 190 remain in place. Those skilled in
the art will recognize that other ways exist to mount the baffles
190 to the conduits 130.
[0072] Adjacent baffles 190 are separated by a gap 194. In use, the
products of combustion flow between the fins 197 of the conduits
130 and pass through the gaps 194 provided between the conduits
130. Inducing the products of combustion through the gaps 194
maximizes heat transfer between the products of combustion and the
fluid within the conduits 130.
[0073] In addition to the baffles 190, a series of baffles 195
(fourteen shown) are positioned in every interior and exterior
crevice defined between adjacent conduits 132, as shown in FIG. 7.
According to one aspect of the invention, the baffles 195 are
provided in the form of fiberglass rope. The baffles 195, however,
may be composed of any material known to those skilled in the
art.
[0074] In use, the products of combustion flow between the fins 197
of the conduits 132. The baffles 195 direct the products of
combustion toward the flow passages of the conduits 132, thereby
maximizing heat transfer between the products of combustion and the
fluid within the conduits 132.
[0075] Referring now to FIG. 9, and according to one exemplary use
of this invention, water is first introduced into an inlet opening
152 provided in the first header 148 and into channel X1. The
symbol `*` denotes that water is entering the end of a conduit,
whereas the symbol ` ` denotes that water is exiting from the end
of a conduit. Upon entering the channel X1, the water fills the
channel X1 and flows into the first end of conduits 132(1) and
132(2). The water travels through conduits 132(1) and 132(2) and
exits into channel X2 of the second header 150. The water then
fills the channel X2 and flows into the second end of conduits
132(3) and 132(4). The water travels through conduits 132(3) and
132(4) and exits into channel X3 of the first header 148. The water
fills the channel X3 and flows into the first end of conduits
132(5) and 132(6). The water travels through conduits 132(5) and
132(6) and exits into channel X4 of the second header 150. The
water fills the channel X4 and flows into the second end of
conduits 132(7) and 132(8). The water travels through conduits
132(7) and 132(8) and exits into channel X5 of the first header
148.
[0076] Water is also introduced into the channel X5 through the
bypass opening 154 of the second header 150. By way of non-limiting
example, about approximately 20% of the water introduced into the
heat exchanger 114 flows into the inlet opening 152 of the first
header 148 and the remaining portion of the water flows into the
bypass opening 154 of the second header 150. A lower proportion of
the water is introduced through the inlet opening 152 in an effort
to reduce the pressure drop through the exterior column of conduits
132. The relative proportions of water flow, however, may be
altered through adjustment of a valve provided on the inlet conduit
(not shown).
[0077] Both sources of water, either alone or in combination, fill
the channel X5 and flow into the second end of conduits 130(5),
130(6), 130(7) and 130(8). The water then travels through conduits
130(5), 130(6), 130(7) and 130(8) and exits into channel X6 of the
second header 150. The water fills the channel X6 and flows into
the first end of conduits 130(1), 130(2), 130(3) and 130(4). The
channel X6 includes the second ends of the entire interior column
C1 of conduits 130. The water then travels through conduits 130(1),
130(2), 130(3) and 130(4) and exits into channel X7 of the first
header 148. The water fills the channel X7 of the first header 148
and flows into the outlet opening 156 provided in the first header
148. The water is ultimately carried away by an outlet conduit (not
shown) that is coupled to the outlet opening 156 of the first
header 148. As noted previously, those skilled in the art will
recognize that various ways exist to direct the flow of water
through the conduits 130 and 132 without departing from the scope
of spirit of the invention, and the invention is not limited to any
particular flow path.
[0078] While preferred embodiments of the invention have been shown
and described herein, it will be understood that such embodiments
are provided by way of example only. Numerous variations, changes
and substitutions will occur to those skilled in the art without
departing from the spirit of the invention. Accordingly, it is
intended that the appended claims cover all such variations as fall
within the spirit and scope of the invention.
* * * * *