Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
INLET FOR A WATER HEATER
FIELD OF THE INVENTION
[0001] The generation of temperature gradients in water heaters
above the desired outlet temperature represents a serious problem. Heating of
water promotes the precipitation of sediment, and excessive temperature
gradients tend to accelerate sediment precipitation. Accumulated sediment
tends to harden, forming a scale on various tank surfaces, which reduces water
heater efficiency and, in many cases, can lead to failure.
[0002] Also, excessive temperature gradients tend to cause
excessive temperature fluctuations. Such fluctuations bring about undue
fatigue
of the water heater tank and can reduce water heater longevity.
[0003] Furthermore, excessive temperature gradients within the
water heater tank can tend to reduce the draw-off ability of the water heater
and can decrease the water heater's response time. Both of these conditions
compromise water heater efficiency.
BACKGROUND OF THE INVENTION
[0004] This invention relates to an inlet for a water heater, which
inlet serves to reduce the generation of temperature gradients within the
water
heater. It is preferably connected into the water heater tank through the top
or a
side wall.
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OBJECTS OF THE INVENTION
[0005] It is an object of the invention to provide an inlet adapted to
reduce the generation of temperature gradients that tend to develop in water
heater tanks.
[0006] It is another object of the invention to provide an inlet adapted
to increase water heater efficiency.
[0007] It is yet another object of the invention to provide a cost
effective inlet that is easy to install at the top or side of a water heater.
[0008] Other objects of the invention will become clear from the
drawings and descriptions that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the appended drawings:
[0010] Fig. 1 is a side view of an embodiment of a top inlet according
to this invention:
[0011] Fig. 2 is an end view of the top inlet shown in Fig. 1.
[0012] Fig. 3 is a side view of a portion of the top inlet shown in Fig.
1.
[0013] Fig. 4 is a cross-sectional side view of a detail of the top inlet
shown in Fig. 3.
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[0014] Fig. 5 is a side view of another embodiment of a top inlet
according to this invention.
[0015] Fig. 6 is a side view of an embodiment of a water heater
comprising the top inlet shown in Fig. 1 or Fig. 5.
[0016] Fig. 7 is a side view of an embodiment of a side inlet
according to this invention.
[0017] Fig. 8 is a front end view of a portion of the side inlet shown in
Fig. 7.
[0018] Fig. 9 is a rear end view of a portion of the side inlet shown in
Fig. 7.
[0019] Fig. 10 is a rear end view of another portion of the side inlet
shown in Fig. 7.
[0020] Fig. 11 is a cross-sectional side view of a detail of the side
inlet shown in Fig. 9.
[0021] Fig. 12 is a side view of an embodiment of a water heater
comprising the side inlet shown in Fig. 7.
SUMMARY OF THE INVENTION
[0022] This invention relates to an inlet adapted for delivering water
into a water heater tank through a top port. The inlet includes a conduit
having
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a proximal portion with a flow opening for water flow into the inlet from a
water
source. The conduit extends from the proximal portion downwardly to a distal
end portion, which includes a flow opening for water flow from the conduit
into
the tank. The conduit defines a longitudinal flow passage. A plurality of wall
openings is provided for radial flow from the flow passage. Means such as a
deflector is provided within the conduit adjacent to each of the wall
openings.
They extend into the flow passage for deflecting at least a portion of the
water
flow radially outwardly through the wall openings.
[0023] Upon installation of the inlet into the water heater tank, the
proximal portion of the conduit extends through the tank's top port and the
distal end portion extends downward toward a bottom surface of the tank. As
water flows into the tank, the wall openings and the deflecting means co-act
to
reduce the generation of temperature gradients in the tank.
(0024] This invention also relates to a water heater that is capable of
reducing the generation of such temperature gradients. It includes an inlet
conduit, as described, as well as a fitting for engaging the inlet conduit to
the
tank's top port.
[0025] Another embodiment relates to an inlet delivering water into a
water heater tank through a side port. The inlet includes a conduit having a
proximal portion with a flow opening for water flow into the inlet from a
water
source. The conduit also includes an intermediate portion that extends from
the
proximal portion to a distal portion, which includes a flow opening for water
flow
from the conduit into the tank. The proximal, intermediate and distal portions
together define a flow passage. Means such as a deflector is provided within
the distal portion of the conduit. It extends into the flow passage for
deflecting
the water flow.
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[0026] Upon installation of the inlet into the water heater tank, the
proximal portion of the conduit extends through the tank's side port, the
intermediate portion extends toward an interior region of the tank and the
distal
portion extends downward toward a bottom of the tank. As water flows into the
tank, the distal portion of the conduit and the deflecting means co-act to
reduce
the generation of temperature gradients in the tank.
[0027] This invention also relates to a water heater that is adapted to
reduce the generation of such temperature gradients. It includes an inlet
conduit, as described, as well as a fitting for engaging the inlet conduit to
the
tank's side port. The water heater is capable of reduced temperature gradients
in accordance with an object of this invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0028] The following description is intended to refer to specific
embodiments of the invention illustrated in the drawings. While a specific
configuration has been selected for illustration, the flow pattern of incoming
water is highly effective with various modifications. This description is not
intended to define or limit the scope of the invention, which is defined
separately in the claims that follow. Also, it will be appreciated that the
drawings are not necessarily to scale and are merely provided for the purpose
of illustration.
[0029] Generally speaking, the invention relates to an inlet adapted
for delivering cold water into the storage tank of a water heater. Although
the
invention has been discovered to be highly beneficial for use in gas-fired
water
heaters that are intended for commercial use, the inlet is highly effective in
electric, oil-fired and any other type of residential or commercial water
heater.
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[0030] The inlet includes a conduit that is sized and shaped to be
installed through the top port of a water heater. It has a proximal portion
that is
to be connected to the tank's top port by means of a fitting. Extending from
the
proximal portion is a distal portion that terminates at a flow opening for
introducing water from the conduit and into the tank's interior.
[0031] Upon installation of the inlet into the water heater tank, the
proximal portion of the inlet conduit preferably extends through the tank's
top
port. The conduit extends downwardly from the proximal portion, preferably
along a vertical axis. The distal portion preferably extends downwardly toward
a
bottom of the tank and terminates at an end opening that is most preferably
positioned adjacent to the tank's bottom surface.
[0032] The inlet conduit is preferably provided with a substantially
tubular shape with a substantially constant cross-sectional area for the flow
passage that extends through the proximal and distal portions. The flow
opening is optionally reduced or constricted. The preferred inlet conduit
defines
a substantially continuous flow passageway extending from a proximal end
outside the tank to a distal end oriented toward the tank's bottom.
[0033] A plurality of wall openings are provided in the wall of the
conduit at locations between the proximal and distal ends of the conduit,
preferably closer to the distal end. The wall openings provide passages for
flow
from the longitudinal flow passageway in the conduit radially outwardly into
the
tank's interior.
[0034] A means, such as one or more flow deflectors or an
equivalent structure, is connected within the inlet conduit adjacent to each
of
the wall openings. The means is positioned to extend into the water flow path
in
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order to deflect the water flow as it travels through the inlet conduit
radially
outwardly through an adjacent wall opening toward the tank's interior. In a
preferred embodiment, the means for deflecting the water flow includes an
angled surface positioned adjacent to the conduit's wall and extending within
the conduit into the water flow path. The means can be any deflector or
element that redirects the water flow as it passes through the conduit toward
the tank's interior. Most preferably, it takes the form of a tab that is
connected
in the conduit's wall and that extends toward the central axis of the conduit.
Such a preferred tab is located adjacent to a hole in the conduit's wall,
perhaps
a hole created by forming the tab. Most preferably such a tab is positioned
just
downstream from the wall opening. Although the means for deflecting the water
flow is preferably integral with the inlet conduit or the wall thereof, it can
be
formed from a separate component that is attached to the conduit by a
fastener, snap-in or press-fit engagement, weld, threads, or any other known
or
equivalent fastening means.
[0035) A threaded fitting is preferably used to connect the inlet
conduit to the tank's top port. In a preferred embodiment, a threaded fitting
is
engaged over the proximal portion of the inlet conduit so that it can be
threaded
into a spud attached to the water heater tank's top. The fitting is preferably
engaged to the inlet conduit so that longitudinal movement of the inlet
conduit
through the fitting is prevented. In a preferred structure, this is
accomplished by
forming a ring-type groove in the outer surface of the fitting in order to
create a
radially inwardly extending surface within the fitting that can capture the
conduit. It is this ring groove that prevents such longitudinal movement.
[0036] Although the deflecting means and wall openings are
preferably positioned along the conduit so that the orientation of the conduit
about its longitudinal axis is not critical for optimal performance, the ring
groove
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can be adapted to permit rotation of the inlet conduit even after the inlet is
installed in the water heater. Accordingly, a means is preferably provided for
rotating the conduit in the fitting to adjust the conduit's orientation. The
means
may include a recess, such as a slot for example, or any surface positioned
near or at the proximal end of the conduit. Engagement of such a surface
facilitates the conduit's rotation after the fitting is threaded into the
spud. A
visual indicator is preferably provided to indicate the orientation of the
conduit
from outside of the tank.
[0037] In an optional feature of the invention, the proximal end of the
inlet conduit extends outwardly beyond the proximal end of the fitting. This
feature provides unobstructed access to the proximal end of the conduit for
rotational adjustment. Also, when a source of cold water is connected to the
proximal end of the fitting to make the necessary connection, the proximal end
of the inlet conduit can extend outwardly beyond the end of the fitting. It
has
been discovered that water flow from the source into the inlet is directed
toward
the central interior region of the inlet. Such flow reduces the wear and
erosion
that can otherwise be caused when flowing water directly impacts against the
fitting. Instead, a buffer of slow-moving water is trapped adjacent to the
fitting's
end. Such an optional feature may be especially desirable when dielectric
insulation is positioned between the fitting and the conduit. The optional
extension of the conduit beyond the fitting's end prevents accelerated erosion
of the dielectric insulation.
[0038] The invention further relates to an inlet adapted for delivering
cold water through a side port. Although the invention has been discovered to
be highly beneficial for use in gas-fired water heaters that are intended for
commercial use, the inlet is highly effective in electric, oil-tired and any
other
residential or commercial water heaters.
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[0039] The inlet has a proximal portion that is to be connected to the
tank's side port by means of a fitting. Extending from the proximal portion is
an
intermediate portion that is intended to be positioned within the tank so that
it
extends from the side port and preferably toward a central region of the
tank's
interior, most preferably toward the central, vertical axis of the water
heater.
From the end of the intermediate portion extends a distal portion that
terminates at a flow opening for introducing water from the conduit and into
the
tank's interior.
[0040] Upon installation of the inlet into the water heater tank, the
proximal portion of the inlet conduit preferably extends through the tank's
side
port. The intermediate portion preferably extends toward the tank's interior.
Most preferably, the intermediate portion is horizontal or near horizontal so
that
it extends toward the tank's interior in a plane that is substantially
parallel to the
tank's bottom. The distal portion preferably extends downwardly toward a
bottom of the tank. From the downstream end of the intermediate portion, the
conduit's distal portion most preferably curves downwardly toward the tank's
bottom surface. Such curvature is preferably gradual so that the conduit can
easily be formed by a bending process, if desired.
[0041] The flow opening through which water flows from the inlet is
positioned at the downstream end of the distal portion. The opening is
preferably oriented at some angle to the axis of the distal portion. In other
words, the flow opening preferably lies in a plane that is at an angle to the
distal
portion's axis; most preferably an acute angle such that the opening generally
faces the central region of the tank's interior.
[0042] The inlet conduit is preferably provided with a substantially
tubular shape with a substantially constant cross-sectional area for the flow
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passage that extends through the proximal, intermediate and distal portions
and through the flow opening. The preferred inlet conduit defines a
substantially continuous flow passageway extending from a proximal end
outside the tank to a distal end oriented toward the tank's bottom central
region.
(0043] A means, such as one or more flow deflectors or an
equivalent structure, is connected adjacent to and within the distal portion
of
the inlet conduit and is positioned to extend into the water flow path in
order to
deflect the water flow as it travels through the inlet conduit toward the
tank's
interior. In a preferred embodiment, the means for deflecting the water flow
includes an angled surface positioned adjacent to the distal portion's wall
and
extending within the distal portion into the water flow path. The means can be
any deflector or element that redirects or disturbs the water flow as it
passes
through the distal portion toward the tank's interior. Most preferably, it
takes the
form of a tab that is connected in the distal portion's wall and that extends
toward the central axis of the conduit. Although such a preferred tab may be
located adjacent to a hole in the distal portion's wall, perhaps a hole
created by
forming the tab, it is not necessary for such a hole to exist and the
conduit's
end opening may be the only opening. Also, although the means for deflecting
the water flow is preferably integral with the inlet conduit or the wall
thereof, it
can be formed from a separate component that is attached to the distal portion
by a fastener, snap-in or press-fit engagement, weld, threads, or any other
known or equivalent fastening means.
[0044] A threaded fitting is preferably used to connect the inlet
conduit to the tank's side port. In a preferred embodiment, a threaded fitting
is
engaged over the proximal portion of the inlet conduit so that it can be
threaded
into a spud attached to the water heater tank wall. The fitting is preferably
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engaged to the inlet conduit so that longitudinal movement of the inlet
conduit
through the fitting is prevented although rotational movement of the inlet
conduit about the conduit's axis is permitted. In a preferred structure, this
is
accomplished by forming a ring-type groove in the outer surface of the fitting
in
order to create a radially inwardly extending surface within the fitting that
can
capture the conduit. It is this ring groove that prevents such longitudinal
movement while permitting rotational movement.
[0045] Such rotational movement of the conduit in the fitting confers
a significant benefit because the downward orientation of the conduit's distal
portion should be maintained for optimal performance of the inlet and because
this orientation will change as the fitting is threaded into the tank.
Accordingly, a
means is preferably provided for rotating the conduit in the fitting to adjust
the
orientation of the distal portion. The means may include a recess, such as a
slot for example, or any surface positioned near or at the proximal end of the
conduit. Engagement of such a surface facilitates the conduit's rotation after
the fitting is threaded into the spud. A visual indicator is preferably
provided to
indicate the orientation of the conduit from outside of the tank.
[0046] In another preferred feature of the invention, the proximal end
of the inlet conduit extends outwardly beyond the proximal end of the fitting.
This preferred feature provides unobstructed access to the proximal end of the
conduit for rotational adjustment. Also, when a source of cold water is
connected to the proximal end of the fitting to make the necessary connection,
the proximal end of the inlet conduit extends outwardly beyond the end of the
fitting. It has been discovered that water flow from the source into the inlet
is
directed toward the central interior region of the inlet. Such flow reduces
the
wear and erosion that can otherwise be caused when flowing water directly
impacts against the fitting. Instead, a buffer of slow-moving water is trapped
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adjacent to the fitting's end. Such a preferred feature is especially
desirable
when dielectric insulation is positioned between the fitting and the conduit.
The
preferred extension of the conduit beyond the fitting's end prevents
accelerated
erosion of the dielectric insulation.
[0047] Referring to Figs. 1-4, a preferred embodiment of an inlet
according to this invention, designated by the numeral "10", will now be
described. Fig. 1 shows a side view of inlet 10 having an inlet conduit 12
with a
proximal portion 12A and a distal portion 12B that extends to the end of the
inlet conduit. Together, portions 12A and 12B define a continuous flow
passageway with a tubular cross-section, although other cross-sections are
contemplated as well. In this embodiment, portions 12A and 12B share the
same axis, and portion 12B is substantially an extension of portion 12A. The
inlet conduit can be formed from plastic or metal, as desired.
[0048] Engaging the proximal portion 12A of the conduit is a fitting
14 that is preferably formed from a metal such as steel. Fitting 14 includes
male
pipe threads 16 and 18 at each end. Pipe thread 16 is used for water-tight
connection to a source of cold inlet water (not shown). Pipe thread 18 is
intended for threaded engagement of fitting 14 into the spud of a water
heater's
storage tank (not shown in Fig. 1 ). Within fitting 14,' and captured between
fitting 14 and the inlet conduit, is a dielectric insulator 20, preferably in
the form
of an insulating polymeric tube. Dielectric insulator 20 provides dielectric
isolation between the metallic fitting 14 and the inlet conduit.
[0049] A ring-type groove 22 is formed in the outer surface of fitting
14 by known manufacturing methods. The groove 22 provides the interior
surface of fitting 14 with a radially inwardly extending surface that captures
dielectric insulator 20 as well as proximal portion 12A of the inlet conduit.
A ring
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groove is preferably used to serve this purpose because it prevents
longitudinal
movement of the inlet conduit through fitting 14, along its axis. At the same
time, groove 22 can be adapted to permit rotational movement of the inlet
conduit with respect to the fitting 14 so that their relative positions can be
adjusted, if desired. A proximal end 24 of the inlet conduit optionally
extends
outwardly beyond the proximal end of the fitting 14 in the preferred
embodiment
for the reasons set forth in the general description of the invention.
Although
not shown, the proximal end of the inlet conduit preferably includes a pair of
slots, or some other equivalent recess or surface, in order to facilitate
rotation
of the conduit within the fitting 14. A tool can be positioned across such
slots
and rotated until a desired position is obtained, if necessary. The slots
themselves, or a separate indicator such as an arrow or other indicia, can act
to
signify the orientation of the conduit with respect to the fitting and tank.
[0050] At the other end of the inlet conduit, an opening 26 is
provided at the downstream end of distal portion 12B. In this preferred
embodiment, opening 26 occupies a plane that is substantially horizontal and
normal to the longitudinal axis of portions 12A and 12B. The opening 26
extends entirely across the distal portion 12B and, when viewed from the
bottom (Fig. 2), it has a cross-sectional area as large as the cross-sectional
area of the flow passageway through the inlet conduit.
[0051] One possible form of a deflector or deflecting means is
designated with the numeral "28", although many other possible forms and
configurations are contemplated. In this embodiment, a plurality of deflectors
or
tabs 28 are integrally connected to the interior surface along distal portion
12B
of the inlet conduit. Tabs 28 extend inwardly toward the central region of the
flow passageway in order to deflect the water flow through adjacent wall
openings 30 that are located just upstream of corresponding deflectors. The
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tabs 28 cooperate with the inlet conduit to reduce the generation of
temperature gradients within the water heater.
[0052] Further details of a preferred tab 28 will now be described
with reference to Figs. 2, 3 and 4. Tab 28, in this embodiment, takes the form
of
an integral, semi-circular tab that is cut into the wall of the inlet conduit
and
bent along a fold line 29 (Fig. 3) in a direction toward the conduit's central
axis.
In so doing, the corresponding opening 30 is created in the conduit's wall
adjacent to and upstream of tab 28. It is important to note that tab 28 can be
formed in a wide variety of manners. In fact, deflector 28 can be formed as an
entirely separate component that can be attached to, or mounted within, the
distal portion 12B of the inlet conduit.
[0053] As shown in Fig. 4, which provides a cross-sectional view of a
portion of a wall 32 in the distal portion 12B, the tab 28 extends into the
flow
path at an angle such as angle "a'". The distance it extends into the flow
path is
designated by the letter "D" in Fig. 4, and the size of the gap or opening 30
adjacent to the tab 28 is indicated by the letter "G". Angle a is preferably
an
acute angle in order to best deflect the water flow out through the wall
openings.
[0054] Although only one deflector means arrangement is illustrated
in the embodiment shown in the Figures, it is of course contemplated that a
wide variety of arrangements can be used and that deflecting means can be
positioned in a variety of locations and orientations.
[0055] Referring again to Fig. 1, the preferred embodiment of inlet
includes a series of tabs 28 positioned in four planes separated along the
length of distal portion 12B. Three tabs 28 are preferably provided in each of
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the four planes. Referring to Fig. 2, deflectors 28 extend inwardly and
upwardly
toward the central axis of the longitudinal flow passageway. In this
embodiment, tabs 28 extend inwardly from the wall 32 of inlet conduit 12 from
its inside diameter ID. Shown in dotted lines is a central region C of
unobstructed flow through the plane of tabs 28. Central region C can vary in
diameter from zero or near zero to a diameter corresponding to the inside
diameter of the inlet. However, central region C is preferably limited in
diameter
so that significant flow is directed through the wall openings. Most
preferably,
the cross-section area of central region C is substantially less than the
cross-
sectional area of inside diameter ID. For example, each tab 28 most preferably
blocks between about 10% and 50% of the flow path, although smaller and
larger tabs are contemplated as well.
[0056] In operation, as water flows downwardly through the flow
passageway, a portion of the water flow impinges against tabs 28 and is swept
radially outwardly in the general direction indicated by the arrows in Figs. 1
and
4. The rest of the water flow that remains in the flow passageway exits inlet
conduit 12 through end opening 26 toward the bottom of the tank. Accordingly,
water flows out through each of the wall openings 30 (by action of the
adjacent
tabs 28) and through end opening 26. This preferred flow pattern is capable of
reducing the generation of temperature gradients within the water heater tank.
[0057] Referring now to Fig. 3, each tab 28 has a width W and a
height H, which also corresponds to the dimensions of the adjacent wall
opening 30 in this embodiment. Together, width W and height H define the
surface area of the deflector, which can be adjusted depending on factors such
as the number of deflectors used, the relative position of the deflectors, the
inside diameter ID of the inlet conduit 12 (Fig. 2), the capacity and diameter
of
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the water heater tank, and the position of the deflector along the length of
inlet
conduit 12.
[0058] Inlet conduit 12 is especially well adapted for use in
commercial water heaters and, accordingly, may have an inside diameter as
large as about 1'4 " or larger. For this reason, tabs 28 should be large
enough
to "pull" or redirect a significant portion of the water flow out from the
flow
passageway. In order to encourage such flow, inlet 12 is optionally provided
with a constriction such as the plug 13 shown in Fig. 5 in order to form a
reduced flow opening 15 for flow into the tank. Such a reduced opening
increases the pressure in the inlet conduit 12 to encourage maximum flow
through tabs 28.
[0059] Referring now to Fig. 6, a portion of a water heater 40 is
illustrated with an inlet according to this invention as a component thereof.
Water heater 40 includes an inlet spud 42 with female pipe threads (not shown)
positioned on a top surface 41. Male pipe threads 18 of fitting 14 are
threaded
into spud 42 in the usual manner until inlet 10 is sealingly engaged to the
water
heater 40. In order to install inlet 10, a pipe wrench or other tool can be
used to
rotate fitting 14 with respect to spud 42 to engage the threads. When the
desired water-tight seal is created between the fitting and the spud, the
orientation of the inlet conduit can then be adjusted (if necessary).
Thereafter,
the source of cold inlet water (not shown) can be connected to the male
threads 16 on the proximal end portion of fitting 14. The inlet is then ready
for
use in operation.
[0060] Referring to Figs. 7-11, a preferred embodiment of an inlet
according to this invention, designated by the numeral "10", will now be
described. Fig. 7 shows a side view of inlet 10 having an inlet conduit with a
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proximal portion 12A, an intermediate portion 12B extending from the
downstream end of the proximal portion, and a distal portion 12C that extends
from the downstream end of the intermediate portion 12B to the end of the
inlet
conduit. Together, portions 12A, 12B and 12C define a continuous flow
passageway with a tubular cross-section, although other cross-sections are
contemplated as well. In this embodiment, portions 12A and 12B share the
same axis, and portion 12B is substantially an extension of portion 12A. The
axis of portion 12C curves downwardly from that of portions 12A and 12B. The
inlet conduit can be formed from plastic or metal, as desired.
[0061] Engaging the proximal portion 12A of the conduit is a fitting
14 that is preferably formed from a metal such as steel. Fitting 14 includes
male
pipe threads 16 and 18 at each end. Pipe thread 16 is used for water-tight
connection to a source of cold inlet water (not shown). Pipe thread 18 is
intended for threaded engagement of fitting 14 into the spud of a water
heater's
storage tank (not shown in Fig. 7). Within fitting 14, and captured between
fitting 14 and the inlet conduit, is a dielectric insulator 20, preferably in
the form
of an insulating polymeric tube. Dielectric insulator 20 provides dielectric
isolation between the metallic fitting 14 and the inlet conduit.
[0062] A ring-type groove 22 is formed in the outer surface of fitting
14 by known manufacturing methods. The groove 22 provides the interior
surface of fitting 14 with a radially inwardly extending surface that captures
dielectric insulator 20 as well as proximal portion 12A of the inlet conduit.
A ring
groove is preferably used to serve this purpose because it prevents
longitudinal
movement of the inlet conduit through fitting 14, along its axis. At the same
time, groove 22 permits rotational movement of the inlet conduit with respect
to
the fitting 14 so that their relative positions can be adjusted. A proximal
end 24
of the inlet conduit extends outwardly beyond the proximal end of the fitting
14
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in the preferred embodiment for the reasons set forth in the general
description
of the invention.
[0063] At the other end of the inlet conduit, an opening 26 is
provided at the downstream end of distal portion 12C. In this preferred
embodiment, opening 26 occupies a plane that is substantially vertical and
normal to the axis of portions 12A and 12B. It is most preferably oriented at
an
acute angle with respect to the axis of distal portion 12C. The opening 26
extends entirely across the distal portion 12C and, when viewed from the left
in
Fig. 7, it has a cross-sectional area at least as large as the cross-sectional
area
of the flow passageway through the inlet conduit.
[0064] One possible form of a deflector or deflecting means is
designated with the numeral "28", although many other possible forms and
configurations are contemplated. In this embodiment, deflector 28 is
integrally
connected to the interior, lower surface of distal portion 12C of the inlet
conduit.
Deflector 28 extends inwardly toward the central region of the flow passageway
in order to deflect the water flow and to cooperate with the inlet conduit to
reduce the generation of temperature gradients within the water heater.
[0065] Further details of preferred deflector 28 will now be described
with reference to Figs. 8, 9 and 11. Deflector 28, in this embodiment, takes
the
form of an integral semi-circular tab that is cut into the wall of the inlet
conduit
and bent along a fold line 29 toward the conduit's central axis. In so doing,
an
opening 30 is created in the conduit's wall adjacent to and downstream of
deflector 28. Although such an opening may be preferred, it is important to
note
that deflector 28 can be formed in a wide variety of manners both with and
without the formation of a hole in the conduit's wall. In fact, deflector 28
can be
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formed as an entirely separate component that can be attached to, or mounted
within, the distal portion 12C of the inlet conduit.
[0066] As shown in Fig. 11, which provides a cross-sectional view of
a portion of a wall 34 in the distal portion 12C, the deflector 28 extends at
an
angle such as angle "a" a predetermined distance into the flow path defined by
the inlet conduit: This distance is designated by the letter "D" in Fig. 11,
and the
size of the gap or opening 30 adjacent to the deflector 28 is indicated by the
letter "G". Although only one deflector means is illustrated in the embodiment
shown in the Figures, it is of course contemplated that more than one
deflector
can be used and that they can be positioned in a variety of locations and
orientations.
[0067] Fig. 10 illustrates a preferred embodiment of the proximal end
of the inlet conduit. It preferably includes a pair of slots 32, or some other
equivalent recess or surface, in order to facilitate rotation of the conduit
within
the fitting 14. In this embodiment, a tool can be positioned across slots 32
and
rotated until the distal portion 12C of the inlet conduit is facing in the
optimal
direction, which is toward a bottom region of the water heater tank. The slots
32
themselves, or a separate indicator such as an arrow or other indicia, act to
signify the orientation of the conduit with respect to the fitting and tank.
[0068] Referring now to Fig. 12, a portion of a water heater 40 is
illustrated with an inlet according to this invention as a component thereof.
Water heater 40 includes an inlet spud 42 with female pipe threads (not
shown). Male pipe threads 18 of fitting 14 are threaded into spud 42 in the
usual manner until inlet 10 is sealingly engaged to the water heater 40. In
order
to install inlet 10, a pipe wrench or other tool can be used to rotate fitting
14
with respect to spud 42 to engage the threads. When the desired water-tight
CA 02575965 2007-01-31
seal is created between the fitting and the spud, the orientation of the inlet
conduit can then be adjusted utilizing the slots 32 shown in Fig. 10 so that
distal portion 12C is directed toward the tank's bottom. Thereafter, the
source
of cold inlet water (not shown) can be connected to the male threads 16 on the
proximal end portion of fitting 14. The inlet is then ready for use in
operation.
(0069] The following Examples illustrate significant benefits
according to this invention. The Examples are provided for illustrative
purposes
only, and they are not intended to limit the invention in any way.
EXAMPLE 1
[0070] An inlet such as the one illustrated in Fig. 1 was constructed
and tested in commercial water heaters heated by gas-fired burners. The inlet
was tested in comparison to a conventional top inlet that comprised a dip tube
connected to the tank spud. The relative inlet performances were measured in
relation to so-called "stacking" or "build-up". The stacking effect is
described in
U.S. Patent No. 5,341,770.
[0071] In this test, each water heater was allowed to heat up to a
predetermined storage tank temperature of 180°F. Immediately after the
main
burner turned off, water was drawn off at a rate of 5 gallons per minute. The
draw continued until the heater's thermostat called for heat (the main burner
turned on). This cycle was repeated continuously until the measured outlet
water temperature did not vary by more than 1 °F for three consecutive
draws.
The test results are summarized in the following Table 1.
CA 02575965 2007-01-31
21
Table 1
Water Input Max. Temp.Temp. Max. Temp. Decrease
Heater (BTUs) (F) Gradient Temp. Gradientin Temp.
Capacity (conventionalabove (F) (Fig.above Gradient
180F
(gallons) inlet) (F) 1 inlet)180F (%)
(F)
(conventional (Fig.
1
inlet) inlet)
100 88,000 200 20 196 16 20
100 250,000 206 26 198 18 31
80 250,000 204 24 194 14 42
(0072] The tests revealed that the temperature gradient resulting
from stacking was reduced by replacing a conventional top inlet with the inlet
embodiment shown in Fig. 1. The temperature gradient above the 180°F
starting point was reduced by as much as 42%. Such reduced temperature
stratification is expected to reduce lime precipitation, lengthen the life of
the
water heater, and reduce or even eliminate the need for periodic cleaning to
remove precipitated sediment.
EXAMPLE 2
[0073] An inlet such as the one illustrated in Fig. 1 was tested in
commercial storage-type water heaters. The inlet was tested in comparison to a
conventional top inlet, as in Example 1, to measure relative inlet performance
in
relation to so-called "draw-off ability", which is the ability of the storage
water
heater to deliver as much water as possible before the water's outlet
temperature drops below a predetermined temperature.
[0074] In this test, each storage water heater was allowed to heat up
to a predetermined storage tank temperature of 180°F. Once the burners
turned off, they were disconnected from the water heater's thermostat. Water
CA 02575965 2007-01-31
22
was then drawn off at a rate of about 5 gallons per minute and the temperature
of the outlet water was measured along with its volume. The draw was
continued until the outlet temperature dropped to about 150°F. The test
results
are summarized in the following Table 2.
Table 2
Storage WaterInput (BTUs)Drawn-off Drawn-off Volumetric
Heater Capacity Volume (gallons)Volume (gallons)Increase
(gallons) (conventional(Fig. 1 inlet)(%)
inlet)
75 160,000 63 65 3
80 250,000 64 66 3
100 250,000 108 112 4
100 300,000 69 76 10
[0075] The tests revealed that the drawn-off volume before reaching
150°F was increased by replacing a conventional top inlet with the
inlet
embodiment shown in Fig. 1. The drawn-off volume was increased by as much
as 7 gallons (10%). Accordingly, more hot water is available during a draw and
hot water is available for a longer period of time. Also, the increase in the
drawn-off volume is expected to reduce temperature spikes at the delivery
point
and reduce the amount of work required for any external equipment such as
booster water heaters.
EXAMPLE 3
[0076] An inlet such as the one illustrated in Fig. 1 was further tested
in commercial water heaters in relation to so-called "burner on time". The
amount of elapsed time was measured between burner shut-off and actuation
of the thermostat to call for heat. The test was similar to the test described
in
Example 2 except, instead of measuring the water temperature, the time until
CA 02575965 2007-01-31
23
the thermostat calls for heat was measured. The results of this test are
summarized in Table 3.
Table 3
Water Heater Input (BTUs)Elapsed TimeElapsed TimeTime Increase
Storage Capacity (seconds) (seconds) (%)
(gallons) (conventional(Fig. 1
inlet) inlet)
80 250,000 124 128 3
100 250,000 127 129 2
100 300,000 185 215 16
100 88,000 174 187 7
[0077] This test revealed that the amount of time in between the
point when the burners are turned off and the point when the thermostat later
calls for heat was significantly increased by replacing a conventional top
inlet
with the inlet embodiment shown in Fig. 1. The time was increased by as much
as 30 seconds (16%), which is expected to reduce thermostat cycling and tank
fatigue.
[0078] The exact reason for these significant benefits is not certain.
Nevertheless, it is speculated that the openings in the wall of the inlet
conduit,
together with the utilization of means for deflecting the water flow path
through
the openings, creates an extremely beneficial flow pattern. In the preferred
configuration, it creates a number of streams that are directed out to the
side of
the conduit and downwardly at an angle as the water enters the interior of the
tank. It is believed that such a flow pattern creates a thermal balance within
the
storage tank and enables a more rapid equilibrium between any stratified
layers. Accordingly, the water temperature differential from side-to-side and
from top-to-bottom within the tank is lower as compared to results from
CA 02575965 2007-01-31
24
traditional open end or closed end inlet supply tubes. It is also speculated
that
the wall openings and deflecting means tend to distribute turbulent flow that
may exist in the conduit into the tank while creating a vertical circular flow
pattern. With such a pattern, the inlet encourages water circulation
throughout
the water heater tank and reduces the temperature gradients that tend to be
generated in such tanks.
[0079] Also, when used with a burner-heated system with higher
input and perhaps multiple flue tubes, the inlet according to this invention
reduces short cycling of the burner and causes it to fire for a longer period
of
time. This has been discovered to enable better polarization for the cathode,
reduce the amount of stress at the weld between the flues) and the base, and
reduce carbonate precipitation as a result of better thermal balance.
[0080] Many modifications to the disclosed embodiments are
contemplated. For example, although the top inlet according to this invention
confers many benefits when used in a gas-fired commercial water heater, it can
be used in any residential water heater as well, heated by any available heat
source. Also, the optional end constriction embodiment illustrated in Fig. 5
can
be removed entirely or replaced with an alternative construction such as a
plug
that extends into the conduit, an inwardly bent wall portion of the conduit
itself,
a twisted end portion of the conduit that defines a constricted outlet
diameter,
or a welded or otherwise attached component that extends the conduit and
positions the constricted opening adjacent to the conduits distal end. In some
circumstances it may even prove desirable to entirely close the conduit's end
opening in order to direct all of the water flow radially outwardly through
the
wall openings.
CA 02575965 2007-01-31
[0081 ] The size and shape of the deflecting means, as well as their
number, can vary widely. Although the shape illustrated in the Figures is
preferred, it is believed that the surface area and angle of the preferred
deflectors may be at least as effective as their shape. For example, a tab or
deflector of small width W and large height H can be exchanged with a
deflector of large width W and small height H. Also, a semicircular deflector
with a particular surface area can be exchanged with a deflector having a
different shape but a similar surface area, although surface area can be
changed as well to suit a particular application. It is also contemplated that
the
preferred deflectors on the same conduit may differ from one another in terms
of their size and/or shape.
[0082] The number of preferred deflectors that are positioned in the
same plane can vary from a single deflector to 3 or 4 or more, limited only by
the diameter and strength of the inlet conduit. The distance between adjacent
planes may vary or remain constant if more than two planes of deflecting
means are used. Also, the preferred deflectors can be provided in linear rows
along the length of the inlet conduit as shown in Fig. 1, for example, or they
can
be staggered or helically arranged along the conduit's length. While
deflectors
such as tab 28 are a preferred form of deflecting means, any structure can be
alternatively used so long as it is capable of deflecting water flow outwardly
through openings in the inlet conduit.
EXAMPLE 4
[0083] An inlet such as the one illustrated in Fig. 7 was constructed
and tested in commercial water heaters heated by gas-fired burners. The inlet
was tested in comparison to a conventional side inlet that comprised a nipple
CA 02575965 2007-01-31
26
connected to the tank spuds. The relative inlet performances were measured in
relation to so-called "stacking" or "build-up".
[0084] In this test, each water heater was allowed to heat up to a
predetermined storage tank temperature of 180°F. Immediately after the
main
burner turned off, water was drawn off at a rate of 5 gallons per minute. The
draw continued until the heater's thermostat called for heat (the main burner
turned on). This cycle was repeated continuously until the measured outlet
water temperature did not vary by more than 1 °F for three consecutive
draws.
The test results are summarized in the following Table 4.
Table 4
Water Input Max. Temp.Temp. Max. Temp. Decrease
Heater (BTUs) (F) Gradient Temp. Gradientin Temp.
Capacity (conventionalabove (F) (Fig.above Gradient
180F
(gallons) inlet) (F) 1 inlet)180F (%)
(F)
(conventional (Fig.
1
inlet) inlet)
100 200,000 198 18 196 16 11
100 250,000 205 25 195 15 40
100 300,000 201 21 196 16 24
[0085] The tests revealed that the temperature gradient resulting
from stacking was reduced by replacing a conventional side inlet with the
inlet
embodiment shown in Fig. 7. The temperature gradient above the 180°F
starting point was reduced by as much as 40%.
EXAMPLE 5
[0086] An inlet such as the one illustrated in Fig. 7 was tested in
commercial storage-type water heaters. The inlet was tested in comparison to a
CA 02575965 2007-01-31
27
conventional side inlet, as in Example 4, to measure relative inlet
performance
in relation to so-called "draw-off ability", which is the ability of the
storage water
heater to deliver as much water as possible before the water's outlet
temperature drops below a predetermined temperature.
[0087] In this test, each storage water heater was allowed to heat up
to a predetermined storage tank temperature of 180°F. Once the burners
turned off, they were disconnected from the water heater's thermostat. Water
was then drawn off at a rate of about 5 gallons per minute and the temperature
of the outlet water was measured along with its volume. The draw was
continued until the outlet temperature dropped to about 150°F. The test
results
are summarized in the following Table 5.
Table 5
Storage WaterInput (BTUs)Drawn-off Drawn-off Volumetric
Heater Capacity Volume (gallons)volume (gallons)Increase
(gallons) (conventional(Fig. 1 inlet)(gallons)
inlet)
75 160,000 46 60 14
80 250,000 62 72 10
100 250,000 87 94 7
100 300,000 89 92 3
[0088] The tests revealed that the drawn-off volume before reaching
150°F was increased by replacing a conventional side inlet with the
inlet
embodiment shown in Fig. 7. The drawn-off volume was increased by as much
as 14 gallons (30%).
CA 02575965 2007-01-31
28
EXAMPLE 6
[0089] An inlet such as the one illustrated in Fig. 7 was further tested
in commercial water heaters in relation to so-called "burner on time". The
amount of elapsed time was measured between burner shut-off and actuation
of the thermostat to call for heat. The test was similar to the test described
in
Example 5 except, instead of measuring the water temperature, the time until
the thermostat calls for heat was measured. The results of this test are
summarized in Table 6.
Table 6
Water Heater Input (BTUs)Elapsed TimeElapsed TimeTime Increase
Storage Capacity (seconds) (seconds) (seconds)
(gallons) (conventional(Fig. ~
inlet) inlet)
75 160,000 71 75 4
80 250,000 125 126 1
100 250,000 171 192 21
100 300,000 343 403 60
75 300,000 429 443 14
[0090] This test revealed that the amount of time in between the
point when the burners are turned off and the point when the thermostat later
calls for heat was significantly increased by replacing a conventional side
inlet
with the inlet embodiment shown in Fig. 7. The time was increased by as much
as 60 seconds (17%), which is expected to reduce thermostat cycling and tank
fatigue.
[0091] The exact reason for these significant benefits is not certain.
Nevertheless, it is speculated that the shape of the inlet conduit, together
with
the utilization of means for deflecting the water flow path, creates a
beneficial
CA 02575965 2007-01-31
29
flow pattern. It is similar to the flow pattern created when one places a
finger or
thumb over the end of a hose to modify the flow path. This so-called "hose
spray effect" encourages water circulation throughout the water heater's tank.
It
also reduces the temperature gradients that tend to be generated in such
tanks.
[0092] Although this invention has been described with reference to
specific forms selected for illustration in the drawings, and with respect to
various modifications thereof, it will be appreciated that many other
variations
may be made without departing from the feature of reducing the generation of
temperature gradients within a water heater tank. All such variations,
including
the substitution of equivalent elements or materials for those specifically
shown
and described, are within the spirit and scope of the invention as defined in
the
appended claims.
