Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02467519 2004-05-18
TITLE
IMPROVED POTABLE WATER HEATER
INTRODUCTION
This invention relates to a improved hot water
heater and, more particularly, to an improved hot water
heater for marine or vehicle use and which utilises diesel
fuel for heating potable water and which heater utilises the
exhaust of the burner to improve the efficiency of the
heating process.
BACKGROUND OF THE INVENTION
Hot water heaters for heating potable water for
use in cooking, showers, baths and the like, and which
potable water heaters are used in recreational vehicles,
boats, motor homes and other vehicles are, of course, well
known. The fuel typically used in such heaters is electric
power or propane. The disadvantages in using propane are
ti
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well known since propane is maintained in its liquid state by
a pressurized storage vessel. In a boat, the gas, being
heavier than air, will accumulate in the lower portions of the
boat in the event there is a leak. The fuel is volatile and
if it is ignited, an explosion may occur. More mundane
considerations include the fact that propane fuel is not
readily available. Statutes and local regulations may require
that such fuels be stored under stringent conditions and
commercial outlets are therefore not always at hand.
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Yet a further consideration is the efficiency of the
potable water heater itself. In a boat or vehicle, the space
available for a water heater is at a premium. It is desirable
to have the water heater take up a relatively small volume.
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SUMMARY OF THE INVENTION
According to one aspect of the invention there is
provided a hot water heater for heating water, said
heater being diesel powered and comprising a burner having an
axis and an open end, said burner being operable to have
combustion taking place within said burner, an exhaust jacket
surrounding said burner to carry the exhaust of said
combustion leaving said burner from said open end, an exhaust
manifold connected to said exhaust jacket by an opening
located at the end of said burner remote from said open end,
said exhaust manifold being operable to carry said exhaust
emanating from said burner from said opening, a water jacket
carrying said water and being defined by an outer
circumference of a water tank which water tank surrounds said
burner, said exhaust jacket and said exhaust manifold, said
exhaust manifold running from said opening through said water
jacket for a longitudinal distance generally approaching the
length of said water jacket and being generally parallel to
the axis of said burner, said exhaust manifold carrying said
hot exhaust through said water jacket and discharging said hot
exhaust from said exhaust manifold to an exhaust stack located
remotely from said opening.
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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Specific embodiments of the invention will now be
described, by way of example only, with the use of drawings
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in which:
Figures 1A and 1B are diagrammatic side and end
views, respectively, of a potable water heater according to
the invention;
Figure 2 is a schematic of the circuit used with
the water level sensor according to a further aspect of the
invention;
Figure 3 is an isometric and partial cutaway view
of one end of the heater according to the invention
particularly illustrating the accessibility of the various
components for serving and the water inlet and outlets;
Figure 4 is a diagrammatic schematic of a zone
heater which zone heater is used in operable association
with the heater according to the invention; and
Figures 5A and 5B are diagrammatic end and side
cutaway views of a further embodiment of the invention in
which a heater according to the invention may be used in two
different applications.
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DESCRIPTION OF SPECIFIC EMBODIMENT
Referring now to the drawings, the potable water
heating system is generally illustrated at 100 in Figure 1A.
The exhaust is created by a centrally located burner 101
which is conveniently diesel fuel powered and which burner
101 utilises pressurized air for the nozzle 102 where the
diesel fuel and the air combine to provide the combustion
flame 122. The burner 101 is conveniently a burner utilised
in a HURRICANE (Trademark) heating system manufactured by
International Thermal Research Ltd. of Richmond, British
Columbia, Canada.
The heating system 100 includes an exhaust jacket
103 surrounding the burner 101 which exhaust jacket 103
conveys hot exhaust to an exhaust manifold 104 and thence to
a stack 110 which releases the hot gases to the atmosphere,
the direction of flow of the hot exhaust being illustrated
by the arrows.
A potable water jacket 110 surrounds the burner
101 and carries potable water. Cold potable water enters
the water jacket 110 at cold water inlet 112 (Figure 1B)
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and, after being heated by the hot gases in the exhaust
jacket 103, the now heated potable water leaves at water
outlet 113.
An electrical or resistance element 114 is
inserted into the water jacket 110 from the end as
illustrated in Figure 1B. The electrical element 114 is a
resistance type 120 volt heater and is electrically powered
to assist in maintaining the temperature of the potable
water when the burner 101 is not operating such as when the
vehicle or boat has an independent source of power
available.
The heating system 100 is pressurized; that is,
the heating system 100 is a closed system. As such, there
are forces acting on the end portions 120, 121 of the water
jacket 110. The end portions 120, 121 are each generally
convex on the outside surface and concave on the inside
surfaces 126, 127 which inside surfaces 126, 127 are exposed
to the potable water under pressure in the water jacket 110.
A water level sensor generally illustrated at 130
(Figure 1B) is inserted into the potable water heater 100.
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Water level sensor 130 is used to sense the presence of
water within the heater 100. In the event the sensor 130
does not sense water within the heater 100, a signal 131 is
sent to a control board (not illustrated) which signal
results in heater shutdown with the control board
terminating operation of the burner 101.
Referring now to Figure 3, one end of the heater
100 is illustrated. It will be appreciated that the heater
100 is conveniently installed in a recreational vehicle (not
shown) from the end; that is, it is mounted endwise and, if
servicing is required, it is conveniently done by opening
access to one end of the heater 100 only so that the heater
100 need not be removed in its entirety for servicing. To
that end, a single removable and peripheral wrap around
panel member partially shown at 140 which covers the two
sides and the top of the heater 100 is conveniently attached
with removable attachments 141 (one of which is shown) such
as screws, bolts and the like on opposite sides of the
heater 100. A further and front panel member 142 is
conveniently attached to the front of the heater 100 and is
similarly easily removed by removing its attachment screws
(not shown). When the end panel 142 and/or the side panel
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140 are removed, the operating components of the heater 100
are readily visible and manually accessible from the end of
the heater 100 and servicing is possible without the removal
of the heater 100 from the recreational vehicle or boat.
The burner assembly 143, the compressor 144, the aquastats
150 mounted in the water jacket and at the end of the
combustion chamber, the combustion fan 151, and the fuel
pump 152 are all readily accessible to a user of the heater
100 and may be removed and serviced from the end of the
heater 100 without removal of the heater 100 from the
vehicle in which it is installed. In addition, the cold
water inlet 153 and the hot water outlet 154 are similarly
conveniently located at the and of the heater 100 with a
mixing valve 160 also conveniently located at the end of the
heater 100 for access.
OPERATION
In operation, ignition of the fuel and air will
take place as is usual, such as with the use of an ignition
electrode (not shown) and a combustion flame 122 will appear
in the burner tube 101 from the combustion of the
pressurized air and fuel combined in the nozzle 102 (Figure
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1A). Hot gases will subsequently emanate from the
combustion flame 122 and leave the end of the burner tube
101 as is shown by the arrows, the hot gases traveling first
into the exhaust jacket 103 to a first stack 124 which
transfers the exhaust gases to a second passageway 104
located within the water jacket 110 of the burner 100. The
exhaust will exit the second passageway 104 through outside
stack 110 and subsequently is released to the atmosphere.
Thus, it will be seen that the heat from the
exhaust gases are used to heat the exhaust manifold 104
which manifold is in contact with the potable water within
the heater 100. Additional heat is therefore provided to
the potable water through the exhaust manifold 104 which,
because of its location within the potable water jacket 110,
will enhance the heating of the potable water prior to the
exhaust gases being released to the atmosphere and improve
the efficiency of the burner. A further advantage is that
the stack temperature will be reduce because heat in the
exhaust gases will be transferred to the potable water
before the exhaust gases reach stack 100.
Because the water is under pressure within the
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water jacket 110, the force of the water will act against
the end portions 120, 121 of the water heater 100. This
force may be intermittent with the result that cyclical
stress arises. It has been found that having the end
portions 120, 121 assume a convex outside configuration and
a concave inside configuration will reduce the amplitude of
the cyclic stress on heater 100. The forces acting on the
end portions, therefore, are better absorbed by the housing
of the heater 100.
Access to the operating components associated with
the combustion in heater 100 is conveniently provided by the
removable side and end panels 140, 142 respectively (Figure
3). The user or operator may unscrew the attachment screws
141 and remove the side and top panel 140 and likewise
remove the end panel 142. The burner assembly 143 may then
be removed for servicing. If the other operating components
need servicing or replacement such as the compressor 144,
the combustion fan 151, the fuel pump 152 or the aquastats
150, their location on one end of the heater 100
conveniently provides access without removal of the heater
100 from the vehicle and without the necessity of removing
panels other than those located at one end of the heater
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100. similarly, the mixing valve 160 may easily be adjusted
for raising or lowering the temperature of the hot water
exiting the water heater 100 from hot water outlet 154.
A further embodiment of the invention is
illustrated in Figure 4 from which a zone heater generally
illustrated at 161 is operably connected to the potable
water heater 100. Zone heater 161 conveniently includes a
fan 162 which blows air over a radiator within the zone
heater 161. A glycol mixture circulates through the zone
heater 161 and a heat exchanger 163 by the use of a pump 164
which is operably connected to an aquastat 170 which
measures the temperature of the circulating glycol mixture.
An expansion tank 170 is conveniently provided in the
circuit of the zone heater 162.
A second pump 172 and an associated aquastat 173
are provided to pump the potable water heated within the
potable water heater 100 through the heat exchanger 163
thereby to exchange heat with the glycol mixture circulating
through the zone heater 161. The pumps 164, 171 are
initiated by a thermostat located in the zone serviced by
the zone heater 161.
~'nyel~rFi~3.Xi!121~
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Reference is now made to Figures 5A and 5B-which
illustrate an improved efficiency heater similar to the
potable water heater 100 of Figures 1A and 1B. In this
embodiment, however, a coolant other than potable water may
be used with the same efficiencies, such a coolant being,
for example, glycol. A further aspect of the Figure 5
embodiment lies in a configuration which may be adapted for
heater use in two(2) installations. The first installation,
as shown in Figure 5B, incorporates a final exhaust stack
180 which extends downwardly within the heater 181 and exits
the heater 181 from the bottom. This exhaust configuration
may conveniently be used for recreational vehicles and other
vehicles where the exhaust is routed along the bottom of the
vehicle. A second final exhaust configuration is shown in
broken lines at 182. A hole is cut in the top of coolant
stack 183 and the final exit or exhaust stack 182 is
connected and exits the top of the coolant heater 181.
Electric elements 190, 191 are conveniently provided to heat
the coolant when electric power is available. Cold coolant
enters the coolant heater at 192 and may conveniently exit
the heater 181 at 193 although ingress and egress of the
coolant may be similar to that in the Figure 1 embodiment.
Other operating configurations particularly described in
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association with the Figure 1 embodiment may likewise be
useful in the Figure 5 embodiment.
Many modifications will readily occur to those
skilled in the art to which the invention relates. For
example, although the exhaust stack is shown to be in a
rectangular configuration as viewed in Figure 2, the shape
could of course change as design circumstances change and
while the exhaust stack is shown as traveling down only one
side of the water jacket 110, the hot exhaust could also
travel within the water jacket 110 in several other
configurations on various sides of the burner tube 101 and
on each side of the burner tube 101 if desired. And while
only one pass of the hot exhaust through the water jacket
114 is described and illustrated, more than one pass for the
hot exhaust is readily contemplated.
It is further contemplated that the potable water
heater according to the invention may conveniently be used
in a living environment other than in marine or vehicle use.
Such a heater requires initial power to initiate the
combustion flame but, following that ignition, the heater
could operate on minimal power or the energy generated by
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the heater could be used to produce the necessary power for
continued operation.
Many further embodiments will readily occur to
those skilled in the art to which the invention relates and
the particular embodiments described are given by way of
example only and are not intended as limiting the scope of
the invention as defined in accordance with the accompanying
claims.
