Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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HEATING DEVICE COMPRISING A HEAT EXCHANGER SYSTEM
The present invention relates to the field of heating apparatus or devices, in
particular, comprising a heat exchanger system. The invention will be more
particularly described and exemplified with respect to a heating device for
heating
water in a swimming pool.
Currently, domestic swimming pool heating is performed via a hydraulic system
using
a heat exchanger. There are two methods of implementation of such a system
- using a tubular heat exchanger, with either an array of tubes or a
drum, that is usually made from metal or composite material ; these
systems have the advantage of being able to cope with the total
volume of fluid to be heated pumped through the system;
- using a plate heat exchanger, whereby the plates are made of
titanium or stainless steel, that are enclosed between a mounting
block and a cover plate ; these systems can be easily unmounted,
serviced, are adaptable and are also very efficient with respect to
energy transmission.
The disadvantages of the tubular heat exchange system are that they can not be
unmounted, are not adaptable, and have very poor heat transmission
performance.
~0 On the other hand, the disadvantages of the plate heat exchange system are
that the
dimensions of the conduits formed within the plates for passage of heating
fluid and
the plate geometries means that it is impossible to handle the totality of the
volume of
fluid to be heated being pumped through the system. This problem is currently
solved
by only pumping a small part of the total volume, say 10 to a maximum of 20%
thereof, through the heat exchange plates. The rest of the volume of fluid to
be
heated is bypassed outside of the heat exchange system. The problem with this
is
that it is necessary for the swimming pool vendor or fitter, and more often
than not
the local artisan, such as a plumber or mason, or even the buyer, to create,
install
and set the bypass manually to obtain the maximal flow rate with maximal heat
transmission. Such bypasses are generally made of PVC material and connected
in
parallel to, but outside of the heat exchange unit. This adds to the
complexity and
bulk of the system as a whole.
US°5°575°329 describes a heat exchange system for motor
vehicle oil, that has a
bypass system incorporated into it. However, the aim of this patent is to
enable the
heat~exchange system to work at high initial oil pressures, when the viscosity
of cold
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motor vehicle oil decreases heat transfer efficiency, and thereby to limit the
reduction
of heat transfer efficiency in the heat exchange system alone.
The present applicant has sought to overcome the problems and disadvantages of
the prior art. Accordingly, it is an object of the present invention to
provide a heating
device adapted for heating a fluid, and preferably water for a swimming pool,
comprising
- a heat exchanging system having means for passage of at least one fluid ;
- a mounting block on which the heat exchanging system is mounted
comprising at least one fluid flow inlet of a fluid to be heated, and at least
one fluid flow outlet of the same fluid that has been heated ; and
- a fluid bypass system arranged between the at least one fluid flow inlet of
a
fluid to be heated and the at least one fluid flow outlet of the same fluid
that
has been heated,
- wherein the fluid bypass system comprises at least one preset fluid flow
obstruction means regulating excess fluid flow, in a preset manner, of the
fluid to be heated between the at least one fluid flow inlet of a fluid to be
heated and the at least one fluid flow outlet of the same fluid that has been
heated.
The device of the present invention is particularly adapted to swimming pool
heater
systems, wherein the pool water is the fluid to be heated, and is transferred
through
the device by the filtration pump. The pump's general role is to pump the pool
water
through a filtration device, such as a sand filter, or diatomaceous earth
filter, in order
to purify and clean the water. The flow rates of such pumps are imposed by the
regulations currently in force for such material. For most domestic swimming
pool
filter pumps, the flow rates are comprised between about 10 to about 25 m~/h.
These
pumps function discontinuously, and do not therefore provide a continuous
supply of
pool water to the heating device. The consequence of this is that the heating
device
of the invention is adapted to obtain a balance of the loss of head between
the heat
exchange system flow and bypass flow. Most of the known heating devices are
only
concerned with limiting loss of head, and the corresponding reduction in heat
transfer
efficiency from the heat exchange system, since the primary objective in the
prior
systems is to be as efficient as possible in the heat exchange step.
In a preferred embodiment of the present invention, the fluid bypass system is
a
chamber and the at least one preset fluid flow obstruction means is located
within the
chamber.
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In another preferred embodiment of the present invention, the fluid bypass
system is
a chamber housed within the mounting block and the at least one preset~fluid
flow
obstruction means is located within the chamber.
In yet a still more preferred embodiment of the present invention, the fluid
bypass
system is a chamber formed within the mounting block and the at least one
fluid flow
obstruction means is located within the chamber. This particular set up is
very
advantageous in that it reduces the both the size and the weight of the total
installation, since the bypass is actually part of the mounting block to which
the inlet
and outlet of the fluid to be heated are connected. This set up also enables a
temperature sensor to be fitted within the chamber, which is connected to a
control
unit, by any conventional means, such as an electrical, fibre optic or
wireless
connection, e.g. via radio or light waves. In a particularly preferred
embodiment, the
temperature sensor may be slipped inside a finger, or be screwed into a screw
fitted
metallic insert. The temperature sensor can preferably be located at or in the
fluid
flow inlet that carries the fluid to be heated into the device, whereby in
this
configuration one improves the performance of the system, since the thermal
inertia
incumbent in the system is reduced.
The applicant has also advantageously and surprisingly determined that the
chamber
of the fluid bypass system can be of a general shape that will enable maximum
volume throughput of the fluid to be heated without exceeding the mechanical
resistance of the material from which it is made due to the pressure caused by
the
turbulence of the circulating fluid. In particular, the general shape of the
chamber,
when it is formed or located within the mounting block, is preferably such
that the
mounting block is still sufficiently mechanically resistant to prevent
buckling of the
heat exchanging plates when they are mounted and fixed, e.g by screws, to the
mounting block. Accordingly, the most preferable shape for the chamber is
roughly
triangular. In addition, the applicant has determined that it is most
advantageous
when the chamber has substantially rounded pockets located at at least two of
the
corners of'the triangle, and the third angle is substantially truncated. The
reason for
this is so that the mounting block, when the chamber is formed or located
therein, still
retains enough material for it to stand up to the mechanical constraints of
the plates
that are fixed against it under pressure, e.g. by screwing of a cover plate.
According to another preferred embodiment of the invention, the at least one
fluid
flow obstruction means comprises a wedge, a plate, a baffle, a deflector, a
substantially rectangular block, a generally Y-shaped block, a generally T-
shaped
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block, a generally I-shaped block, a tube, a sphere, a cone, and a truncated
cone.
Most preferably, the fluid flow obstruction means has a generally
parallelepiped
shape. Preferably, the flow obstruction means is made of a plastic material,
but can
also be made of metal or any suitably resistant material adapted to the
pressures that
are generated by the turbulence of the fluid to be heated. Alternatively, the
flow
obstruction means can even be formed as part of the chamber, and where the
latter
is formed in the mounting block, as part of the mounting block, for example
via
molding, cutting, grinding, honing or metal working. Additionally, the flow
obstruction
means can provide supplementary mechanical support to the mounting block vis- -
vis the mechanical constraints of mounting the heat exchanging plates, as
discussed
above in relation to the shape of the chamber. Where the flow obstruction
means is a
separate element, it can be fixed to the fluid bypass means using traditional
fixing
means, such as soldering, screwing, gluing, welding, nailing and the like. It
should be
borne in mind that the flow obstruction means is preset during manufacture of
the
heating device to obtain the maximal flow rate with maximal energy
transmission, as
a function of the volume of fluid to be heated that is going to be pumped
through the
heating device. As will be readily understood, the term preset used within the
context of the present specification indicates that the parameters of the
fluid flow
obstruction means, such as size, shape, angle with respect to fluid volume
flow,
2b displacement volume, surface rugosity, and the like are determined and
fixed during
manufacture or assembly of the heating device at the manufacturing plant. In
this
way, the installer, vendor or home user does not have to face the problem of
manually setting up a bypass system and fiddling with the setting in the hope
of
getting it right. Preferably, the at least one fluid flow obstruction means is
fixed to the
chamber between the at least one fluid flow inlet of a fluid to be heated and
the at
least one fluid flow outlet of the same fluid that has been heated. The
dimensions
and number of fluid flow obstruction means are designed to obtain optimal
performance, both in terms of energy transmission and reduction of noise, and
thus
may vary according to the dimensions of the chamber and the volume of fluid to
be
heated that is being pumped and bypassed through the system. As a general rule
however, the height of the fluid flow obstruction means will generally
represent about
3l5 to about 4l5 the height of the chamber. Alternatively, and in a
particularly
preferred embodiment, the at least one fluid flow obstruction means comprises
of
least one flow passage allowing fluid to flow therethrough from one side of
the fluid
flow obstruction means to another side of the fluid flow obstruction means.
Preferably
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between two and four flow passages are provided that allow fluid to flow
through from
one side of the fluid flow obstruction means to another side of the fluid flow
obstruction means. By side, it is meant a face of the obstruction means
represented
as a horizontal plane perpendicular. to the axis of vision of a viewer looking
at the
obstruction means. It will be readily understood by any skilled person that
this means
that, for example, when the obstruction means is a parallelepiped, the
passages
extends from one face to another face, preferably the opposite face.
Preferably, the
at least one fluid flow obstruction means is an integral part of the mounting
block, and
is located substantially perpendicular to fluid flow across a chamber between
the fluid
flow inlet and fluid flow outlet. Thus, when the fluid flow obstruction means
is integral
with the mounting block, the chamber is divided into two parts or halves, a
fluid entry
half, and a fluid exit half, and the obstruction means comprise at least one
passage
allowing fluid to flow from the fluid entry half, through the passage to the
other side of
the obstruction means and into the exit half of the chamber. The number of
passages
is adapted to the size of swimming pool to be heated, and is preferably
between 2
and 4.
The at least one flow passage can be of a suitable shape and diameter to allow
optimised flow of the bypassed fluid. Preferably, the at least one passage is
circular,
but other forms may be used as appropriate, for example, elliptical,
frustoconical,
~2'0 square, rectangular, triangular, or other polygonal shapes. Even more
preferably, the
diameters of the passages will be from about 15 millimeters to 25 millimeters
across.
The above description serves to provide the skilled person with the
information to
adapt the heating device to all situations and will be guaranteed to function
optimally
without the need for human intervention on the bypass, whilst at the same time
limiting the size of the equipment to be installed.
In another preferred embodiment, the flow obstruction means can have a smooth
or
a rough surface, depending on whether it is desired to increase or decrease
the
effects of turbulence within the fluid bypass means.
The mounting block also has an important role in the present invention, since
in a
particularly preferred embodiment, it has the chamber of the fluid bypass
system
housed or formed within it. Consequently, the mounting block can be made from
a
material that can withstand the mechanical constraints, such as pressure, and
wear
and tear, caused by the turbulence of the pumped fluid flow inside the bypass
chamber. Preferably, the mounting block is formed of a single piece of
material. More
preferably, the mounting block is formed of a composite material. When the
material
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is a composite material, it can comprise, for example, carbon or tungsten or
titanium
fibres impregnated or surrounded by polymer resins, wherein the fibres can be
oriented or not, or even contain multiple layers of different materials, each
layer
contributing to the overal strength and resistance of the mounting block. Even
more
preferably, the mounting block is made of a material comprising expanded
plastic,
moulded plastic, ceramic and/or metal. Suitable plastic materials are ABS,
PVC, high
impact plastic, high density polypropylene, high density polyethylene,
expanded
polyurethane or polyamide, polyethylene terephthalate and the like. Similarly,
the
metals can be chosen from titanium, aluminium, stainless steel, galvanized
steel, and
the like, and the ceramic material from known high impact resistant ceramics.
It is
preferred that the mounting block be made of a material that is as light, yet
as
resistant as possible, and for this reason, expanded plastic materials such as
ABS,
expanded polyurethane and polyethylene terephthalate are preferred. The latter
is
particularly preferred due to its excellent properties in wear resistance,
hardness and
stiffness, continuous operating temperature, mechanical strength, good
dimensional
stability, weather resistance, chemical resistance and low coefficient of
friction.
In a most preferred embodiment, the heat exchanging system is in direct
contact with
the fluid bypass system. In this case, it is also preferable that the chamber
of the fluid
bypass system be in direct contact with the heat exchanging system, since this
will
2n ensure a direct transfer of the fluid to be heated into the heat exchange
system,
whilst at the same time ensuring an adequate bypass, i.e. optimal functioning
of the
heating device.
In an alternatively preferred embodiment, the mounting block is provided with
at least
one reinforcing means for supporting the heat exchanging system. The
reinforcing
means can preferably be an integral part of the mounting block, or inserted
into the
mounting block. Most preferably, the reinforcing means are located in the
rounded
pockets at the corners of the chamber.
In still yet another alternatively preferred embodiment, the heat exchanging
system is
in indirect contact with the fluid bypass system.
With regard to the heat exchanging system used, the invention preferably uses
a
heat exchanging system based on a set of heat exchange plates, that are formed
in
such a way that when two or more plates are laid one on top of the other, a
heating
fluid passageway is formed enabling heating fluid to flow and dissipate its
thermal
energy to the plates. Such heat exchanging systems are well known in the art,
and
the plates are often made of stainless or galvanized steel or titanium. The
heating
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fluid provided to the heat exchanging system will generally come from a
primary
source of heat, such as solar power or a burner powered by gas, petrol, fuel,
coke,
coal, oil or electricity. Since domestic installations, for which the current
inventive
device is preferably designed, often use these types of burners, they will
readily
provide a constant source of primary heat that can be circulated into the heat
exchanging system of the heating device of the current invention it order to
provide
heat by thermal exchange to the fluid to be heated. The heat exchanging system
also
provides for passage of the fluid to be heated, but the two fluid sources do
not come
into direct contact. The fluid to be heated obtains its thermal energy by
transfer from
the plates that have been heated by the fluid from the primary source of heat.
Since
the passage for the fluid to be heated is relatively small in diameter and
total surface
area, the total volume of fluid to be heated being pumped into the heating
device can
not pass through the heating system. This is why the heating device of the
invention
is provided with flow bypass means comprising fluid flow obstruction means, to
divert
fluid to be heated back out of the heating device.
Although the present invention has been described with respect to a heating
device
for use in heating water in a swimming pool, it is to be understood that such
a heat
exchanger system and device comprising it can also be used, e.g. for domestic
hot
water supply requirements, whereby the heat exchange system could be connected
2~ to a boiler or gas, coal or oil fired burner that is used for general
radiation heating of a
building, and the water to be heated for the hot water supply could be pumped
through from and back to a storage tank via the heating device of the present
invention.
The present invention will now be exemplified in more detail through the
description
of a most preferred embodiment, and making reference to the non-limiting
figures in
which
- Figure 1 represents a top side perspective view of part of a preferred
heating device of the present invention°;
- Figure 2 represents a closer top side view of the same part of the
preferred heating device of Figure 1 °;
- Figure 3 represents a bottom side view of the same part of the
preferred heating device of Figure 1 °;
- Figure 4 represents a side view of the preferred heating device of
Figure°1.
- Figure 5 represents a most preferred embodiment of the device of the
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invention seen from a top perspective view.
Detailed Description of the Invention
In Figures 1 to 3, part of a preferred heating device is shown, with the
assembled
device being represented in Figure 4. The device, which is adapted for heating
fluid,
comprises a heat exchange system 1, not shown in Figure 1 but displayed in
Figure
4. The heat exchange system 1 comprises one or more heat exchange plates 2, 3,
preferably between two and thirty plates. These plates are generally made of
stainless or galvanized steel or titanium, since such materials have high
resistance to
corrosion and relatively high thermal conductivities. The resistance to
corrosion is
advantageous when the fluid to be heated is water from a swimming pool, since
such
fluids generally contain corrosive chemical substances that are necessary for
microbiological control, such as chlorine and salts, or other oxidative or
reductive
active species, such as the hypochlorite anion. The heat exchange plates are
provided with at least one passageway that allows fluid to flow between the
plates.
These passageways are not shown in the' figures since the kind of plates that
are
useful in the invention are well known in the art and can be readily acquired
in
commerce. The plates comprise a passageway for fluid flow of a fluid that is
hot, or
has a greater thermal energy than the fluid of the swimming pool to be heated.
This
hot fluid is typically known as a primary source, and is often generated by a
primary
source heater means, such as solar power, or a burner, that may be
electrically
powered, or powered by combustible fuels, such as coke, coal, gas, petrol,
fuel and
oil. In the case of application of the present invention for use with a
domestic
swimming pool, the hot fluid can come from the household central heating
system.
The primary heater source that provides the fluid with greater thermal energy
enters
and leaves the heat exchange system via an inlet 4 and an outlet 5
respectively,
provided in a mounting block 6, on which the heat exchange plates 2, 3 are
mounted.
These plates 2, 3 are stacked one on top of the other with the aid of plate
guides 7, 8
that efetend substantially vertically, from the mounting block 6, and have the
general
shape of a rod. These plate guides can be made of metal, wood or plastic, as
long as
they are adapted for the application envisaged, but such choice of materials
for the
guides is within the general knowledge of the skilled person. A cover plate 9
serves
to hold down the top heat exchange plate and provide a seal with respect to
the fluid
passageway provided within the latter. The cover plate 9 can be made of metal,
for
example the same material as the heat exchange plates, or it can also and more
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preferably be made of the same material as the mounting block 6. As mentioned
previously, the mounting block can be made of metal, such as stainless or
galvanized
steel or titanium, expanded plastic, moulded plastic, and/or ceramic, but
preferably it
is made from plastic material, and more preferably from expanded plastic
materials,
such as expanded polyurethane and ABS, or high impact plastics such as
polyethylene terephthalate , since these are relatively tight weight and are
generally
classed as high impact resistant materials. The cover plate 9, heat exchange
plates
2, 3 and mounting block 6 are connected in a sealtight manner together by a
classical mounting system, comprising for example threaded bolts or rods and
corresponding nuts or a clamping system, not shown on the figures, for which
bores
12, 13, 14, 15 are provided in the mounting block 6 and the cover plate 9.
As mentioned previously, Figures 1 and 2 represent top side perspective views
of
part of the heating device of the present invention, and in particular the
mounting
block 6. As can be seen in these figures, the mounting block serves as a base
for the
plate guides 7, 8, which extend substantially vertically therefrom. The
mounting block
6 also comprises at least one fluid flow inlet 10 of a fluid to be heated, and
at least
one fluid flow outlet 11 of the same fluid that has been heated by the heating
device,
which in the preferred embodiment is water from a swimming pool. The diameters
of
inlet 10 and outlet 11 are substantially greater than those of inlet 4 and
outlet 5, and
as will be apparent from the figures and the arrangement of inlets 4 and 10,
and
outlets 5 and 11, the respective hot or high thermal energy fluid circuit and
the circuit
containing ~ftuid to be heated, i.e. the one bringing water to be heated from
the
swimming pool, are set counter-current to each other. It has been discovered
by the
present inventors that this arrangement offers the optimum performance of the
heating device with respect to the fluid to be heated.
The device according to the present invention also comprises a fluid bypass
system°16 arranged between the fluid flow inlet 10 of a fluid to be
heated and the
fluid flow outlet 11 of the same fluid that has been heated after passing
through the
heat exchange system. The bypass system enables optimisation of the pass
through
flow rate for the heating device, minimizing thermal energy loss, by
redirecting a
predetermined flow from the inlet 10 to the outlet 11, whilst maintaining
maximum
throughput through the heat exchange system. In order to do this, the fluid
bypass
system comprises at least one preset fluid flow obstruction means 17
regulating
excess fluid flow, in a preset manner, of the fluid to be heated between the
at least
one fluid flow inlet 10 of a fluid to be heated and the at least one fluid
flow outlet 11 of
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the same fluid that has been heated after passing through the heat exchanging
system. In the preferred embodiment illustrated in the figures, particularly
figures 1
and 2, the preset fluid flow obstruction means is a parallelepiped shaped
block, that
is arranged between the inlet 10 and the outlet 11. As has been mentioned
previously, this block can be fixed, e.g. via a screw, bolt, nut, glue, etc,
or other
suitable fixing means 18 (cf. Figure°4) to the mounting block 6.
Alternatively, the fluid
flow obstruction means 17 can be formed as part of the mounting block 6, for
example by molding. The position of the obstruction means, its size, angle,
surface
smoothness/rugosity in relation to the incoming and outgoing fluid flows is
set during
manufacture and assembly of the heating device at the manufacturing facility,
as a
function of the volume of fluid to be heated, and therefore bypassed, and also
as a
function of the materials from which the mounting block and the device in
general are
made.
As is apparent from the figures, the fluid bypass system 16 is a chamber 22
and the
fluid flow obstruction means 17 is located within the chamber 22,
substantially in the
midpoint between the inlet 10 and the outlet 11. The chamber 22 is housed, or
in the
preferred embodiment formed within the mounting block 6, for example when the
mounting block 6 is molded from plastic or shaped from metal. The chamber 22
has
a generally triangular shape, for this has been demonstrated by the applicant
to be
the optimal shape capable of dealing with the high mechanical shear generated
by
the flow of fluid in, and out, of the chamber 22 via the inlet 10 and outlet
11. It is to be
noted in this preferred embodiment that the inlet 10 and outlet 11 communicate
directly with the chamber 22, through the face opposite to that on which the
heat
exchange plates 2, 3 are mounted with the aid of the guide rods 7, 8. In this
particular
embodiment, the heat exchanging plates 2, 3 are also directly mounted on the
mounting block 6 and therefor are in direct contact with the chamber 22, and
form a
peripheral sealtight contact with the latter. As an option, a seal may be
provided, for
example a silicon rubber torus arranged around the upper peripheral edge of
the
chamber 22. The generally triangular shape of the chamber 22 described
previously
is slightly modified in two respects, in that it has a substantially rounded
pocket 19,
20 located at at least two of the corners of the triangle, and the third angle
21 is
substantially truncated to give a general shape to the chamber that ressembles
a
clothes hanger without the hook. The rounded pockets 19, 20, which are
generally
circular, are substantially displaced with respect to the vertex of the
triangle that runs
parallel to the longitudinal axis of the mounting block 6, whereas the
vertices that run
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to the summit of the truncated angle 21 are substantially tangential to the
outer
radius of the arc described by the pockets 19, 20. These pockets 19, 20 enable
substantial alignment with the passageways formed in the heat exchange plates
2, 3.
This enables fluid that is to be heated to flow through the plates 2, 3, by
leaving
chamber 22 via pocket 20. Once the fluid to be heated has finished its course
through the heat exchange plates 2, 3, it will be at a higher temperature than
on entry
into the heat exchange system, and the fluid that is now heated will exit the
heat
exchange plates 2,3 and re-enter the chamber 22 via pocket 19, and from there
will
exit the chamber via outlet 11.
In a second and most preferred embodiment, and as illustrated schematically in
Figure 5, the device additionally comprises reinforcing means 23, 24, which
are
located in the rounded pocketsl9, 20 of the chamber 22 and form an integral
part of
the mounting block. These reinforcing means 23, 24 can be, for example,
inserts that
have a generally toric shape, and are inserted into the pockets and held by
chemical
or mechanical bonding. Alternatively, the reinforcing means can be bridging
material
that is integral to the material of the mounting block, which means that they
can be
molded or machined along with the mounting block. The reinforcing means can
also
have any suitable shape, such as an angle,°an arc, a segment, and the
like. The role
of the reinforcing means 23, 24 is to provide mechanical support for the
bottom heat
2'0 exchange plate of the heat exchanging system. Since such heat exchange
plates are
generally made of titanium, they tend to be rather flexible, and under the
operational
conditions of pressure at which the device of the invention operates, this can
lead to
leakage of heat exchange fluid into the by-pass system containing the fluid to
be
heated. Since the two circuits are intended to be separate, it is preferable
to avoid
such an inconvenience by providing the reinforcing means as described.
Additionally, the device contains a fluid obstruction means 17 that extends
from one
side of the chamber 6 to the other, forming a complete barrier to flow of
fluid coming
from the fluid inlet 10, and flowing towards the fluid outlet 11. The
obstruction means
17 comprises a set of fluid flow passages 25, 26, 27, which allow fluid to
flow from
one side of the obstruction means to the other, and thereby allowing fluid to
by-pass
the heat exchanging system in a controlled manner. The number and diameter of
the
fluid flow passages are determined so that the loss of head between the heat
exchange system 1 and the by-pass system 16 is balanced out, i.e. there is
substantially no overall loss of head in the device. In Figure 5, three fluid
flow
passages are shown, but the number can be anything be from one to six, and
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preferably is from two to four, and most preferably three. In terms of
diameter, one
can consider that diameters varying from 15 to 25 mm, and preferably 19 to 20
mrn,
are preferred.
The device functions as follows when used for heating water from a swimming
pool:
- hot water coming from a primary heat source is introduced into the
heat exchange circuit via inlet 4 and runs through the plates 2,3 to exit
the heat exchange system via outlet 5 ;
- significantly cooler water, in a larger volume than that of the primary
hot water circuit is taken from the swimming pool and introduced into
the chamber 22 via inlet 10. It is to be noted that the primary heat
source and the cooler water are arranged in counter-current flows to
each other, thus enabling optimum efficiency in heat transfer through
the heat exchange plates. The obstruction means 17 is of a size,
dimension and angle to the incoming cool water flow that it provides
resistance, while at the same time letting cool water through which will
then mix with water that has been heated leaving the heat exchange
system 1 and entering the chamber 22 again. The obstruction means
17 is setup on manufacture to provide the optimum resistance and
maximum flow throughput via inlet 10 of the water to be heated
2b through the heat exchange system, which will depend on the volume
of the swimming pool water to be heated. The heated water and
overflow or bypassed water mix together in the chamber 22 near outlet
11, before being circulated back into the swimming pool.
The temperature difference between the inlet water and the outlet water can
vary
between about 0.1 iC and 0.5iC, depending on the power of the heat exchanger,
which is in turn adapted in size and volume flow to the to volume of the water
reservoir, e.g. swimming pool, to be heated. The power of the heat exchanger
also
depends partly on the number of heat exchange plates provided, as well .as the
available Beating power of the primary heat source. In general, economical
heating of
a swimming pool can be achieved with the invention over a period of 4 to 5
days
maximum.
It is to be understood that other components can be added to the mounting
block 6
and/or the chamber 22, such as, for example, an air-vent, a drainage system,
anti-
return valves, stop valves and the like.
12
CA 02542637 2006-04-13
WO 2004/036135 PCT/IB2003/004578
The table below gives details of examples of ,three devices that can be made
according to the present invention, and shows variation in the number and
diameter
of the fluid flow passages, the corresponding number of heat exchange plates,
and
flow rates that are attainable with the device of the present invention
adapted for use
in heating swimming pools
Table 1
8 plates12 plates16 plates 24 plates
Maximum total
pool
filtration circuit12 12 18 5
flo
rate (m3/h)
Bypassed flow
rate
8.9 to 8.9 to 13.4 to 19.7 0 to 27.3
13.5 13.5
(m3/h)
Flow rate in hea
0.9to1.30.9to1.31.4to2 1.7to2.3
exchanger (m3/h)
Loss of head in
hea
11 to 11 to 11 to 24 9 to 16
23 23
exchanger (kPa)
Loss of head in
by
11 to 11 to 11 to 24 9 to 16
23 23
pass chamber (kPa)
Bypass fluid flo 1.90 1.90
to to
.20 to 5.1 1.6 to 6.50
speed (m/s) 3.80 3.80
Ni Passages 2 3
Diameter 0 mm 0 mm 19 mm 19 mm
13
