Note: Descriptions are shown in the official language in which they were submitted.
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Vortex Shedding Electrical Generator
Background Of The Invention
Field Of The Invention
The device pertains to converting kinetic energy from a fluid flow into
electrical energy.
Description Of Prior Art
In light of the national focus on reducing energy costs, many home owners are
seeking ways of
implementing renewable energy technologies. In response, businesses such as
home builders are
changing the way they build homes, such as building them to generate as much
energy as they use.
Unfortunately, this approach comes at a higher cost to traditional home
construction.
In addition, many of the mechanisms used to produce renewable energy, such as
windmills, solar
panels, and hydroelectric generators, continue to remain at a high cost for
the average consumer, in
spite of subsidies and other programs. In response, consumers are constructing
mechanisms that are
not CSA approved, making the consumer liable for potential property damages if
the homemade
mechanisms fail.
Homes have a readily available supply of kinetic energy stored in the fluid
flow of the water main,
during usage. This overlooked source of potential energy can be converted to
electricity to reduce
home owners electricity costs, providing a low cost alternative to existing
renewable energy
technologies.
The following patents illustrate some methods for what has been tried to
harness the kinetic energy
of a fluid flow to electrical energy. CA Patent application 2640868 to Bowles,
Adrian Robert, GB,
on December 21, 2005. The disadvantages of this invention include, but are not
limited to: The
invention primarily utilizes the movement of a blunt body, which is not an
efficient use of the fluid
flows potential generation of vortices. The invention also requires the moving
blunt body to have a
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fixed support arm, which fixed end opposite of the blunt body would act as an
unnecessary blunt
object within a fluid flow, whereby this would produce undue flow restriction.
Figure 8 calls for a
cruciform arrangement of blunt bodies, which would produce vortices in
opposing directions to each
35 other, whereby reducing the oscillation of the bodies. Figure 9 calls
for a blunt body containing
magnet stacks, and magnetic permeable cores wound with coils, which creates a
significant mass to
oscillate. This large mass would require a high fluid flow rate, which could
lead to resonance
failure. The invention also calls for figures such as 6, 7, 8, and 9 to have
electrical leads attached to
a primary moving part of the invention ¨ the arm, whereby the constant motion
of the arm would
40 fatigue the leads to failure. Lastly quoted as a disadvantage on page 7
of the application,
"...electrical output of a piezoelectric material is generally proportional to
the level of induced stress
but such materials exhibit relatively small strain rates even under high
forces..." which means the
invention's electrical generation would be limited by the piezoelectric
material.
45 Patent application CA 2753413 issued to Pabon, Jahir on 5 June 2009. The
disadvantages of the
invention include, but are not limited to: All the embodiments comprise a
series of mechanical parts
such as: springs, masses, and vortex shedding portions. All of which have the
potential to rub
improperly against the invention's other parts. In addition possessing so many
moving parts
increases maintenance and manufacturing costs of the invention.
US Patent 7986051 issued to Shawn Michael Frayne on 26 July 2011. The
disadvantages of this
invention include, but are not limited to: The configuration of the invention
does not suit it for
usage in pipes or other similar contained fluid flow. Claim 3 describes a
tension device, which
keeps tension on the membrane so that it will flutter in a fluid flow, whereby
the movement of the
membrane is converted to electricity. This suggests that the invention
requires regular adjustments
or tuning in order to achieve the optimal flutter.
CA Patent application 2707177 to Frayne Shawn M. The disadvantages mentioned
for the
previously listed patent also apply to this invention. Other disadvantages
include, but are not
limited to: The coils are illustrated as being attached to the membrane, which
will fatigue the coil as
it moves with the membrane, leading to breaks in the coil's leads.
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CA Patent 2266632 issued to Arnold, Lee on 9 March 2004. The disadvantages of
this invention
include, but are not limited to: The use of mechanical linkage, gears, and
flywheels to harness the
65 fluid flow induced flutter of the hydrofoils to electrical energy. This
increases maintenance and
manufacturing costs of the invention. Not only that, but it is an inefficient
method of converting the
kinetic energy from the fluid flow, resulting in lost energy when converting
the kinetic energy to
mechanical, to mechanical again, to generate electricity.
70 The present device seeks to use the well-known effect of Karman vortex
street, for converting a
fluid flows kinetic energy to electrical energy. Karman vortex street thus
described as, when a blunt
body, streamlined body, bluff body or other such body is placed against a
fluid flow of a certain
Reynolds number. Flow past such bodies experiences boundary layer separation
and a turbulent
wake, comprising of vortices downstream.
In addition, it is known that a high Reynolds number range will produce a
periodic flow pattern of
vortices shed regularly, alternating from opposite sides of the body. As the
vortices are shed, the
corresponding uneven pressure distributions upon the opposite sides of the
body generate an
alternating oscillation.
From the previously listed prior art one can conclude that they fail to teach
or suggest an invention
that would convert fluid flow kinetic energy to electrical, in the manner of
the device. It is proposed
that at least one device be configured with at least one section of water
main, to provide a cost-
effective alternative to costly renewable energy technologies. Furthermore the
nature of the device
would not significantly reduce the existing pressure of the water main. It
should also be noted that
the present device usage is not limited to water mains. It should also be
noted that the embodiment
of fig.2 has been tested in a fluid flow with favorable results.
Summary Of The Invention
The device comprises, at least one blunt body situated crosswise to a fluid
flow, with at least one
flexible membrane attached to the blunt body, with at least one magnet
attached to the flexible
membrane, and there is at least one electrical conducting coil. As the fluid
flow interacts with the
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blunt body, a Karman vortex street is generated. As the vortices are shed on
alternating sides of the
95 blunt body, the flexible membrane is driven in an oscillating manner,
thus propelling the magnet
towards and away from each electrical conducting coil. Through the relative
motion of the magnet,
electricity is induced in the coils.
Some of the advantages of the device over the prior art include, but are not
limited to:
100
= A blunt body whose width is in a fixed position, and whose width is at
least as wide as the
fluid flow, enabling it to utilize more potential vortices within a fluid
flow.
= A blunt body configured, so as not to create competing vortices.
= A device anchored within the fluid flow by means of the blunt body,
bypassing the need for
105 additional fixed points.
= The magnet is of a lesser mass, compared to a heavier mass combination
such as magnet
stacks, and magnetic permeable cores wound with coils, wherein the lesser mass
requires a
slower fluid flow in order to move.
= The devices electrical conducting coils are situated in such a way that
they do not fatigue the
110 coil leads.
= The device does not employ springs, gears, mechanical linkages, turbines,
flywheels, or
other such parts. And for this reason maintenance and manufacturing costs are
cost
effective.
= The electrical conducting coils can be of a different gauge and number of
turns, without
115 affecting the oscillations of the flexible membrane, because the
electrical conducting coils
are not attached to the flexible membrane.
= The device can be employed with a pipeline, without significantly
reducing transport
pressure.
= Materials to construct the device are readily available.
120 = The device, in some embodiments can be virtually silent.
= The device employs a resilient material, situated between the magnet and
coil, which allows
the magnets movement to: Get closer to the electrical conducting coil core,
thus inducing a
greater current, to increase the rate of relative movement between coil and
magnet, thus
increasing current, to reduce operating noise levels, to reduce potential
damage to the coil,
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125 membrane and the magnet from mechanical interactions, and to keep
the fluid flow
contained in a housing or pipe.
Additional features and advantages of the device will become apparent in the
description of the
preferred embodiment, figures, and claims.
130
Brief Description Of The Drawings
Fig.1 is a side view of the device in one embodiment.
Fig.2 is a side view of another embodiment of the device.
Fig.3 is a side view of the preferred embodiment of the device.
135 Fig.4a is a top down side view of a variation in surface of the blunt
body of the device.
Fig.4b is a top down side view of a variation in surface of the blunt body of
the device.
Fig.4c is a top down side view of a variation in surface of the blunt body of
the device.
Description Of The Preferred Embodiment
140
It should be noted that the Venturi effect will be utilized in the preferred
embodiment. The Venturi
effect being described as: A fluid flow pressure being reduced in a portion of
the fluid flow, due to a
constricted portion of the fluid flow, by means of a constricted pipe or other
means. Fluid flow in
the constricted portion has a higher rate of flow.
145
Fig.3 depicts the preferred embodiment of the device, wherein a blunt body
(12) is placed crosswise
to at least one fluid flow (F), whereby the interaction generates a Karman
vortex street (v). At least
one flexible membrane (14), preferably made of plastic is attached to the
blunt body (12), and
oscillates in response to the Karman vortex street (v).
150
At least one magnet (16), preferably made of NdFeB is attached to the flexible
membrane (14),
which moves (x) with the flexible membrane (14) oscillations, with a section
of flexible membrane
(14) extending past the magnet (16).
155 At least one electrical conducting coil (18), preferably made of
enameled copper wire, is configured
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to the magnet (16). At least one diaphragm (20), preferably made of a
resilient material, is situated
between the magnet (16) and the electrical conducting coils (18), whereby
reducing mechanical
damage to the magnet (16), electrical conducting coils (18), and the flexible
membrane (14).
160 And at least one method of inducing at least one Venturi effect (22) is
employed in the device. From
the movement (x) of the magnet (16), in relation to the electrical conducting
coils (18), an electrical
current is induced.
In another embodiment, illustrated by Fig.1, at least one blunt body (12) is
placed against the
165 direction of fluid flow (F) within a pipe (10). As the flow (F)
interacts with the blunt body (12), a
Karman vortex street (v) is formed downstream. The votices within the Karman
vortex street (v)
interact with at least one flexible membrane (14). The membrane (14) is
attached to the blunt body
(12), so as the vortices interact with it, the membrane (14) oscillates. There
is at least one electrical
conducting coil (18) inside the pipe (10).
170
There is at least one magnet (16) attached to the membrane (14), which moves
toward and away
from each electrical conducting coil (18). The relative motion (x) of the
magnet (16) to the coils
(18) induces an electrical current within each coil (18).
175 In another embodiment, illustrated by Fig.2, at least one blunt body
(12) is placed crosswise a fluid
flow (F) within a pipe (10). The fluid flow (F) interacts with the blunt body
(12), producing a
Karman vortex street (v) downstream. At least one attached flexible membrane
(14) oscillates in
response to the vortices within the Karman vortex street (v). And attached to
the membrane (14) is
at least one magnet (16), which moves (x) in a similar oscillating manner as
the membrane (14).
180
Situated in relation to the movement (x) of the magnet (16) are at least one
juxtaposed diaphragm
(20), preferably made of a resilient material. And situated to the diaphragm
(20) is at least one
electrical conducting coil (18), preferably made of enameled copper wire. As
the magnet (16)
moves with the membrane (14), it flexes each diaphragm (20) alternately into
the core of each coil
185 (18). Simultaneously, its magnetic field interacts with the electrical
conducting coils (18), inducing
an electrical current in each coil (18). The diaphragm (20) also serves the
purpose of keeping the
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fluid flow (F) contained in the pipe (10), and allowing the magnet (16) to get
closer to the coils (18),
so as to induce more current.
190 In another embodiment, illustrated by Fig.4, at least one blunt body
(12) is placed against the
direction of fluid flow (F) within a pipe (10). As the flow (F) interacts with
the blunt body (12), a
Karman vortex street (v) is formed downstream. The votices within the Karman
vortex street (v)
interact with at least one flexible membrane (14). The membrane (14) is
attached to the blunt body
(12), so as the vortices interact with it, the membrane (14) oscillates. There
is at least one electrical
195 conducting coil (18) outside the pipe (10).
There is at least one magnet (16) attached to the membrane (14), which moves
toward and away
from each electrical conducting coil (18). The relative motion (x) of the
magnet (16) to the coils
(18) induces an electrical current within each coil (18).
200
Figures Fig.5 to Fig.7, illustrate variations of the blunt body surface.
Illustrated in Fig.5 comprises a
surface of polygonal or platonic shape dimples, for reduced turbulent wake.
Fig.6 comprises a
circular shape dimpled surface, for reduced turbulent wake. Fig.7 comprises a
smooth surface for
increased turbulent wake. Increasing turbulent wake may result in greater
electrical generation and
205 vibrations, whereas a reduction of turbulent wake may result in reduced
vibrations and less electrical
generation.
As a warning, at least one method of preventing resonance disaster may also
need to be employed
for the device. Resonance disaster being described as, the destruction of a
system or mechanism due
210 to stored up induced vibrations, at the resonance frequency of the
system or mechanism, that
overload a system or mechanisms capacity to failure.
In the case of the device, whatever is being employed to house the device or
the device itself,
through generated vibrations of the devices resonance frequency, cause
whatever is being employed
215 to house the device or the device itself to oscillate. As this result
repeats, the vibrations are stored
within the device or housing. Because of this repeated storage and additional
energy input, the
method of housing the device oscillates more and more, until its load limit is
exceeded, and the
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housing or device destroys itself. Shock mounts, dampening materials, tuned
mass damper or other
methods could be employed to prevent this.
220
Although the preferred embodiment of the device has been described, it should
be noted that
modifications, additions and alterations can be made to the device by one
skilled in the art without
departing from the spirit and scope of the device as defined in the following
claims.
225
