Note: Descriptions are shown in the official language in which they were submitted.
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~AC~GROUND OF T~ INVENTI~
The present invention relates to a circulator device
for creating a flow of water, for example in a remote water
body. More particularly, the invention relates to a
circulation pump to be used in natural and man-made water
bodies for water circulation for applications in temperature
and water quality control, e.g. ice control, aeration and
oxygenation, coolingl warming, mixing of chemicals and mixing
of fertilizers.
Submersible pumps for creating circulation of water in
water bodies are known in the prior art. Henegar Canadian
Patent No. 1r031r584 issued May 23~ 1978~ for example,
describes and illustrates a water circulating device for a
lake, pond or reservoir in which a windmill supported on a
flotation raft drives a propeller in a mixing chamber suspended
in the water below the raft, the upper edges of the mixing
chamber being located above the surface of the waterO A pipe
extends from the mixing chamber to the bottom of the lake~
When the windmill drives the propeller, watex is drawn upward
from the bottom of the lake through the pipe into the mixing
chamber, and is aerated as it spills over the upper edges of
the mixing chamber~ Cramer Jr. U.S. Patents Nos. 3,667,873
issued June 6, 1972 and 3,865,909 issued February 11, 1975,
describe and illustrate high speed (3,000 to 3,500 r.p.m.)
submersible motors driving propellersO The propellers direct
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water in each case towards the downwardly pointing apex of an
inverted conical structure to diffuse the water outwardly for
removal of barnacles and the like (U.S. Patent No. 3,667,873)
or for purposes of aeration (U.S. Patent No. 3,865,909). The
motor and propeller of this latter Cramer, Jr. patent are
suspended from a float member.
Cramer, Jr. U.S. Patent No. 4,014,526 issued March 29,
1977 describes and illustrates a liquid moving and mixing
apparatus wherein a submersible motor is suspended from a float
into a liquid, and drives a propeller beneath a diffusing
member in which liquids to be diffused are introduced.
Springston U.S. Patent No. 4,302,162 issued November
24, 1981 describes a venturi-type water pumping device again
having a submersible motor driving a propeller~ The motor and
propeller axe held in a housing to be dropped to the level of
the water where it is intended to pump water.
All of the above-noted patents, except Canadian Patent
No. 1,031,584 of Menegax, appear to require, for their
operation, electrical power from conventional sources such as
power grids or generators.
It is an object of the present invention to provide a
novel low energy consumption water circulator, designed for use
at remote sites without access to conventional electrical power
sources. It is a further object of the present invention to
provide an effective and economical system for circulating
water in man-made or natural water bodies.
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SU~MARY OF T~ I~V~TION
In accordan~e with the present invention a low energy
consumption water circulator device for creating a flow of
water in a remote water body is provided. The device comprises
a support raft which is to be supported on the water body. A
number of photovoltaic panels are mounted on the raft to
generate electrical energy. A DC motor is suspended from the
raft in the water body, the motor receiving its power from the
solar cell. A propeller, to be also immersed in the water
body, is attached to the motor and is driven thereby at a low
angular velocity thus creating a large, low velocity flow of
water in the water body. An intake pipe is suspended from the
raft and has an outlet end to be positioned close to the
surface of the water body and an inlet end to be positioned
close to the middle elevation depths of the water body. The
propeller, during operation, is located in the intake pipe. A
water circulation direction means is associated with the outlet
end of the intake pipe to change the direction of the water
leaving the outlet end of the pipe so that it reaches the
surface of the water body and does not immediately plun~e back
downwards.
In a preferred embodiment of the present invention, the
motor means is a DC motor whichl by direct drive, turns the
propeller at an angular velocity in the range of between 150
and ~00 revolutions per minute. The water circulation
direction means may be an inverted flow direction cone
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positioned directly above the outlet end of the intake pipe or
a slightly buoyant plastic sheet floating on the water just
below the surface of the water and means directing water from
the outlet end of the inlet pipe to the top of the plastic
sheet.
Unlike many of the previously mentioned prior art
aeration devices, applicant's device in accordance with the
present invention is used primarily to break water
stratification. This has many applications. For example, in
situations where low oxygen is present in water, applicant's
device may be used to stir water from the middle and bottom of
a lake to the surface where oxygen exchange can take place.
This may be important for the survival of fish in lakes where
serious oxygen depletion may take place. ~s well, in cold
climates, applicant's device may be used in winter months to
prevent a lake from completely icing over by bringing warmer
water from lower layers in the lake up to the surface and by
creating a flow of water along the surface of the lake. This
may be important in lakes where game fish such as rainbow trout
exist, since, in winter months, dissolved oxygen in the wat~r
may become too low for such fish to survive after formation of
complete icecap over the lake.
Other applications of applicant's water circulator
device include its use in pumping cooler water from lower
depths of the lake to the surface where, for example, pens of
young fish may be held. Such fish often cannot survive in
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warmer, surface waterl for example when the surface water
reaches a temperature in excess of 19 C. The device may also
be used to stir injected pellets, fine powders or solutions of
nutrients into pristine lakes, i.e. as a dispersal mechanism.
BRIEF D~SCRIPTIO~ OF THE DRAWIRGS
These and other objects and advantages of the invention
will become apparent upon reading the following detailed
description and upon referring to the drawings in which:
FIGURE 1 is a schematic section elevation view of an
example embodiment of a water circulator device in accordance
with the present invention;
FIGU~E 2 is a schematic elevation view of an
alternative embodiment of the present invention in position in
a lake; and
FIGURE 3 is an exploded view of the motor and propeller
of the water circulator device in accordance with the present
invention.
While the invention will be described in conjunction
with example embodiments, it will be understood that it is not
intended to limit the invention to such embodiments. On the
contrary, it is intended to cover all alternatives,
modifications and equivalents as may be included wlthin the
spirit and scope of the invention as defined by the appended
claims.
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DETAILEO D13SCRIPTIO~ OF TIDE D ~WI~GS
In the following description, similar features in the
drawings have been given similar reference numerals.
Turning to FIGURE l there is illustrated a water
circulator device 2 in accordance with the present invention.
The device comprises an appropriate raft 4 upon which is
supported a series of photovoltaic panels 6 as an energy
source. Energy from photovoltaic panels 6, if not used
directly, may be stored in an appropriate storage battery
system 8 (phantom). Raft 4 is preferably appropriately
anchored, e.g. by anchor means or on an ice sheet (in winter
time). Suspended below raft 4 for example by cables 14 is an
intake pipe 12 having a flared, lower inlet end 16 and an
upper, outlet end 18. Intake plpe 12 is preferably made of
steel and is positioned such that outlet end 18 is relatively
close to the surface of the lake whereas inlet end 16 is close
to the middle elevation depths of the body of water within
which pipe 12 is suspended (see e.g. FIGUR~ 2). In normal
circumstances, the length of this pipe may, for example, be 3
to 7 meters.
Suspended from platform 20 on raft 4, from bar or
cabie 22 is a DC motor 24 which derives its power from
photovoltaic panels 6 or, as required, from storage battery 8.
Motor 24 drives propeller blade 26 which, during operation, is
positioned within the upper end 18 of pipe 12, to thereby
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create an upwards flow of water through pipe 12. It is
preferred that the propeller turn at low speeds, i~e. in the
range of 150 to 500 revolutions per minute. This means that
the motor may be operated at a fraction of its design speed and
that the motor may be directly coupled to the propeller.
(Alternatively the motor may be connected to the propeller by a
gear reduction of about 3 to 1.) It is preferred, on the
inside of the intake pipe 12, where the propeller 26 is
located, to provide a constriction 28 to ensure that the gap
between the propeller and the pipe is sufficiently small to
cause good propeller performance and flow of water through pipe
12.
Electric DC motor 24 maybe either a submersible DC
motor or a DC motor designed for in-air operation, the latter
being illustrated in FIGURE 3. In this latter case, motor 24
is contained in a pressurized housing 30. The propeller shaft
32 turns against a spring loaded, free running 'ITeflon" (trade
mark~ ring seal 34/ this preventing the air inside the housing
from escaping. Air pressure within the housing is permanently
established initially or is automatically maintained by a
miniature cylinder 36 (phantom) of compressed gas located
inside the housing. Cover 38 secures to one end of housing 30
to cover direct drive coupling 40 and seal 34.
Also suspended from cable 22, as can be seen in FIGURE
1, is a circulation direction means 44, consisting of an
inverted flow direction cone with its apex positioned over
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outlet end 18 of pipe 12. This cone ensures that the water
leaving this outlet end 18 reaches the surface of the water
body and does not immediately plunge back downwards.
The alternative embodiment of the present invention
illustrated in FIGUR~ 2 is very similar to that of FI~URE 1,
except that the circulation direction means, instead of being
an inverted conical structure 44, is a slightly buoyant large
plastic sheet 46 floating just below the surface of the water
body. As can be seen in this drawing, circulated flow water
leaving outlet end 18 of pipe 12 passes on top of this sheet
thereby producing a proper circulation flow.
The device in accordance with the present invention is
designed to run efficiently on very little power e.g. 25 to 250
watts. A very high efficiency of transfer of energy from power
supplied to the electric motor to final power associated with
the flow and velocity of water circulated is achieved. In
FI~URE 2 the desired positioning of pipe 12 within a lake body
may be seen, inlet end 16 being positioned towards the middle
elevation depths of the body of water. A series of fish pens
50 can be ~een in this drawing near the surface of the water to
which cooler water (e.g. +12C) from the depths of the water
body is circulated to the surface (surface water temperature
e.g. +22C) by the device of the present invention.
Thus it is apparent that there has been provided in
accordance with the invention a water circulator device that
fully satisfies the objects, aims and advantages set forth
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above. While the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art in light of the foregoing
description. Accordingly, it is intended to embrace all such
alternatives, modifications and variations as fall within the
spirit and broad scope of the invention.
