Note: Descriptions are shown in the official language in which they were submitted.
CA 02337842 2001-O1-16
WO 99/66199 PCT/GB99/01917
INEXHAUSTIBLE PRIME MOVER
DESCRIPTION
This invention concerns a method and apparatus for providing motive
power.
In W091109224 there is described apparatus for providing motive power
comprising first and second columns of liquid, the liquid in the second column
being substantially the same as in the first column but containing a finely
divided
material to increase its specific gravity relative to the liquid in the first
column,
means for reducing pressure above said columns, whereby liquid height in the
respective columns is different, means for causing liquid from the first
column to
overflow into the second column, means for converting energy from resultant
movement of liquid into motive power and means for returning liquid to the
first
column.
It was found that the means for reducing pressure above the columns
was not really necessary and a second apparatus was proposed in W092/1984,
wherein that feature was omitted. The apparatus in W092/1984 required a
pump to maintain the finely divided material in suspension. However, that
apparatus did not operate successfully because of the energy consumed in
operating the pump.
An object of this invention is to provide improved method and apparatus
for providing motive power.
CA 02337842 2001-O1-16
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According to a first aspect of the invention there is provided apparatus for
providing motive power comprising first and second communicating columns of
liquid, the liquid in the second column being substantially the same as in the
first
column but containing a_ finely divided material to increase its specific
gravity
relative to the liquid in the first column, means for maintaining the finely
divided
material in suspension in the second column, whereby liquid height in the
respective columns is different, so that liquid from the first column
overflows into
the second column, means for converting energy from resultant movement of
liquid into motive power, means for returning the liquid to the first column,
and
liquid agitating means associated with the second column, wherein the
agitating
means comprises at least one propeller or impeller.
According to a second aspect of the invention there is provided a method
of providing motive power comprising the steps of providing in a first column
a
liquid and in a second column the same liquid but containing a finely divided
material to increase its specific gravity relative to the liquid in the first
column,
maintaining the finely divided material in suspension in the second column,
the
two columns communicating whereby liquid height in the respective columns is
different, so that liquid from the first column overflows into the second
column,
converting energy from resultant movement of liquid into motive power and
returning the liquid to the first column, wherein the means for converting
energy
from liquid movement into motive power is a turbine.
. Thus the invention provides a circulatory system for providing motive
power. Overflow of liquid from the first to the second columns may be
controlled
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by a valued outlet located below the level at which the first column would be
in
dynamic balance with the second column. It is preferred to keep the -finely
divided material substantially evenly dispersed throughout the liquid in the
second column. It r~nay be advantageous to have two or more propellers or
impellers at different heights in the column.
The turbine may be located at any point in the apparatus where
movement of the liquid only can be utilised. In one preferred embodiment the
turbine may be associated with the second column for falling liquid to impinge
directly on rotating blades thereof. In another preferred embodiment the
turbine
may be associated with the first column itself to be driven by liquid rising
or
pressurised in that column.
The second column preferably has a second limb communicating with the
main column from just below the turbine to a lower part of the column, which
limb may include said agitating means to provide circulatory 'motion for the
liquid
in the second column and hence even dispersion of the finely divided material
therein.
The second column is preferably taller than its width, to minimise mixing
energy requirements. Preferably two or more agitators will be used spaced
apart on a single shaft for achieving suspension of the finely divided
material.
The preferred finely divided material is one that can readily be separated
from the liquid in the second column so that the liquid only can be returned
from
the second column to the first column. Possibly the finely divided material
may
be of a magnetic substance such as magnetite or fen-osilicon or a mixture of
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WO 99!66199 PCT/GB99/01917
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both, so that magnetic means may be used to remove or hold back the finely
divided material from the liquid being returned to the first column.
Alternatively,
mechanical separation means may be used such as filter means or a settling
tank. The finely divided material is preferably of a particle size that will
pass a
0.25mm mesh.
The design of settling vessel needs careful consideration as the rate of
suspension separation may determine the maximum system liquid flow, and
hence energy available to the turbine. An outwardly conically shaped vessel is
adequate but settling rates can be improved by installing suitable baffle
plates to
induce !anger flow paths for the suspension, and hence longer residence time
for the separation phase to take place. The angle of the outer wall of a cone
shaped vessel may be significant in facilitating settlement. Angles of at
least 70°
to the horizontal are believed to be desirable. Alternatively, appropriately
sized
filter screens can be employed in the second column or an associated vessel or
vessels to achieve the phase separation of the suspension. Vibration of these
screens may be desirable to minimise blinding and maximise separation rates.
Suitable vibration devices may be mounted in an airlock at the upper end of
the
second column and motive power provided by small turbines operated from
pressurised liquid in the first column. A further energy efficient method that
may
be emplayed either alone or in conjunction with other separation methods is to
direct the suspension flow within the settling vessel through a weakly
magnetic
field, which has the effect of agglomerating the individual magnetic particles
together, into heavier clusters, which causes them to sink faster, speeding up
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PCT/GB99/01917
the separation process.
Separation areas ideally will be minimised otherwise commercial scale
separation requirements may be too great. Therefore, it is further proposed
that
tilted tube settling devices be used. Such tubes are commercially available
and
can reduce the area required for gravity settling by about 50°/a
without
substantial pressure loss.
An alternative separation method for use in the apparatus of the invention
may be to use cyclone separation.
ft is believed that the apparatus is able to produce a surplus of output
energy from gravitational force greater than the energy required for its
sustained
operation. Liquids of different densities are used in the respective first and
second columns. The liquids are freely miscible with each other and are used
to
establish the different levels between the first and second columns. It is
this
difference in levels that gives the separated water its potential energy
relative to
the media in the second or mixing column.
The use of finely divided material enables the necessary height
differential between the first and second columns to be established. The
miscible properties of the suspension of finely divided materials and the
liquid in
the first column enable continuous flow conditions within the apparatus to be
maintained. The separation of the clear liquid from the finely divided
material is
achieved by using gravity again, to settle out the material.
By connecting the higher liquid column to the top of the second or mixer
column a flow rate can be established to convert potential energy into useful
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6
power by a water turbine.
The off take pipe is always located below the dynamic balance level of
the liquid column to ensure that the system cannot balance and stop. Gravity
acting equally on each column wilt cause liquid to move upwards in the first
column as the liquids attempt to rebalance. It is this continuous upwards
displacement of the lighter liquid in the first column that maintains the
height
differential between the two columns and provides the energy output.
The apparatus requires comparatively small amounts of energy to
circulate and maintain the finely divided material in suspension within the
second
column. The net energy output from the apparatus is the energy available at
the
turbine shaft, less the energy required to maintain the finely divided
material in
suspension. The apparatus of the invention does not contravene the first and
second laws of thermodynamics. The energy produced is significantly less than
the total gravitational force input.
This invention will now be further described by way of example only, with
reference to the accompanying drawings, in which:-
Figure 1 is a schematic representation of apparatus according to the
invention;
Figures 2 and 3 show the apparatus of Figure 1 in operation;
Figure 4 shows schematically an alternative embodiment of the invention;
Figure 5 shows schematically coupling of apparatus of the invention; and
Figure 6 shows a variation on the embodiment of Figure 4.
Referring to Figures 1 to 3 of the accompanying drawings, apparatus for
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7
providing motive power comprises a first column 10 in the form of an annular
tank having flared sides and a base formed as a plurality of cone shaped
separating zones 12 and a second column 14 surrounded by the ftrst column 10.
The first and second columns 10, 14 communicate in three ways. Firstly, a
lower region of the second column communicates with a lower region of the
first
column almost at the top of the cones 12 by means of pipe 16. Secondly at the
bottom of the cones 14 there are pipes 18 extending from the cones via rotary
valves 20. (Any other suitable valves may be used, such as sock valves).
Thirdly, via a header tank 22 and a valve 24 there is a pipe 26 from the top
of
the first column down to the top of the second column.
The second column 14 contains an aerofoil or propeller type mixer 28
operating in a lower region thereof. The column 14 also includes a plurality
of
baffle plates 30 spaced around its outer region to promote mixing.
The first column 10 initially contains water and the second column 14
contains water and finely divided magnetite (or any suitable dense medium) in
suspension. The suspension is maintained by the mixer 28 operating at a
relatively low speed, simply to maintain a mixture of magnetite and water.
Because the two columns are in communication via pipe 16 and the
liquids therein have different specific gravities, the water in the first
column rises
relative to the mixture in the second column. Some magnetite will enter the
first
column but settles out and is returned to the second column via the rotary
valves
20.
As shown in Figure 2, with the valve 24 closed, the water in the first
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WO 99/66199 PCT/GB99/01917
8
column rises to a first height. Then when the valve 24 is opened as shown in
Figure 3 water can return to the second column.
Assuming that the valve outlet 24 is positioned below the static level of
the liquid in the first column on opening the valve liquid will flow down pipe
26
and a turbine on the pipe (not shown) can extract the energy available from
the
head pressure times the volume flowing and convert this kinetic energy into
shaft power.
The system is now unbalanced and gravity will continue to force the
lighter separated water to the top of the first column in an attempt to re-
balance
the system. Provided the magnetite is maintained in suspension and the rate of
separation is maintained within the first vessel 10 the circulation and energy
extraction will be constantly maintained.
The foregoing description is simplified for the purpose of initial
illustration
and basic understanding of the principles involved with the system.
Essentially gravity is providing the turbine motive power as it attempts to
re-balance a constantly unbalanced liquid circulatory system and in doing so
generates kinetic energy as both liquid head pressure and flow. Gravity is
also
made to serve a secondary function in effecting the phase separation of the
magnetite and liquid, within the first column 10.
Turning to Figure 4 of the accompanying drawings, apparatus for
providing motive power comprises a first column 100 in the form of four q
uadrant
section tanks 101, each communicating via valued connections 102 with the
base of a second column 104 around which they are arranged. The tanks 101
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together form a generally cone shaped outer surface. The second column or
tank 104 has a lower conical portion 106 widening to an upper cylindrical
portion
10$.
Each tank 101 has a pipe 110 from its upper end communicating with the
top of the second column via a turbine 112.
The tanks 101 have flexible bellows type connections 113 to the second
tank 104 and are suspended via load cells 114 from rigid supports 116. The
second tank is mounted on the rigid supports 116 with load cells 120
therebetween. The load cells 114 and 120 enable the weights of the various
tanks to be monitored and hence operating conditions recorded. That can
provide a basis for automatic operation control.
The second column contains an aerofoil or propeller type mixer having a
shaft 124 and a series of spaced three bladed aerofoils 126 for agitation of
the
contents of the tank. The shaft is driven by a water motor 130 in an airlock
cylinder 131 at the top of the second column to shroud the drive unit and
protect
it from the media. The shaft is supported intermediate its ends by a bearing
132
supported from sides of the tank and within an airlock 134. Alternatively, an
electric motor could be used for driving the shaft.
The first tanks 101 initially contain water and the second tank 104
contains water and finely divided magnetite or ferrosilicon in suspension. The
agitation of the aerofoil blades keeps the finely divided material in
suspension.
The aerofoil blades are designed to urge the suspension downwards drawing a
central core of suspended media down to the base of the tank and to flow
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upwards in the outer regions of the tank. The outer sides of the first tanks
slope
at an angle of about 70° to the horizontal, so that there is less
likelihood of the
finely divided material settling on the sides of the tanks.
Because the two tanks are in communication and the liquids therein have
different specific gravities, the water in the first tanks rises relative to
the media
in the second tank. Some of the finely divided material will enter the first
tanks
but will settle out and return to the second tank via the valued connections.
The
water rising in the first tanks flows back to the second tank via the turbines
thus
generating power in the same way as described for the first embodiment.
Experiments have shown that rotating the blades at about 56 rpm is
sufficient to pump about 41 m3 of media per minute. The second tank contains
about 8 tonnes of magnetite to form a media ranging in density from 2sg at the
base to l.8sg at the top of the tank.
The mixer blades can operate adequately using around 750 watts to
provide a re-mixing capability of around 5m3 per minute. With an achieved
pressure head of 2.75 metres a turbine output, net of mechanical losses, in
excess of 2Kw may be achieved showing an exportable energy output of around
1.4Kw. More blades may be fitted to the shaft but that does not seem to
require
a linear progression in the amount of power drawn.
There will obviously be a limit to the height of any single mixer tank
(second column) caused by either loss of media density at the top of the tank
or
unacceptable power input to maintain fluidisation. Therefore, as shown in
Figure
5 of the accompanying drawings, it is proposed to mount apparatus 200A and
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2008 of the invention in a vertical series. The apparatus 200 can be of the
type
shown in Figure 4, for example. Top apparatus 200A delivers water under
pressure from its first column 202A to the second coumn 2048 of the bottom
apparatus 2008. The water pressure is further increased by the operation of
apparatus 200B and the water is then delivered to turbine 206. The turbine is
located at ground level for convenience and is of a type designed to extract
energy from the difference in the inlet pressure water flow and the back
pressure
on the discharge.
Finally, in Figures 6 and 6A of the drawings, there is shown an alternative
to the embodiment of Figure 4, wherein valued connections between the first
(300) and second columns (302) are replaced by having the bottom of the
second column Iouvred (304) to form vertical slots for the finely divided
material
to return to the base of the second column. The louvres are formed by vanes
306.
