Note: Descriptions are shown in the official language in which they were submitted.
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
DESCRIPTION
TITLE OF INVENTION: MINERAL LIFTING SYSTEM AND MINERAL LIFTING
METHOD
Technical Field
[0001] The present invention relates to a mineral lifting
system and a mineral lifting method for mining and mineral
lifting of valuable metals and other mineral resources present
on a seabed.
Background Art
[0002] For example, an art, by which sand iron, tin, etc.,
contained in seabed sand in a shallow sea of approximately 20
m water depth, are sucked in together with the sand by a pump
and conveyed onto land, has been established and is already
being put to practical use industrially. Also, an art, by which
bedrock, etc., containing mineral ore, is pulverized and
fragmented at such a shallow seabed, is an art that is widely
used in the mining field.
[0003] However in recent years, it has become clear, from
actual surveys, etc., that numerous seabed mineral deposits are
present in the territorial 'waters and the Exclusive Economic
Zone (EEZ) of Japan. If iron, copper, zinc, gold, etc.,
contained in such mineral deposits can be mined and these metals
can be conveyed to above a sea surface, even Japan, which is
basically deemed to be poor in resources and has depended
exclusively on imports, will be able to obtain resources
domestically. Industries can thereby be activated further,
especially domestically, and contributions can also be made to
1
= CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
the global supply of resources.
[0004] An art of pulverizing mineral ore on a deep seabed
of, for example, 1600 to 5000 m water depth by a drilling machine
already exists. However, an art for conveying the mineral ore,
which has been pulverized in the deep sea, to above a sea surface
has yet to be established. Although pump conveying and
mechanical type (bucket type) conveying may be considered as
conveying arts, mechanical types are extremely low in
productivity and presently, pump type arrangements are mainly
proposed. As an example of such a pump type arrangement, there
is a mineral lifting apparatus described in Patent Literature
1.
[0005] The mineral lifting apparatus described in Patent
Literature 1 has an arrangement where a U-pipe, with one side
being a downcomer and the other side being a riser
(corresponding to a mineral lifting pipe), is held vertically
from a deep seabed to a sea surface, seawater is transported
from an upper end opening of the riser to an upper end opening
of the downcomer so that the seawater circulates inside the
U-pipe, mineral masses mined at the deep seabed are delivered
to a bottom portion of the riser, and, the characteristic of
the U-pipe that liquid levels at the opening portions at both
ends are maintained at the same height is used to make the mineral
masses ride on the rising seawater rising through the riser and
float to the sea surface.
Citation List
Patent Literature
2
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
[0006] Patent Literature 1: Japanese Published Unexamined
Patent Application No. 2003-269070
Summary of Invention
Technical Problem
[0007] However, the conventional mineral lifting
apparatus described above has the following problems.
That is, in a case of lowering and installing a steel
mineral lifting pipe onto a seabed of, for example, 1600 to 5000
m water depth from a mineral ore processing ship, even if some
buoyancy acts on the mineral lifting pipe itself, its practical
weight will still be 50 to 150 tons. To support the mineral
lifting pipe, which is such a heavy object, a large-scale
mineral ore processing ship, etc., that is sturdy and has
surplus buoyancy so as to be capable of bearing such weight
sufficiently is required.
[0008] Also, with a long mineral lifting pipe that is
connected to a mineral ore processing ship, etc., and is formed
by connecting a large number of pipe bodies, which are
constituent units, a large load such as mentioned above is more
likely to be applied to a connection portion, the closer it is
to the sea surface, and it was therefore an extremely difficult
problem as to how to arrange a structure to firmly connect the
respective pipe bodies.
[0009] Further difficulties such as the following are
expected when an extremely long and heavy mineral lifting pipe
such as described above is lowered and put in operation from
a mineral ore processing ship or supporting ship. First, due
3
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
to agitation of the sea surface due to waves, the mineral ore
processing ship, etc., will undergo movement such that the
mineral lifting pipe shakes or bends relatively and there is
a high possibility for this to become a cause leading to damage
or destruction of the mineral lifting pipe.
[0010] Another
point is that when the mineral ore
processing ship, etc., must temporarily leave for safety when
the weather is rough, as in a typhoon, etc., the mineral lifting
pipe may have to be disconnected because travel may be
obstructed if the mineral lifting pipe is kept connected. In
such a case, there are such maj or problems as to how to disconnect
the mineral lifting pipe, how to recover the disconnected
mineral lifting pipe, etc.
[0011] Further,
a problem, next to the mineral lifting pipe,
is the development of a pump system capable of conveying the
seawater, containing the pulverized mineral ore, from the deep
seabed to the mineral ore processing ship on the sea surface.
That is, although such conveying as described above from a deep
sea of, for example, 1600 to 6000 m inevitably exceeds the
capacity of a single pump and a pump system arranged by combining
a plurality or a large number of pumps is thus needed, sufficient
measures have not been taken conventionally.
[0012] The
present invention has been invented in view of
the above points, and an object thereof is to provide a mineral
lifting system and a mineral lifting method incorporating a pump
system capable of conveying seawater, containing pulverized
mineral ore, from a deep seabed to a mineral ore processing ship
4
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
on a sea surface and being arranged so that a mineral lifting
pipe, lowered to deep sea, will not drop off due to its own weight
from a connection portion of a pipe body, etc., so that a mineral
ore processing ship, etc., that supports the mineral lifting
pipe does not have to be made larger than necessary to secure
buoyancy, and so that when the sea is rough due to a typhoon,
etc., the mineral lifting pipe will not become damaged due to
rocking by waves of the mineral ore processing ship, etc., and
the mineral ore processing ship, etc., will not have to discard
the mineral lifting pipe in leaving for safety.
Solution to Problem
[0013] (1) To
achieve the above object, a mineral lifting
system according to the present invention is a mineral lifting
system including a seabed working machine, capable of being
operated to move and having an excavating portion, excavating
minerals on a seabed surface or below a seabed, and a pump,
sucking in and pumping a solid-liquid mixture containing the
minerals obtained by excavating and seawater, an electric power
supplying portion, having an electric power cable that supplies
electric power to power the seabed working machine, amain float,
having a predetermined buoyancy and floated on a sea surface
or undersea, a mineral lifting pipe, having a predetermined
length, connecting the main float and a pump of the seabed
working machine, and conveying the solid-liquid mixture, sucked
in by the pump and containing the minerals and seawater, to the
main float side, auxiliary floats, disposed at predetermined
intervals along a length direction of the mineral lifting pipe
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
and imparting a predetermined buoyancy to the mineral lifting
pipe, and a mineral sorting portion, sorting and collecting the
minerals from the solid-liquid mixture conveyed to the main
float side by the mineral lifting pipe.
[0014] Actions of the mineral lifting system according to
the present invention shall now be described for an operation
of lifting valuable metals in a deep sea to above a sea surface
as an example.
With the mineral lifting system, the seabed working
machine is disposed at a prescribed deep seabed with a mineral
deposit and the main float floats on the sea surface. Also,
the mineral sorting portion or the electric power supplying
portion, etc., can be installed, for example, on a mother ship
or other working ship, and the electric power cable that
constitutes the electric power supplying portion is connected
to an electric power receiving portion of the seabed working
machine. A traveling portion, the excavating portion, and the
pump of the seabed working machine are driven by the electric
power that is supplied.
[0015] Also, a signal cable, performing exchange of signals
for performing control of the excavating portion, control of
the traveling portion, or control of the pump, etc., of the
seabed working machine, may be installed together with the
electric power cable in a form of being attached thereto.
[0016] The pump of the seabed working machine and the main
float are connected by the long mineral lifting pipe that is
suspended in a vertical direction from the main float, and the
6
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
solid-liquid mixture conveyed by the mineral lifting pipe is
arranged to be conveyed further to the mineral sorting portion
installed on the working ship, etc.
[0017] A large number of the auxiliary floats are mounted
to predetermined locations, for example, at fixed intervals of
the mineral lifting pipe and impart the prescribed buoyancy to
the mineral lifting pipe. The mineral lifting pipe is thereby
floated so as not to drop to the seabed. Also, a lower end
portion of the mineral lifting pipe close to the seabed and the
pump of the seabed working machine are preferably connected with
a flexible pipe so as not to hinder moving operations of the
seabed working machine or so as not to cause hindrance even when
a position of the mineral lifting pipe, which is buoyant
undersea, changes.
[0018] By means of the main float and the auxiliary floats,
the mineral lifting system imparts, to the long mineral lifting
pipe, a buoyancy of a degree such that the mineral lifting pipe
will not drop to the seabed. The auxiliary floats are disposed
at predetermined intervals in the long direction of the mineral
floating pipe and the weight of the mineral lifting pipe is
sharingly supported by the auxiliary floats.
[0019] That is, if, when a large number of the auxiliary
floats are mounted at predetermined intervals in the length
direction of the mineral lifting pipe, each auxiliary float is
made to impart a buoyancy corresponding to just the weight of
a length of the mineral lifting pipe between each auxiliary
float, the load of the long mineral lifting pipe can, in theory,
7
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
be prevented from acting on an upper portion of the mineral
lifting pipe.
[0020] By thus making an appropriate buoyancy be imparted
by the auxiliary floats, a large load in the gravity direction
will not act biasedly on a certain portion, and the above
arrangement is also effective in terms of making the load be
applied evenly at predetermined intervals in the length
direction of the mineral lifting pipe. Also by the above, the
mineral lifting pipe can be prevented from breaking in the
middle due to its own large load, and if the mineral lifting
pipe is arranged by connecting a large number of pipe bodies,
destruction of a connection portion of a pipe body, etc., can
be prevented so that the mineral lifting pipe will not drop to
the seabed.
[0021] Although the total buoyancy of the main float and
the respective auxiliary floats that float the mineral lifting
pipe is set as suited, a buoyancy sufficient to make the
uppermost main float float on the sea surface is not necessarily
required, and it is preferable for the buoyancy to be such that
at least the lower end portion of the mineral lifting pipe can
be made buoyant so as to be maintained in a state of not dropping
to the seabed (a state of being adrift undersea without
sinking).
[0022] Also, it is preferable for the buoyancy to be such
that can maintain a state where, even if the lower end portion
side of the mineral lifting pipe contacts the seabed, at least
a further upper portion side is vertically buoyant undersea.
8
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
The mineral lifting pipe, which is a heavy object, is
imparted with buoyancy by the main float and the respective
auxiliary floats so that the mother ship or other working ship
or processing ship that performs control of the mineral lifting
system is not necessarily required to support the mineral
lifting pipe, and therefore there is no need to make the ship
large.
[0023] Also, while the system is in operation, the
practical weight of the mineral lifting pipe will be heavier
than when it is empty because the weight of the solid-liquid
mixture conveyed through its interior is added thereto.
Therefore, the buoyancy provided by the respective floats must
obviously be set in consideration of this point and must not
be set on the basis of the weight of the empty mineral lifting
pipe.
[0024] By remote operation, the seabed working machine is
made to move as suited and in the meantime, for example,
excavation by the excavating portion is performed on or below
the seabed with the mineral deposit to obtain mineral granules
pulverized to a predetermined particle diameter. The mineral
granules, together with the surrounding sand and seawater, are
sucked in by the pump, passed through the mineral lifting pipe
as a solid-liquid mixture, and conveyed to the main float side
on the sea surface. The solid-liquid 'mixture that has been
conveyed to the main float side is conveyed to the mineral
sorting portion, and valuable minerals are collected therefrom.
[0025] The seabed working machine is used upon being placed
9
CA 02964213 2017-04-10
English Translation of PCT/J2016/O61280
File No. 34485-19
on the seabed in a region that not only has valuable minerals,
such as noble metals, rare metals, etc., present on the seabed
surface or below the seabed at a water depth, for example, of
several thousand meters, but also has large amounts of useful
resources, such as methane hydrate (for example, near-surface
methane hydrate), which is a fossil fuel, etc. The mineral
lifting system is also usable as a system that lifts useful
resources other than minerals from a deep seabed to above a sea
surface.
[0026] (2) The present invention may be of an arrangement
where the pump that the seabed working machine has is a slurry
pump.
In this case, the solid-liquid mixture that contains the
minerals and seawater can be conveyed (pumped) without damaging
movable portions of the pump. Also, with a slurry pump, a
solid-liquid mixture that contains a comparatively large amount
of sand and mineral granules can be conveyed. With the present
arrangement, even when a ratio of the solid, such as sand or
the mineral granules, etc., and seawater changes during
operation, this can be accommodated flexibly without difficulty
and operation can be continued. Further, a slurry pump is
structurally excellent in suction ability and can perform
conveying of the solid-liquid mixture efficiently.
[0027] The slurry pump is not restricted in particular in
type or structure as long as it can convey the above-described
solid-liquid mixture without damaging the movable portions. A
gravel pump, sand pump, or hose pump, etc., can be cited as
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
examples.
[0028] (3) The present invention may be of a structure that
includes an auxiliary pump that injects a liquid flow of
predetermined pressure to a predetermined location of the
mineral lifting pipe to assist the conveying of the solid-liquid
mixture.
In this case, even if a pump, capable of singly conveying
the solid-liquid mixture to above the sea surface from a deep
seabed of, for example, several thousand meters, is not
available, conveying of a long distance of, for example, several
thousand meters from the deep seabed to above the sea surface
is made possible by the auxiliary pump assisting the conveying
by injecting the liquid flow of predetermined pressure to an
intermediate portion of the mineral lifting pipe.
[0029] From the above-described purpose, the auxiliary
pump is not required to inject the solid-liquid mixture into
the mineral lifting pipe and suffices to inject seawater in the
surroundings, and therefore a pump other than a slurry pump,
for example, a pump, such as a multistage centrifugal pump
having an impeller or a diaphragm pump, etc., may be adopted.
[0030] Presently, it is considered difficult to develop a
practical pulverized mineral ore conveying pump for a deep sea,
for example, of not less than 1600m, and it is easily imagined
that development of superabyssal parts of 4000 to 6000 m is
extremely difficult. As a solution, it is effective to combine
a plurality or a large number of existing pumps. When the
mineral lifting pipe becomes as long as several thousand meters,
11
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
a solid-liquid mixture, containing pulverized mineral ore,
cannot be conveyed in particular to a working ship on the sea
surface by a single sea-submerged lift pump (mixed flow or
diagonal flow).
[0031] However, if the problem is that there is
insufficient energy to convey the solid-liquid mixture to an
intermediate portion of the mineral lifting pipe, this can be
solved by injecting high-pressure seawater at a low flow rate
into the intermediate portion of the mineral lifting pipe by
a pump. The power (energy) that a pump transmits to a fluid
is determined by the product PxQ of pressure P and flow rate
Q, and therefore a pump with a pressure that is an ultrahigh
pressure and an extremely low flow rate is favorable for
improving efficiency. Also, the pump can be made compact if
the flow rate is low.
[0032] (4) The present invention may be of an arrangement
that includes a GPS receiver and a position correcting apparatus,
which compares position information, received by the GPS
receiver, with a predetermined set position of the mineral
lifting system to perform correction of position so as to
maintain the set position.
In this case, a GPS (global positioning system) can be
used to maintain the position of the mineral lifting system that
has been set in advance. That is, the position information,
indicating the position of the mineral lifting system, is
acquired by the GPS receiver that is installed at a
predetermined location (for example, on the main float, etc.)
12
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
of the mineral lifting system.
[0033] Next,
position information, which is set in advance
and serves as a basis, and the position information acquired
by the GPS receiver are compared by means of the position
correcting apparatus. Then, based on the difference, the
position of the mineral lifting system (the position of the main
float in the present case) is corrected by being moved by the
position correcting apparatus so as to maintain the position
(set position) serving as the basis or so as to approach (move
toward) the position serving as the basis. The correction of
position may be performed constantly during the operation of
the system or may be performed at every fixed time interval.
[0034] The
position correcting apparatus is disposed at a
predetermined position of the mineral lifting system, which is
buoyant in the sea as a whole, and is capable of moving a portion
or an entirety of the system. The arrangement of the position
correcting apparatus is not restricted in particular as long
as it can compare the position information, obtained by the GPS
receiver, and the basis position information, determined in
advance, and can correct the position based on the difference.
[0035] For
example, there are a motor, a plurality of screws,
driven by the motor and differing in propulsion direction, a
battery, which is to be a drive source of the motor, a control
portion, which compares the position information and
selectively drives the motor and the screws according to the
comparison result, etc. Also, a plurality of position
correcting apparatuses may be disposed inside the system.
13
CA 02964213 2017-04-10
English Translation of PCT/J22016/061280
File No. 34485-19
[0036] Also,
although the position correcting apparatus is
preferably provided at a member on which the GPS receiver is
installed, this does not have to be so necessarily, and setting
maybe performed as suited. For example, both the GPS receiver
and the position correcting apparatus may be provided on the
main float, or the GPS receiver may be provided at a float that
supports the electric power cable if such a float is provided
and the position correcting apparatus may be provided on the
main float. Even in the latter case, correction of position
is made possible practically without any difference to the
former case as long as a distance between the float that is the
supporting portion of the electric power cable and the main
float is structurally kept fixed or substantially fixed.
[0037] (5) The
present invention may be of an arrangement
that includes a water feeding/draining apparatus that adjusts
the buoyancy of the main float by feeding water into an interior
and draining water to an exterior of the same float.
In this case, the buoyancy of the main float itself can
be adjusted by taking seawater into the interior of the main
float or draining the seawater in the interior to the exterior
by means of the water feeding/draining apparatus. By thus
adjusting the buoyancy of the main float, a portion of the main
float can be exposed from the sea surface or the entirety can
be sunken below the sea surface. Also, when made to sink, the
main float can be adjusted in height below the sea surface.
[0038] When the
main float is sunken below the sea surface,
the main float is made less likely to be influenced by waves
14
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061.280
File No. 34485-19
(up/down motion of the sea surface) . For example, if, when the
weather is rough, as in a typhoon or when a typhoon approaches,
the main float is kept floating on the sea surface, it will
receive the influence of violent waves and undergo up/down
motion and rolling repeatedly, thereby increasing a possibility
of deformation or damage of a mounting portion of the mineral
lifting pipe connected to the main float or a peripheral portion
thereof. Waves at the sea surface occur from several meters
to approximately 10 m below the sea surface in many cases, and
therefore if the main float can be maintained to be buoyant at
a deeper position, the influence of waves can mostly be avoided
even in a typhoon.
[0039] Although the structure of the water
feeding/draining apparatus is not restricted in particular, the
structure may be such that the main float is equipped with a
waterproof lithium storage battery, a pump driven by the
electric power of the battery, a water intake valve, and a water
draining valve, and seawater in a space in the interior of the
main float can be drained or water can be taken in from the
outside by driving of the pump to adjust the amount of seawater.
[0040] (6) The
present invention may be of an arrangement
that includes a working ship and where the working ship has the
electric power supplying portion and the mineral sorting
portion, and the electric power cable, constituting the
electric power supplying portion, and a feed pipe, constituting
the mineral sorting portion and receiving the solid-liquid
mixture from the mineral lifting pipe, can be disconnected in
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
a state enabling recovery of system operation.
[0041] In this
case, the electric power cable and the feed
pipe are connected and are functioning respectively during
system operation. When the working ship must leave the site
sea area, such as when the working ship must call at a port,
for example, when the weather is rough due to the approaching
of a typhoon or by some other reason, etc., the electric power
cable or the feed pipe can be disconnected.
[0042] In such
a case, even after being disconnected, the
disconnected side is arranged to be in a state of being fixed
or connected to some supporting portion, such as a float, etc.,
so that the electric power cable or the feed pipe will not sink
undersea or drop to the seabed even upon disconnection.
[0043] When the
reason for causing the working ship to leave
is resolved, system operation can be restarted by making the
working ship return to the working sea area, connecting the
electric power cable or the feed pipe to the working ship side,
and recovering the mineral lifting system to the original state.
Disengagement and recovery of the working ship from and to the
system are thus enabled, and the system can thus be employed
readily because movement of the working ship can be performed
flexibly without occurrence of a circumstance where, for
example, the ship must leave for safety upon discarding the main
float or the mineral lifting pipe, etc.
[0044] (7) The
present invention may be of an arrangement
having a suspension apparatus, supporting the same mineral
lifting pipe, at a portion of the main float to which the mineral
16
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
lifting pipe is connected, and where, at a vicinity of the
suspension apparatus, the same mineral lifting pipe is made
capable of vibrating within a predetermined range of deflection
inside a gap through which the same mineral lifting pipe is
passed.
In this case, the mineral lifting pipe is supported by
the suspension apparatus at the main float, through or to which
the mineral lifting pipe is passed or connected, and moreover,
at the vicinity of the suspension apparatus, the same mineral
lifting pipe is made capable of vibrating or swinging within
a predetermined range of deflection inside the gap, and
therefore the corresponding portion of the mineral lifting pipe
is high in degree of freedom of movement and will not be in a
fixed state.
[0045] With the present arrangement, especially when the
main float is floating on the sea surface, the mineral lifting
pipe can undergo advancing and retreating movements in the
length direction, vibration or swinging in a diameter direction,
etc., and thus move freely to some degree in a state of not
accompanying much deformation at the vicinity of the suspension
apparatus even if the main float undergoes up/down motion and
rolling repeatedly upon receiving the influence of waves, and
therefore damage or destruction due, for example, to metal
fatigue is unlikely to occur.
[0046] Although the structure of the suspension apparatus
is not restricted in particular, it is constituted, for example,
of a link mechanism, etc., combined with a coil spring or
17
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
energizing body capable of supporting the mineral lifting pipe.
The suspension apparatus has an arrangement capable of
supporting the practical weight of the mineral lifting pipe,
to which buoyancy is imparted by the auxiliary floats at the
undersea side, and having a cushioning action when the mineral
lifting pipe undergoes advancing and retreating movements in
its length direction.
[0047] (8) The present invention may be of an arrangement
where auxiliary floats are disposed at predetermined intervals
in a length direction of the electric power cable and impart
a predetermined buoyancy to the electric power cable. In this
case, as in the case of the mineral lifting pipe described above,
the predetermined buoyancy is imparted to the electric power
cable by the buoyancy of the auxiliary floats. The electric
power cable can thereby be prevented from breaking at an
intermediate portion in the length direction due to its own
weight.
[0048] (9) The present invention may also be of an
arrangement where the mineral sorting portion includes a
wastewater processing apparatus . In this case, at the same time
as sorting and collecting the minerals by means of the mineral
sorting portion, clarified water, resulting from applying a
predetermined processing to wastewater by means of the
wastewater processing apparatus, can be disposed of by ocean
disposal (also referred to as "ocean dumping"), etc.
[0049] (10) The present invention may also be of an
arrangement where the mineral sorting portion includes a
18
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
magnetizing apparatus that magnetizes and sorts the minerals.
In this case, to counter a problem where seabed mud, which rises
together with the lifted water, becomes a cause of environmental
destruction, metals or minerals contained in the lifted sea can
be collected by the magnetizing apparatus, which is an electric
type magnet, etc., provided on a mineral ore processing ship,
and thereafter, the seabed mud can be eliminated by the same
method as a method used in general sewage processing, such as
a sedimentation method, etc. That is, the present arrangement
may be accommodated by the working ship being a mineral ore
processing ship equipped with the wastewater processing device.
[0050] Iron, chromium, nickel, cobalt, etc., can be cited
as examples of minerals with magnetic properties. All of these
minerals are valuable metals and can be collected by performing
sorting efficiently from lifted water lifted from the seabed
to above the sea surface.
[0051] (11) The present invention may be of an arrangement
where the mineral lifting pipe has a double pipe structure made
of steel and a light alloy, a structure, with which a steel pipe
is reinforced with carbon fibers, or a structure, with which
a peripheral wall is made hollow. In this case, the mineral
lifting pipe can be made light in weight. In the first place,
the greatest problem with a mineral lifting system is how to
lighten the weight of the mineral lifting pipe that may reach
several thousand meters in total length. For lightening the
weight of the mineral lifting pipe, there is, in addition to
the method of lightening the practical weight by imparting
19
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
buoyancy to the mineral lifting pipe as described above, the
method of lightening the weight of the mineral lifting pipe
itself as in the invention of the present clause.
[0052] As a
method of lightening the weight of the mineral
lifting pipe itself, there is, for example, a method of
arranging the mineral lifting pipe to have a double pipe
structure made of light alloy or steel and having an airtight
space between an inner pipe and an outer pipe. It is also
possible to provide an airtight space in a peripheral wall to
cancel out, by its buoyancy, a portion of the weight of the
mineral lifting pipe, and burdening of another location due to
the weight of the mineral lifting pipe itself can thereby be
alleviated.
[0053] As
another method for lightening the weight of the
mineral lifting pipe itself, there is, for example, a method
of arranging the mineral lifting pipe to be one where an outer
surface of an inner pipe, manufactured from steel, is made of
resin reinforced with carbon fibers. A reinforcing pipe made
of resin also contributes to protection of an inner pipe made
of metal.
[0054] (12) The
present invention is a mineral lifting
method where a mineral lifting pipe, conveying a solid-liquid
mixture, containing minerals, excavated at a seabed surface or
below the seabed and pulverized, and seawater, to above a sea
surface, is imparted with a predetermined buoyancy by a float.
With the present method, when the mineral lifting pipe is
supported using a main float, floating on the sea surface, etc.,
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
so that the mineral lifting pipe does not sink to the seabed,
the predetermined buoyancy can be imparted to the mineral
lifting pipe so that, for example, by making the weight of the
mineral lifting pipe be the same as the weight resulting from
subtracting the buoyancy from the weight of the mineral lifting
pipe, weight is practically made not to act on the main float
that supports the mineral lifting pipe. Also, by making the
buoyancy due to the float slightly less than that described
above, the mineral lifting pipe can be kept balanced so as to
be oriented in a vertical direction.
[0055] The present invention is one where the mineral
lifting pipe and a communication/electric power cable are
supported by a float to lighten a gravitational force on the
mineral lifting pipe. Also, the present invention may
incorporate a large float, which is made of metal, is buoyant
on the sea surface, and has a cavity in its interior, and a
mineral lifting pipe and a communication/electric power cable
that are supported by the float, and may also incorporate a large
float, having seawater draining and seawater intake valves for
buoyancy adjustment to accommodate the weight of the mineral
lifting pipe.
[0056] Also, by driving a waterproof storage battery and
a pump made to ride on (installed on) the large float and feeding
and draining seawater to and from a cavity portion at a lower
portion of the large float, the large float can be made to have
a submerging function.
[0057] Further, to lighten the weight of the mineral
21
CA 02964213 2017-04-10
English Translation of PCT/J2016/O61280
File No. 34485-19
lifting pipe supported by the large float, a set of small floats,
installed at intermediate portions of the mineral lifting pipe
sea undersea, may also be included. Also, a mineral lifting
pipe, made of resin reinforced with carbon fibers to lighten
weight and maintain strength, may be included.
[0058] To lighten the weight, a mineral lifting pipe having
a cavity in a gap of a double pipe may be included. A structure
may be arranged with which the mineral lifting pipe and the
communication/electric power cable that are supported by a
large float can be disengaged from a mineral ore processing ship
during rough weather or when the mineral ore processing ship
leaves a site.
[0059] A system may be arranged where a mineral ore
conveying pump is made to ride on (is installed on) a seabed
mineral ore mining machine and an intake pipe is shortened. A
pump system, which injects pressurized water into an
intermediate portion of the mineral lifting pipe to supply fluid
energy, may also be included.
[0060] Further, an electric type or permanent magnet type
magnet apparatus, arranged to collect mineral ore from seawater,
which contains pulverized mineral ore (finely granulated
mineral ore) and is conveyed from the mineral lifting pipe to
the mineral ore processing ship on the sea surface, may be
included. Also, an apparatus that performs wastewater
processing after mineral ore collection may be equipped on the
mineral ore processing ship.
Advantageous Effects of the Invention
22
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
[0061] The
present invention can provide a mineral lifting
system and a mineral lifting method incorporating a pump system
capable of conveying seawater, containing pulverized mineral
ore, from a deep seabed to a mineral ore processing ship on a
sea surface and being arranged so that a mineral lifting pipe,
lowered to the deep seabed, will not drop off due to its own
weight from a connection portion of a pipe body, etc., so that
a mineral ore processing ship, etc., that supports the mineral
lifting pipe does not have to be made larger than necessary to
secure buoyancy, and so that when the sea is rough due to a
typhoon, etc., the mineral lifting pipe will not become damaged
due to rocking by waves of the mineral ore processing ship, etc.,
and the mineral ore processing ship, etc., will not have to
discard the mineral lifting pipe in leaving for safety.
Brief Description of Drawings
[0062] [Fig. 1]
is an explanatory diagram of an embodiment
of a mineral lifting system according to the present invention.
[Fig. 2] is a partially-omitted sectional explanatory
diagram of a structure that suspends a mineral lifting pipe by
means of a main float and auxiliary floats.
[Fig. 3] is a sectional explanatory diagram of a structure
of the main float and its vicinity.
[Fig. 4] is an explanatory diagram of a structure of a
wastewater processing apparatus included in a working ship used
in the mineral lifting system.
[Fig. 5] is a sectional explanatory diagram of a structure
of a pipe body that constitutes the mineral lifting pipe used
23
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
in the mineral lifting system.
[Fig. 6] is a sectional explanatory diagram of another
structure of a pipe body that constitutes the mineral lifting
pipe used in the mineral lifting system.
[Fig. 7] shows another structure of an auxiliary float,
with Fig. 7(a) being a vertical sectional explanatory diagram
and Fig. 7(b) being a sectional explanatory diagram
corresponding to A-A.
Description of Embodiments
[0063] An embodiment of the present invention shall now be
described in further detail with reference to Fig. 1 to Fig.
6.
Amineral lifting system S includes a mining unit 1, which
performs mining of minerals at a seabed, a mineral lifting unit
2, which lifts the mined minerals and seawater to above a sea
surface, and a sorting unit 3, which is a mineral sorting portion
that sorts valuable minerals from a solid-liquid mixture lifted
by the mineral lifting unit 2.
[0064] (Mining Unit 1)
The mining unit 1 has a seabed working machine 13 that
can be externally operated to move. The seabed working machine
13 includes a crawler traveling machine 130, an excavator 131,
installed on an upper portion thereof, and a slurry pump 132,
which sucks in and pumps the solid-liquid mixture containing
the mineral, obtained by excavation, and seawater. The seabed
working machine 13 is arranged with a structure capable of
working under high pressure at a deep seabed by making
24
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
respective portions highly watertight, etc. The slurry pump
132, together with respective pressure injection pumps 24 to
be described later, constitutes a pump system.
[0065] The excavator 131 is arranged to be capable of
pulverizing and excavating minerals of a mineral deposit by
rotation or vibration of a drill at a tip. Another structure
may be adopted instead for the excavator. The slurry pump 132
is capable of pumping the mixture (solid-liquid mixture) of the
excavated and pulverized minerals and seawater and, for example,
a diagonal flow type or a mixed flow type may be adopted.
[0066] The slurry pump 132 is not restricted in particular
in pumping capability and suffices to have a capability of being
able to lift the solid-liquid mixture of seawater and the
pulverized minerals to above the sea surface, at least in
cooperation with the pressure injection pumps 24 that are
auxiliary pumps to be described later. In this case, for
example, a conveying energy from the slurry pump 132 to a lower
portion of a mineral lifting pipe 21, to be described later,
may be supplied by the slurry pump 132, and a conveying energy
inside the mineral lifting pipe 21 further upward may be
supplied by the pressure injection pumps 24, which are a
plurality of auxiliary pumps to be described later that are
provided at intermediate portions of the mineral lifting pipe
21.
[0067] In the seabed working machine 13, an electric power
cable 12 arranged to supply electric power to power the crawler
traveling machine 130, the excavator 131, and the slurry pump
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
132, is connected to an electric power receiving portion (symbol
omitted) . An end portion at a side of the electric power cable
12 above the sea surface is connected once to a float 11 floating
on the sea surface and a weight of the electric power cable 12
is thus supported by the float 11. To lighten the weight of
the electric power cable 12 applied to the float 11, an auxiliary
float that imparts buoyancy may be mounted in the same manner
as with the mineral lifting pipe 21 to be described later.
[0068] Electric power from a generator (not shown) , which
is an electric power supplying portion installed on a working
ship 10, which is a mother ship, is arranged to be supplied via
an electric power cable 120 to the electric power cable 12
connected to the float 11. Also, a signal cable (not shown) ,
which exchanges signals for performing control of the excavator
131, control of the crawler traveling machine 130, or control
of the slurry pump 132 of the seabed working machine 13, etc.,
with a control portion included in the working ship 10, is
installed on the power cables 12 and 120 in a form of being
attached thereto.
[0069] (Mineral Lifting Unit 2)
The mineral lifting unit 2 has the mineral lifting pipe
21. The mineral lifting pipe 21 is formed by connecting a large
number of pipe bodies 210 of predetermined length to a length,
for example, of 5000 m in correspondence to a depth of a sea
area to be subject to mineral lifting work. The structure of
each pipe body 210 shall be described in detail later. The long
mineral lifting pipe 21 is practically connected to a main float
26
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
20 so as to be hung thereon with an upper end side floating on
the sea surface. Also, at an undersea side, the mineral lifting
pipe 21 is practically connected to auxiliary floats 22 so as
to be hung thereon at every predetermined interval in a length
direction (at every pipe body 210 in the present embodiment).
[0070] First, a structure of the main float 20 and a
structure connecting the mineral lifting pipe 21 to the main
float 20 shall be described with reference to Fig. 3.
The main float 20 has a sealed case 200 with a structure
that is watertight and hollow. An outer shape of the sealed
case 200 is a so-called donut shape and a space portion 201 is
formed in an interior so as to draw a circle in plan view. Also,
a through hole 202 of circular hole shape, which is separated
by a wall portion from the space portion 201, is provided so
as to penetrate through a central portion of the sealed case
200.
[0071] The space portion 201 inside the sealed case 200 is
divided into upper and lower portions in a liquid-tight state
by a separating member 203 that is fixed across an entire
circumference at a substantially middle position in an up/down
direction. A water feeding/draining pump 204, which is fixed
to the separating member 203 and constitutes a water
feeding/draining apparatus, is disposed in an upper space
portion 201a. Also, similarly, a battery 205 is disposed that
is fixed to the separating member 203, and as the battery 205
in the present embodiment, a waterproof lithium storage battery
is adopted and supplies electric power to the water
27
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
feeding/draining pump 204.
[0072] The battery 205 is connected to a control board 206,
and an electric power cable 26 is connected from the exterior
to the control board 206. The electric power cable 26 is
connected to a generator (not shown), which is an electric power
supplying portion installed on a mineral processing ship 30 to
be described later, and electric power supplied from the
generator is stored in the battery 205.
[0073] A lower space portion 201b, which is divided by the
separating member 203 inside the sealed case 200, is a water
storage tank, and an arrangement is made so that a water amount
(and if necessary an air amount) in an interior of the lower
space portion 201b can be adjusted by the water feeding/draining
pump 204. By adjustment of the water amount, the main float
20 can be made to float on the sea surface by increasing its
buoyancy or can be made to submerge by decreasing the buoyancy
as necessary. The submerging may be performed so that just the
main float 20 becomes submerged or so that an entirety,
including the mineral lifting pipe 21, becomes submerged and
a selection can be made as suited.
[0074] A GPS receiver 207, which receives signals from a
GPS satellite 27, is installed on an upper surface of the sealed
case 200. Electric power is arranged to be supplied via the
electric power cable 26 to the GPS receiver 207 as well. Also,
a plurality of propulsion machines 208, which constitute a
position correcting apparatus, are mounted to a lower surface
of the sealed case 200. Each propulsion machine 208 has a
28
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
structure by which a propulsive force is obtained by rotating
a screw by a motor.
[0075] The arrangement of the position correcting
apparatus includes the control board 206, which is a control
portion capable of comparing position information, obtained by
the GPS receiver, and basis position information, determined
in advance, and actuating the respective propulsion machines
208 based on the difference to correct a position. The
respective propulsion machines 208 are arranged to be supplied
with the electric power from the battery 205, and by suitably
combining and driving the respective propulsion machines 208
by automatic control based on GPS, the main float 20 can be moved
in a predetermined direction on the sea surface.
[0076] A pipe body 210 at an upper end portion of the mineral
lifting pipe 21 is passed through the through hole 202 of the
sealed case 200. Each of the large number of pipe bodies 210
that constitute the mineral lifting pipe 21 has the structure
shown in Fig. 5. Each pipe body 210 has connection flanges 211
and 212 at respective ends in a length direction and the pipe
portion has a double pipe structure constituted of an inner pipe
213 and an outer pipe 214. A space portion 215 of so-to-speak
circular pipe shape, which gives rise to buoyancy to achieve
lightweightness, is formed between the inner pipe 213 and the
outer pipe 214.
[0077] An outer diameter of the outer pipe 214 of the pipe
body 210 is formed to a diameter smaller than an inner diameter
of the through hole 202 of the sealed case 200, and a gap 209
29
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
is provided between the pipe body 210 and the through hole 202.
Also, with the uppermost pipe body 210, the flange 211 (attached
after inserting the pipe body 210 through the through hole 202)
is at an upper side of the sealed case 200 and a compression
coil spring 28, which is made gradually smaller in diameter at
an upper portion side, is disposed between the upper surface
of the sealed case 200 and the flange 211.
[0078] By the present structure, the pipe body 210 and the
large number of other pipe bodies 210 connected therebelow are
cushioned by an energizing force of the compression coil spring
28 even upon moving up and down, and impacts and large loads
applied to the main float 20 can be lightened. Also, by an
action of the gap 209, the pipe body 210 is made capable of moving
freely or swinging within a certain fixed range in an interior
of the through hole 202. A flexible supply pipe 25 is connected
to an upper end of the pipe body 210 at the upper end portion,
and a tip side of the supply pipe 25 is introduced into the
sorting unit 3 to be described later.
[0079] As described above, the mineral lifting pipe 21 is
arranged by connecting the large number of pipe bodies 210 in
watertight manner, and one end portion of a flexible relay pipe
23 of predetermined length is connected to a lower end portion
of a lowermost pipe body 210. Another end portion of the relay
pipe 23 is connected to a discharge port (symbol omitted) of
the slurry pump 132. An intake port (symbol omitted) of the
slurry pump 132 is disposed at a vicinity of a drill of the
excavator 131 and is made capable of sucking in excavated and
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
pulverized minerals together with seawater.
[0080] As mentioned above, at the undersea side, the long
mineral lifting pipe 21 is practically connected at every pipe
body 210 to the auxiliary floats 22 in a length direction in
a manner such that the upper portion side flanges 211 are hung
thereon. Each auxiliary float 22 has a sealed case 220 with
a structure that is watertight and hollow. An outer shape of
the sealed case 220 is a so-called donut shape and a space portion
221 is formed in an interior so as to draw a circle in plan view.
Also, a through hole 222 of circular hole shape, which is
separated by a wall portion from the space portion 221, is
provided so as to penetrate through a central portion of the
sealed case 220.
[0081] An outer diameter of the outer pipe 214 of each pipe
body 210 is formed to a diameter smaller than an inner diameter
of the through hole 222 of the sealed case 220, and a gap 229
is provided between the pipe body 210 and the through hole 222.
Although a specific structure of the auxiliary float 22 is not
shown, it is a structure (known structure) that enables
installment in a fitting manner onto and detachment from a pipe
portion of the pipe body 210 in a lateral direction.
[0082] With the present structure, the large number of
auxiliary floats 22 are capable of sliding relative to the
respective pipe bodies 210 even when the respective pipe bodies
210 move up and down, and the sliding relative to each other
stops when an auxiliary float 22 contacts the flange 211 of a
pipe body 210 or contacts an injection pipe 241 of a pressure
31
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
injection pump 24 to be described below. There is effective
mutual clearance between the auxiliary floats 22 and the
respective pipe bodies 210 and therefore impacts and large loads
are unlikely to act. Also, by an action of the gap 229, each
pipe body 210 is made capable of moving freely or swinging within
a certain fixed range in an interior of the through hole 202.
[0083] Also, the respective auxiliary floats 22 are capable
of imparting a predetermined buoyancy to the mineral lifting
pipe 21. This buoyancy may be set, for example, to be the same
as a weight of the mineral lifting pipe 21 so that the weight
of the mineral lifting pipe 21 is hardly applied to the main
float 20. Or, the buoyancy may be set to be slightly less than
the weight of the mineral lifting pipe 21 so that the weight
of the mineral lifting pipe 21 is applied suitably to the main
float 20 and the mineral lifting pipe 21 is more stabilized
undersea. An auxiliary float 22 that is positioned in a deep
sea may include a rib structure for reinforcement in its
interior as in an auxiliary float 22a to be described later so
as to withstand high water pressure.
[0084] Injection pipes 241, each connected to a discharge
port (symbol omitted) of a pressure injection pump 24, are
connected to pipe portions of pipe bodies 210, which, among the
pipe bodies 210 constituting the mineral lifting pipe 21, are
positioned at predetermined intervals. Each pressure
injection pump 24 sucks in seawater in its surroundings and
injects it into an interior of the mineral lifting pipe 21 and
assists upward conveying (pumping) of the lifted water
32
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
(solid-liquid mixture) passing through the mineral lifting pipe
21.
[0085] Each pressure injection pump 24 is arranged to be
maintained at a predetermined depth by being imparted with a
buoyancy of a float 242 connected by a suspending wire 243. Also,
electric power is suppled to each pressure injection pump 24
via an electric power cable 240 connected to the generator on
the mineral processing ship 30 that is the working ship. Afloat
for imparting buoyancy may also be attached to the electric
power cable 240.
[0086] The electric power cable 120, connecting the working
ship 10 to the float 11, is of a structure enabling disconnection
from the float 11. Also, the mineral processing ship 30 is of
a structure capable of disconnecting the supply pipe 25 and the
electric power cable 26 from the main float 20. By these
arrangements, when the working ship 10 and the mineral
processing ship 30 are to call at a port, etc., the ships can
be made to leave a work site in a state enabling recovery
subsequently.
[0087] (Sorting Unit 3)
The sorting unit 3 is installed on the mineral processing
ship 30. The generator (not shown) is installed on the mineral
processing ship 30 and this generator supplies electric power
to the main float 20 and the respective pressure injection pumps
24. The sorting unit 3 sorts valuable minerals from the
solid-liquid mixture of seawater and pulverized minerals lifted
by the mineral lifting unit 2.
33
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
[0088] Fig. 4 shall now be referenced. A method for
processing the solid-liquid mixture, which contains pulverized
minerals 50 and has risen inside the mineral lifting pipe 21
and has reached the mineral ore processing ship 30 on the sea
surface through the supply pipe 25, shall now be described.
The sorting unit 3 includes, in the order of processing,
a sorting tank 31, a sedimentation tank 32, a water storage tank
33, and a collection tank 34. The sedimentation tank 32, the
water storage tank 33, and the collection tank 34 constitute
a wastewater processing apparatus.
[0089] The solid-liquid mixture that contains the
pulverized minerals 50 is conveyed to the sorting tank 31 from
the supply pipe 25. Pulverized minerals 50 that are magnetic
materials are magnetized and collected by an electromagnet
(symbol omitted) mounted to a tip of an arm of a rotating body
311. Minerals that are not magnetic materials and other
valuable minerals are collected by any of various known means,
for example, by using a sieve, etc.
[0090] Also, seawater containing sludge, which has passed
through the sorting tank 31, is conveyed to the sedimentation
tank 32 upon passing through a screen 320 and the sludge
sediments to a tank bottom and is thereby separated. The
seawater removed of the sludge is conveyed to the water storage
tank 33 upon passing through a screen 331 and is conveyed to
the subsequent collection tank 34 by a pump 330. Inside the
collection tank 34, finer sludge is made to sediment by chemical
processing, etc., and is thereby removed, and the clarified
34
,
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
seawater after processing is made to pass through a drain pipe
35 and be discharged to the exterior (sea) by a waterwheel 340.
[0091] (Actions)
Actions of the mineral lifting system S according to the
present invention shall now be described by way of a case of
performing a process of lifting valuable minerals in the deep
sea to above the sea surface as an example.
As shown in Fig. 1, with the mineral lifting system S,
the seabed working machine 13 is disposed at a prescribed deep
seabed 4 with a mineral deposit 5 and the main float 20 floats
on the sea surface.
[0092] The seabed working machine 13 is operated by signals
from a control portion on the working ship 10 and using the
electric power supplied via the electric power cable 120 to
perform excavation by means of the excavator 131 while moving
by means of the traveling machine 130. In parallel to the
excavation, the mixture (solid-liquid mixture) of the
pulverized minerals 50 (shown in Fig. 4) and seawater is sucked
in and pumped upward, from the relay pipe 23 and through the
mineral lifting pipe 21, by the slurry pump 132. In this process,
energy due to water flows is injected by the large number of
pressure injection pumps 24 into a vertical direction path of
the mineral lifting pipe 21, the solid-liquid mixture is lifted
to the sorting unit 3 on the mineral processing ship 30 at the
upper side, and just the clarified processed water is dumped
to the sea.
[0093] Also, the large number of auxiliary floats 22 are
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
connected to the mineral lifting pipe 21 and impart the
prescribed buoyancy to the mineral lifting pipe 21. With the
mineral lifting system S, a buoyancy that is approximately such
that the long mineral lifting pipe 21 of several thousand meters
will not drop to the seabed 4 is imparted to the mineral lifting
pipe 21 by the main float 20 and the respective auxiliary floats
22. A predetermined number (a large number) of the auxiliary
floats 22 are disposed in the length direction of the mineral
lifting pipe 21, and therefore the weight of the mineral lifting
pipe 21 is sharingly supported according to the pipe bodies 210
by the auxiliary floats 22.
[0094] That is, if when the large number of auxiliary floats
22 are mounted at predetermined intervals in the length
direction of the mineral lifting pipe 21, each auxiliary float
22 is made to impart a buoyancy corresponding to just the weight
of a length of the mineral lifting pipe 21 between each auxiliary
float 22, the load of the long mineral lifting pipe 21 can, in
theory, be prevented from acting on an upper portion of the
mineral lifting pipe 21.
[0095] By thus making an appropriate buoyancy be imparted
by the auxiliary floats 22, a large load in the gravity direction
will not act biasedly on a certain portion. The above
arrangement is thus also effective in terms of making the load
be applied evenly at predetermined intervals in the length
direction of the mineral lifting pipe 21. Also by the above,
the mineral lifting pipe 21 can be prevented from breaking in
the middle due to its own large load and destruction of a
36
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
connection portion of a pipe body 210, etc., can be prevented
so that a problem of the mineral lifting pipe 21 dropping to
the seabed will not occur.
[0096] Although the total buoyancy of the main float 20 and
the respective auxiliary floats 22 that float the mineral
lifting pipe 21 is set as suited, a buoyancy sufficient to make
the uppermost main float 20 float on the sea surface is not
necessarily required, and it is preferable for the buoyancy to
be such that at least the lower end portion of the mineral lifting
pipe 21 can be made buoyant so as to be maintained in a state
of not dropping to the seabed, that is, in a state of being adrift
undersea without sinking. Also, it is preferable for the
buoyancy to be such that can maintain a state where, even if
the lower end portion side of the mineral lifting pipe 21
contacts the seabed, at least a further upper portion side is
vertically buoyant undersea.
[0097] The mineral lifting pipe, which is a heavy object,
is imparted with buoyancy by the main float and the respective
auxiliary floats so that the working ship 10 or the mineral ore
processing ship 30 that performs control of the mineral lifting
system is not necessarily required to support the mineral
lifting pipe, and therefore there is no need to make the ships
large.
[0098] Also, while the system is in operation, the
practical weight of the mineral lifting pipe 21 will be heavier
because the weight of the solid-liquid mixture conveyed through
its interior is added thereto. Therefore, the buoyancy
37
CA 02964213 2017-04-10
=
English Translation of PCT/JP2016/061280
File No. 34485-19
provided by the respective floats 2 and 22 must be set in
consideration of this point and must not be set on the basis
of the weight of the empty mineral lifting pipe 21.
[0099] Also, the main float 20 can be adjusted in buoyancy
by adjusting the amount of water in its interior by means of
the water feeding/draining pump 204. A portion of the main
float 20 can thereby be exposed from the sea surface or the
entirety can be sunken below the sea surface, for example, like
a submarine. Also, when made to sink, the main float 20 can
be adjusted in height (depth) below the sea surface.
[0100] When the main float 20 is sunken below the sea
surface, the main float 20 is made less likely to be influenced
by waves. For example, if, when the weather is rough, as in
a typhoon or when a typhoon approaches, the main float 20 is
kept floating on the sea surface, it will receive the influence
of violent waves and undergo up/down motion and rolling
repeatedly, thereby increasing a possibility of deformation or
damage of a mounting portion of the mineral lifting pipe 21
connected to the main float 20 or a peripheral portion thereof.
[0101] Waves at the sea surface occur from several meters
to approximately 10 m below the sea surface in many cases, and
therefore if the main float 20 can be maintained, by remote
operation, to be buoyant at a deeper position together with an
upper portion of the mineral lifting pipe 21 and floating up
of the main float 20 thereafter is made possible, the influence
of waves can mostly be avoided even in a typhoon.
[0102] Also the main float 20 includes the GPS receiver 207
38
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
and the propulsion machines 208 and a GPS can thus be used to
maintain the position of the mineral lifting system S that has
been set in advance. That is, the position information,
indicating the position of the mineral lifting system, is
acquired by the GPS receiver 207 installed on the main float
20, and the position information, which is set in advance and
serves as the basis, and the position information acquired by
the GPS receiver 207 are compared by means of the position
correcting apparatus.
[0103] Then, based on the difference, the position
correcting apparatus performs correction of position by
actuating the respective propulsion, machines 208 so that the
position of the main float 20 is maintained at the position (set
position) serving as the basis or made to approach (move toward)
the position serving as the basis. The correction of position
may be performed constantly during the operation of the mineral
lifting system S or may be performed at every fixed time interval
(intermittently) .
[0104] The seabed working machine 13 may be used upon being
placed on the seabed in a region that not only has valuable
minerals, such as noble metals, rare metals, etc., present on
the seabed surface 4 or below the seabed at a water depth, for
example, of several thousand meters, but also has large amounts
of useful resources, such as methane hydrate (for example,
near-surface methane hydrate) , which is a fossil fuel, etc. The
mineral lifting system S is also usable as a system that lifts
such useful resources other than minerals from a deep seabed
39
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
to above a sea surface.
[0105] Fig. 6 shall now be referenced. Fig. 6 shows another
structure of a pipe body that constitutes the mineral lifting
pipe used in the mineral lifting system.
A pipe body 210a has a double pipe structure, with which
an outer pipe 214a of an inner pipe 213a, made of steel, is formed
integrally from acrylic resin reinforced with carbon fibers.
The pipe body 210a is thereby made light in weight and increased
in tensile strength. Also, flanges 211a and 212a are provided
at respective end portions of the pipe body 210a. By combining
the inner pipe 213a, which is made of steel and has sufficient
strength, and the lightweight and tough outer pipe 214a, the
weight can be suppressed to be equivalent to the pipe body 210
described above while maintaining a prescribed strength.
[0106] Fig. 7 shall now be referenced. An auxiliary float
22a shown in Fig. 7 has a sealed case 220a, formed to be
watertight and having an outer shape that is a circular columnar
shape. In a space portion 221a in an interior of the sealed
case 220a, reinforcing ribs 225, arranged by combining ribs
horizontally and vertically, are provided so as to be fixed to
an inner surface of the sealed case 220a. The auxiliary float
22a is mounted to the mineral lifting pipe 21 via a coupling
member 226. A prescribed buoyancy is thereby imparted to the
mineral lifting pipe 21.
[0107] Also, by being provided with the reinforcing ribs
225 in its interior, the auxiliary float 22a can secure the space
portion and maintain the prescribed buoyancy without collapsing
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
under deep sea high pressure.
[0108] The terms and expressions used in the present
description and the claims are only descriptive, are by no means
restrictive, and are not intended to exclude terms and
expressions equivalent to features and portions thereof
described in the present description and the claims. Also,
obviously, various modified modes are possible within a scope
of the technical concept of the present invention.
Reference Signs List
[0109] S Mineral lifting system
1 Excavating unit, 10 Working ship, 11 Float,
12 Electric power cable, 120 Electric power cable,
13 Seabed working machine, 130 Crawler traveling machine,
131 Excavator, 132 Slurry pump,
2 Mineral lifting unit, 20 Main float, 200 Sealed case,
201 Space portion, 201a Upper space portion, 201b Lower
space portion,
202 Through hole, 203 Separating member, 204 Water
feeding/draining pump,
205 Battery, 206 Control board,
207 GPS receiver, 208 Propulsion machine, 209 Gap,
21 Mineral lifting pipe, 210 Pipe body, 211, 212 Flange,
213 Inner pipe, 214 Outer pipe, 215 Space portion,
210a Pipe body, 211a, 212a Flange, 213a Inner pipe,
214a Outer pipe,
22 Auxiliary float, 220 Sealed case, 221 Space portion,
222 Through hole,
41
=
CA 02964213 2017-04-10
English Translation of PCT/JP2016/061280
File No. 34485-19
22a Auxiliary float, 220a Sealed case, 221a Space portion,
225 Reinforcing rib, 226 Coupling member, 229 Gap,
23 Relay pipe, 24 Pressure injection pump, 240 Electric
power cable,
241 Injection pipe, 242 Float, 243 Suspending wire,
25 Supply pipe, 26 Electric power cable, 27 GPS satellite,
28 Compression coil spring,
3 Sorting unit, 30 Mineral processing ship, 31 Sorting
tank,
311 Rotating body,
32 Sedimentation tank, 320 Screen, 33 Water storage tank,
330 Pump, 331 Screen, 34 Collection tank, 340 Waterwheel,
35 Drain pipe
Mineral deposit, 50 Pulverized minerals
42
