JPS6327516B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for collecting manganese nodules existing on the deep seabed.

Manganese nodules, which are attracting attention as inexhaustible mineral resources such as nickel, cobalt, copper, and manganese, are flat, like gravel spread on the surface of fine seafloor sediments (i.e., mud) on the ocean floor, several thousand meters deep. is present in Therefore, it is not possible to obtain a large amount of ore at once from the sea using grab buckets, etc., and various mining methods have been considered. It is said that a so-called fluid dredge method, in which the manganese nodules collected by an ore collecting device installed at the lower end of the pipe are sucked out to sea along with the water flow, has great potential.

However, ore collectors generally collect a large amount of seafloor sediment and small-grained nodules that are not suitable for ore lifting, along with nodules with grain sizes suitable for ore lifting. It is necessary to separate and dispose of it as much as possible to prevent it from entering the mine pipes. Conventionally, it has been considered to use a suitable mesh net or the like as the separation means, but screening means such as the mesh tend to become clogged, and it is often necessary to remove the clogging. However, it is common for manganese nodules collectors to continue operating for several months without being salvaged once they fall to the seabed at a depth of several thousand meters. It cannot be said that it is appropriate to use it. It is conceivable to equip a device such as a brush to remove clogging during operation, but this has the disadvantage that the remote control device is complicated.

The present invention solves the above-mentioned problems of conventional manganese nodule collectors, has a simple configuration, and is capable of collecting manganese nodules and simultaneously separating and discharging seabed sediments and small-sized nodules. The purpose is to provide an ore collecting device that can be used.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

FIGS. 1 and 2 are a sectional view and a plan view showing a state in which an ore collector according to an embodiment of the present invention is installed on a seabed surface 1 for operation.

Since the seabed where manganese nodules exist is often muddy, the ore collecting device is supported on the seabed surface 1 by a pair of skis 2 on the left and right, and is transported by a ship at sea using an ore lifting pipe 3 or a tow rope (not shown). It is designed to move on the seabed surface 1 in the direction of the arrow. On the ski 2, there is a cylindrical ore collecting tube 4 with an open top and bottom and an axis in the vertical direction.
is provided. The ore collecting cylinder 4 forms a right cylinder with the same diameter up to the middle in the height direction, and above it forms an inverted truncated conical cylinder whose diameter gradually increases upward. The lower edge of the ore collecting tube 4 has a slight gap with the seabed surface 1, and at the bottom of the internal space, an appropriate number of seawater injection nozzles 5 are installed in the tangential direction of the ore collecting tube with their spout ports directed diagonally downward. It is provided. A strip-shaped vortex guide plate 6 of an appropriate length forming part of a spiral is provided corresponding to each nozzle 5 from a position at an appropriate distance from the injection port of the nozzle 5. The seawater injection nozzle 5 is connected to the discharge port of one water pump 7, and the suction port of the water pump 7 is open to the open sea.

An appropriate number of appropriately sized nodule trapping openings 8 are provided at a certain level on the conical surface of the ore collecting tube 4, and each opening 8 is provided outside the ore collecting tube 4 through a conduit 9. It is connected to one hopper 10. A screw feeder 11 is provided between the bottom of the hopper 10 and the lower end of the ore lifting pipe 3.
An ore lifting pump (not shown) is provided in the middle of the ore lifting pipe 3, and seawater is sucked through the opening 3a at the lower end of the ore lifting pipe 3 in the shape of a flap to create a water flow inside the pipe.

Since this device is constructed as described above, when seawater is injected obliquely downward in the tangential direction of the ore collecting tube from each seawater injection nozzle 5 by the water pump 7, the manganese nodules present on the seabed surface 1 are removed from the seabed. It floats up into the seawater along with sediment. The seawater injected in the tangential direction from each nozzle 5 swirls along the inner surface of the ore collecting cylinder, and is guided by the vortex guide plate 6 and rises while swirling, generating a vortex. Since there is only a small gap between the lower edge of the ore collecting tube 4 and the seabed surface 1, and the top of the ore collecting tube is open, seawater is sprayed from the seawater injection nozzle 5 to the bottom of the internal space of the ore collecting tube. Most of the seawater rises inside the ore collecting cylinder and overflows into the open sea through the upper opening. Since the amount of water rising in each horizontal section of the ore collecting tube 4 per unit time is constant, the vertical flow velocity of the seawater rising while swirling in the right cylindrical section below the middle of the ore collecting tube is constant. However, as the cross-sectional area of the conical surface increases upward, the upward flow velocity of seawater gradually decreases.

Now, the relative settling velocity of a solid in a fluid is determined by the downward gravitational force due to the weight of the solid, the upward buoyant force due to the volume of the solid and the specific gravity of the fluid, and the fluid resistance when the solid settles in the fluid. It sinks through the fluid at balanced relative velocities. Therefore, if the fluid is raised at a speed higher than this settling speed, the solid will rise relative to the ground, and if the rising speed of the fluid is lower than the above-mentioned settling speed, the solid will fall relative to the ground. The fluid resistance of solids of similar shape is proportional to the square of the length, and the gravity and buoyancy are proportional to the cube of the length, so the larger the size, the greater the gravity compared to the resistance, and the faster the sinking speed. . Therefore, for a certain upward flow rate of fluid, solids larger than a certain size will fall, and solids smaller than that will rise.

Therefore, the vertical flow velocity of the right cylindrical part of the ore collection cylinder 4 of this device is set to a cross-sectional area that is equal to or higher than the upward flow velocity at which the largest nodule within the size range of nodules suitable for ore lifting can rise. If the upward flow velocity at the outlet of the upper inverted cone section is set to a cross-sectional area that is less than the velocity at which the minimum size of nodules suitable for lifting ore sinks, all nodules of the size of the ore lifting range can be straightened. The nodules and seabed deposits having dimensions below the lifting range of the ore are moved up the cylindrical portion and overflow from the upper opening of the ore collection cylinder 4 together with seawater. Nodules with dimensions larger than the ore lifting range are removed in advance by means not shown so that they do not reach the bottom of the ore collection tube 4.

Therefore, the nodules in the ore lifting range are suspended from the conical part of the ore collection tube 4 and rotated together with seawater, so that they escape from the nodule catching opening 8 due to centrifugal force and are collected in the hopper 10. The escape of the nodules from the trapping opening 8 is based on the same theory as the rise and sinking of solids in the fluid, and they escape in the radial direction through the fluid at a speed where the centrifugal force and the fluid resistance of the solids are balanced. . Therefore, fine seafloor sediment particles and small nodules are
Due to centrifugal force, the nodule overflows from the upper part before it escapes from the nodule trapping opening. The rate of rise of seawater in the ore collecting pipe 4 changes depending on the nodule content and is not always constant, so nodules with dimensions within the ore lifting range move up and down the conical part of the ore collecting pipe. The sludge will eventually escape from the trapping opening, be accumulated in the hopper 10, and be fed from its lower end to the lower end of the ore lift pipe 3 by the screw feeder 11. The screw feeder 11 does not use a fluid pressure difference, but mechanically conveys the nodules, so if the nodules are conveyed without much gap, almost no water will move. , the water in the ore collection tube 4 hardly flows out from the trapping opening 8, and therefore, small-sized nodules and fine sediments hardly ever escape from the trapping opening 8. do not have. The nodules sent to the lower end of the ore lifting pipe 3 by the screw feeder 11 are carried inside the ore lifting pipe 3 by a water flow generated in the ore lifting pipe by an ore pump (not shown) to be lifted to a ship on the sea. be done. At the lower end of the ore lifting pipe 3, there is a rack pipe 3a.
is installed, the seawater that generates the water flow in the ore lifting pipe is sucked in from outside the range of the screw feeder 11.

The shape of the ore collecting cylinder 4 is not limited to the one in which the cross-sectional area changes continuously, such as an inverted truncated cone connected to a right cylinder as in the above embodiment; for example, as shown in FIG. Two right cylinders 21 with different diameters,
22 can also be connected by a conical surface 23 with an appropriate slope to form the ore collecting cylinder 20. The diameter of the lower cylinder 21, which has a smaller diameter, is set to a size that provides a rising flow velocity that can raise the maximum size of the nodules in the ore lifting range, and the diameter of the upper cylinder 22 is equal to or smaller than the minimum size of the nodules in the ore lifting range. A suitable number of openings 24 for capturing nodules are provided in the lowermost pipe wall of the upper right cylinder 22. In this case, the lifted ore range and smaller nodules and deposits all rise within the lower right cylinder 21, and the small nodules and deposits below the lifted ore range overflow from the upper opening. However, since the nodules having the size of the ore lifting range gather below the upper right cylinder 22, they are discharged from the trapping opening 24 by centrifugal force, and the ore is lifted by the same means as in the previous embodiment.

Furthermore, as shown in FIG. 4, by providing a cylindrical core material 31 with its center lines aligned inside the ore collecting cylinder 30 having the same external shape as the first embodiment, the formation of a swirling flow is ensured. It can be done. In this case as well, by providing the nodule trapping opening 32 on the conical surface of the ore collection tube, nodules in the ore lifting range can be captured.

Moreover, as shown in FIG. 5, when the ore collecting cylinder 40 is a right cylinder and the upper part of the core material 41 is an upright conical shape,
Since the cross-sectional area of the space between the ore collecting cylinder 40 and the core material 41 increases as it goes upward, the rising speed of the swirling flow can be gradually reduced, making it possible to sort out nodules according to the present invention.

In the case of the embodiments shown in Figures 4 and 5, it seems at first glance that the nodules on the seabed directly below the core material are not collected, but this ore collection device is towed forward and performs the collection and sorting as described above. As this action takes place, at some point the seabed beneath the core material will also come within the action range of the swirling flow between the core material and the ore collection tube, and will be swept across the entire width of the ore collection tube.

As described above, according to the present invention, with a relatively simple configuration, it is possible to simultaneously collect seabed manganese nodules, sort out the nodules within the lifting range, and discard small particle size nodules and seabed sediments. Moreover, since wire mesh or the like is not used for sorting, clogging does not occur, and long-term maintenance is not required, resulting in significant improvements in operating efficiency and economic efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the invention, FIG. 2 is a plan view thereof, and FIGS. 3, 4, and 5 are sectional views showing other embodiments of the invention. 3...Ore lifting pipe, 4,20,30,40...Ore collecting pipe, 5...Seawater injection nozzle (rising vortex generation means),
6... Vortex guide plate, 8... Opening for capturing nodules, 10
...Transportation means.

Claims (1)

[Scope of Claims] 1. A cylindrical shape having an opening at the top and bottom, the lower opening being movable close to the seabed surface, and having a vertical axis in which the horizontal cross-sectional area of the internal space increases upward. an ore collecting tube; a means for generating an upward vortex within the internal space of the ore collecting tube; a means for bringing manganese nodules on the seabed below the inner space of the ore collecting tube into water above the ore collecting tube; A manganese nodule collector characterized by having an opening for capturing manganese nodules provided at an appropriate height on a wall surface, and a screw feeder for transferring the manganese nodules captured from the opening to the ore lifting pipe entrance. Device. 2. As a means for generating the upward eddy current and a means for bringing the seabed manganese nodules into the water above, an appropriate number of devices are installed at the bottom of the space inside the ore collecting cylinder in the tangential direction of the ore collecting cylinder and obliquely to the seabed. The manganese nodule collector according to claim 1, characterized by having a seawater injection nozzle.