US3620572A

US3620572A - Sea mining vessel

Info

Publication number: US3620572A
Application number: US723191A
Authority: US
Inventors: Manfred G Krutein
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-04-22
Filing date: 1968-04-22
Publication date: 1971-11-16
Anticipated expiration: 1988-11-16

Abstract

A sea mining vessel is disclosed wherein desired minerals lying at the sea bottom are first conveyed from the sea bottom to the submersed portion of an elongate vessel floating substantially vertically in the sea and then conveyed vertically from the submersed portion of the vessel to the surface of the sea. The vessel is constructed for floating horizontally on the ocean surface and ballast means shiftable for positioning the vessel substantially vertically in mining position. Hydraulic conveying equipment is used to convey the minerals from the sea bottom into a chamber in the vessel below the surface but maintained at atmospheric pressure and wherein minerals are dewatered and conveyed to the surface.

Description

United States Patent 72] Inventor Manfred G. Krutein General Dynamics Boat Div., Marine Technology Center, P.O. Box 91 1, San Diego, Calif. 92112 21 App1.No. 723,191 [22] Filed Apr. 22, 1968 [45] Patented Nov. 16, 1971 Original application June 7, 1965, Ser. No. 461,785, now Patent No. 3,438,142, dated Apr. 15, 1969. Divided and this application Apr. 22, 1968, Ser. No. 723,191

[54] SEA MINING VESSEL 6 Claims, 6 Drawing Figs.

[52] US. Cl

[51 Int. Cl [50] Field of Search [56] References Cited UNlTED STATES PATENTS 3,522,670 7/1967 Flipse et a1.; 3,080,583 3/1963 Fuller Primary Examiner- Ernest R. Purser Attorney-Limbach, Limbach & Sutton ABSTRACT: A sea mining vessel is disclosed wherein desired minerals lying at the sea bottom are first conveyed from the sea bottom to the submersed portion of an elongate vessel floating substantially vertically in the sea and then conveyed vertically from the submersed portion of the vessel to the surface of the sea. The vessel is constructed for floating horizontally on the ocean surface and ballast means shiftable for positioning the vessel substantially vertically in mining position. Hydraulic conveying equipment is used to convey the minerals from the sea bottom into a chamber in the vessel below the surface but maintained at atmospheric pressure and wherein minerals are dewatered and conveyed to the surface.

PATENTEDunv 1s :97:

FIGJB FIG.IA

REJECTS WATER PRESSURE INVEN'IOR.

MANFRED G. KRUTE l N ATTORNEYS SEA MINING VESSEL This application is a division of application Sea Mining Method, Ser. No. 461,785, filed June 7, 1965, and now US. Pat. No. 3,438,142

The present invention relates to dredging or mining from the sea bottom.

Broadly stated, the present invention to be described in greater detail below is directed to a sea mining method and apparatus wherein desired minerals lying at the sea bottom are first conveyed from the sea bottom to the submersed portion of an elongate vessel floating substantially vertically in the sea and are then conveyed vertically from the submersed portion of the vessel to the surface of the sea. The apparatus in accordance with the present invention includes an elongate vessel having an extended tank portion sealed for submersion over a major portion of its length, ballast means for shifting the center of gravity of the vessel between a transport position with the sealed tank lying substantially horizontally in the sea and a mining position with the vessel and tank floating in a vertical position. In mining position the major portion of the sealed tank is submersed in the sea, and minerals are brought to the vessel by dredging or conveying equipment mounted on the furthest submersed portion of the vessel. In accordance with one aspect of the invention, the dredged matter is brought into the submersed portion of the sealed tank. There the matter is dewatered and the desired minerals conveyed upwardly through the tank to the surface of the sea.

The minerals are then preferably transported to an underwater stockpile where they can be reclaimed as desired.

Dredging equipment utilized in the past has been mounted on a vessel which floats horizontally on the surface of the sea and which is exposed to continuous wave action at the surface of the sea. This wave action produces a rolling motion to the vessel and deleteriously affects the operative capabilities and maneuverability of dredging equipment mounted on the vessel. The resultant effect of the wave motion on the vessel is to reduce the efficiency of the mining operation and limit the length of the dredging equipment and therefore the sea depth at which the mining or dredging operation can take place effectively. Dredging operations in the past have only been able to extend to depths on the order of between 100 and 200 feet. However, the continental shelves where large mineral reserves lie have an average depth of 423 feet and the most prolific form of mineral deposits in the sea is nodular grains lying on the surface of the sea floor at depths of from 3,000 to 19,000 feet. Ocean mining cannot be successfully performed at these depths with the conventionally used dredge equipment mounted on vessels floating on the surface of the sea.

The dredging vessel in accordance with the present invention is designed to float in a vertical position during dredging or mining operations so that with the major portion of the vessel submerged the vessel is affected to a minimum extent by wave action adjacent the surface of the sea. This mining vessel is highly stable in vertical position thereby providing great stability and thus maneuverability to the actual equipment that picks up and moves the mined minerals. The stability of the mining vessel permits ocean mining at virtually any depth desired since mining equipment extending to any depth can be attached to this vertically floating vessel. In one embodiment of the present invention, the cross-sectional area of the mining or dredging vessel is reduced or suitably shaped over the region of heavy wave action to maintain the affects of wave motion on the dredging vessel at a minimum.

With a dredge constructed in accordance with the present invention and having the mining or dredging equipment which conveys the minerals from the sea bottom to the vessel located on the submerged end of the vessel, the required length of the dredging or conveying equipment is effectively reduced from that presently used by the submerged length of the vessel. This construction provides better maneuverability for the conveying equipment due to the shorter length of mining equipment in mining operations where the distance between the lower submersed end of the vessel and the sea bottom is small.

In accordance with another aspect of the present invention,

the dredging vessel is powered to move through the sea at selectible low rates of speed whereby the dredging operation can take place during patterned slow traverses across a mineral deposit lying on the sea bottom for maximum recovery of the desired minerals.

In accordance with still another aspect of the present invention, hydraulic conveying equipment is used to convey the minerals from the sea bottom into a portion of the dredge vessel which is located far beneath the surface of the sea but maintained at atmospheric pressure due to communication with atmosphere upwardly through the vessel. This construction permits the utilization of the difference in pressure at the bottom of the sea and at the location within the dredging vessel to convey the minerals into the vessel. After the minerals have been passed into the vessel and separated from the conveying hydraulic fluid or water, the water can then be conveniently pumped out of the vessel. This arrangement eliminates the amount of work required to move the minerals from the sea bottom to the level of the lower submersed portion of the vessel.

In accordance with still another aspect of the present invention, the matter recovered from the sea bottom and conveyed into the dredge or vessel is separated as to desired and undesired minerals. Then the desired minerals can be conveyed vertically within the vessel to the surface of the sea and the undesired minerals exhausted from the vessel back into the sea. This arrangement reduces the amount of work that would otherwise be required in past methods for the recovery of desired minerals since it is unnecessary to convey undesired minerals the submersed length of the vessel.

Other objects and advantages of this invention will become apparent when reading the following description and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. 1A is a schematic elevational view of a mining or dredge vessel constructed in accordance with the present invention and floating in its horizontal position;

FIG. 1B is a schematic elevational view of the vessel of FIG. 1A illustrated in its vertical dredging position and partially broken away;

FIG. 2 is a cross-sectional view of a portion of the vessel illustrated in FIG. 1A taken along line 22 in the direction of the arrows;

FIG. 3 is a cross-sectional view of a portion of the structure shown in FIG. 1A taken along line 3--3 in the direction of the arrows:

FIG. 4 is an enlarged elevational sectional view of the lower portion of the dredge illustrated in vertical position in FIG. 1B and showing an alternative embodiment of the present invention; and

FIG. 5 is an enlarged elevational sectional view of a portion of the structure in FIG. 4 delineated by line 33 schematically illustrating operation of a portion of the structure illustrated in FIG. 4.

Referring now to the drawings with particular reference to FIGS. 1A and 1B, the present invention is directed to a sea mining method and apparatus wherein matter generally designated at A is dredged or conveyed from the bottom of the sea B by a conveying or dredging apparatus C to the lower submerged portion of an elongate vessel D floating substantially vertically in the sea. The material from the lower portion of the vessel D is conveyed to the surface E of the sea and onto the transportation means such as, for example, the barge schematically illustrated as F. While the invention is particularly adaptable for ocean mining and will be described with reference thereto, the term sea is used herein to mean any body of water whether it be a land-locked lake area, a river region or the ocean either above a continental shelf adjacent a large land mass or over the deep sea bottom at a region far from a land mass.

The vessel D is provided with an elongate hull 11 which is constructed for floating in a substantially horizontal position for transportation to and from the mining or dredging area as shown in FIG. 1A and which includes ballast associated therewith for changing the center of gravity of the vessel to cause the hull to float in a vertical mining position as shown in FIG. 18 with the major portion of the hull l1 submerged beneath the sea surface E. Naturally, by proper adjustment of the ballast the vessel D can be caused to float in positions in between the horizontal and vertical positions illustrated to account for irregularities in the sea floor being mined.

In the embodiment of the present invention illustrated in FIGS. 1 and 2, the hull 11 includes a central substantially cylindrical, preferably framed, chamber or tank 12 sealed along its length from the stem 13 of the vessel which in mining position is located far below the surface of the sea to the bow 14 of the vessel which in mining position projects a short distance above the surface of the sea. An outer shell 15 surrounds and forms with the tank 12 ballast tanks 16 which can be flooded for causing the hull 11 to float in vertical mining position as illustrated in FIG. 1B or which can be filled with pressurized air for bringing the hull 11 back into horizontal position.

The shape of the shell 15 is selected to provide desired stability and form minimum resistance for motion through the sea in the various operable positions of the vessel. While the tank 12 is illustrated and described as cylindrical in shape for withstanding high pressures when the vessel is in mining position, the tank can be of any suitable cross section or can be in the form of several cylindrical tanks.

In accordance with one aspect of this invention, the crosssectional area of the hull structure 11 is reduced or suitably shaped over the length of the structure that would normally be subjected to the greatest wave action when the vessel is arranged in vertical mining position. This construction is illustrated in FIG. 3 which shows the reduced cross-sectional area structure G adjacent the surface of the sea when the vessel is in vertical position.

The vessel D can either be provided with its own propulsion system for driving in horizontal transportable position or can be towed in this position. It is also provided with a suitable propulsion system for moving the vessel when it is located in vertical mining position. This propulsion system can include regular propellers or thrusters or Voith-Schneider propellers located at certain positions along the length of the vessel.

The fuel tanks for the vessel propulsion system are convenie'ntly located between the shell 15 and the tank 12 at suitable locations along the length of the hull l l, and a control room 18 provided with separate sections for operation in horizontal and vertical positions is located at the bow 14 of the vessel which is positioned above the surface of the sea when the vessel is in vertical mining position.

The conveying or dredging apparatus C can be any one of a wide variety of conventional or especially adapted dredging assemblies such as, for example, bucket ladder, grab bucket, clam shell, drag line, hydraulic, suction, or air lift dredging equipment.

As illustrated in FIG. 1, a hydraulic dredge assembly uniquely cooperating with the mining vessel D to permit mining with a minimum of work includes an exterior conveying pipe 21 provided with a head 22 such as a cutter head on he end thereof and connected via a swivel coupling 23 and a connection pipe 24 to the interior of the tank 12. The position of the conveying pipe 21 is controlled by a winch schematically illustrated as 25 operable from the control room 18 for lowering the conveying pipe 21 to the sea floor when the vessel is in vertical mining position and where the pipe end can be supported by suitable rollers 22' or a carlike member. A stantion 26 is provided on the deck of the vessel for transportation of the conveying assembly in horizontal transporting position.

The connection pipe 24 provides communication between the conveying pipe 21 and an interior conveying pipe 27 adapted for conveying the dredging material interiorly of the tank 12 in the vessel D to a separating location H therein below the surface of the sea. With the interior of the tank 12 communicating upwardly through the vessel with atmosphere, the differential in pressure between the bottom of the sea and the separating location H within the dredging vessel forces the dredged matter A hydraulically by means of sea water upwardly through the exterior pipe 21 and interior conveying pipe 27. At the location H within the vessel, the conveying water is separated in a dewatering chamber 28 from the mined matter and exhausted to the sea from a sump 29 via an exhaust pump 30. The dewatered mined matter can then be lifted from the chamber 28 by a conventional bucket elevator arrangement 31 to the bow of the vessel for discharge through a chute 20 into the transport barge F. The water exhausted via pump 30 can be utilized to aid in the forward propulsion of the vessel D in its vertical position.

The construction illustrated in FIG. 1 permits the material being mined to be hydraulically conveyed into the vessel by the difference in hydraulic pressure from the bottom of the sea to a location within the vessel thereby reducing the work required to lift the material.

The mining vessel positioned in mining position vertically in the sea is affected to a minimum degree by the wave action of the sea since the wave action is primarily concentrated at the surface of the sea, and the required length of the dredging equipment exteriorly of the vessel is reduced over that required in conventional dredging operations by the submersed length of the vessel.

FIG. 4 illustrates an alternative embodiment of the present invention wherein the mined matter is separated within the vessel into desired and undesired minerals, and only the desired minerals are conveyed to the surface of the sea while the undesired minerals are exhausted from the lower submersed portion of the vessel. As illustrated in FIG. 4, the dewatered matter 32 is conveyed via a conventional conveyor 33 to a series of separating

stages

34, 35 and 36 located within the tank 13 below the separating location H. The construction of the separating

equipment

34, 35 and 36 can include screen members or riffles or magnetic separators for separating the desired from the undesired minerals and depends upon the types of minerals being mined. The desired minerals are drawn off from

separators

34, 35 and 36 via

conduits

34, 35 and 36, respectively, to the elevator 31 for conveyance to the bow of the vessel above the surface of the sea. The undesired or waste minerals are dropped through one of a plurality of drop chambers 37 back to the sea bottom.

A typical chamber 37 as illustrated schematically in FIG. 5 includes an inlet opening 38 for receiving the waste minerals from the lowest separator chamber 36 and a lower outlet opening 39 for returning the waste mineral to the sea. A pair of

valves

41 and 42 provide communication from the top of the drop chamber 37 to the sea and are operable from the interior of tank 12 via handles 41' and 42'. Additionally, a spill valve 43 when opened near the top of chamber 37 permits water spillage into a spill tank 44.

In typical operation of the illustrated drop chamber 37 with the outlet opening 39 and the

valves

41 and 42 closed and the spill valve 43 open the inlet 38 is opened and waste materials dropped into chamber 37 until the chamber is substantially full. Then inlet opening 38 and spill valve 43 are closed and

valves

41 and 42 opened so that water fills up the chamber 37 forcing air out of the upper of the two valves thereby to eq ualize the water pressure interiorly of the drop chamber 37 with the water pressure at the exterior of the submerged portion the vessel. Then outlet opening 39 can be opened to permit the waste minerals to drop by gravity to the ocean floor. By then closing outlet opening 39 and

valves

41 and 42, spill valve 43 can be opened and some water spilled into tank 44 to equalize the pressure in the drop chamber 37 with that in theinterior of the vessel. Then inlet opening 38 can again be opened and waste minerals again dropped into the chamber 37 while permitting the water displaced by the waste to flow out through the spill valve 43 into tank 44. By utilizing a plurality of drop chambers 37 at the lower submerged end of the vessel, certain of the chambers 37 can be in the process of exhausting waste materials back to the sea while waste materials are being dropped from the last separating chamber 36 into another drop chamber 37. a

As will be appreciated from the above, the various sizes and shapes of the mining vessel and associated equipment depend to a large extent on the particular conditions of the mining site in which the vessel is used. If the vessel is maintained at sea at the mining site for an extended period of time, such as years at a time, the design of the vessel is primarily governed by the desired characteristics for floating the vessel in vertical mining position. On the other hand, if the mining vessel is to be operated at an area reasonably accessible to a harbor for repairs or for return after a short length of time, greater emphasis is placed on the design of the vessel for transportation in horizontal transporting position. Naturally, the length of the vessel and its associated mining equipment depend upon the particular mining operation to which it is to be applied and the mining area which it is designed to handle.

The minerals recovered from the ocean bottom in accordance with the present invention can be stockpiled and blended for use by the underwater stockpiling and blending method and apparatus described and illustrated in the aforementioned Pat. application Ser. No. 461,785.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention as limited only by the scope of the appended claims.

What is claimed is:

l. A dredge comprising: an elongate hull; means sealing at least a major portion of the length of said hull for submersion in the sea; ballast means for shifting the center ofgravity ofthe dredge between a transport position with said hull lying horizontally in the sea and a dredging position with the hull lying substantially vertically in the sea with the major portion of the length of said hull floating submersed; conveying means mounted on submersible portion of said hull for conveying matter from below the surface of the sea only up into said hull when said hull is in floating dredging position; means for providing atmospheric pressure within said hull when said hull is in floating dredging position; means mounted within said sealed portion of said hull for separating desired matter from undesired matter conveyed into said hull by said conveying means; means for exhausting said separated undesired matter from said submersed portion of said hull; and means for conveying said separated desired matter through said bull to the surface of the sea.

2. The dredge of claim 1 wherein said conveying means includes pipe means for hydraulically conveying minerals from the sea bottom of a location within said hull and below the surface of the sea with hydraulic pressure due at least primarily to the difference in the pressure due to the weight of the matter in said pipe means and the pressure at the submerged open entrance to the pipe means mounted within said hull for separating said minerals from conveying hydraulic fluid; and means for discharging said separated hydraulic fluid from said hull.

3. The dredge of claim 2 wherein said pipe means includes an exterior conveying pipe connected adjacent one end to said hull and having a head at the other end and means for moving said conveying pipe to place said head on the sea bottom when in dredging position and on the deck of said hull when in horizontal transport position.

4. A sea bottom mining vessel comprising: a hull; a tank mounted on said hull and sealed over a major portion thereof for submersion; ballast tanks mounted within said hull; means for flooding and exhausting said ballast tanks to cause said hull to shift between a horizontal floating position and a substantially vertical floating position, at least part of said sealed portion of said tank submersed below the surface of the sea when said hull is floating in substantially vertical position; means mounted on said hull and in communication with said submersible portion ofsard tank for conveying minerals from the sea bottom into said tank when said hull is in said vertical position; means providing atmospheric pressure within said tank when said hull is in vertical floating position; means mounted within said sealed portion of said tank for separating desired matter from undesired matter conveyed into said tank by said conveying means in communication therewith; means for exhausting said separated undesired matter from said submersed portion of said tank; and means for conveying said separated desired minerals upwardly through said tank to a location above the surface of the sea when said hull is in said vertical position.

5. The vessel of claim 4 wherein said conveying means in communication with said submersible portion of said tank includes means for hydraulically conveying minerals from the sea bottom to a location within said tank and below the surface of the sea with hydraulic pressure due at least primarily to the difference in the pressure at the sea bottom and at said location within said tank; means mounted within said tank for separating said minerals from conveying hydraulic fluid; and means for discharging said separated hydraulic fluid from said tank.

6. The vessel of claim 5 wherein said means for conveying material includes an exterior conveying pipe connected adjacent one end to said hull and having a head at the other end and means for moving said conveying pipe to place said head on the sea bottom when in mining position and on the deck of said hull when in horizontal transport position.

Claims

1. A dredge comprising: an elongate hull; means sealing at least a major portion of the length of said hull for submersion in the sea; ballast means for shifting the center of gravity of the dredge between a transport position with said hull lying horizontally in the sea and a dredging position with the hull lying substantially vertically in the sea with the major portion of the length of said hull floating submersed; conveying means mounted on submersible portion of said hull for conveying matter from below the surface of the sea only up into said hull when said hull is in floating dredging position; means for providing atmospheric pressure within said hull when said hull is in floating dredging position; means mounted within said sealed portion of said hull for separating desired matter from undesired matter conveyed into said hull by said conveying means; means for exhausting said separated undesired matter from said submersed portion of said hull; and means for conveying said separated desired matter through said hull to the surface of the sea.

4. A sea bottom mining vessel comprising: a hull; a tank mounted on said hull and sealed over a major portion thereof for submersion; ballast tanks mounted within said hull; means for flooding and exhausting said ballast tanks to cause said hull to shift between a horizontal floating position and a substantially vertical floating position, at least part of said sealed portion of said tank submersed below the surface of the sea when said hull is floating in substantially vertical position; means mounted on said hull and in communication with said submersible portion of said tank for conveying minerals from the sea bottom into said tank when said hull is in said vertical position; means providing atmospheric pressure within said tank when said hull is in vertical floating position; means mounted within said sealed portion of said tank for separating desired matter from undesired matter conveyed into said tank by said conveying means in communication therewith; means for exhausting said separated undesired matter from said submersed portion of said tank; and means for conveying said separated desired minerals upwardly through said tank to a location above the surface of the sea when said hull is in said vertical position.