ES2230982A1 - Sunken tanker petrochemical cargo extractor comprises submersible hot water tank with means for perforating cargo holds and ejection of oil by water - Google Patents

Abstract

System for the extraction of petrochemical in tanks of a sunken ship, at grand depths, which uses an unmanned submersible, which is a general body tank (1) fitted with tubular structures (4) that stand the general body submersible tank (1) incorporated into their free ends a large spherical (5) provided with means for fixing to the hull (2), because this deposit submersible (1) incorporates means drilling ship's hull (2) and pumping means. System for the extraction of petrochemical tanks of a sunken ship, at grand depths, which uses an unmanned submersible, which is a general body tank (1) fitted with tubular structures (4) that stand the general body submersible tank (1) incorporated into their free ends a large spherical (5) provided with means for fixing to the hull (2), because this deposit submersible (1) incorporates means drilling ship's hull (2) and pumping means, and because of under this system the tank submersible (1) is filled hot water (11) on the surface is submerged and fixed to the hull ship (2), to then pierce the hull, to reach inside the tank to empty and, through one or more perforations (12) carried the insert in the tank hot water (11) that is pumped from the tank submersible (1), latter originating in a depression, so that the petrochemical (13) stay in the tank is going to submersible tank (1), by one or more of the perforations (12) made, switching the hot water (11) by the product (13) until, after emptying the tank, the submersible tank (1) rises to the surface for emptying petrochemical product (13).

Description

Product extraction system Petrochemicals from the tanks of a sunken ship.

The present invention aims at a system intended to extract petrochemical products from tanks sunken ships, using a submersible tank provided with means for attaching to the sunken ship's hull and means for pierce said hull of the ship, to transfer the product petrochemical from inside the vessel to the depot submersible.

Background of the invention

In the maritime transport of products petrochemicals are turning to ships that, every time, have a greater load capacity, to reduce the costs of transport.

These large ships pose a huge risk ecological in the case of a collision or mishap that entails the spill into the sea of the cargo transported.

In the sinking of these ships it happens that, despite the deterioration of the hull, some of the ship's tanks they keep the transported product that generally begins to flow through cracks in the tanks giving rise to a process of continuous contamination that lengthens until the emptying of said tanks

In these cases and when the depth at which the wreck is found so allows it, it is used to extract the product contained in the tanks, pumping it up to the surface.

Such is the case of the solutions included in the PCT patents WO 02/057131 and WO 92/05998; as well as in the patent of the United States US 5,795,103 and in the French FR 2,406,605.

It is also known, when the depth of sinking allows it, to resort to refloating solutions of the ship, by means of floats that are attached to the structure of the flotsam.

The problem arises when the wreck is found sunk to great depths. For example in the recent sinking of the ship "Prestige", its hull has been broken in two halves, one the stern part and the other the bow part, which they are separated by more than 3.5 km. and these two halves are They are located more than 3,500 m deep.

At this great depth the wreck is enduring pressures greater than 360 atmospheres, when the pressure in the surface area is 1 atmosphere, equivalent to 1,033 kg / cm2.

The tanks on this ship carried 77,000 tons of fuel and it is estimated that in sunken wreck tanks there are still more than 50,000 tons of fuel. To be some of the semi-empty tanks the empty space is occupied by air that has a much higher degree of compression that of the fuel; so that the external pressure that exists at this depth, greater than 360 atmospheres, will lead to the bulge of The tanks and their bursting.

To try to avoid the ecological risk that would mean the discharge of more than 50,000 tons of fuel are being studying solutions, such as:

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Pumping of fuel Because of the great depth to which the wreck is has contemplated using a drilling robot that pierces the hull of the ship reaching the tank and pumping the fuel towards the surface through a pipe that should be heated so that the fuel flows easily. This solution, in addition to the pumping difficulties, incorporates the problem of heat more than 3,500 m. of hose.

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A second option is to plug the cracks through which the fuel flows. This solution, in addition to the difficulties inherent in the conditions in which the work is carried out, it does not solve definitely the problem.

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I also know has contemplated causing, through explosion, the fuel outlet and Entrust your surface collection. This solution has the problem of the drifts of the mass of fuel in its ascent during the 3,500 m., Due to the different currents and, consequently, the difficulty of providing a specific area of outcrop to the surface, along with the own difficulty of operations subsequent retention and collection.

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By last it has also been contemplated to cover the wrecks with a structure that It would be covered later with cement. This solution is very complex of carry it out at 3,500 m. deep and with some wrecks that They have great dimensionality, considering that the ship It had a length in the surroundings of 280 m.

Object of the invention

In accordance with the present invention it is recommended a new system to extract and recover petrochemical products of a sunken ship at great depth.

According to the invention a unmanned submersible which is itself a large capable tank to collect all the product contained in each of the tanks of the sunken ship.

This submersible tank incorporates means for be attached to the hull of the ship with great grip strength, such such as electromagnets arranged at free ends of, preferably, three large ball joints supported by others so many arms protruding from the general body of the tank submersible.

In this way, the kneecaps allow positioning the electromagnets according to any orientation to adapt well perfectly to the shape of the ship's hull in the area of encounter, whatever its geometric form.

In addition, the submersible tank incorporates means for piercing the hull of the ship and to suck the product content in the tank to empty.

This submersible tank is filled in the surface with hot water and then submerged, moving until reaching the wreck, at which point it is located in the area corresponding to the tank to be emptied, at that time ship's hull through the three electromagnets.

The ship's hull is then drilled; from so that at least one of the perforations is in relation to the bottom of the submersible tank and at least one other drilling is in relation to the top.

For the perforation or inferior perforations pumps the hot water contained in the submersible tank into the inside of the tank; while by drilling or upper perforations the product begins to be extracted Contained in the vessel's tank.

In this way, by injecting hot water from the submersible tank to the vessel's tank is achieved following effects: hot water causes a decrease in viscosity of the petrochemical product contained in the tank and, in addition, the hot water outlet creates a small depression in the upper part of the submersible tank, which causes suction of said petrochemical product, the hot water being exchanged of the submersible tank by the petrochemical product contained in the tank.

The submersible tank will preferably have a capacity equal to or greater than that of each of the tanks at empty; so that in each dive of the submersible tank I emptied a tank.

The submersible reservoir involves motor means own, as well as addressing, lighting, vision, work and how many conventional means are typical of a submersible.

It is envisioned that, according to one embodiment Preferably, the submersible tank adopts a general conformation double hull cylindrical, made of steel or carbon fiber with a filling in a sandwich structure capable of supporting compression pressures greater than 400 kg / cm2.

From one of the sides of the general body of the submersible tank protruding tubular structures, each of which ends at its free end in one of the three large ball joints with their corresponding electromagnet; so that by establishing these three large kneecaps three support points allow to obtain a stable support of the submersible tank against the ship's hull in any situation.

It is provided according to a preferred embodiment, that on each of these kneecaps, which can reach a diameter of two or more meters, a mechanism with a drilling tool; so that the hot water towards the Inside the vessel's tank and the flowing petrochemical product of this, they pass through the interior of the tubular structures that They support the kneecaps.

On the other hand, it is planned that the deposit submersible is connected to a command ship located in the surface, through a cable, by which the power supply to the submersible tank, control of the same; sending images, etc.

Brief description of the drawings

Figure 1 shows in section the arrangement of a submersible tank according to the invention coupled in the position of I work on the hull of a ship.

Figure 2 shows in longitudinal section a exemplary embodiment of the submersible tank according to the invention, with propulsion means to maneuver by turbines.

Figure 3 is a cross section to larger scale of the submersible tank according to the previous embodiment.

Figure 4 is a cross section of the submersible tank looking at the stabilization counterweight in radial direction

Figure 5 is an enlarged detail of the part end of one of the tank fixing structures submersible on the sunken ship's hull.

Figure 6 is a detail like the previous one in a fixing arrangement inclined on the hull of the ship sunken.

Figure 7 is a detail like that of Figure 5 in the drilling arrangement of the sunken ship's hull.

Figure 8 is a detail showing the flow of hot water injection into the tank to be emptied, through of the corresponding drilling performed on the ship sunken.

Figure 9 schematically shows the arrangement of the submersible tank on the sides and on the Deck of a sunken ship.

Figure 10 represents the fastening of a plate or block through the submersible tank, for transport up to The seabed.

Figure 11 shows an arrangement of cover of a sunken ship.

Description of the preferred embodiment

The object of the invention is a system for extract petrochemical products from large sunken ships depth, using an unmanned submersible that is able to reach the sunken ship and look at it, to perform perforations and through them transfer the product petrochemical to be extracted from inside the vessel to submersible.

The submersible intended for this purpose is a tank (1), preferably cylindrical, for example about 40-50 meters in length and about 4.5 meters of inner diameter, without these measures being limiting, because in in any case they must correspond so that the cargo volume of said tank (1) is equal to or greater than the volume of each tank of the sunken vessel (2), since in each dive the submersible must be able to collect the entire product from a tank of said vessel (2).

The tank (1) is structured with a double hull (1.1-1.2), which can be steel, carbon fiber (composite) or any other suitable material, including in the sandwich-shaped interior a stiffening means (3), which can be formed by frames and stringers, honeycomb structures of bee and, in short, any of the solutions so far known, to achieve the necessary stiffness in the body of the tank (1), as to withstand the high pressures acting on The depths of the sea.

In addition, it is also planned to have among the two helmets (1.1 and 1.2) a filler in thermal insulation functions, to maintain as much as possible the temperature inside the deposit (1).

The volume between the two helmets (1.1 and 1.2) must be compensated so that the total weight of the deposit (1) is higher than the pushing force of the water up, for which a separation thickness between the two helmets (1.1 and 1.2) is expected of the order of 0.5 meters, without this measure being limiting.

The junction between the submersible (1) and the post of command is provided by a cable that includes all connections necessary for the control of maneuvers and operations to carrying out, said cable of a light material being provided and resistant, such as carbon fiber or "kewlar", since heavier materials, such as steel, for large lengths (4,000-5,000 meters) result from a weight that practically absorbs most of its carrying capacity.

On the side of the tank (1) there are some structures (4) as arms, which behave in their free ends large-sized ball joints (5) order of 2-3 meters in diameter), going provided said ball joints (5) with electromagnets (6) of great capacity attraction (about 50,000 kg each), as well as an elastic joint (7) in the frontal contour.

The structures (4) are provided tubular, going in the inside of the ball joints (5) a drilling tool (8) capable of drilling the wall of the sunken ship (2) to reach the inside the tanks of the same. In each kneecap (5) the corresponding tool (8) is incorporated into a mechanism that comprises an axial feed actuator (8.1) and an actuator swivel (8.2), as seen in figures 5 to 7, for Perform drilling operations.

The drilling tool (8) of the ball joints (5) it also includes a permanent magnet (8.3), by which it is removed the cut part (2.1) of the ship's hull (2) that results in each perforation, preventing said cut part (2.1) from falling into inside the vessel's tank (2).

The ball joints (5) have the function of establishing a strong fixing on the outer wall of the sunken ship (2), which is achieved by the attraction of electromagnets (6), while the peripheral joint (7) makes the joint result hermetic

To achieve a rigid fixation on the ship (2), whatever the geometric shape of the corresponding zone, in the submersible tank (1) there are three structures (4), of which two are in a lower position and the other in a upper position, which achieves a higher fixation resistance against upward thrust forces when the application is on a vertical wall of the sunken ship (2).

In relation to tubular structures (4) of the bottom part also includes a motorcycle pump (9), whereby a drive is created by the interior of said tubular structures (4), for sending a flow (10) through the corresponding ball joint (5) towards the sunken ship (2), as shown in figure 8.

With all this, for the extraction of the product housed in the sunken ship's tanks (2), the process is the next:

Before the dive the tank (1) is filled with hot water (11) (between 30-80ºC of temperature) and then said tank (1) is submerged, leading to the area of the vessel (2) that corresponds to the tank of the same to be emptied, setting the fixation on said area by means of kneecaps (5) of tubular structures (4).

Once like that, using the tools drills (8) incorporated in the corresponding ball joints (5) a perforation (12) of the vessel wall (2) is carried out to the inside the tank, in the place where the structure is fixed tubular (4) of the upper part of the tank (1) and in the place of fixing of at least one of the tubular structures (4) of the bottom.

Through the perforation (12) of the part bottom is then pumped (10) hot water (11) from inside from the tank (1) to the vessel's perforated tank (2), whereby create a depression at the top of the tank (1), producing a suction that passes the product (13) from the tank from the vessel (2) to the tank (1), through the drilling (12) of the upper part and the corresponding tubular structure (4) faced with it.

Hot water injection (11) in the tank of the vessel (2), increases the pressure inside the tank, to the Once the hot water temperature (11) causes a decrease in product viscosity (13) contained in the tank, since petrochemicals, such as fuel or oil, their viscosity decreases with increasing temperature, which facilitates fluidity and therefore the passage of the product (13) from the vessel's tank (2) to the tank (1).

Thus, as shown in Figure 1, a exchange of water (11) for the product (13) from the vessel tank (2), in the tank (1), decreasing the weight of this as this exchange takes place, due to the minor product weight (13) with respect to water (11), which results in a push up the tank (1).

The adhesion strength of electromagnets (6) of the ball joints (5) must be calculated to be higher at the maximum thrust of the tank (1) upwards by the effect previous; being provided that between the two helmets (1.1 and 1.2) of the tank (1) there is an area (14) destined for compensation tank,  as seen in figure 2, to keep the weight stable, with in order not to subject the vessel wall (2) to loads unnecessary, regulating the entry of water into the mentioned compensation zone (14), proportionally to the water exchange (11) for the product (13) inside the deposit (1).

Inside the tank (1) are provided float means (15), to indicate the water level (11) in said interior, thus allowing to know at all times the quantity of product (13) that is transferred to the tank (1), during the operation of the transfer.

In the deposit (1) two are also included counterweights systems (16 and 17) that can be moved so adjustable, with one of which (16), which can be seen in the figure 2, the center of gravity can be varied longitudinally and with the other (17), which can be seen in figures 2 and 4, you can vary the center of gravity radially. The change of the center gravity in the longitudinal direction allows to keep the desired tilt of the reservoir (1) to adjust to position of inclination of the sunken ship (2); while changing the center of gravity radially allows to vary and stabilize the positioning of the kneecaps (5) for adaptation to the sides or to the deck of the ship (2), as shown in figure 9, depending on whether the product (13) is removed from the side tanks or central.

The ball joints (5) are provided with a control of positioning, which allows to detect if there are sea currents or alternative movements of water by waves; being planned that the kneecaps (5) can swing between more-less 45º (± 45º), which allows the submersible tank (1) to oscillate without transmitting dangerous cargo to the ship's hull (2). The ball joints (5) include electromagnets (5.1) that allow blocking the movable part thereof in the fixation position on the ship hull (2).

Depending on the degree of rotation required, the ball joints (5) they can be simple, or of a double embodiment, so that if the submersible tank (1) has to operate in adverse conditions by maritime forces, the system keeps you within oscillation limits of the kneecaps (5), preventing transmission of dangerous cargo, both for the hull of the ship (2) and for the own submersible tank (1). That is to say, the deposit submersible (1) is like a barnacle that adheres to the deck or to the sides of the sunken ship (2), as shown in figure 9, being able to have oscillations without causing dangerous loads in Neither side.

The mechanism that goes in the kneecaps (5) and the corresponding perforated tools (8) are hollow shaft, to through which an ultrasonic sensor is arranged, to inspect the ship's hull (2) in order to prevent the perforations (12) coincide with some inner frame of the frame that prevents or hinders drilling.

The submersible tank (1) will be provided with all the necessary means for the government and control of operations to be done with him, as well as with lighting and vision.

For movement in the necessary maneuvers, said submersible tank (1) is provided with means of propulsion, which can be for example two adjustable propellers located at the ends or a turbine system.

As a practical embodiment, a system of turbine propulsion, as shown in figures 2 and 3, comprising a longitudinal turbine (18) to drive the forward and reverse movements in the longitudinal direction and some transverse turbines (19 and 20), some (19) vertical to drive movements of ascent and descent of depth in the water and others (20) horizontal to drive lateral movements.

The preferred embodiment has been the filling the submersible tank (1) with hot water (11), but of similarly, within the same framework of the invention, they can be also used other liquids, as well as non-hot water, or mixtures of different liquids.

Given the power of attraction of electromagnets (6) of the ball joints (5) that are incorporated into the tubular structures (4), the submersible tank (1) can be also used to hold and transport, as the figure shows  10, objects (21), such as buckets, structures, blocks of concrete, etc., for the preparation of the area of operations in the seabed or any kind of complementary actions, including for the incorporation or formation of an envelope covering (22), as shown in Figure 11 on the sunken ship (2), before or after extracting the product (13) from its tanks.

Claims (8)

1. System for the extraction of petrochemical products from the tanks of a sunken ship, at great depths, characterized in that according to the same one an unmanned submersible is used, whose general body is a tank (1) provided with tubular structures (4) protruding from the general body of the submersible tank (1) by incorporating large spherical ends (5) provided with fixing means to the hull of the ship (2); because this submersible tank (1) incorporates drilling means of the ship's hull (2) and pumping means; and because according to this system the submersible tank (1) is filled with hot water (11) on the surface; it is submerged and fixed to the hull of the ship (2), to then drill said hull, until it reaches the inside of the tank to be emptied and, through one or more of the perforations (12) made, introduce the hot water into the tank ( 11) which is pumped from the submersible tank (1), causing depression within the latter; so that the petrochemical product (13) housed in the tank is passed to the submersible tank (1), by another or other of the perforations (12) made, the hot water (11) being exchanged for said product (13) until, once the tank has been emptied, the submersible tank (1) emerges to the surface, for emptying the extracted petrochemical product (13). 2. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the previous claim, characterized in that three tubular structures (4) are provided in the submersible tank (1), each provided in its free end of the corresponding large patella (5) that allows positioning of the fixing means according to the different geometries of the hull of the ship (2); because according to a preferred embodiment the fixing means are electromagnets (6) and because, these three tubular structures (4) that comprise the large ball joints (5), are distributed, two of them being arranged, in relation to the lower part of one side of the submersible tank (1); while the third is arranged in relation to the upper part of said lateral. 3. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the first and second claims, characterized in that, according to a preferred embodiment, in relation to each ball joint (5) respective drilling means are installed , constituted by an actuator mechanism and the corresponding drilling device (8); so that the hot water (11) is pumped from the inside of the submersible tank (1) to the tank to be emptied through at least one of the two lower tubular structures (4) kneecap holders and the petrochemical (13) passes into the submersible tank (1) through the tubular structure (4) ball-and-socket holder
higher. 4. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the first, second and third claims, characterized in that each of the three large ball joints (5) carries a positioning control device and a seal (7) of tight connection between the ball joint (5) and the hull of the sunken ship (2); because said ball joints (5) can oscillate up to about forty-five degrees (± 45 °), to allow oscillations of the submersible tank (1) with respect to the hull of the ship (2), without transmitting dangerous loads to said hull; provided that said ball joints (5) can be single or double, depending on the degree of rotation desired. 5. System for the extraction of petrochemical products from the tanks of a sunken ship, in all in accordance with the first, second, third and fourth claims, characterized in that the actuator mechanism and the drilling tool (8) are provided to be hollow shaft, to pass through it an ultrasonic sensor that allows inspecting the sunken ship's hull (2) and establish the correct drilling point. 6. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the first claim, characterized in that according to a preferred embodiment the general body of the submersible tank (1) is a double cylindrical hull (1.1-1.2 ), incorporating between the two helmets (1.1 and 1.2) a sandwich (3) capable of withstanding high pressures and thermally insulating the inside of the tank; having provided between both helmets (1.1 and 1.2) an area (14) destined for compensation tank and because the submersible tank (1) carries inside it two counterweight devices (16 and 17) that allow to vary the center of gravity of the tank submersible (1) longitudinally and radially. 7. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the first claim, characterized in that the submersible tank (1) incorporates the corresponding driving, maneuvering, lighting, vision and other own means conventional to establish its operation underwater; having provided that the submersible tank (1) is connected to the surface through a connection cable. 8. System for the extraction of petrochemical products from the tanks of a sunken ship, in all according to the first claim, characterized in that the means of fixing the large ball joints (5) to the hull of the ship (2) are electromagnets ( 6).