ES2615519T3 - Equipment and method of dredging for dredging or extraction with said equipment - Google Patents

Abstract

Dredging equipment (1) comprising at least: - a ship (2); - pumping means (7); and, - one or more suspension cable systems (39.54) on the ship (2) each with lifting means (40.45.48.51.55) for winding and unwinding one or more cables ( 42,44,46,49,52,56) which are linked to the pumping means (7); the pumping means (7) comprising at least: - a pumping duct (8), consisting of a suction tube (9), a submersible pump (10) and a discharge tube (11); - an inlet (12) of the submersible pump (10) that is connected to a first end (13) of the suction tube (9) and an outlet (14) of the submersible pump (10) that is connected to a first end (15) of the discharge tube (11) - where a second end (16) of the suction tube (9) is a free end that forms an inlet of the suction tube (17) for the suction of a mixture of water and material of loose seabed (18); where the pumping duct (8) is an articulated pumping duct (8) comprising two or more pumping duct sections (28,32,33,34), where the adjacent pumping duct sections are connected to each other in a rotating manner by means of a joint (31,36,38), where the different parts of the pumping means (7) are linked to one or more cables (42, 44, 46, 49, 52,56) of one of the above-mentioned suspension cable systems (39,54) so that, on the one hand, by winding the affected cables, the articulated pumping conduit (8) can be folded to a reduced state with reduced dimensions and brought to an on-board position, in whose reduced state at least some of the sections of the pumping duct (28, 32,33) are carried in parallel and close to each other by a substantial part of their length, and, on the other hand, by unwound the affected cables of the articulated pumping duct (8) can be deployed to a stage or extended with extended dimensions where the sections of the pumping duct (28,32,33,34) are distanced from each other except in their interconnection by the affected joint (31,36,38), where the pumping duct (8 ) articulated comprises a part of the pumping conduit on the side of the vessel (27) and an extension part of pumping conduit (28) connected to one another in a rotating manner at a first of its ends (29,30) by means of a first joint (31), where the part of the pumping conduit on the side of the vessel (27) is suspended with respect to the vessel (2) at least partially by one or more cables (42,44,46,49,52) of a suspension cable system of the part of the pumping conduit on the side of the ship (39), and the extension part of the pumping conduit (28) has at its second end (16) a free end forming the inlet of the suction tube (17) and is suspended at least partially from the vessel (2) by the cable (56) or cables of a suspension cable system of the pumping duct extension part (54), characterized in that the pumping means comprise a sliding connection of the stump (20) of the pumping conduit (8) with the vessel (2) at the second end (19) of the part of the pumping conduit on the side of the vessel (27), where the sliding connection of the stump (20) is such that the pumping conduit (8) can move between the on-board position for the storage of the pumping duct (8) on board the ship (2) and a submerged position off-board the ship (2) and below the water level (21) to use the pumping means (8 ), where the part of the pumping conduit on the side of the vessel has a length (L) corresponding approximately to the length (M) between the position of the stump sliding connection (20) of the pumping means (7) with the ship (2) and the stern (5) of the ship (2).

Description

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spring 60 compressed when the inner tube is pushed towards the outer tube.

[0111] In this way, the impacts between the inlet of the suction tube 17 and the seabed 18 produced by movements of the ship 2 can be absorbed, so that no other part of the pumping conduit 8 is subjected to this type of impacts or at least on a very small level.

[0112] At great depths of water, the vacuum in the suction tube 9 created by pumping the submersible pump 10 can cause implosions or water knocking.

[0113] Therefore, another aspect according to the invention is that the pumping line 8 is preferably provided with vacuum relief valves 61 to prevent such a phenomenon from occurring or causing damage.

[0114] These vacuum relief valves 61 can be of an active or passive type and compensate for the pressure differences affected and will allow a regular flow through the pumping line 8.

[0115] In the embodiment of the dredging equipment 1 shown in the figures the upper section of the part of the pumping conduit on the side of the ship 32 and the intermediate section of the part of the pumping conduit on the side of the vessel 34 they are metal tube sections, while the bottom section of the part of the pumping conduit on the side of the vessel 33 and the extension portion of the pumping conduit 28 comprise one or more plastic pipes that are provided on a lattice beam 62 metallic

[0116] These lattice beams 62 also increase the resistance of the pumping conduit 8 against impacts in the pumping conduit 8.

[0117] The bottom section of the part of the pumping conduit on the side of the vessel 33 and the extension portion of the pumping conduit 28 can be constructed from a lightweight glass reinforced epoxy tube (GRE) or any other plastic material.

[0118] According to a preferred embodiment of the dredging equipment 1 according to the invention, the inlet of the suction tube 17 is provided with sensors for measuring the position of the inlet of the suction tube 17 with respect to the vessel 2 and which provide an input for a controller that controls the position of the inlet of the suction tube 17 by means of the suspension cable systems 39 and 54.

[0119] The cable or cables of the suspension cable systems 39 or 54 are hereby preferably provided with an interactive cable tension control system whereby the tension in the corresponding cables is maintained within certain limits.

[0120] To use dredging equipment 1 according to the invention, a method for dredging or extraction according to the invention is proposed as follows.

[0121] First, ship 2 navigates to an area to be dredged or removed, where the pumping line 8 is in a reduced state, as shown in Figure 1 stored on board the ship.

[0122] After positioning the vessel 2, prepared for operations, the pumping duct 8 is raised from its supports on the deck 6 and is turned overboard.

[0123] Then the pumping means 7 are brought to a submerged position and the articulated pumping conduit 8 is deployed to an extended state by unwinding the cables 42, 44, 46, 48,52 and 56 of the suspension cable systems 39 and 54 in an appropriate manner until the inlet of the suction tube 17 reaches the seabed 18.

[0124] Hereby, before actually deploying the articulated pumping duct 8, the pumping duct 8 is lowered from the deck level to the underwater level by unwinding the cables 42, 44, 46,49 and 52 of the suspension cable system of the part of the pumping conduit on the side of the vessel 39 and the cable 56 of the suspension cable system of the pumping extension portion of the pump 54 simultaneously and all at about the same speed, so that the pumping conduit 8 is kept in the reduced state and is kept parallel to the cover 6.

[0125] Meanwhile, the second end 19 of the pumping conduit 8 slides in the sliding guide of the stump 22, until the bottom 24 of the hull is reached, after which the discharge tube 11 of the pumping means 7 It is connected to a discharge pipe in hull 3 of ship 2.

[0126] This is the situation as depicted in Figure 2.

[0127] Then, the articulated pumping conduit 8 is deployed to the extended state, which requires at least the following steps.

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Claims (1)

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