A METHOD AND A SYSTEM FOR COLLECTING FLOATING OBJECTS ON A SURFACE OF WATER

Abstract

A method and system for collecting objects floating on or suspended near a surface of water. A collecting system is employed comprising a floating barrier. The collecting system is unanchored to or on the seabed such that the collecting system is free to move along the surface of the water. A submerged portion and non-submerged portion is provided connected to the floating barrier, such that a velocity of the floating barrier along the surface of the water differs from a surface velocity of the water at the location of the floating barrier. Collected plastic objects can be recycled. Further, the ocean currents are followed while being able to collect plastic.

Claims

1. A method for collecting objects floating on or suspended near a surface of water by means of a collecting system comprising a floating barrier, wherein, in use, the collecting system is unanchored to or on the seabed such that the collecting system is free to move along the surface of the water, the method including: providing the floating barrier having a non-submerged portion and a submerged portion, wherein at least the non-submerged portion provides air resistance when subjected to wind, and at least the submerged portion provides drag when the floating barrier is moved along the surface of the water, wherein as a result of the air resistance and the drag a difference is obtained in a velocity of the floating barrier along the surface of the water with respect to a velocity of the objects floating on or suspended near the surface of water at the location of the floating barrier.

2. The method according to claim 1, wherein the air resistance and drag cause the collecting system to move slower through the water than the objects.

3. The method according to claim 1, wherein the ratio of air resistance and drag for the floating barrier is smaller than the ratio of air resistance and drag of the objects to be collected.

4. (canceled)

5. The method according to claim 1, wherein the objects include debris, such as plastic waste.

6. (canceled)

7. The method according to claim 1, wherein at least one connection line is provided configured for connecting two parts of the elongated floating barrier so as to maintain a curved floating barrier.

8. The method according to claim 1, wherein the floating barrier comprises at least one floater and a screen connected thereto, wherein the screen extends downwards in the water and provides drag when the floating barrier is moved along the surface of the water, and wherein at least a non-submerged portion of the floater of the floating barrier provides air resistance.

9. (canceled)

10. (canceled)

11. The method according to claim 1, including collecting plastic objects floating on or suspended near a surface of water and recycling the plastic.

12. (canceled)

13. (canceled)

14. A collecting system for collecting objects floating on or suspended near a surface of water comprising a floating barrier, arranged for freely moving along the surface of the water, wherein the floating barrier comprises a non-submerged portion and a submerged portion, wherein the non-submerged portion is configured to provide air resistance when subjected to wind, and the submerged portion is configured to provide drag when the floating barrier moves along the surface of the water, wherein as a result of the air resistance and the drag a difference is obtained in a velocity of the floating barrier along the surface of the water with respect to a velocity of the objects floating on or suspended near the surface of water at the location of the floating barrier.

15. The collecting system according to claim 14, wherein the air resistance and drag cause the collecting system to move slower through the water than the objects.

16. The method according to claim 14, wherein the ratio of air resistance and drag for the floating barrier is smaller than the ratio of air resistance and drag of the objects to be collected.

17. (canceled)

18. (canceled)

19. The collecting system according to claim 14, wherein the floating barrier comprises at least one floater and a screen connected to each other, wherein the screen extends downwards in the water.

20. (canceled)

21. The collecting system according to claim 14, wherein the floating barrier forms an elongated floating barrier line.

22. (canceled)

23. The collecting system according to claim 14, further comprising a buffer unit including a space for storing collected objects, such as debris.

24. The collecting system according to claim 14, wherein at least one connection line is provided configured for connecting two parts of the elongated floating barrier so as to maintain a curved floating barrier.

25. The collecting system according to claim 14, wherein the floating barrier comprises at least one floater and a downwardly extending screen connected thereto, wherein at least the screen is configured to provide drag when the floating barrier is moved along the surface of the water, and wherein at least a non-submerged portion of the floater of the floating barrier is configured to provide air resistance.

26. The collecting system according to claim 25, wherein the depth of the screen adjacent the first and second end is reduced towards the first and second end of the floating barrier.

27. (canceled)

28. Plastic obtained by employing the method according to claim 11.

29. The method according to claim 1, wherein the submerged portion includes a submerged member connected to the floating barrier at a first attachment portion and at a second attachment portion, the first and second attachment portions being spaced apart along the floating barrier, so that the floating barrier automatically re-orients itself when the direction of water current, waves and/or wind changes, such that a concave collecting region is formed facing an upstream direction of the flow.

30. The method according to claim 1, wherein the submerged member includes for increasing the drag of the submerged member one or more drag members, such as one or more sea anchors, drift anchors, drogues, parachute anchors, drift socks, para-anchors, parachute sea anchors and/or boat brakes.

31. The collecting system according to claim 14, wherein the submerged portion includes a submerged member connected to the floating barrier at a first attachment portion and at a second attachment portion, the first and second attachment portions being spaced apart along the floating barrier, such that the floating barrier automatically re-orients itself when the direction of water current, waves and/or wind changes, such that a concave collecting region is formed facing an upstream direction of the flow.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0111] The invention will further be elucidated on the basis of exemplary embodiments which are represented in a drawing. The exemplary embodiments are given by way of non-limitative illustration. It is noted that the figures are only schematic representations of embodiments of the invention that are given by way of non-limiting example.

[0112] In the drawing:

[0113] FIG. 1 shows a schematic diagram of an embodiment of a collecting system;

[0114] FIG. 2 shows a schematic diagram of an embodiment of a collecting system;

[0115] FIG. 3 shows a schematic diagram of an embodiment of a collecting system;

[0116] FIG. 4 shows a schematic diagram of an embodiment of a collecting system;

[0117] FIG. 5 shows a schematic diagram of an embodiment of a collecting system;

[0118] FIG. 6 shows a schematic diagram of an embodiment of a collecting system;

[0119] FIG. 7 shows a schematic diagram of an embodiment of a collecting system;

[0120] FIG. 8 shows an embodiment of a part of a floating barrier;

[0121] FIG. 9 shows an embodiment of a part of a floating barrier;

[0122] FIG. 10 shows a schematic diagram of a method for collecting objects on or near a surface of water;

[0123] FIG. 11 shows a schematic diagram of a method for collecting objects on or near a surface of water; and

[0124] FIG. 12 shows a schematic diagram of an embodiment of a collecting system;

[0125] FIG. 13 shows a schematic diagram of an embodiment of a collecting system;

[0126] FIG. 14 shows a schematic diagram of an embodiment of a collecting system;

[0127] FIG. 15 shows a schematic diagram of an embodiment of a floating barrier holding portion;

[0128] FIG. 16 shows a schematic diagram of an embodiment of a collecting system;

[0129] FIG. 17 shows a schematic diagram of an embodiment of a collecting system;

[0130] FIG. 18 shows an embodiment of a drag member of a submerged member; and

[0131] FIG. 19 shows an embodiment of drag members of a submerged member.

DETAILED DESCRIPTION

[0132] FIG. 1 shows a schematic diagram of an embodiment of a collecting system 1 for collecting objects 2 floating on or suspended near a surface of water 4. The collecting system 1 comprises a floating barrier 6, wherein, in use, the collecting system 1 is unanchored to or on the seabed 10 such that the collecting system 1 is free to move along the surface of the water 4. The floating barrier 6 has a non-submerged portion 7a and a submerged portion 7b, wherein at least the non-submerged portion 7a provides air resistance when subjected to wind, and at least the submerged portion 7b provides drag from the water when the floating barrier is moved along the surface of the water 4, wherein as a result of the air resistance and the drag a difference is obtained in a velocity of the floating barrier 6 along the surface of the water 4 with respect to a velocity of the objects 2 floating on or suspended near the surface of water at the location of the floating barrier. Hence, the effect of wind and water on the velocity of the floating barrier 1 differs from the effect of wind and water on the velocity of the objects 2. The collecting system 1 can be driven by wind, waves and/or currents, for example lacking an active propulsion means such as a motor.

[0133] The air resistance and drag can cause the collecting system to move faster through the water than the objects. Both the collecting system and the to be collected objects can be carried along the water current. When the collecting system is arranged to catch more wind than the to be collected objects, the collecting system can move with a higher speed along the water surface, under the influence of wind. The obtained speed difference obtained between the collecting system and the to be collected floating objects can ensure that these floating objects are collected in a more efficient manner by the floating barrier. The to be collected objects can for instance be substantially made out of plastic, such as but not limited to pieces of plastic, plastic foils, plastic bottles, plastic nets, plastic parts, etc.

[0134] FIG. 2 shows a schematic diagram of an embodiment of a collecting system 1. Advantageously, in this embodiment, the floating barrier 6 forms an elongated floating barrier line having a first end 9a and a second end 9b. The floating barrier 6 is configured such that the drag encountered by the submerged-portion of the floating barrier at and near the first 9a and second end 9b of the floating barrier 6 relative to other parts of the floating barrier 6 is reduced. Additionally or alternatively, the air resistance encountered by the non-submerged-portion of the floating barrier 6 at and/or near the first end 9a and second end 9b of the floating barrier relative to other parts of the floating barrier 6 can be increased (not shown).

[0135] Advantageously, the collecting system 1 can become more wind-driven than current-driven. However, the collecting system 1 can still follow ocean gyres under the influence of ocean currents.

[0136] In the shown embodiment of FIG. 2, the floating barrier comprises at least one floater 22 and a screen 24 connected thereto, wherein the screen 24 extends downwards in the water and provides drag when the floating barrier 6 is moved along the surface of the water 4, and wherein at least a non-submerged portion of the floater 22 of the floating barrier 6 provides air resistance. The drag encountered by the submerged-portion of the floating barrier 6 at and near the first and second end 9a, 9b of the floating barrier 6 is reduced by reducing a depth of the screen at and near the first and second end 9a, 9b.

[0137] The collecting efficiency can be improved as both wind and (ocean) currents are taken into account, influencing movement and orientation of the floating barrier on the water. In this way, the drag encountered by the submerged portion of the floating barrier at and near the first end 9a and the second end 9b of the floating barrier 6 can be effectively reduced. The first end and the second end 9a, 9b can be more easily re-orientated relative to other parts of the floating barrier 6, under the influence of wind forces as they are less subject to drag.

[0138] FIG. 3 shows a schematic diagram of an embodiment of a collecting system 1. The floating barrier 6 has a screen 24 having a smaller depth towards the first end 9a and the second end 9b. In this way, a more gradual relative difference in encountered drag can be obtained over the length of the floating barrier 6. Between the first end 9a and the second end 9b, a part has a larger overall depth. It is appreciated that other relative screen depths can be employed. For instance, in a middle portion between the first end 9a and the second end 9b, optionally a reduced screen depth may be employed. This may increase the ‘flexibility’ of the floating barrier 6 to movements when floating on water.

[0139] In this example, the wind can exert a substantially equal load on the floating barrier of the collecting system. Further, the screen 22 provides drag under water due to relative motion between the collecting system 1 and the water. By reducing the screen depth at and near the ends 9a, 9b of the floating barrier 6, the drag encountered at those portions of the floating barrier 6 can be reduced. In this way, the first end and the second end 9a, 9b may more easily follow the wind, leading the floating barrier towards objects. Also the orientation stability of the floating barrier can be improved in this way. The floating barrier 6 of the collecting system 1 can orient itself on the basis of wind. Further, the wind is used for driving the floating barrier 6 towards objects 2 for collecting said objects 2. In an example, the screen has a first depth over a larger portion of the total length of the floating barrier 6, wherein near the first and second ends 9a, 9b one or more sections are provided with a screen with reduced second depths. At those one more sections, also a gradual change of the depth may be achieved. The second depth may be a fraction of the first depth, for instance ½, ⅓, ¼, ⅕, ⅙, etc. One or more gradual transitions can be provided in which the screen depth is gradually changed. It is also possible to omit the screen at the first and second end, or at a section near the first end and the second end, i.e. second depth equal to substantially zero. For example, the first depth is 4 meter and the second depth is 2 meter (½). Other, dimensions are also possible. For instance, the first depth may be more than 0.5 meter, more than 2 meter, more than 5 meter, etc. In an example, a plurality of sections are provided having a different screen depths. For example, one or more sections may be provided in which the screen depth is varied gradually. Preferably, the first depth is around 3.5-4.5 meters and the second depth around 1.5-2.5 meters. Other combinations are also possible.

[0140] Also the floating barrier 6 can have various lengths. For example the length of the floating barrier 6 may be larger than 300 m, larger than 500 meter. Preferably, the length of the floating barrier is between 600 and 900 meters. The floating barrier can e.g. be tubular, e.g. having a diameter of about 1-2 m, e.g. 1.2 m.

[0141] FIG. 4 shows a schematic diagram of an embodiment of a collecting system 1 comprising a connection line 13 configured for connecting two parts of the elongated floating barrier 6 so as to maintain a curved floating barrier 6. In the shown embodiment, the first end 9a and the second end 9b are connected with respect to each other by means of the connection line 13. Also in this embodiment, the floating barrier has a variable screen depth along its length, more particularly, the screen depth is gradually reduced towards the first end 9a and the second end 9b of the floating barrier 6.

[0142] FIG. 5 shows a schematic diagram of an embodiment of a collecting system 1 comprising a submerged member 8 connected to the floating barrier 6 such that the velocity of the floating barrier 6 along the surface of the water 4 differs from the velocity of the objects 2 floating on or suspended near the surface of the water 4 at the location of the floating barrier 6. The submerged member 8 comprises a line extending in the water. One or more drag members can be attached to the submerged member 8 for increasing the drag. Since, the submerged member 8 is connected to a central portion of the floating member 6 between the first end 9a and the second end 9b, the central portion can encounter more drag relative to the first end 9a and the second end 9b. Furthermore, in the shown embodiment, the first end 9a and the second end 9b are free of a screen 24 extending in the water. The floater 22 of the floating barrier 6 may provide a sufficient barrier substantially preventing collected objects 2 from escaping the collecting system 1.

[0143] FIG. 6 shows a schematic diagram of an embodiment of a collecting system 1. In this example, the floating barrier 6 comprises a screen with a substantially constant depth along its length. A plurality of submerged members 8 are arranged for locally increasing the drag encountered by the floating barrier 6. A drag member 14 is connected to each submerged member 8 for increasing the encountered drag. It is also possible that a drag member 14 is only connected to some or none of the one or more submerged members 8 connected to the floating barrier 6. The submerged members 8 are arranged between the first end 9a and the second end 9b, such that the drag encountered by the first end 9a and the second end 9b is lower with respect to the other parts of the floating barrier 6.

[0144] Additionally, or alternatively, the air resistance at the first and second end 9a, 9b of the floating barrier 6 is increased by arranging wind resistance members 17 at said first and second end 9a, 9b. In this way, more wind can be captured by the floating barrier at the first end and the second end 9a, 9b. Hence, in this embodiment, the air resistance encountered by the non-submerged-portion of the floating barrier 6 at the first end 9a and second end 9b of the floating barrier relative to other parts of the floating barrier 6 is effectively increased. Additionally or alternatively, the screen 24 may be made deeper for locally increasing the drag encountered by the floating barrier moving along the surface of the water.

[0145] FIG. 7 shows a schematic diagram of an embodiment of a collecting system 1 comprising a plurality of connection lines 13 configured for connecting parts of the elongated floating barrier 6 so as to maintain a curved floating barrier 6. In this example, the depth of the screen 24 of the floating barrier is stepwise reduced towards the first end 9a and the second end 9b. In this example, at a center portion of the floating barrier, between the first end 9a and the second end 9b, an optional reduction in screen depth is present for positioning of a buffer unit (not shown).

[0146] FIG. 8 shows an embodiment of a part of a floating barrier 6. The floating barrier 6 comprises at least one floater 22 and a screen 24 which are connected to each other. The screen 24 of the floating barrier extends downwards in the water. The floater 22 floats on the surface 4 of the water and may be partially submerged in the water. The floater 22 is arranged to maintain buoyancy of the floating barrier. Water at the surface 4 and objects 2 floating on or suspended near the surface 4 of the water may move in a flow direction A and encounter the floating barrier 6. Water and/or sea life are allowed to pass underneath the screen 24. However, the objects 2 are blocked by the floater 22 and/or the screen 24 and can accumulate. The floater 22 may have an empty inner section and/or include materials with a low density for increasing the buoyancy.

[0147] By means of the screen 24 underflow caused by currents or waves carrying objects/debris outside the collecting region 16 can be avoided or reduced. By means of the floater 22, splash-over caused by waves carrying objects/debris over the floating barrier and outside the collection region 16 can be avoided or reduced. In the example of FIG. 8, a lower end of the screen 24 is weighted to keep the screen substantially vertical. Thereto a ballast 25 may be included by the screen, e.g. a ballast chain attached along a lower edge of the screen 24.

[0148] The optional submerged member 8 can be attached to the floater 22. Alternatively, or additionally, the submerged member 8 can be attached to the screen 24, e.g. to a lower edge of the screen.

[0149] An elongated floating barrier line 6 may be formed by means of a plurality of sections 26a, 26b, 26c pivotally connected to each other to enable a bending flexibility. The pivots have sufficient stiffness to prevent folding of the elongate floating barrier line due to pulling forces by the submerged member. The sections 26a, 26b, 26c may be substantially rigid, wherein a flexible connection portion between the multiple sections is provided so as to avoid debris or objects 2 from escaping the flexible barrier 6 while allowing relative movement between the sections 26a, 26b, 26c. Alternatively, or additionally, the sections 26a, 26b, 26c can be substantially rigidly coupled, e.g. welded. Then the sections 26a, 26b, 26c can having a bending flexibility, and yet sufficient stiffness to prevent folding.

[0150] The floater 22 may have different cross sectional shapes, such as circular, oval, triangular, square. Other more complex shapes are possible.

[0151] As can be seen in the embodiment shown in FIG. 8, the depth of the screen 24 is varied along the length of the floating barrier 6. By changing the depth of the screen 24, the drag encountered by the floating barrier along its length can be changed. Hence, the drag encountered by the first end 9a and the second end 9b relative to other parts of the floating barrier can be reduced.

[0152] FIG. 9 shows an embodiment of a part of a floating barrier 6 comprising a floater 22 and a screen 24 with a variable screen depth along at least a portion of its length. More particularly, at the first end 9a, the screen 24 is shown to have a reduced depth into the water. Additionally, the first end 9a of the floating member 6 comprises a wind resistance member 17, such as a vane, tower, sail, or the like, for increasing the air resistance at the first and second end 9a, 9b of the floating barrier 6.

[0153] FIG. 10 shows a schematic diagram of a method for collecting objects on or near a surface of water by means of a collecting system 1 comprising a floating barrier 6. In a first step 1001, the collecting system 1 is unanchored to or on the seabed such that the collecting system 1 is free to move along the surface of the water. In a second step 1002, a floating barrier 6 having a non-submerged portion 7a and a submerged portion 7b is provided. In a third step 1003, air resistance is provided by means of at least the non-submerged member 7a when subjected to wind, and drag is provided at least by means of the submerged portion when the floating barrier is moved along the surface of the water. In a fourth step 1004, as a result of the air resistance and the drag a difference is obtained in a velocity of the floating barrier 6 along the surface of the water 4 with respect to a velocity of the objects 2 floating on or suspended near the surface of water 4 at the location of the floating barrier 6.

[0154] In an example, the air resistance and drag cause the collecting system to move faster through the water than the objects. The collecting system may move under the influence of water flow/current (drag) and wind (wind resistance) while approaching objects floating on or suspended near a surface of water for collection. Advantageously, the collecting system may be configured such that the ends are more susceptible to wind than the portion between the two ends (e.g. middle portion). The ends of the floating barrier of the collecting system may have a lower drag and/or a higher air resistance. As a result, the floating structure can (self-) orient itself towards the to be collected objects. In an example, the ends are more susceptible to wind, as a result of reduced drag encountered by the submerged-portion of the floating barrier at the ends of the floating barrier. The middle portion between the two ends may experience more drag than the ends of the floating barrier. Additionally or alternatively, a higher air resistance can be provided at the ends of the floating barrier.

[0155] FIG. 11 shows a schematic diagram of a method for collecting objects on or near a surface of water. In a first step 2001, an unanchored collecting system 1 is provided including a floating barrier 6 forming an elongated floating barrier line having a first end 9a and a second end 9h. The method further includes at least one of the: reducing the drag encountered by the submerged-portion of the floating barrier 6 at the first and second end 9a, 9b of the floating barrier 6 relative to other parts of the floating barrier 6 (step 2002), or increasing the air resistance encountered by the non-submerged-portion of the floating barrier 6 at the first end and second end 9a, 9b of the floating barrier 6 relative to other parts of the floating barrier 6 (step 2003). This may also aid in automatically, passively steering the collecting system for collecting the objects.

[0156] It is noted that within ocean currents plastic tends to gravitate towards high concentration zones. Because substantially the same forces act on the floating barrier as on the plastic debris, they will both be pushed to the same areas. Hence, the collecting systems will automatically gravitate to where these high concentration zones are.

[0157] The collecting system 1 of the shown embodiments can function equally well in any body of liquid wherein the objects/debris 2 on the surface thereof has a lesser density than the body of liquid.

[0158] Although the examples show screens 22 with different depths, the encountered drag along the length of the floating barrier can be varied in other ways. For instance, the screens may have openings, wherein the size, shape and location of the openings can influence the encountered drag. Other ways for influencing the encountered drag by means of screens are also possible. For example, the screens can be connected to additional drag members which locally can increase the encountered drag relative to other parts (e.g. tapered portions).

[0159] FIG. 12 shows a schematic diagram of an embodiment of a collecting system 1. The collecting system 1 is arranged for collecting objects 2 floating on or suspended near a surface 4 of water comprising a floating barrier 6 floating on the surface 4. The system further includes a submerged member 8 connected to the floating barrier 6 arranged for providing a difference between the velocity of the floating barrier 6 along the surface 4 of the water and a surface velocity of the water at the location of the floating barrier 6. The floating barrier 6 can freely move along the surface of the water 4, although the velocity of the floating member 6 may be affected by the submerged member 8. here, the submerged member comprises a line connected to the floating barrier 6. Ocean debris or objects 2 are collected by the floating barrier 6. The floating barrier 6 includes a concave portion at which a collecting region is formed where debris may collect. Hence, the floating barrier has a capture form defining a collecting region where debris can accumulate. Many shapes can be employed, such as a parabolic-shape, V-shape, U-shape. However, other more complex shapes can also be used, for example including a plurality of concave portions.

[0160] FIG. 13 shows a schematic diagram of an embodiment of a collecting system 1. The system 1 comprises a submerged member 8 connected to the floating barrier 6. The submerged member 8 is arranged for providing a difference between the velocity of the floating barrier 6 along the surface of the water and a flow velocity of the surface water at the location of the floating barrier 6. The collecting system 1 is unanchored to or on the seabed 10 such that it is free to move along the surface 4 of the water. A number of objects 2, 2a, 2b floating on or suspended near the surface 4 of water are shown. The objects 2, 2a, 2b are dispersed on the surface 4 of the water and may be collected by the floating barrier 6. The water surrounding the floating barrier 6 may have a flowing direction A at and/or near the surface 4 which may be the result of a current (e.g. ocean current resulting from a gyre). By means of the submerged member 8 connected to the floating barrier 6, a velocity V2 of the floating barrier 6 along the surface of the water 4 differs from a surface velocity V1 of the water at the location of the floating barrier 6. In other words, the velocity of the floating barrier 6 has been changed with respect to the velocity of the water at the surface 4 near or directly surrounding the floating barrier 6. As can be seen in FIG. 13, object 2a can be directed to the collecting region 16 in which objects 2 can be collected. The shape of floating barrier 6 is such that the collected objects 2 are retained within the collecting region 16. The submerged member 8 comprises a line 12 connected to the floating member 6. The submerged member 8 further includes a drag member 14 arranged for increasing the drag of the submerged member 8 when moving through water.

[0161] In the shown embodiment of FIG. 13, the floating barrier 6 has a substantially fixed form or shape (e.g. by using stiff or rigid elements). In this way, the collecting region 16 in which objects 2 can accumulate is pre-formed.

[0162] FIG. 14 shows a schematic diagram of an embodiment of a collecting system 1. The floating member 6 of the collecting system 1 is floating on a surface 4 of water having a flow direction A resulting from a water current. The water current may be an oceanic current resulting from a gyre. The collecting system 1 is not anchored and can move freely along the surface 4 of the water. In this way, the collecting system 1 can be carried along with the current. The water at the surface 4 has a certain velocity V1. Also the debris and objects 2 can move along with the water at the surface 4 in the flow direction A. The submerged member 8 is connected to the floating member 6 through a first line 18a and a second line 18b. The floating barrier 6 forms a U-shaped collecting region 16 in which debris or objects 2 accumulate.

[0163] Contrary to the embodiment of FIG. 13, here the floating barrier 6 has a flexible form such that the shape of the collecting region 16 in which objects 2 accumulate can change. The floating barrier 6 forms an elongated floating barrier line 6 having a first end 20a and a second end 20b, wherein the first end 20a and the second end 20b are connected to the submerged member 8. The first end 20a is connected to the first line 18a and the second end 20b is connected to the second line 18b. Although two lines 18a, 18b are shown, it will be appreciated that more than two lines are also possible, such as for example three, four, six or eight lines. The elongated floating barrier line 6 has a bending flexibility. As a result of the bending flexibility a collecting region 16 is formed between the first end 20a and the second end 20b. Notwithstanding the bending flexibility, the elongate floating barrier line 6 has sufficient stiffness to prevent folding of the elongate floating barrier line due to pulling forces in the first and second lines 18a, 18b. Further, the submerged member comprises a drag member 14 configured to increase the resulting drag of the submerged member 8 so that the velocity of the floating barrier 6 can be changed with respect to the surface velocity of the water and thus also the velocity of the objects 2 floating on or suspended near the surface 4 of the water moving in flow direction A, for example as a result of water currents induced by oceanic gyres. Thus the collecting system can move along with the currents.

[0164] Flexibility of the floating barrier 6 also allows the floating barrier 6 to move along with the waves so that the floating barrier can conform to the non-planar surface of the water in the event of waves. Thus also the collecting system 1 can also be able to survive extreme weather conditions.

[0165] The elongated floating barrier line 6 disposed between the first end 20a and the second end 20b results in a parabolic shape in use when the floating barrier 6 is deformed as a result of the flowing water at the surface 4, because the first end 20a and the second end 20b are connected with the submerged member 8 providing additional resistance to the movement of the elongated floating barrier line 6 moving along on the surface of the water 4 in a flow direction A. Since the first and second ends 20a, 20b are pulled in a direction different from the direction A of the flowing water at the surface 4, a collecting region 16 can be automatically formed, in which the collected objects/debris can be effectively held. This arrangement enables automatic maneuverability of the collecting system 1, wherein the floating barrier 6 being carried along with a water current automatically re-orients itself when the flowing direction A of the water current is changed, such that a concave collecting region is formed facing an upstream direction of the flow. In this way, the objects/debris can be effectively collected downstream as a result of the velocity difference obtained as a result of the additional resistance provided by the submerged member 8 connected to the first and second end 20a, 20b of the elongated floating barrier line 6. It will be appreciated that more in general it is possible that the first line 18a is attached to the floating barrier 6 at a first attachment position and the second line 18b is attached to the floating barrier 6 at a second attachment position, the first and second attachment positions being spaced apart along the floating barrier. The first attachment position may e.g. have a first offset relative to the first end 20a. The second attachment position may e.g. have a second, different or same, offset relative to the second end 20b.

[0166] FIG. 15 shows a schematic diagram of an embodiment of a floating barrier holding portion 28 connecting the floating barrier 6 with the submerged member 8. The holding portion 28 is formed at an end 20a of an elongated floating barrier line 6 and holds a first line 18a. The first line 18a is connected to the submerged member 8. The connection portion 28 is arranged such that the orientation of the submerged member 8 with respect to the floating barrier 6 can be changed under influence of external forces, for example as a result of the flow of water, currents, wind, etc. In this way, the collecting system 1 may adapt better to the dynamic water conditions. It will be clear that a similar, or identical, second holding portion can be provided at the other end 20b, e.g. for attachment to the other line 18b.

[0167] FIG. 16 shows a schematic diagram of an embodiment of a collecting system 1 comprising a floating barrier 6 with a plurality of sections 26i movably connected to each other to form an elongated floating barrier line 6. The floating barrier 6 is at a first end 20a and a second end 20b connected with a submerged member 8. The submerged member 8 includes a drag member 14 for further increasing the resulting drag. As a result, a difference between the velocity of the floating barrier 6 along the surface 4 of the water and a surface velocity of the water at the location of the floating barrier 6 is provided, allowing a more effective collection of objects by the floating member 6, since the objects 2 can be carried along with the water at a different velocity than the floating barrier 6. As a result of extra drag obtained by means of the submerged member 8, the elongated floating barrier line 6 can be slowed down (brake effect resulting from the extra drag/resistance), so that objects 2 can rather easily enter the collecting region 16 of the floating barrier 6. For instance, in the surrounding area of the elongated floating barrier line 6, objects 2e and objects 2f may be swept along with the current in a flow direction A. The velocity V1a of objects 2e and velocity V1b of objects 2f may be more or less the same. Variations are possible. However, a substantial difference between velocities V1a, V1b of the objects 2e, 2f floating on or suspended near the surface of the water, and the velocity V2 of the floating barrier 6 can be provided as a result of the additional resistance/drag obtained by the submerged member 8. Advantageously, the objects 2e, 2f may be carried along on the surface 4 of the water ending up in the collecting region 16 of the collecting system 1 when the velocity V2 of the floating barrier 6 is smaller than the velocities V1a, V1b of the objects 2e, 2f. The objects 2, 2e, 2f can further accumulate while the unanchored collecting system 1 is carried along with the water current in the flow direction A.

[0168] FIG. 17 shows a schematic diagram of an embodiment of a collecting system 1. The submerged member 8 comprises a plurality of drag members 14 arranged for increasing the drag of the submerged member 8. In this example, the plurality of drag member 14 are placed in parallel. The drag members 14 are attached to a line connecting the ends 20a, 20b of the floating barrier 6. The floating barrier 6 is arranged to freely move along the surface 4 of the water. For this purpose, the floating barrier is unanchored to a bottom 10 (e.g. seabed) of the water mass. As a result of the additional resistance/drag obtained by means of the submerged member 8, the floating barrier 6 can be advantageously slowed down with respect to the water at the surface at the location of the floating barrier 6.

[0169] Many types of submerged members 8 can be deployed beneath the surface 4 of the water for resisting movement through the water. Additionally, the submerged member 8 may also be beneficial for resisting movement of the floating barrier 6 as a result of wind. Most of the time, the submerged member 8 is used to slow down the speed of the floating barrier 6 moving along the surface 4 of the water. The submerged member 8 may comprise adjustment means for changing an extent to which it can provide resistance to movement through water. For this purpose, the submerged member 8 may have pull-type controls for varying the amount of drag to be obtained. In general, the resulting drag of a submerged member 8 can be changed by changing geometrical parameters of the submerged member 8. A change of the shape or geometry (e.g. angle between two parts) of a submerged member 8 or drag member 14, the drag can be influenced. For example, the submerged member 8 may comprise a parachute with a central opening, wherein the opening is adjustable. Many variants are possible.

[0170] Advantageously, also in this embodiment it is possible to better take into account dynamic ocean conditions. If the floating barrier 6 is fixed or anchored in one direction, objects 2 floating on or suspended near a surface of water (e.g. plastic garbage 2) may be lost during the collecting process. The collecting system 1 according to the current invention can more easily follow the water currents and reduce the risk of the objects escaping. Next to the braking effect, also an advantageous steering effect may be obtained by means of the submerged member 8. The submerged member 8 allows the collecting system 1 to be steered by creating a pivoting momentum which orientation enables the collecting system 1 to be perpendicular to the current. In this way, the collecting system can automatically reorient itself when for example the current changes orientation. Moreover, the loads encountered by the collecting system 1 may be reduced. Indeed, a collecting system being unfixed or unanchored at a location in the water mass (e.g. unanchored to a seabed or bottom of an ocean) may have to cope with lower static loads.

[0171] FIG. 18 shows an embodiment of a drag member 14 of a submerged member 8. The drag member 14 is formed by a hollow tube 14 comprising a plurality of holes 30 in the side wall. The tube may further have one or more open ends 32 such as to further increase the drag. The submerged member 8 can be held by a line 34 directly or indirectly connected to the floating member 6.

[0172] Other types of drag members 14 may also be employed. According to an embodiment, the submerged member includes a drift anchor, sea anchor and/or drogue. Other similar means may also be used, such as a parachute anchor, drift sock, para-anchor, parachute sea anchor or boat brake. Many variants are possible for increasing the resistance of the floating barrier 6 when being carried along water currents for obtaining a velocity difference between the floating barrier 6 and the velocity of the water at the surface.

[0173] Advantageously a drift anchor or the like may also result in an improved stabilization of the floating barrier 6 of the collecting system 1. This may be particularly advantageous in heavy weather and/or turbulent water conditions. Rather than tethering the floating barrier to the seabed, the sea anchor increases the drag through the water and thus acts as a brake. Furthermore, such a configuration also allows autonomous orientation of the floating barrier 6 carried along by the water current so that debris and/or objects can easily be collected in a collected region 16 of the collecting system 1. In this way, the floating barrier 6 can be slowed down and move in a more controlled way.

[0174] Many types of structures can be used as drag member 14 for acting as a source of drag in the water. The drag may be used to slow the floating barrier moving on the surface 4 of the water. A simple form of a drag member is just a line (e.g. anchor rode) submerged in the water. Although in some cases the resulting increase in drag may be limited, it may suffice for obtaining a velocity difference. A cloth, for instance shaped like a parachute or cone may also be employed as a drag member 14. This type of drag members 14 may require a smaller operating depth. For instance, a cloth-type drag member 14 may be configured to be submerged just under the surface. Water moving past the cloth-type drag member 14 may keep it filled. An adjustable opening may be arranged in a rear side allowing the amount of braking to be adjusted when deployed.

[0175] FIG. 19 shows an embodiment of a submerged member 8 comprising a plurality of drag members 14a, 14b, 14c arranged for further increasing the drag/resistance when moving through water. In accordance with the embodiment of FIG. 18, the drag members 14a, 14b, 14c comprise a plurality of holes 30 for influencing the underwater resistance to movement or drag. By increasing the drag forces, the velocity of the floating barrier carried along in a flow direction A can be effectively influenced.

[0176] Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications, variations, alternatives and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged and understood to fall within the framework of the invention as outlined by the claims. The specifications, figures and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense. The invention is intended to embrace all alternatives, modifications and variations which fall within the spirit and scope of the appended claims. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

[0177] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.

[0178] According to an aspect, the invention also relates in general terms to the following clauses:

1. A method for collecting objects floating on or suspended near a surface of water by means of a collecting system comprising a floating barrier, wherein, in use, the collecting system is unanchored to or on the seabed such that the collecting system is free to move along the surface of the water, the method including:

[0179] providing a submerged member connected to the floating barrier, such that a velocity of the floating barrier along the surface of the water differs from a velocity of the objects floating on or suspended near the surface of the water at the location of the floating barrier.

2. A method according to clause 1, wherein at least one line connected to the floating barrier is employed as the submerged member.
3. A method according to clause 1 or 2, wherein the submerged member includes one or more drag members for increasing the drag of the submerged member.
4. A method according to any one of the preceding clauses, wherein a sea anchor, drift anchor and/or drogue is employed as the submerged member.
5. A method according to any one of the preceding clauses, wherein the objects include debris, such as plastic waste.
6. A method for recycling plastic, wherein the plastic is obtained by collecting plastic objects floating on or suspended near a surface of water by means of a collecting system comprising a floating barrier, wherein, in use, the collecting system is unanchored to or on the seabed such that the collecting system is free to move along the surface of the water, the collecting including:

[0180] providing a submerged member connected to the floating barrier, such that a velocity of the floating barrier along the surface of the water differs from a velocity of the objects floating on or suspended near the surface of the water at the location of the floating barrier.

7. A method according to clause 6, further including using the collected plastic as base material for manufacturing plastic objects, such as portions of the collecting system.
8. A method for collecting objects floating on or suspended near a surface of water the method including:

[0181] providing an unanchored collecting system comprising a floating barrier, and allowing the collecting system to follow ocean currents.

9. A collecting system for collecting objects floating on or suspended near a surface of water comprising a floating barrier, arranged for freely moving along the surface of the water, wherein the system further includes a submerged member connected to the floating barrier arranged for providing a difference between the velocity of the floating barrier along the surface of the water and a velocity of the objects floating on or suspended near the surface of the water at the location of the floating barrier.
10. A collecting system according to clause 9, wherein the submerged member comprises at least one line connected to the floating barrier.
11. A collecting system according to clause 9 or 10, wherein the submerged member further includes one or more drag members arranged for increasing the drag of the submerged member.
12. A collecting system according to any one of the clauses 9-11, wherein the submerged member includes a sea anchor, drift anchor and/or drogue.
13. A collecting system according to any one of the clauses 9-12, wherein the floating barrier comprises at least one floater and a screen connected to each other, wherein the screen extends downwards in the water.
14. A collecting system according to any one of the clauses 9-13, wherein, in use, the floating barrier forms a V-shaped or U-shaped collecting region in which debris accumulates.
15. A collecting system according to any one of the clauses 9-14, wherein the floating barrier forms an elongated floating barrier line.
16. A collecting system according to clause 15, wherein the elongated floating barrier line has a first end and a second end, wherein the first end and the second end are connected to the submerged member, wherein the elongated floating barrier line has a bending flexibility such that, in use, a collecting region is formed between the first end and the second end.
17. A collecting system according to clause 15 or 16, wherein the elongated floating barrier line comprises a plurality of sections connected to each other.
18. A collecting system according to any one of the clauses 9-17, further comprising a buffer unit including a space for storing objects, such as debris.
19. Plastic obtained by employing the method according to any one of the method clauses 1-8.