NO347560B1

NO347560B1 - Sorting unit and trawling system for collecting and sorting floating waste

Info

Publication number: NO347560B1
Application number: NO20221305A
Authority: NO
Inventors: Terje Olav Hansen
Original assignee: Lovemar As
Priority date: 2022-06-30
Filing date: 2022-12-05
Publication date: 2024-01-15
Also published as: WO2024005646A1; NO20221305A1

Description

Sorting unit and trawling system for collecting and sorting floating waste

Field of the invention

The invention relates to a trawling system for collecting waste from oceans and lakes. The invention also relates to a sorting unit for sorting floating objects by size. The invention also relates to a trawling system for collecting waste floating and/or mixed into water column from oceans and lakes.

Background

Large amounts of floating plastic waste in the sea is a serious global environmental concern that threatens both marine life and human living conditions. Coastal nations have realized the problem, and a number of measures and regulations are being worked on to stop sea pollution and to carry out clean-up.

The environmental effect of cleaning up floating waste in rivers and seas is assumed to be obvious. Plastic waste in the sea either settles on the sea bed, is carried by the water masses out to sea or ends up along the coasts on the shore, beaches or in mangrove areas. The waste creates problems for both marine wildlife, birds, and for human livelihoods such as fishing and tourism. Plastic waste is broken down very slowly in the sea, and therefore accumulates to the great detriment of the environment. Small plastic particles and microplastics spread in the oceans all over the globe, creating concern for both the biological life in the ocean and for the business activities that are based on clean and fresh oceans. Effective methods of clean-up, in addition to effective prevention, could save the environment millions of tonnes of plastic waste going astray.

Floating waste collection technology will be a significant tool in the fight against global marine litter. Marine waste that spreads freely at sea will relatively quickly have a low concentration due to possible turbulent diffusion. It is therefore important to utilize trawling equipment which is able to cover a sufficiently large area coverage in a short period of time to achieve good efficiency. Technology based on open booms at relatively high towing speeds achieve efficient trawling capacity. The systems on the market have a very low area coverage / unit of time and are therefore inefficient.

Smaller floating waste can be handled at a much higher rate than large floating waste. Technology based on continuous vacuum technology using a water jet pump used in fish farming (removal of lice and transport of fish) without vacuum tanks can be used to gather floating waste quickly. It is an object of the invention, in order to increase trawling efficiency, to provide a trawling system which sorts and collects smaller floating objects efficiently.

In general, it is an object of the invention to provide an efficient trawling system which gathers, concentrates, sorts and collects floating waste.

US4305830A describes a water surface cleaner that floats on top of the water and includes a water guide passage that has an intake port and a rear end connected to a surface flotage collecting system. The cleaner also includes a surface current generating means that uses a pump with two nozzles to create an effective current flowing toward the water guide passage. The surface flotage collecting section can be detachable or fastened to the body and can be made of various porous materials. The method of cleaning involves generating the current, collecting materials in the collecting section, and controlling the cleaner with a propulsion means and radio control receiver. The cleaner also includes an enclosure that substantially surrounds the pump inlet and has an opening facing the front end of the body to allow the pump to suck water into the enclosure. The method includes discharging water into the guide passage in the direction of the rear end of the body and discharging water in the opposite direction forward of the front end of the guide passage.

Summary of the invention

The invention relates to a sorting unit for receiving and sorting floating objects comprising a housing comprising an intake portion for the intake of a water current and floating objects, an exit portion, a bottom surface comprising a hole connectable to a vacuum hose, a first side surface extending upwards from the bottom surface, a second side surface extending upwards from the bottom surface, a shelf located above the bottom surface and extending between the first side surface and the second side surface, a tapered conduit located between the bottom surface and the shelf, the conduit being tapered towards the hole, wherein the tapered conduit provides a conduit intake aperture having a height for receiving floating objects of a first size and encouraging objects of a second size, larger than the first size, over the shelf and towards the exit portion.

The invention further relates to said sorting unit wherein the tapered conduit comprises a first conduit side wall and a second conduit side wall extending between the bottom surface and the shelf, wherein the conduit side walls are tapered towards the hole forming a water-tight conduit.

The invention further relates to said sorting unit wherein the conduit side walls are curved, forming a convex shape.

The invention further relates to said sorting unit wherein the conduit has a widened exit portion.

The invention further relates to said sorting unit wherein the housing further comprises:

● a top surface located above the shelf extending between the first side surface and the second side surface;

● wherein the top surface, the bottom surface, the first side surface and the second side surface provide the exit portion which is connectable to a trawl.

The invention further relates to said sorting unit comprising deflection means for further encouraging objects of the second size over the shelf and/or manipulate the water current, located between the shelf and the intake portion.

The invention further relates to said sorting unit further comprising:

● a deflector connected to the bottom surface between the intake portion and the shelf.

The invention further relates to said sorting unit further comprising:

● at least one slat connected to the bottom surface positioned between the deflector and the tapered conduit.

The invention further relates to said sorting unit further comprising:

● a first ledge connected to an upstream edge of the shelf extending between the shelf and the deflector.

The invention further relates to said sorting unit further comprising:

● a second ledge connected to a downstream edge of the shelf extending between the shelf and the bottom surface.

The invention further relates to said sorting unit wherein the shelf is at least partly inclined towards the exit portion at an angle.

The invention further relates to said sorting unit wherein the angle is 5-10 degrees, preferably 7 degrees.

The invention further relates to said sorting unit wherein the shelf is curved to form an apex located over the hole, and wherein the hole located proximate to the exit portion.

The invention further relates to said sorting unit wherein at least one of the conduit side walls is provided at least one side barrier for creating a vortex between the at least one barrier and the hole for rotating the floating objects passing through.

● wherein the shelf, the first side surface, the second side surface and the top surface provide a second aperture at the intake portion; ● wherein the second aperture has a height (H2);

● wherein the height (H2) > the height (H1); and

● wherein the top surface, the bottom surface, the first side surface and the second side surface are connectable to a trawl at the exit portion.

The invention also relates to a trawling system for collecting floating and dispersed objects at sea, comprising a substantially V-shaped boom having an upstream facing open end for receiving floating objects and a tapered area for gathering and concentrating the floating objects;

i. wherein the boom is configured to be towed by a first towing vessel at one end, and by a paravan or a second vessel at another end; and

ii. wherein the boom is connected to an inlet means downstream of the tapered area;

• a first trawl and a second trawl;

• the said sorting unit located to the downstream end of the inlet channel for sorting the floating objects passed through the inlet channel by size;

• a vacuum hose for transporting at least one of floating objects, water, air slugs, and air bubbles

i. wherein the vacuum hose is connected to a vacuum source; and

ii. wherein the vacuum hose inlet is connected to the sorting unit and the vacuum hose outlet is connected to the second trawl;

The invention further relates to said trawling system;

• wherein the sorting unit is connected to the downstream end of the inlet channel; and

• wherein the first trawl is connected to the downstream end of the sorting unit.

The invention relates to a sorting unit for receiving and sorting floating objects including:

a housing comprising:

i. an intake portion for the intake of water current and floating objects;

ii. an exit portion;

iii. a bottom surface comprising a hole connectable to a vacuum hose, the hole being located proximate to the exit portion;

iv. a first side surface extending upwards from the bottom surface;

v. a second side surface extending upwards from the bottom surface;

vi. a shelf located above the bottom surface and extending between the first side surface and the second side surface;

vii. a tapered conduit located between the bottom surface and the shelf, the conduit being tapered towards the hole;

wherein the bottom surface, the first side, the second side and the shelf provide a first intake aperture having a height at the intake portion for receiving floating objects of a first size and encouraging objects of a second size, larger than the first size, over the shelf and towards the exit portion.

The invention further relates to said sorting unit, wherein the shelf is at least partly inclined towards the exit portion at an angle.

The invention further relates to said sorting unit, wherein the angle is degrees, preferably 7 degrees.

The invention further relates to said sorting unit, wherein the shelf is curved to form an apex located over the hole.

The invention further relates to said sorting unit, wherein the tapered conduit comprises a first conduit side wall and a second conduit side wall extending between the bottom surface and the shelf, wherein the side walls are tapered towards the hole forming a water-tight conduit.

The invention further relates to said sorting unit, wherein at least one of the side walls is provided at least one side barrier for creating a vortex between the at least one barrier and the hole for rotating the floating objects passing through.

The invention further relates to said sorting unit, wherein the side walls are curved, forming a convex shape.

The invention further relates to said sorting unit, wherein the conduit has a widened exit portion for allowing objects to rotate.

The invention further relates to said sorting unit, wherein the housing further comprises:

a. a top surface located above the shelf extending between the first side and the second side;

b. wherein the shelf, the first side, the second side and the top surface provide a second aperture at the intake portion (20);

c. wherein the second aperture has a second aperture height;

d. wherein the second aperture height > the first aperture height; and e. wherein the top surface, the bottom surface, the first side surface and the second side surface are connectable to a trawl at the exit portion.

• a first trawl and a second trawl;

• a sorting unit according to any of the preceding claims located to the downstream end of the inlet channel for sorting the floating objects passed through the inlet channel by size;

i. wherein the vacuum hose is connected to a vacuum source; and

The invention further relates to said trawling system;

• wherein the sorting unit (200) is connected to the downstream end of the inlet channel (130); and

• wherein the first trawl (500) is connected to the downstream end of the sorting unit (200).

Brief description of figures

Fig. 1 is a perspective view of a trawling system according to the invention;

Fig. 2 is a perspective view of the trawling system inlet according to the invention; Fig. 3 is a perspective view of the sorting unit according to the invention;

Fig. 4 is a cross-sectional side view of the sorting unit according to the invention; Fig. 5 is an elevation of the sorting unit according to the invention;

Fig. 6 is a perspective view of a sorting unit 300 according to an embodiment of the invention; and

Fig. 7 is an elevation of the embodiment of Fig.6.

Detailed description of embodiments

Fig. 1 is a perspective view of a trawling system 10 according to the invention. The trawling system is indented to collect and store floating objects and debris such as plastic, metal or fabric objects at sea or in lakes.

The trawling system 10 comprises a substantially V-shaped boom 100, forming two boom 100 arms having an angle of approximately 40-80 degrees between them, preferably 60 degrees. The boom 100 is connected to a towing vessel 110 at one end 121, and to a paravan 120 or another towing vessel (not shown) at the other end 121’. The boom 100 ends 121, 121’ may be extended with lines or ropes.

In operation the boom 100 can be towed by towing vessel 110 in a forward direction while a floating paravan 120 or another vessel maintains a lateral distance between the ends 121, 121’ providing a large intake perimeter.

The at least one towing vessel 110 travels typically 0-5 knots in operation providing a current through the trawling system 10 so that the trawling system 10 receives floating waste. The vessel 110 and the trawling system may also in a mode of operation maintain a speed of 0 knots over ground provided a natural current can transport floating objects at least about 1-3 knots relative to the trawling system 10. The trawling system 10 may also be anchored only reliant on a natural current

When towed the open end of the V-shaped boom 100 faces upstream. The V-shaped boom naturally comprises a tapered area 140 wherein the floating objects are gathered and concentrated.

An inlet channel 130 is provided at the inner part of the tapered area 140 through which water and floating objects may pass. The inlet channel 130 forms part of the V-shaped boom 100 and typically includes a floating element. The boom 100 arms extend from the inlet channel 130. The inlet channel 130 is typically an openended housing with a floor, a roof and two side walls. The inlet channel may include buoyancy means.

The inlet channel 130 serves to connect the two boom 100 arms and to provide an intake aperture which allows floating objects to pass through the inlet channel. The intake aperture formed by the inlet channel 130 also acts as a filter, preventing excessively large objects to pass through the inlet channel 130. These objects may be removed from the trawling system and handled manually outside of the trawling system 10. The inlet channel 120 also serves as a utility structure and a connection point for other components of the trawling system 10 located downstream the inlet channel.

In the embodiment shown in Fig.1 the trawling system 10 further includes a sorting unit 200 connected directly to the downstream end of the inlet channel 130. In this configuration the inlet channel 130 serves as a first passage and a barrier for large floating objects while the sorting unit 200 provides a second sorting means for objects to be collected by a trawl 501. In another embodiment not shown, the inlet channel 130 may be completely replaced by the sorting unit 200.

The trawling system 10 further includes a trawl 500 connected to the downstream end of the sorting unit 200 to collect objects passing through the sorting unit 200. The trawl 500 may include buoyancy means.

The trawling system 10 includes a vacuum hose 150. The sorting unit 200 is connected to the vacuum hose 150 which is powered by a vacuum source 160 such as an ejector 160. The ejector 160 may be located on board the towing vessel 110. A pump (not shown) provides seawater to the ejector, preferably at a rate of 800 m<3>/hour which generates a strong current within the sorting unit 200.

The vacuum hose 150 stretches between the sorting unit 200 and the towing vessel 110 and may be attached to a boom 100 arm along the way. The inlet of the vacuum hose 150 is connected to the sorting unit 200 and configured to transport water, smaller floating objects, debris and air bubbles and slugs from the sorting unit 200 to a second trawl 501 i.e. a net. Therefore, the outlet of the vacuum hose is connected to the second trawl 501.

Air bubbles and air slugs may be injected into the vacuum hose 150, typically proximate to its inlet, to accelerate objects passing through the hose and furthermore to provide variating buoyancy to prevent clogging (relieve) of the vacuum hose (cargo hose). A further advantage is that the vacuum hose 150 becomes more horizontally aligned in parallel with the boom 100 facilitating internal transport.

The vacuum hose 150 also provides a substantial amount of suction which accelerates the water current through the inlet channel 130 and the sorting means 200. This is advantageous in that the towing vessel 110 may propagate in slow speeds while maintaining a sufficient flow rate through the sorting system.

A second trawl 501 is connected to and towed by the towing vessel 110 and may include floating means. Preferably the second trawl 501 is connected to the aft of the towing vessel 110.

The second trawl 501 provides a repository for smaller floating objects retrieved from the sorting unit 200. The first trawl 500 provides a repository for larger objects filtered out by the sorting unit 200. The larger objects typically have a dimension e.g. length, height or diameter exceeding the diameter of the vacuum hose 150 and are therefore unsuitable for the vacuum hose 150. Therefore, the sorting unit 200 will guide the larger objects directly to the first trawl 500.

Fig. 2 is a perspective view of the trawling system inlet according to the invention. A horizontal net 101 may be provided between the boom 100 arms and the inlet channel 130 and is located below sea level during operation. The horizontal net 101 serves to scoop up and elevate floating objects as they propagate towards the inlet channel 130. The horizontal net 101 may be provided with a bubble dispenser 102 in front (at its upstream end) extending between the boom 100 arms. The bubble dispenser 102 dispenses air bubbles throughout its length and creates a curtain of air bubbles for intimidating approaching fish and preventing fish from entering the inlet channel 130. The bubble dispenser 102 is provided with pressurized air via an air supply tube 151.

Fig. 3 is a perspective view of the sorting unit 200. Fig.4 is a cross-sectional side view of the sorting unit 200 according to the invention. Both figures will be discussed in the below paragraphs. The sorting unit 200 is suitable for receiving and sorting floating and dispersed waste and includes a housing 209.

The water current direction is indicated by the two large arrows.

The housing 209 has two open ends forming an intake portion 250 for the intake of water and floating objects, and an exit portion 251 for allowing water and floating objects to pass through the sorting unit (see Fig.4). The housing further includes a bottom surface 201 comprising a hole 223 connectable to the inlet of the vacuum hose 150 entering from below the bottom surface 201. The hole 223 is located proximate to the exit portion 251 and is preferably laterally centred with respect to the bottom surface 201, i.e. centered between the sides of the bottom surface 201.

The housing 209 may include or be connected to a buoyancy element (not shown).

The housing 209 further includes a shelf 202 extending between a first side surface 204 and a second side surface 204’. The side surfaces 204, 204’ serve as side walls for channelling and guiding the floating objects through the sorting unit 200 while preventing the objects from moving laterally, but also as a structural support.

The bottom surface 201, the first side surface 204, the second side surface 204' and the shelf 202 form a first intake aperture 233 having a height H1 (see Fig.4) and a width W1 at the intake portion 250 for receiving floating objects of a first size.

A conduit intake aperture X1 having a height H1 is formed by the upstream ends of the bottom surface 201, the first side wall 230, the second side wall 230’ and the shelf 202

Objects of a second size, larger than the first size, having a dimension e.g. height, width or a diameter exceeding the size of the first aperture 233 are naturally prevented from entering the first intake aperture 233. Furthermore, objects of the second size are forced over the shelf due to the momentum created by the water flowing over the shelf 202.

The housing 209 may further include a tapered conduit 231 located between the bottom surface 201 and the shelf 202, the conduit 231 being tapered towards the hole 223. The conduit 231 may comprise conduit side walls 230, 230’ extending between the bottom surface 201 and the shelf 202 throughout their length forming a water-tight conduit 231. The conduit side walls 230, 230’ may be curved providing a convex shape to the conduit 231. The conduit side walls 230, 230’ may be curved away from each other towards the hole 223, forming a widened end for allowing objects to rotate horisontally. The conduit walls 230, 230’ may be provided with side barriers 232, 232’ inside the conduit 231 located upstream the hole 223 for creating vortexes and vortex shedding downstream between the side barriers 232, 232’ and the hole 223. The vortexes help the floating objects rotate to help the objects align with the vacuum hose 150. The vortexes may also prevent objects from clogging the conduit. The side barriers 232, 232’ may be of any shape, preferably semi-cylindrical. The 232, 232’ are preferably oriented vertically, and they may extend between the bottom surface 201 and the shelf 202.

In operation the sorting unit 200 is partly submerged so that the water line is located above the upstream end (at the intake portion 250) of the shelf 202.

Therefore, the conduit 231 will be completely submerged. As the trawling system 10 propagates forward, a current is generated through the sorting unit going from the intake portion 250 to the exit portion 251. Water therefore flows both on top of the shelf 202 and through the conduit 231. Simultaneously, a negative pressure is provided by the vacuum hose 150 generating suction and an increased flow through the sorting unit 200. The vacuum hose 150 is connected to the hole 223 is proximity to the exit portion 251 of the sorting unit. Therefore, the vacuum hose 150 also draws water flowing over the shelf 202 generating increased flow over downstream end of the shelf 202.

The conduit 231 provides a flow restriction for water flowing through the conduit 231 by gradually reducing its cross-section. Water is therefore encouraged over the shelf 202 so that large objects are passed over the shelf 202 opposed to blocking the first intake aperture 233.

In an embodiment the sorting unit 200 may also include a top surface 205 forming a roof/ceiling. In this embodiment a second intake aperture 234 is formed by the shelf 202, the side surfaces 204, 204’ and the top surface 205 having a height H2 and a width W1. The height H2 is substantially larger than H1 so that large objects may pass though the housing 209.

Fig. 4 is a side view of the sorting unit 200 according to the invention. Fig.4 shows the intake portion 250 and the exit portion 251. Fig.4 also shows an embodiment where the shelf 202 is inclined towards the exit portion 251 at an angle A, preferably 5-10 degrees, more preferably 7 degrees. The shelf 202 may also include a curved portion forming an apex 253 located over the hole 223, at a height H3 over the hole 223, providing a wing shape to the shelf 202. This is advantageous for several reasons. The increased distance over the hole 223 allows objects to rotate vertically an orient to an upright position before entering the hole 223. The wing shape also provides increased flow velocity over the shelf 202 and directs the current above the shelf towards the hole 223, so that the suction from the hole 223 accelerates water flowing above the shelf 202.

In an embodiment including a top surface 205, a frame structure is formed at the exit portion 251 by the bottom surface 201, the side surfaces 204, 204’ and the top surface 205. A trawl 500 may easily be fixed to said frame structure forcing the large objects passing over the shelf 202 to gather in the trawl 500.

Fig. 5 is an elevation of the sorting unit 200 according to the invention seen from beneath the shelf 202. Fig.5 shows how the conduit walls 230, 230’ incline against each other forming a tapered conduit 231. Fig.5 also shows how the conduit walls 230, 230’ way have a widened end portion.

Fig. 6 is a perspective view of a sorting unit 300 according to an embodiment of the invention. The sorting unit 300 may interact with and be connected to the trawling system 10 in the same way as the previously disclosed sorting unit 200.

The water flow direction through the sorting unit 300 is indicated with large arrows.

The sorting unit 300 includes a housing 309 having an intake portion 350 for the intake of a water current and floating objects and an exit portion 351 (se also Fig. 7).

The housing 309 includes a bottom surface 301 comprising a hole 323 connectable to a vacuum hose (not shown).

The housing 309 may include a first side surface 304 (removed from Fig.6) extending upwards from the bottom surface 301 and a second side surface 304’ extending upwards from the bottom surface 301.

Th housing 309 may optionally include a top surface 305, i.e. a roof/ceiling.

The intake portion 350 faces the water current and may be formed only by the perimeter of the upstream end of the bottom surface 301. The intake portion 350 may also be formed by the upstream ends of the bottom surface 301, the two side surfaces 304, 304’ and optionally the top surface 305 forming a square or semisquare opening.

The exit portion 351 is located on the opposite end of the intake portion 350 and may be formed only by the perimeter of the downstream end of the bottom surface 301. The exit portion 351 may also be formed by the downstream ends of the bottom surface 301, the two side surfaces 304, 304’ and optionally the top surface 305 forming a square or semi-square opening. The exit portion 351 is connectable to a trawl 500.

The housing 309 includes a shelf 302 located above the bottom surface 301 and extending between the first side surface 304 and the second side surface 304’. The shelf 304 is preferably a smooth plate arranged horizontally above the bottom surface 301.

The housing 309 further includes a tapered conduit 331 connected to the bottom surface 301.

The tapered conduit 331 may comprise a first conduit side wall 330 and a second conduit side wall 330’ connected to and extending upwards from the bottom surface 301. The side walls 330, 330’ are preferably smooth surfaces of plastic, composite materials or metal.

The conduit side walls 330, 330’ are tapered towards the hole 323 and therefore guides water and floating objects towards the hole 323. The shelf 302 is located above the hole 323 and the suction from the vacuum hose will thereby cause the water to be drawn under the shelf 302 and through the hole 323. The conduit side walls 330, 330’ may also extend well above the shelf 302.

The conduit side walls 330, 330’ are preferably taller at their upstream ends than their downstream ends. This provides taller side barriers for objects at the intake portion 350. This encourages objects to travel in the water current direction and guides the water current towards the longitudinal centre axis (parallel with water current) of the sorting unit 300.

The shelf 302 preferably extends between conduit side walls 330, 330’. The shelf 302 may be fixed or welded to the side walls 330, 330’, preferably to an upper portion of the side walls 330, 300’.

The side surfaces 304, 304’ may function as an additional side barrier preventing floating objects from flowing sideways back into the surrounding waters.

The tapered conduit 331 provides a conduit intake aperture X2 having a height H3 for receiving floating objects of a first size and encouraging objects of a second size, larger than the first size, over the shelf 302 and towards the exit portion 351. A tunnel is formed by the conduit 331 and the shelf 302. The hole 323 is located within the tunnel. By providing such an enclosed passage, the suction and water flow increases underneath the shelf 302. Smaller size objects are therefore prone to a very strong current from underneath the shelf 302.

The conduit side walls 230, 230’ may be curved, forming a convex shape. The conduit side walls 230, 230’ may be shaped so that they provide a widened exit portion at their downstream ends. This has the same effects as for the previously described sorting unit 200.

The sorting unit 300 may include deflection means 370, 371, 371’, 372 for further encouraging objects of the second size over the shelf 302 and/or manipulate the water current, located between the shelf 302 and the intake portion 351.

A deflector 370 may be connected to the bottom surface 301 upstream the shelf 302. The deflector 370 may be of any shape but is sized to fit between the conduit side walls 330, 331’. The deflector 370 acts as a reef upstream the shelf 302.

Objects colliding with the deflector 370, preferably larger objects, is encouraged over the shelf 302. However, the deflector 370 does not prevent smaller objects from moving underneath the shelf 302.

The deflector 370 also disrupts the water current and generates vortex shedding downstream. This is beneficial for the same reasons as for the side barriers 232, 232’ (see Figure.5). The vortex shedding causes the objects to rotate and generates air bubbles and turbulent flow downstream which facilitates transport of objects through the hose 150 (see Fig.3).

The deflector 370 may have a curved or concave top surface to avoid blockage of objects. The deflector 370 may be roughly as tall as the height of the shelf 302, i.e. H3. However, the deflector 370 may also be somewhat taller or shorter than the height of the shelf 302. The deflector 370 may have a hydrodynamical shape but is also shaped to generate vortex shedding.

The deflector 370 is spaced apart from the shelf 302, creating a gap between the deflector 370 and the shelf 302 through which water may pass.

The sorting unit 300 may further comprise slats 371, 371’ connected to the bottom surface 301 positioned between the deflector 370 and the first conduit side wall 330 or between the deflector 370 and the second conduit side wall 330’.

Preferably a first slat 371 is provided between the first conduit side wall 330 and the deflector 370, and a second slat 371’ is provided between the second conduit side wall 371’ and the deflector 370.

The slats 371, 371’ may be shaped as narrow plates with a curved shape. The slates are connected to the bottom surface 301 extends upwards. Each slat 371, 371’ is preferably directed inwards towards the longitudinal centre axis of the housing 309, and towards the hole 323.

The slats 371, 371’ among other things serve to guide the water current towards the hole 323 but also provide a laminar and fast-moving flow. Additionally, the slats 371, 371’ encourages larger objects above the shelf 302 preventing them from getting stuck and obstructing the water current upstream the shelf 302. The slats 371, 371’ are relatively narrow and allow a relatively a wide opening for smaller objects to pass on each side of the slats 371, 371’.

In a configuration where both slats 371, 371’ and a deflector 370 are present, the main route for smaller objects to the hole 323 will be on each side of the deflector 370, not along the longitudinal centre axis of the sorting unit.

A first ledge 372 may be connected to an upstream edge 3021 of the shelf 302, as a cantilever, extending between the shelf 302 and the deflector 370. The ledge 372 may be semi-circular or curved. The ledge 372 narrows the gap between the deflector 370 and the shelf 302, therefore preventing smaller objects from getting stuck between the deflector 370 and the shelf 302, while at the same time allowing maximum flow on each side of the deflector 370. The first ledge 372 may be inclined downwards.

Furthermore, a second ledge 373 may be connected to a downstream edge 3022 of the shelf 302 extending between the shelf 302 and the bottom surface 301. The second ledge 373 is inclined downwards to provide an obstruction for preventing objects from being drawn through the exit portion of the conduit 331 which may cause a blockage downstream. The sorting unit 300 therefore is allowed an effective water flow/current through the sorting unit 300, wherein the water flow/current which is not obstructed by anything other than the components of the sorting unit 300. This causes objects to move effectively through the sorting unit 300 without causing a blockage.

The hole 323 is preferably located proximate to the upstream edge 3021 of the shelf 302 which is shown in Fig.7.

Fig. 7 is an elevation of the embodiment of Fig.6. Fig.7 may be used as further reference for the description relating to Fig.6. Fig.7 indicates the position of the intake portion 350 and the exit portion 351 more clearly with stapled lines.

Claims

PATENT CLAIMS

1. Sorting unit (200, 300) for receiving and sorting floating objects comprising:

● a housing (209, 309) comprising:

● an intake portion (250, 350) for the intake of a water current and floating objects;

● an exit portion (251, 351);

● a bottom surface (201, 301) comprising a hole (223, 323) connectable to a vacuum hose (150),

● a first side surface (204, 304) extending upwards from the bottom surface (201, 301);

● a second side surface (204', 304’) extending upwards from the bottom surface (201, 301);

● a shelf (202, 302) located above the bottom surface (201, 301) and extending between the first side surface (204, 304) and the second side surface (204', 304’);

● a tapered conduit (231, 331) located between the bottom surface (201) and the shelf (202), the conduit (231, 331) being tapered towards the hole (223, 323);

● wherein the tapered conduit (231, 331) provides a conduit intake aperture (X1, X2) having a height (H1, H3) for receiving floating objects of a first size and encouraging objects of a second size, larger than the first size, over the shelf (202, 302) and towards the exit portion (251, 351).

2. Sorting unit according to claim 1, wherein the tapered conduit (231, 331) comprises a first conduit side wall (230, 330) and a second conduit side wall (230’, 330’) extending between the bottom surface (201, 301) and the shelf (202, 302), wherein the conduit side walls (230, 230’) are tapered towards the hole (223, 323) forming a water-tight conduit.

3. Sorting unit according to claim 2, wherein the conduit side walls (230, 230’) are curved, forming a convex shape.

4. Sorting unit according to any preceding claim, wherein the conduit (231) has a widened exit portion.

5. Sorting unit according to any preceding claim, wherein the housing further comprises:

● a top surface (305) located above the shelf (302) extending between the first side surface (304) and the second side surface (304’);

● wherein the top surface (205), the bottom surface (201), the first side surface (204) and the second side surface (204’) provide the exit portion (351) which is connectable to a trawl (500).

6. Sorting unit according to any preceding claim, comprising deflection means (370, 371, 371’, 372) for further encouraging objects of the second size over the shelf (302) and/or manipulate the water current, located between the shelf (302) and the intake portion (350).

7. Sorting unit according to any preceding claim, further comprising:

● a deflector (370) connected to the bottom surface (301) between the intake portion (350) and the shelf (302).

8. Sorting unit according to claim 7, further comprising:

● at least one slat (371) connected to the bottom surface (301) positioned between the deflector (370) and the tapered conduit (331).

9. Sorting unit according to any preceding claim 7-8, further comprising:

● a first ledge (372) connected to an upstream edge (3021) of the shelf (302) extending between the shelf (302) and the deflector (370).

10. Sorting unit according to any preceding claim, further comprising:

● a second ledge (373) connected to a downstream edge (3022) of the shelf (302) extending between the shelf (302) and the bottom surface (301) .

11. Sorting unit according to any of the preceding claims 1-4, wherein the shelf (202) is at least partly inclined towards the exit portion (251) at an angle (A).

12. Sorting unit according to claim 11, wherein the angle (A) is 5-10 degrees, preferably 7 degrees.

13. Sorting unit according to any of the preceding claims 11-12, wherein the shelf (202) is curved to form an apex (253) located over the hole (223), and wherein the hole (223) is located proximate to the exit portion (251).

14. Sorting unit according to any of the preceding claims 1-4, wherein at least one of the conduit side walls (230, 230’) is provided at least one side barrier (232, 232’) for creating a vortex between the at least one barrier (232, 232’) and the hole (223) for rotating the floating objects passing through.

15. Sorting unit according to any preceding claims 11-14, wherein the housing further comprises:

● a top surface (205) located above the shelf (202) extending between the first side surface (204) and the second side surface (204’);

● wherein the shelf (202), the first side surface (204), the second side surface (204’) and the top surface (205) provide a second aperture (234) at the intake portion (250);

● wherein the second aperture has a height (H2);

● wherein the height (H2) > the height (H1); and

● wherein the top surface (205), the bottom surface (201), the first side surface (204) and the second side surface (204’) are connectable to a trawl (500) at the exit portion.

16. Trawling system (10) for collecting floating and dispersed objects at sea, comprising:

● a substantially V-shaped boom (100) having an upstream facing open end for receiving floating objects and a tapered area (140) for gathering and concentrating the floating objects;

i. wherein the boom (100) is configured to be towed by a first towing vessel (110) at one end, and by a paravan (120) or a second vessel at another end; and

ii. wherein the boom (100) is connected to an inlet means (130, 200) downstream of the tapered area (140);

● a first trawl (500) and a second trawl (501);

● a sorting unit (200, 300) according to any of the preceding claims located to the downstream end of the inlet channel (130) for sorting the floating objects passed through the inlet channel (130) by size; ● a vacuum hose (150) for transporting at least one of floating objects, water, air slugs, and air bubbles

i. wherein the vacuum hose (150) is connected to a vacuum source (160); and

ii. wherein the vacuum hose inlet (151) is connected to the sorting unit (200, 300) and the vacuum hose outlet (152) is connected to the second trawl (501);

17. Trawling system (10) according to claim 16;

● wherein the sorting unit (200, 300) is connected to the downstream end of the inlet channel (130); and

● wherein the first trawl (500) is connected to the downstream end of the sorting unit (200, 300).