FIELD OF THE INVENTION

The invention relates to a water cleaning system for removing objects such as plastic, floating on or suspended near a surface of water in a free-flowing water way, such as a river. The invention also relates to a method for distributing waste in a water cleaning system. BACKGROUND TO THE INVENTION

Pollution of oceans and free-flowing water ways has a significant environmental impact. Pollution may for example be formed by objects or debris floating on or suspended near a surface of water. Examples of such objects are bottles, cans, bags, cables, packages but also cables, lines and the like. One of the major pollutants of the oceans at the present day is plastic pollution. It is observed that more and more plastic debris tend to finally end up in coastal and oceanic environments. This may in part be a result of insufficient waste collection and interception infrastructure.

Objects or debris floating on or suspended near a water surface may in time be decomposed into smaller elements. This type of pollution may have severe consequences for the flora and fauna of a waterbody. Moreover, the removal of smaller particles from the water may pose even a greater challenge. Therefore, there is a need to timely collect objects or debris floating on or suspended near a water surface. Additionally, debris floating in a free-flowing water, such as a river or a canal, may tend to migrate to larger water masses, such as lakes, seas and oceans. Effectively collecting the debris in the free-flowing water way is an essential condition for lasting success for cleaning operations in large waterbodies, where debris may accumulate.

Such conveyor belts are for example described in documents W02010107290 and WO2013147712. In W02010107290, a catamaran with symmetrical hulls forming a central tunnel, the shape of which creates a Venturi effect enabling the acceleration of the flow generated by the advancement and the rotation of the propellers. Waste and pollutants are channeled into the funnel by independent arms moving in a translatory manner along the hulls of the catamaran and are guided by said arms towards a conveyor belt that can be raised and is lowered and rotated in order to let water and liquid pollutants pass through and to bring solid and organic waste onto the vessel by means of impellers, into a container, and distribute same after selective sorting into containers loaded and unloaded by means of a crane. Document WO2013147712 also discloses a conveyor belt arranged on a moving catamaran in stagnant water.

In these two applications, large objects may prevent the system from working as these systems are designed to suck up a maximum number of objects, with the translating arms in W02010107290 and funnel jaws for directing the impurities towards the conveyor belt in WO2013147712.

The objects which are carried upwards by the conveyor belt may also fall back into the water if the angle of inclination is too large. Furthermore, objects may get stuck in the conveyor belt system (e.g. between moving elements) so that the relative movement between the moving elements can be obstructed or prevented. Hence, there is also a need for preventing objects being stuck between moving parts of the conveyor belt system.

All water cleaning systems of the prior art require many operators to make the systems work and external assistance in case of failure.

There is a need for improvement in the art.

SUMMARY OF THE INVENTION

According to an aspect there is provided a cleaning system for removing objects floating on or suspended near a surface of water in a free-flowing water way. The cleaning system can e.g. be anchored to a bottom and/or shore of the water way. The cleaning system is arranged to define a water channel through which water of the free-flowing water way is directed. The cleaning system comprises an opening in a front end of the cleaning system which defines an entrance channel of the water channel. The cleaning system comprises a conveyor unit having a conveyor channel of the water channel extending between a first end and a second end, wherein the conveyor unit is arranged to define an inclined path between the first end and the second end, wherein the first end is extendable downward into the water channel for conveying objects from the first end to the second end. The conveyor unit in the water channel is configured to collect objects flowing in the entrance channel. The conveyor unit, at the first end, has a collection surface for collecting the objects from the entrance channel. The collection surface has a width which is at least the width of the entrance channel at the location of the collection surface. The objects which flow in the entrance channel reach the collection surface of the conveyor unit without any obstruction in the flow path and while maintaining the water flow in the water cleaning system. Hence the conveyor unit can be positioned downstream of the entrance channel in such a way that water flowing along the entire width of the entrance can flow onto the conveyor unit. Hence, a flow pattern of the water through the water channel is largely undisrupted, providing reduced flow resistance. Also, a risk of objects bypassing the conveyor unit and/or becoming trapped between the conveyor unit and a wall of the conveyor channel is reduced. Furthermore, such a water cleaning system does not require external assistance or maintenance as it is made extremely robust. Optionally, the width of the entrance channel is constant or increases at least from the opening to the collection surface of the conveyor unit. Any narrowing of the water channel, such as suggested in the prior art with for example funnel types channels, provide risks of obstructions in the channel, but also affects the water flow as it induces resistance in the water flow.

Optionally, the width of the water channel downstream of the collection surface remains constant or increases in the direction of the flow along the water channel. This also prevents flow resistance in the water channel of the water cleaning system.

Any resistance inside the water channel will have the effect of constraining the water of the free-flowing water way to flow around the water cleaning system instead of flowing towards the water cleaning system, and in particular towards the water channel. A drop in water pressure within the water channel behind the conveyor unit enhances a free flow within the water channel and thereby stimulates the flow of objects towards the water cleaning system.

Optionally, the front end of the cleaning system is connected to a floating barrier such that the barrier deviates floating objects towards the opening in the front end of the cleaning system. Hence, objects floating on or suspended near a surface of water can be directed towards the opening. Optionally, the floating barrier is configured to be connected to a shoreline of the free-flowing water way, or to an anchor buoy provided within the free-flowing water way.

Optionally, the front end is slanted. Optionally, the front end is slanted by an angle of preferably 45° or more. The front end of the cleaning system, which is pointed towards the incoming flow of water in the free-flowing water way, may have a slanted side so that large objects such as tree branches or tree stumps can be diverted away. In this way, it can be prevented that large objects block or get stuck in the front end of the conveyor unit. Optionally, the front end is vertically reversible, so it can be used for connecting the barrier on both a port side or on a starboard side of the cleaning system.

Optionally, the floating barrier is configured to be in the prolongation of the slanted front end side opposite to the shoreline side. Hence, the floating barrier can extend substantially in the same direction as the slanted front end side. Thus, directing of objects towards the opening can be improved.

Optionally, the water cleaning system further comprises a frame structure at its front end to attach the floating barrier to the water cleaning system.

Such a frame structure can advantageously absorb the stresses transmitted to the water cleaning system via the floating barrier.

Advantageously, the frame structure is made in steel.

Advantageously, the frame may also be used to provide front deck space. A platform can be advantageously provided on the frame structure.

Optionally, the frame structure is provided on the same side as the floating barrier is to deviate floating objects. The floating barrier can then also be fixed to the shoreline and deviate objects to the opening of the water cleaning system. When the frame structure / floating barrier is installed on the left/right, the system is respectively a left/right-handed system.

Optionally, the frame structure is symmetrical and/or is at least fixed to the water cleaning system on both sides of the water cleaning system, and/or is fixed at a front end of the water cleaning system.

Providing a symmetrical frame structure has the advantage that the system has only one configuration, which can be used in any type of site, and irrespectively of the side on which the floating barrier is to be installed. A symmetrical frame structure can be more compact than an

asymmetrical structure. Less material needs to be used, and therefore the system is also lighter.

Optionally, the frame structure is an isosceles triangle whose apex is at the front end of the water cleaning system.

Advantageously, the frame structure has a reduced size with respect to other configurations.

Preferably, the floating barrier can be suspended to the frame structure above the water level. Advantageously, this provides a more efficient load path and a free path to the floating objects.

Optionally, the floating barrier is fixed to the frame structure at the apex of the frame structure or along an edge of the frame structure. Such a configuration allows to fix the floating barrier at different locations of the frame structure. Depending on the site where the water cleaning system is deployed, the current may vary, and in some sites, backflow current may be more or less strong. Thus, it can also be an advantage to attach the floating barrier along the edge of the frame structure, or directly against the water cleaning system. Furthermore, it is also possible to provide a double barrier.

Fixing the floating barrier to the apex of the water cleaning system further has the advantage, that if too much debris flow by in a given location, a cure could potentially be to rotate the system by for example 5, 10 or even more degrees with respect to the river flow direction.

Optionally, the frame structure defines an opening on one or on each side of the floating barrier.

An opening on the back side of the floating barrier enables back flow, i.e. objects deviated behind the barrier to penetrate the water cleaning system.

Optionally, at least one of the openings can selectively be opened or closed with closing means.

For example, the back-flow opening (behind the floating barrier) could be closed if no back—flow current is present in a certain site. It is also possible to close the main opening, in front of the floating barrier (for objects deviated by the floating barrier) when for example the containers of the water cleaning system are ah full and have not been replaced yet. Optionally, the front end is arranged to prevent oversized objects from reaching the conveyor unit. Optionally, the opening is provided with, e.g. vertical or slanted, bars which are configured to prevent larger objects from reaching the conveyor unit. Hence, obstruction of the water channel can be avoided.

Optionally, a height of the floating barrier is increasing, such that in use, the lower height is placed towards the shoreline and the higher height is placed towards the opening. The height of the floating barrier refers to at least one of the total height of the floating barrier, the height of the floating barrier under water which corresponds to the height of the portion of the floating barrier under water when installed, or the height of the floating barrier above water which corresponds to the height of the portion of the floating barrier above the water when installed.

This allows an improved guiding of the debris, under and/or at the water surface, even when the water or the cleaning system moves in an up-down direction.

Optionally, the conveyor channel further comprises sidewalls. Optionally, the entrance channel comprises sidewalls, preferably the sidewalls are watertight. Hence, water is conducted through the water channel. Furthermore, turbulences in the flow are reduced.

Optionally, the sidewalls of the entrance channel are extendable under water, to a depth comprised in the range of 0.5 meter to 1 meter. By these means, the entrance channel extends under water, and ensures a laminar flow of water also under water.

Optionally, the floating barrier is provided with means to extend the floating barrier under water, to a depth comprised in the range of 0.5 meter to 1 meter.

Optionally, the cleaning system is a floating pontoon. Hence, the cleaning system can easily be positioned at will.

Optionally, the conveyor channel and/or the entrance channel, is defined by substantially parallel floats of the water cleaning system. Optionally, the floating pontoon is a catamaran.

Optionally, the conveyor unit comprises an extraction conveyor belt. The extraction conveyor belt can be actuated in the same direction as the water flow. The extraction conveyor belt can be actuated in both directions, e.g. for

maintenance purposes. Optionally, the extraction conveyor belt comprises a tail pulley and a head pulley, said tail pulley being located at the junction between the entrance channel and the conveyor channel. The extraction conveyor belt can further comprise lateral guides configured to prevent objects from sliding under the lateral guides. The lateral guides can be in the form of a skirt, and preferably extend along the entire conveyor track. The lateral guides are preferably located as close as possible to the extraction conveyor belt to prevent object from entering the conveyor unit and block the system. The lateral guides are further preferably located at the corner between the conveyor unit and the sidewalls of the conveyor unit.

Optionally, the extraction conveyor belt comprises a plurality of openings and/or slits arranged for allowing water to pass there through back to the free-flowing water way. The openings and/or slits may have various shapes and forms. The openings can e.g. have a dimension of about 10 to 30 mm, or 15 to 25 mm, for example a dimension of 17 x 22 mm. Optionally, the extraction conveyor belt is in the form of a grid whose mesh size determines the size of the objects which are conveyed.

Optionally, the cleaning system further comprises means for tilting and/or lowering the conveyor unit. Hence, a height of the conveyor unit relative to the water can be adjusted. Furthermore, the conveyor unit can also be partly under water, such that the collection surface is in the prolongation of the entrance channel, at a depth comprised in the range of 0.5 meters to 1 meter.

Optionally, the extraction conveyor belt is provided with a plurality of conveyor flights configured to collect the objects flowing in the entrance channel.

Optionally, the conveyor flights are uniformly distributed along the extraction conveyor belt. Optionally, the conveyor flights are horizontal rods.

Optionally, the conveyor flights are in the form of flaps or plates which are configured to gather the objects flowing in the entrance channel. According to an aspect is provided a water cleaning system for removing objects floating on or suspended near a surface of water in a free-flowing water way, e.g. as described above, or an other water cleaning system. The water cleaning system includes a conveyor shuttle and a shuttle track. The water cleaning system includes means for moving the conveyor shuttle along the shuttle track from a loading position to at least one unloading position. The loading position is located relative to the conveyor unit such that objects on the conveyor unit fall, e.g. directly, into the conveyor shuttle. The loading position can e.g. be under the head pulley of the extraction conveyor belt.

Optionally, the conveyor unit comprises weight and/or volume measuring means for measuring the weight and volume of the objects which are being conveyed.

Optionally, the weight measuring means are provided on the extraction conveyor belt of the conveyor unit.

The weight measuring means can be provided by a scale at the second end of the conveyor belt. The weight measuring means can also further be provided by means for measuring the energy consumption of the conveyor belt, said measured energy consumption being proportional to the weight of the gathered waste. Measuring the weight by measuring the energy consumption, the power usage of the extraction conveyor unit, is a clever solution to obtain indirectly the weight of the waste which has been extracted from the water. Hence, no additional hardware is required for measuring the weight of the gathered waste.

Optionally, the water cleaning system comprises a primary container position located under the shuttle track to host a primary container when the conveyor shuttle is in the loading position, such that objects on the conveyor unit, e.g. on the extraction conveyor belt, directly fall into the primary container when the conveyor shuttle is in an unloading position.

Optionally, the water cleaning system comprises at least one secondary container position located under the shuttle track to host at least one secondary container such that the conveyor shuttle is configured to unload objects in the secondary container when in an unloading position.

Optionally, the water cleaning system comprises means for mooring a barge under the shuttle track such that the conveyor shuttle is configured to unload objects in the barge when the conveyor shuttle is in a defined position along the shuttle track. The defined position corresponds to a position along the shuttle track such that the waste falls in the barge where desired. Such positions may take into account the distribution of the waste already present in the barge such that it is uniformly distributed in terms of weight, so as to ensure stability of the barge.

As soon as the barge is filled with the gathered waste, the barge can be towed away and a new barge brought in position, under the shuttle track. Optionally, the conveyor shuttle comprises a conveyor shuttle belt. Hence, objects can be moved inside the conveyor shuttle, e.g. for facilitating loading of the conveyor shuttle and/or for facilitating easy offloading of the conveyor shuttle.

Optionally, the conveyor shuttle comprises sidewalls. The sidewalls are advantageously arranged so as to prevent objects from falling unintentionally. Optionally, the conveyor shuttle further comprises lateral guides to prevent objects from getting stuck or blocked in the shuttle conveyor belt. The lateral guides are installed on both sides of the shuttle conveyor belt.

Optionally, the conveyor shuttle belt is made from identical parts as the extraction conveyor belt. Hence, an economical design can be provided.

Optionally, the conveyor shuttle further comprises means for unloading gathered waste. The means for unloading gathered waste can be provided by doors which open e.g. in relation to movement of the conveyor shuttle belt.

Optionally, the conveyor shuttle comprises means for determining the conveyor shuttle weight. The means for determining the conveyor shuttle weight can be provided by, e.g. four, weight sensors, e.g. located at the corners of the conveyor shuttle. Hence, a weight of the objects gathered in the conveyor shuttle can be determined.

Optionally, the conveyor shuttle comprises volume measuring means for measuring the waste volume when a container is located beneath. The means for measuring the waste volume can be provided by ultrasonic means or a camera. Hence, a volume of waste in a container can be determined.

According to an aspect is provided a method for determining a weight distribution in a water cleaning assembly during operation. The method comprises placing the conveyor in the loading position. The method comprises loading waste into the shuttle by means of the extraction conveyor belt. The method comprises determining the weight of the waste in the shuttle. The method comprises offloading waste in a container, wherein the container which receives the waste is determined by the weight of each container stored in a memory. The stored weight of a container is determined by the accumulated weight of waste which has been offloaded into that container by the conveyor shuttle.

Optionally, the container which receives the waste is further determined by the stored volume of waste in each container, the stored volume of waste in a container being determined by volume measuring means of the conveyor shuttle, when the conveyor shuttle is positioned above the container.

It will be appreciated that any of the aspects, features and options described in view of the water cleaning systems apply equally to the method and vice versa. It will also be clear that any one or more of the above aspects, features and options can be combined.

BRIEF DESCRIPTION OF THE DRAWING

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

In the drawing:

Fig. 1 shows a schematic diagram of an example of a water cleaning system;

Fig. 2 shows a top view of the diagram shown in Fig. 1;

Fig. 3 shows an enlarged view of the front end of a water cleaning system;

Fig. 4 is a perspective view of the conveyor unit and the conveyor shuttle of the water cleaning system;

Fig. 5 is a side view of the water cleaning system with a plurality of containers.

Fig. 6 shows a schematic diagram of an example of a water cleaning system;

Fig. 7 is the same water cleaning system as the one illustrated in Fig. 6, wherein the floating barrier is provided at different locations.

Fig. 8 is a schematic diagram illustrating the shape of the hulls of water cleaning system. Fig. 9 is a perspective view of the entrance of an opening and entrance of a water cleaning system.

DETAILED DESCRIPTION

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

The terms "about" or "approximate" and the like are synonymous and are used to indicate that the value modified by the term has an understood range associated with it, where the range can be +20%, +15%, +10%, +5%, or +1%. The term "substantially" is used to indicate that a result (e.g., measurement value) is close to a targeted value, where close can mean, for example, the result is within 80% of the value, within 90% of the value, within 95% of the value, or within 99% of the value.

The water cleaning system described in the present specification is to be installed in a free-flowing water way. A stream of water flows through the water cleaning system along a water channel. The term upstream refers to an element which is located along the stream in the opposite direction from that in which the stream flows. The term downstream refers to an element which is located along the stream in the direction in which the stream flows.

The term conveyor unit is to be understood as a conveyor system which is configured to displace floating objects in a free-flowing water way from one location to another. The conveyor system is described for an extraction conveyor belt but other systems could also be used.

Fig. 1 shows a schematic diagram of an example of a water cleaning system 1. The water cleaning system 1 is arranged for removing objects (e.g. trash, debris) floating on or suspended near a surface of water in a free-flowing water way, such as a river. The cleaning system is arranged to define a water channel 3 through which water of the free-flowing water way is directed.

The water cleaning system 1 comprises a conveyor unit 4 for removing the objects coming from the free-flowing water way. Objects may be concentrated in the water channel so that they can more easily be picked up from the water by means of the conveyor unit. The objects which are gathered by the conveyor unit 4 are then brought via an extraction conveyor belt to a conveyor shuttle 20 responsible for filling a plurality of containers with the gathered objects. The water cleaning system 1 can be described in different parts.

A first part, located upstream of the conveyor unit, is responsible for providing to the water cleaning system objects floating in the free-flowing water way. This first part can also be responsible for deviating objects which are too large from the water cleaning system, such as logs or even tree trunks.

A second part, comprising the conveyor unit, is thus responsible for removing undesired objects from the free-flowing water while maintaining the water flow in the water channel and reduce water turbulence and stagnation. All water is directed through an extraction conveyor belt. To this end, the conveyor is constructed as wide as possible. The gathered objects are lifted via the extraction conveyor belt towards the conveyor shuttle 20.

A third part is dedicated to the distribution of the waste or objects gathered by the extraction conveyor belt with the use of a conveyor shuttle.

The water cleaning system is fixed in the free-flowing water way during use. It can be fixed in the water by means of at least one anchor, or it can also be fixed to the shoreline, or both. The water cleaning system can further be fixed to an anchor buoy provided within the free-flowing water way, for example halfway within the free-flowing water way.

As shown in Fig. 1, the water channel 3, goes through the water cleaning system 1. An opening 2 in the front end of the cleaning system 1 defines an entrance channel 9 of the water channel 3. A convey channel 6 of the water channel is located downstream of the entrance channel 9 and is connected thereto. The convey channel corresponds to the part in which water of the water channel passes through the conveyor unit 4.

The conveyor unit 4 comprises an extraction conveyor belt which defines an inclined path between the first end 8 and the second end 10. The conveyor belt of the conveyor unit is also referred to as the extraction conveyor belt throughout the application. The first end 8 is by definition where the tail pulley of the conveyor unit is located and the second end is at the location of the head pulley of the conveyor unit. The first end 8 is extendable downwards into the water for conveying objects from the first end 8 to the second end 10.

The junction between the entrance channel and the extraction conveyor belt defines a collection surface of the conveyor unit. The collection surface is the usable surface of the conveyor unit through which the water flows and allows the floating objects to be picked up by the extraction conveyor belt out of the water.

The collection surface shall have a width which is at least the width of the entrance channel so as to prevent objects getting stuck at the transition there between and in order to optimize the water flow in the water cleaning system. It is important to provide a collection surface with a width at least as large as the entrance channel so as to ensure a laminar flow in the water channel.

In this example, the conveyor unit further comprises sidewalls 35 for preventing objects to fall off from the extraction conveyor belt back into the water from its sides. The sidewalls are connected to the conveyor unit, and are

substantially perpendicular to the conveyor unit. For example, the sidewalls are sealed or attached to the conveyor unit with rubber strips, or with plastic strips.

Furthermore, the conveyor unit is fixed to the water cleaning system at its sides in such a way that all the water of the water channel 3 passes via the conveyor channel 9 and the collection surface. It is very important to provide a connection between the conveyor unit and the water cleaning system which prevents the occurrence of turbulence in the water flow.

The conveyor unit further comprises lateral guides 41 which can be in the shape of a skirt for example, and extend along the entire inclined path of the extraction conveyor belt. They are located as close as possible to the extraction conveyor belt to prevent objects from entering the conveyor unit and block the actuating mechanism. The lateral guides 41, in the shape of skirts, are shown on Figures 3 and 4. Other types of lateral guides are possible. The lateral guides 41 are placed in the corner between the extraction conveyor belt and the sidewalls.

The extraction conveyor belt of the conveyor unit is provided with a plurality of conveyor flights (not shown in the Figures) configured to collect the objects flowing from the entrance channel. The conveyor flights are uniformly distributed along the extraction conveyor belt and can have different forms or shapes. The shape of the conveyor flights can be adapted to the types of objects which pollute the free-flowing water way. For example, the conveyor flights can be in the form of horizontal rods. The conveyor flights can also be in the form of plates which are inclined when moving up on the extraction conveyor belt such that objects are prevented from falling. The extraction conveyor belt can be a chain supporting spaced, removable or attached‘sticks” on which the objects of the free- flowing water way are hung.

The entrance channel also comprises sidewalls which can be made watertight. Providing watertight means along the entrance channel

advantageously reduces any turbulence in the water flow, and ensures therefore a laminar flow. It is important to provide a laminar flow at the entrance of the water cleaning system in order to maximize the water flow within the water channel.

Furthermore, the entrance channel can extend into the water. In fact, some objects will not be completely floating, such as for example plastic bags. It is therefore important to also guide them under water, and provide a channel under water. In this case, the sidewalls of the entrance channel can be extendable inside the water, up to 1 meter deep. As the water cleaning system can be used in shallow waters, the sidewalls should be extendable between the water surface and a water depth comprised in the range of 0.5 meter to 1 meter, in order to adapt to the depth of the water at the location where the water cleaning system operates.

The first end 8 of the extraction conveyor belt, or the tail pulley is located close to the junction between the entrance channel and the conveyor channel. The width of the extraction conveyor belt is thus at least as large as the width of the entrance channel. This width corresponds to the collection surface of the extraction conveyor belt. The first end 8 of the conveyor unit is also configured to be extendable in the water, up to a depth of 1 meter (in accordance with the depth of the sidewalls of the entrance channel), in order to be in the prolongation of the entrance channel and thereby be capable of gathering the objects located deeper in the water.

The cleaning system further comprises means for tilting and/or lowering the conveyor unit. The angle of inclination relative to the horizontal (i.e. water surface) may be adjusted. For example, the cleaning operation may be halted by raising the lowered conveyor unit up substantially out of the water. Also, the conveyor may be lowered up to 0.5 m or even 1 meter depth in order to operate under water, in the prolongation of the entrance channel, and gather objects which are also underwater.

The extraction conveyor belt comprises a plurality of openings and/or slits arranged for allowing water to pass there through back to the free-flowing water way.. The extraction conveyor belt preferably has openings/slits whose dimensions determine the size of the objects which are captured. Smaller openings/slits are thus provided in order to capture smaller objects. For example, the openings can have a size of about 10 to 30 mm per side, or 15 to 25 mm per side, for example can have a dimension of 17 x 22 mm. The extraction conveyor belt can thus be in the form of a grid, where the mesh size determines the size of the objects which are captured. The extraction conveyor belt can thus also be in the form of chains.

In this way, it can be avoided that water is being carried along with objects towards the second end of the conveyor unit. Furthermore, the loads on the conveyor unit (e.g. as a result of water) can be significantly reduced.

In order to keep the conveyor unit clean, and prevent the accumulation of dirt which could prevent the conveyor to work properly, brushes can be provided. Because the conveyor always moves through the water, it is expected that only passive brushes are sufficient to remove the dirt. The brushes could also be replaced by cleaning system with water and high pressure.

The water cleaning system 1 can be a floating pontoon. The floating pontoon can be in the form of a catamaran having two hulls. The conveyor unit is then attached at its sides to each hull of the catamaran. The water channel, comprising the entrance channel and the conveyor channel, is then between the two hulls of the catamaran.

It is preferred to keep the space along the water channel in the water cleaning system downstream of the conveyor channel as large as possible to avoid water stagnation. A floating pontoon in the form of a catamaran allows such an arrangement.

In this way, the drag can be reduced, possibly facilitating anchoring of the cleaning system. Furthermore, objects may more easily flow into the water channel formed by the cleaning system, so that the efficiency of collecting debris from the free-flowing water way can be improved.

Upstream of the opening 2, a first part of the water cleaning system is responsible for directing as much as possible of the objects in the stream towards the water cleaning system.

In the present example, at least the front end opposite the shore line is slanted. In this example, the water cleaning system is built symmetric such that it can be used in any type of configuration, and thus both front ends 12a and 12b of the water cleaning system are identical. The slanted front end 12b of the water cleaning system is connected to a barrier 30 which is arranged to deviate objects in the free flowing water way towards the opening 2. The barrier 30 can be a floating barrier configured to be connected to a shoreline of the free-flowing water way.

Preferably, the front end is slanted by an angle of at least 45° such that the angle formed by the slanted front end (or the tangent in case of a curved surface) with the flow direction is 45°or less.

In this example, the shoreline is located on the left of the water cleaning system. The barrier 30 is arranged such that it is provided in the prolongation of the slanted front end 12b which is opposite to the shore line. The barrier is arranged on the same side as the shore line.

As shown in Figure 2, objects in the water flowing along the free-flowing water way in direction F will be deviated by the barrier 30 towards the opening 2, along the path Dl.

In an example, the floating barrier can measure up to 100 or 150 meters. It is preferred that the barrier comprises a cable which, under tension, stretches to the appropriate shape (such as a boat mooring line). The barrier can further comprise at least one anchor point or mooring points. If the barrier is longer than 150 meters, it shall further be fixed with at least one buoy, which can be anchored.

The floating barrier can further comprise means to further extend the barrier under the water, for example a sidewall which is configured to extend under the water, as the sidewalls of the entrance channel. The depth of the sidewalls shall be the same as the one of the extendable sidewalls of the entrance channel, in order to guide the objects which are within a certain depth towards the entrance channel. The depth of the of floating barrier, under water, can preferably be in a range of 0.5 meter to 1 meter, however the skilled person will appreciate that the depth strongly depends on the properties of the debris, in addition to the properties of the site, such as its depth and flow.

The water cleaning system can further be configured to absorb the forces which are applied onto the barrier. A second mooring point can be provided to keep the water cleaning system aligned (water channel substantially parallel to the water flow of the free flowing water way) with the water flow. If the forces applied on the barrier are too high, additional mooring points can be incorporated for the barrier to withstand such forces.

As shown in Figure 2, the front end may also be arranged to prevent oversized objects from reaching the conveyor unit. The opening 14 between the barrier 30 and the opposite slanted front end side 12b can be provided with bars which are configured to prevent larger objects from reaching the conveyor unit.

The bars can be vertical or slanted. Longer objects (for example having a size > 3m) and high floating objects will be deviated along path D2 around the water cleaning system. This prevents accumulation and stagnation of material, which is common for example with traditional "litter traps" cleaning systems. The bars can also further extend in the water, in accordance with the sidewalls of the entrance channel and/or the floating barrier.

This arrangement can be provided on both sides of the water cleaning system, left or right.

In this example, the height of the floating barrier is increasing, such that in use, the lower height is placed towards the shoreline and the higher height is placed towards the front end of the water cleaning system. The height of the floating barrier can refer to the total height of the floating barrier, the height of the floating barrier under water when installed, or the height of the floating barrier above the water when installed.

Figure 3 is another view of the water cleaning system 1. The bars 31 in the opening 14 which are configured to prevent larger objects from reaching the conveyor unit are shown. In this example, three vertical bars are provided. It will be appreciated that at least one bar (vertical or slanted) is necessary for preventing larger objects from reaching the conveyor unit.

The water cleaning system can further comprise means for obtaining renewable energy. The means for obtaining renewable energy is at least one of the group including a solar panels 56, water turbine, and/or wind turbine 55, as shown in Figure 2 for example. The water cleaning system can further include a battery unit for storing energy for later use, wherein the actuating unit is at least partially drivable by means of the battery unit.

Figure 4 illustrates a view in perspective from the water cleaning system. As described earlier, by means of the conveyor unit 4 it is possible to effectively remove waste objects of the water. The conveyor unit 4 has a slope arrangement, lifting objects out of the water towards a conveyor shuttle 20. The conveyor shuttle is arranged so as to redistribute the waste towards at least one container.

The conveyor shuttle comprises a conveyor belt which is configured to be actuated in order to redistribute the waste inside. The conveyor shuttle preferably comprises sidewalls (not shown in the Figures) in order to avoid to prevent the debris from falling without actuation of the conveyor belt. The conveyor shuttle preferably comprises two sidewalls along the conveyor belt, as for the extraction conveyor. It may further comprise lateral guides between the sidewalls and the conveyor belt so as to prevent objects from getting stuck there between. The conveyor shuttle may further comprise additional walls or doors at each end of the shuttle conveyor belt.

The conveyor shuttle 20 is a built-in waste distribution system that distributes the waste over dumpsters / containers, but it could also be arranged to redistribute the waste directly to a dock or platform facility, but also to a barge. The conveyor shuttle can thus be moved along a shuttle track 25, which is shown in Figure 5. The shuttle track 25 can be a rail system over which the conveyor shuttle 20 is configured to move from a first to a second position. The position along the shuttle track can be controlled by means of an end stop and an incremental encoder. In the exceptional case of slip, the shuttle position can be reset by means of a calibration point.

The conveyor shuttle can be in a loading position, said loading position being located under the head pulley of the extraction conveyor belt of the conveyor unit such that objects on the extraction conveyor belt fall directly into the conveyor shuttle. Or the conveyor shuttle can be in an unloading position, for example above a container.

The water cleaning system is configured to be used with at least one container 51. For example, a primary container 51 which is beneath the second end of the conveyor unit and beneath the shuttle track, such that objects on the extraction conveyor belt of the conveyor unit directly fall into the primary container 51 while the conveyor shuttle is in an unloading position. The water cleaning system may further comprise or be used with at least one secondary container 52, 53 located under the shuttle track such that the conveyor shuttle is configured to unload objects in the secondary containers 52, 53 when in an unloading position.

In an example, at least one or a plurality of containers are provided consecutively beneath the shuttle track 25. In the example, 3 or 4 containers can be installed. The containers can be fixed to the water cleaning system downstream of the conveyor unit, and above the water surface. The containers can have a size of substantially 8m ³ , which means that they weigh around 2 tons including waste. This weight can be lifted towards the dock with common hydraulic cranes or telehandlers.

In an example, the conveyor shuttle can receive up to 2m ³ of waste.

In place of containers, a barge can be provided. The barge can be attached to the water cleaning system during waste extraction and removed after. Waste can be unloaded by the conveyor shuttle directly to the barge.

The conveyor shuttle may further comprise weight measuring means. The measuring means can be provided by means of four weight sensors arranged at the corners of the conveyor shuttle. From the measured weight of the conveyor shuttle, the weight of each container can be calculated after each unloading from the conveyor shuttle. In this way, the weight of the water cleaning system can be monitored and a uniform distribution of the waste can be ensured.

Furthermore, the conveyor shuttle can be provided with volume measuring means. The volume measuring means are configured to measure the waste volume of a container when the conveyor shuttle is positioned above the container. The latter can be performed by ultrasonic means arranged on the conveyor shuttle. It could also be performed by means of a camera and appropriate image processing.

Weight measuring means and/or volume measuring means can also be provided on the conveyor unit itself. A scale can be provided at the second end of the conveyor unit, on the extraction conveyor belt for example, before the objects are provided to the conveyor shuttle. The weight measuring means can also be provided by measuring the energy consumption of the extraction conveyor belt. In fact, the energy consumption is proportional to the weight of the waste which is gathered by the conveyor unit. Height measuring means for measuring the height of the objects on the extraction conveyor belt can also be provided. The measured height can then be multiplied by the flow to provide an approximation of the volume of the gathered waste.

When a barge is provided in place of containers, the conveyor shuttle can be used to distribute the waste uniformly over the barge. In such a case, additional dock facilities can be required to unload the waste. The barge can also be towed by another boat.

The barge can be moored to the water cleaning system and removed when the barge is full. A new barge can then be provided to allow a continuous extraction of the objects from the water.

Downstream of the conveying unit, it is preferred that the width of the water channel does not decrease. The width of the water channel should remain constant or increase in the direction of the flow along the water channel. This ensures a pressure drop in the water flow downstream of the conveying unit.

The barge can thus be in the form of a catamaran, such as the water cleaning system. The distance between the hulls of the catamaran should correspond at least to the width of the entrance channel, or the width of the collection surface of the conveying unit. It is important to keep the flow resistance to a minimum within the water channel and thereby ensure a natural (free) water flow. In other words, it is important to keep the flow as laminar as possible within the water channel.

The conveyor shuttle comprises a conveyor shuttle belt. The conveyor shuttle belt can be made from identical parts as the extraction conveyor belt, to simplify the design, have identical spare parts and less unique parts. Furthermore the behavior is more predictable.

The conveyor shuttle further comprises means for unloading gathered waste. The means for unloading gathered waste can be provided by doors which open upon cooperation with movements of the conveyor shuttle belt, such that the waste directly falls into the desired container. The unloading means can be actuated by means of a control unit connected to the conveyor shuttle.

A method for measuring the weight distribution in a water cleaning system as described in the previous examples, during operation, is hereby explained. A plurality of containers are provided, wherein a primary container is located directly underneath the second end of the conveyor unit and the other containers are secondary containers. The conveyor shuttle can move along the shuttle track above the plurality of containers. When the conveyor shuttle is located at the second end of the conveyor unit, it is in the loading position, as waste from the conveyor will directly fall into the conveyor shuttle. When the shuttle track is above the secondary containers, it is in an unloading position. While the conveyor shuttle unloads waste in a secondary container, the primary container is being loaded directly from the extraction conveyor belt.

The primary container can also be equipped with load measuring means.

The load measuring means of the conveyor shuttle can be used to track the weight distribution of the water cleaning system by storing the values of the weight of the conveyor shuttle before each unloading of waste. The weight of each container is thus tracked and known at each iteration of the process. When a container has sufficient space and if this improves the balance of the water cleaning system, the conveyor shuttle dumps the waste in this container.

The method for distributing waste is hereby outlined with a given order, however, the order of the steps provided hereunder is not a limitation, as other orders are possible as can be deducted by the skilled person.

The method comprises the following steps:

a) placing the conveyor shuttle in the loading position,

b) loading waste into the conveyor shuttle by means of the extraction

conveyor belt,

c) determining the weight of the waste in the conveyor shuttle,

d) offloading waste in a container, wherein the container which receives the waste is determined by the stored weight of each container, wherein the stored weight of a container is determined based on the weight of the waste which has been offloaded into that container.

It is also possible to determine which container receives the waste based on the stored volume of each container, the stored volume being determined by the volume measuring means of the conveyor shuttle or the conveyor unit. The weight is only unloaded in a container if it has sufficient space.

The weight measurements and/or the volume measurements can be performed by the weight / volume measuring means of the conveyor unit and/or the conveyor shuttle.

The volume measurement can be performed after a container has been filled, but also at different stages of the process, for example before filling a container. It is also possible to measure the volume of each container consecutively before deciding which container is to be filled next. For example, the conveyor shuttle performs a volume measurement of the waste in each container and determines with that information which containers has sufficient space.

Different configurations to attach the floating barrier 30 to the water cleaning system can be provided.

It has been observed that when objects having low buoyancy are approaching the floating barrier, eddy currents may be responsible for drifting these objects under said barrier which then tend to accumulate behind the barrier. In order to avoid such an accumulation of floating objects behind the barrier, an opening between the floating barrier attachment point and the water cleaning system can be provided. The floating objects then enter the water cleaning system and are directed to the conveyor.

For example, as illustrated on Figure 1, frame elements 31 and 15 which are configured to fix the floating barrier 30 to the water cleaning system, may be such that they are provided only above and/or under the water surface, in order to let the floating objects reach the conveyor unit, and thereby get picked up.

Fig. 6 illustrates a water cleaning system comprising a different type of frame structure at the first end of the water cleaning system. The frame structure shown on Figure 6 is symmetric and may provide one opening 114, or two combined or separate openings 114, 115. If two openings are provided, one opening 114 is for debris which are deviated by the floating barrier 30, upstream of the water cleaning system, and opening 115 is for debris which have drifted under the barrier, for example by means of eddy currents.

It may also be possible to open or close an opening, for example opening 115, depending on the properties of the site (such as water current), by closing means, such as a barrier which can be easily tilted between an open and closed configuration.

Openings 114 and/or 115 may also comprise bars 31 in order to filter debris in accordance with their size.

The frame structure can have the shape of an isosceles triangle whose apex 116 is at the front of the cleaning system. The floating barrier 30 is preferably fixed to the apex 116 of the frame structure. The width of the openings 114 and 115 is preferably substantially the same as the width of the collection surface of the conveyor unit 4. For example a width of 2.5 meters is advantageous. Preferably, the width is in the range of 2 to 3 meters.

Other configurations are also possible, as illustrated on Fig. 7. The floating barrier 30 may also be fixed at other locations on the frame structure, for example along the side of the frame. It is also possible to provide a double barrier, as illustrated with floating barriers 30a and 30b on Fig. 7.

Fig. 8 illustrates a possible funnel-shaped hull for use with such a frame. As illustrated in Fig. 9, the frame structure can be provided between the side walls of the hull and the conveyor unit. Providing a symmetric frame structure to the water cleaning system has the advantage that the cleaning system can be installed on either side of a river, as the floating barrier can be installed on either the left or right side, and the design of the water cleaning system is independent thereof. During use, the water cleaning system can also be easily moved to a different location, since left and right configurations of the water cleaning system are both possible.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various

modifications 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 examples or embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

The conveyor unit may be implemented in a pontoon, such as a a ship, a floating installation, etc. Other pontoons are possible as well. It also conceivable that a plurality of conveyor units are included in a (floating) pontoon.

Actuation of the conveyor unit may be performed by means of a mechanical, electrical, electromechanical, hydraulic, pneumatic, electrohydraulic, and/or electro pneumatic actuation system. Other actuation systems can also be used, such as for example hybrid actuation systems. A combination of actuation systems for different components of the conveyor unit is also envisaged.

The system and method for removing objects floating on or suspended near a surface of water in a free-flowing water way can also be employed for obtaining debris filtered water for industrial processes. The debris can be effectively removed from the water prior to entering a plant. In this way, damage caused to equipment can be prevented since it can be prevented that the debris interfere with the continuous operation of industrial processes.

It will be appreciated that the methods may include computer implemented steps. All above mentioned steps can be computer implemented steps. Embodiments may comprise computer apparatus, wherein processes performed in computer apparatus. The invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of source or object code or in any other form suitable for use in the implementation of the processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a ROM, for example a semiconductor ROM or hard disk. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via electrical or optical cable or by radio or other means, e.g. via the internet or cloud.

Some embodiments may be implemented, for example, using a machine or tangible computer-readable medium or article which may store an instruction or a set of instructions that, if executed by a machine, may cause the machine to perform a method and/or operations in accordance with the embodiments.

Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include processors, microprocessors, circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor device, microchips, chip sets, et cetera. Examples of software may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, mobile apps, middleware, firmware, software modules, routines, subroutines, functions, computer implemented methods, procedures, software interfaces, application program interfaces (API), methods, instruction sets, computing code, computer code, et cetera.

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.

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.