ANTIPBIOFOULING ARRANGEMENT AND METHOD OF DESIGNING SUCH AN ARRANGEMENT

Abstract

In an anti-biofouling context, an arrangement (1) is provided which comprises an object (10) and a light-emitting system (20) arranged on at least a main surface (11a) of the object (10). The light-emitting system (20) includes a plurality of light sources (21) for emitting anti-biofouling light and is configured to emit the light in a direction away from the object (10). The light sources (21) are arranged in the light-emitting system (20) in at least two different light-emitting groups (22) having respective main directions of emission (23) of the anti-biofouling light, the main directions of emission (23) of at least two light-emitting groups (22) having different spatial orientations when viewed on an unfolded and flattened area of the main surface (11a) where the light-emitting groups (22) are located. Consequently, the area that is reached by the anti-biofouling light during operation of

Claims

1. An anti-biofouling arrangement, comprising: an object, and a light-emitting system arranged on at least a main surface of the object the light-emitting system including a plurality of light sources configured to emit anti-biofouling light in an activated state thereof, wherein the light sources are arranged in the light-emitting system at least first and second light-emitting groups, each light-emitting group being configured to emit the anti-biofouling light in a respective main direction of emission, and the main directions of emission of the first and second light-emitting groups having different spatial orientations when viewed on an unfolded and flattened area of the main surface where the at least two light-emitting groups are located, wherein the light sources of the second light emitting group are arranged to emit the anti-fouling light in a main direction of emission with a non-normal direction of emission away from the main surface of the object, such that: (i) the anti-fouling light from a particular region of the surface of the object is directed downwardly along the gravity vector or at least with a component downwardly along the gravity vector; or (ii) the anti-fouling light from a particular region of the surface of the object is directed towards a proximal feature of the surface of the object.

2. The anti-fouling arrangement according to claim 1, wherein the light sources of the first light emitting group are arranged to emit the anti-biofouling light in a main direction of emission normally away from the main surface of the object.

3. The anti-fouling arrangement according to claim 1, wherein the anti-fouling light from a particular region of the surface of the object is directed downwardly along the gravity vector or at least with a component downwardly along the gravity vector, wherein the object is a ship and wherein the light sources of the second light emitting group are in the vicinity of the load line of the ship.

4. The anti-fouling arrangement according to claim 1, wherein the anti-fouling light from a particular region of the surface of the object is directed towards a proximal feature of the surface of the object, and the proximal feature is a feature of the object not covered by the light-emitting system.

5. The anti-fouling arrangement according to claim 4, wherein the feature is a protrusion.

6. The anti-fouling arrangement according to claim 1, wherein the anti-fouling light from a particular region of the surface of the object is directed towards a proximal feature of the surface of the object, and the proximal feature is an uneven area of the object.

7. The anti-fouling arrangement according to claim 6, wherein the proximal feature is a concave recess feature.

8. The anti-biofouling arrangement according to claim 1, wherein the object has a symmetrical appearance and the main surface is a single-symmetry surface of the object, wherein the object is a vessel and the main surface a part of the vessel's hull that is located at one side of the vessel.

9. The anti-biofouling arrangement according claim 1, wherein the first and second light-emitting groups are arranged adjacent to each other on the main surface.

10. The anti-biofouling unit configured to be used in an anti-biofouling arrangement according to claim 1, including said at least first and second light-emitting groups of the light-emitting system.

11. A set of anti-biofouling units configured to be used in an anti-biofouling arrangement according to claim 1 for composing at least a portion of the light-emitting system of the anti-biofouling arrangement on a main surface of an object, each anti-biofouling unit including at least a portion of at least one of the first and second light-emitting groups of the light-emitting system, and the set comprising at least two types of anti-biofouling units which together define the first and second light emitting groups.

12. A method of designing an anti-biofouling arrangement with an object and a light-emitting system to be arranged on at least a main surface of the object and to be provided with a plurality of light sources for emitting anti-biofouling light, wherein the light-emitting system is designed to include at least first and second different light-emitting groups of light sources, wherein each light-emitting group is designed to emit the anti-biofouling light in a respective main direction of emission, wherein the main directions of emission of the light-emitting groups of the light-emitting system are determined in dependency of the intended position of the light-emitting groups on the main surface, wherein the light sources of the second light emitting group are arranged to emit the anti-fouling light in a main direction of emission with a non-normal direction of emission away from the main surface of the object such that: (i) the anti-fouling light from a particular region of the surface of the object is directed downwardly along the gravity vector or at least with a component downwardly along the gravity vector; or (ii) the anti-fouling light from a particular region of the surface of the object is directed towards a proximal feature of the surface of the object.

13. The method according to claim 12, wherein the light sources of the first light emitting group are arranged to emit the anti-biofouling light in a main direction of emission normally away from the main surface of the object.

14. The method according to claim 12, wherein the object is designed with at least one protrusion protruding with respect to the main surface, and wherein a portion of the light-emitting system to be located in the vicinity of the at least one protrusion is designed with the second light-emitting group having a main direction of emission towards the at least one protrusion.

14. Method according to claim 12 wherein the main surface designed with at least one uneven area such as a concave recess feature, and wherein a portion of the light-emitting system to be located in the at least one uneven area or in the vicinity of the at least one uneven area is designed with the second light-emitting group having a main direction of emission towards the at least one uneven area.

15. The method according to claim 12, wherein the object is a vessel and the main surface is a part of the vessel's hull, and wherein a portion of the light-emitting system to be located in a hull area at the vessel's load line is designed with the second light-emitting group having a main direction of emission that is downward with respect to the vessel's horizontal or at least has a component that is downward with respect to the vessel's horizontal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which: FIG. 1 diagrammatically illustrates a situation of a human being present on a quay and a ship being present near the quay,

[0038] FIG. 2 diagrammatically shows a side view of a ship and a light-emitting system arranged on the ship's hull,

[0039] FIG. 3 diagrammatically shows an outline of a portion of a ship's hull and a light-emitting system arranged on the hull, the hull portion including a concave area, wherein main directions in which anti-biofouling light shines from the light-emitting system are indicated by means of arrows, and wherein, for the sake of illustration and clarity, only a limited number of light-emitting groups of light sources of the light-emitting system are depicted,

[0040] FIG. 4 diagrammatically shows the portion of the ship's hull and the light-emitting system arranged on the hull of FIG. 3 in an unfolded and flattened condition,

[0041] FIG. 5 diagrammatically shows an outline of a portion of a ship's hull and a light-emitting system arranged on the hull, and also diagrammatically shows a fin protruding from the ship, wherein main directions in which anti-biofouling light shines from the light-emitting system are indicated by means of arrows, and wherein, for the sake of illustration and clarity, only a limited number of light-emitting groups of light sources of the light-emitting system are depicted, and

[0042] FIG. 6 diagrammatically shows an outline of a portion of a ship's hull and a light-emitting system arranged on the hull, and also diagrammatically shows portions of two intersecting welding seams of the hull, wherein main directions in which anti-biofouling light shines from the light-emitting system are indicated by means of arrows, and wherein, for the sake of illustration and clarity, only a limited number of light sources of the light-emitting system are depicted.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] FIG. 1 illustrates a situation in which the invention may be put to practice. FIG. 2 illustrates general aspects of an anti-biofouling arrangement according to the invention, including a ship and a number of discrete anti-biofouling tiles which are part of a light-emitting system used with the ship for the purpose of keeping the ship clean from biofouling at the position of the hull. FIGS. 3-6 relate to various possible applications of the invention and serve to illustrate notable aspects of the invention.

[0044] With reference to the figures, it is noted that a feasible embodiment of an anti-biofouling arrangement 1 according to the invention comprises a ship 10 and a light-emitting system 20 arranged on the ship's hull 11. At the position of the hull 11, the ship 10 is to be subjected to an anti-biofouling action, in order to avoid formation of biofouling deposits on the hull 11 and to thereby avoid an increase of drag of the ship 10. In particular, the anti-biofouling arrangement 1 is designed to have an anti-biofouling action on the ship 10 on the basis of light radiation, continuously or from time to time, wherein it is to be noted that in order to achieve good anti-fouling effects, the light may be ultraviolet light, especially UV-C light.

[0045] As mentioned earlier, the light-emitting system 20 is arranged on the hull 11. The light-emitting system 20 is a type of system that is suitable to be used for realizing anti-biofouling effects on an object by emitting anti-biofouling light in a direction away from the object, as known from WO 2014/188347 A1, for example. In the shown example, the light-emitting system 20 has a number of light sources 21 configured to generate anti-biofouling light. In particular, in the shown example, the light sources 21 are of the type designed to realize emission of generated anti-biofouling light along a main emission axis. A practical example of the light sources 21 of the light-emitting system 20 is UV-C LEDs. Normally, a ship 10 has a vertical plane of symmetry, and the hull 11 comprises two main surfaces 11a, 11b, namely two main surfaces 11a, 11b located at either side of the ship 10. On at least one of those main surfaces 11a, 11b, the light sources 21 are arranged in the light-emitting system 20 in at least two light-emitting groups 22. Each of those light-emitting groups 22 is configured to emit the anti-biofouling light in a main direction of emission 23 that is different from the main direction of emission 23 of at least one other light-emitting group 22. A light-emitting group 22 is a collection of light sources 21 which are configured to emit light in substantially the same direction, i.e. a collection of light sources 21 of which the main emission axes extend in substantially the same direction, besides a limited number of possible exceptions in the form of deviating individual light sources 21.

[0046] The light-emitting system 20 may comprise material that is transparent to the anti-biofouling light, that may have a structural function in embedding the light sources 21, for example, or supporting the light sources 21 in another way, and that may be arranged so as to cover areas of the hull 11. The transparent material may be provided in various slabs 24, in which case the light-emitting system 20 may be realized as a collection of tiles 25, as illustrated in FIG. 2, or strips, for example, wherein the thickness of the slabs 24 of the transparent material may be so small, even in the millimeter range, that the slabs 24 can normally be referred to as pieces of foil. During operation of the light sources 21, the transparent material may have a function in transporting the generated anti-biofouling light along the hull 11 and ensuring that the anti-biofouling light is more or less evenly spread across the hull 11, i.e. may serve as a light guide, wherein the anti-biofouling light is outcoupled from the light guide at various positions, in a direction away from the ship 10. A phenomenon like total internal reflection may contribute to the transportation of the light through the transparent material. A practical example of the transparent material is a silicone material.

[0047] The risk of biofouling of the hull 11 increases as the velocity of the ship 10 relative to its aqueous environment decreases. This means, for instance, that the risk of biofouling organisms growing on the hull 11 is larger when the ship 10 is docked in port than when it is sailing. Thus, it is especially beneficial to have and operate the light-emitting system 20 in the situation of the ship 10 being docked in port, which situation is illustrated in FIG. 1. However, in such a situation, the chance of human beings 5 and/or animals being relatively close to the ship 10 while anti-biofouling light is emitted away from at least a portion of the ship's hull 11 is also bigger, which involves the risk of human beings 5 and/or animals receiving a relatively high dose of anti-biofouling light which may be harmful to their health. In order to address this issue, the invention provides the option of having an embodiment of the light-emitting system 20 in the anti-biofouling arrangement 1 that is designed so as to ensure that anti-biofouling light that is emitted from a portion of the light-emitting system 20 located in a hull area 12 at the ship's load line 13 is emitted in a direction that is downward with respect to the ship's horizontal 14. This may be realized by having such an arrangement of the light sources 21 in the light-emitting system 20 that the main direction of emission 23 of the one or more light-emitting groups 22 present in the portion of the light-emitting system 20 covering the hull area 12 at the ship's load line 13 has a downward orientation, while the main direction of emission 23 of the one or more light-emitting groups 22 present in a lower portion of the light-emitting system 20 may have a more or less horizontal orientation, i.e. a portion that is closer to the ship's bottom 15, as illustrated in FIGS. 3 and 5. In the specific context of the ship 10, the hull area 12 at the ship's load line 13, i.e. the hull area 12 that is covered by a portion of the light-emitting system 20 in which the light sources 21 are predominantly arranged so as to emit light in a downward direction, may extend from a predetermined distance below the ship's load line 13 to a predetermined distance above the ship's load line 13.

[0048] By emitting part of the anti-biofouling light in a downward direction, it is achieved that a total area of reach of the light associated with an overall horizontal or (slightly) upward orientation of the main direction of emission 23 of one or more light-emitting groups 22 is reduced, wherein particularly an area at the level of the ship's load line 13 and higher cannot be reached by the light, or only by a small dose of the light. Thus, by making certain choices in respect of the orientation of the main direction of emission 23 of the light-emitting groups 22 in different portions of the light-emitting system 20, it can be achieved that human beings 5 and/or other living organisms cannot be reached by the light, or only by a small dose of the light, so that safety of use of the anti-biofouling arrangement 1 is enhanced.

[0049] In general, a surface subject to biofouling is not necessarily planar/flat, but may instead be curved in one or more directions and include one or more convexly curved areas and/or concavely curved areas. A ship's hull 11 is an example of a curved surface, and an area of the ship's hull 11 including a concave area 16 is illustrated in FIG. 3. Further, protrusions may be arranged on the surface, which protrusions may or may not be part of the light-emitting system 20. Examples of protrusions in the context of a ship 10 include a fin 17 on the ship's hull 11, as illustrated in FIG. 5, a welding seam 18a, 18b on the ship's hull 11, as illustrated in FIG. 6, and a protrusion (not shown) arranged to protect the light-emitting system 20 against impacts of external objects such as tree trunks floating in water. In all possible cases, it is desirable to realize an anti-biofouling effect on the entire surface, whatever shape the surface may have, and also on any protrusions. According to the invention, this is done by having at least one light-emitting group 22 of which the main direction of emission 23 is particularly towards a concavely or convexly curved area, or at a protrusion, which is to be understood so as to mean that at least a component of the main direction of emission 23 of the light-emitting group 22 is oriented so as to intersect the concavely or convexly curved area, or the protrusion. This is a local application of the invention in the sense that it suffices if only one or a limited number of light sources 21 in the vicinity of a concavely/convexly curved area or a protrusion is/are arranged so as to shine anti-biofouling light on the concavely/convexly curved area or protrusion while the other light sources 21 can be arranged so as to shine light in a direction as generally intended, such as a more or less horizontal direction.

[0050] In respect of the example of welding seams on a ship's hull 11, it is noted that it is possible for the welding seams to intersect. In FIG. 6, portions of two intersecting welding seams 18a, 18b of the hull 11 are shown. In order to enable an anti-biofouling action on both welding seams 18a, 18b, it is advantageous if a portion of the light-emitting system 20 located in the vicinity of the respective welding seams 18a, 18b comprises two light-emitting groups 22 of light sources 21, wherein the main direction of emission 23 of the one light-emitting group 22 is towards one of the welding seams 18a, 18b, while the main direction of emission 23 of the other light-emitting group 22 is towards the other of the welding seams 18a, 18b.

[0051] A notable aspect of the invention is the fact that the main directions of emission 23 of the various light-emitting groups 22 have different spatial orientations when viewed on an unfolded and flattened area of a main surface 11a, 11b of an object 10. When the light-emitting system 20 is seen in a condition in which at least a portion thereof is shaped so as to follow a main surface 11a, 11b, the orientations of the main directions of emission 23 of the light-emitting groups 22 of the at least a portion of the light-emitting system 20 are partially determined by the shape of the main surface 11a, 11b. FIG. 4 is related to FIG. 3 and serves to illustrate what it looks like when an imaginary unfolded and flattened condition of a main surface 11a, 11b is considered and it is assumed that a portion of the light-emitting system 20 is arranged on the main surface 11a, 11b in that particular condition, in which the influence of the shape of the main surface 11a, 11b on the main directions of emission 23 of the light-emitting groups 22 in the portion of the light-emitting system 20 is eliminated. In the two-dimensional depiction provided by FIG. 4 of the portion of the hull 11 and the portion of the light-emitting system 20 arranged on the portion of the hull 11, it can clearly be seen that the spatial orientations of the main directions of emission 23 of the light-emitting groups 22 are different.

[0052] It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details which are not required for understanding the invention may have been omitted, and not necessarily to scale.

[0053] Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word “comprising” does not exclude other steps or elements, and the indefinite article “a” or “an” does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0054] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0055] The term “comprise” as used in this text will be understood by a person skilled in the art as covering the term “consist of”. Hence, the term “comprise” may in respect of an embodiment mean “consist of”, but may in another embodiment mean “contain/include at least the defined species and optionally one or more other species”.

[0056] For the sake of completeness, it is noted that in the examples described on the basis of the figures, desired effects of i) avoiding at least to a considerable extent that anti-biofouling light reaches a location where human beings 5 and/or animals may be present and ii) providing deviations from a planar surface with a sufficient amount of anti-biofouling light are obtained on the basis of choosing a certain orientation of the main directions of emission 23 of the light-emitting groups 22 of light sources 21 which are included in the light-emitting system 20. This should not be understood so as to mean that the invention is limited to setting a main orientation of light to be emitted from the light-emitting system 20 during operation thereof by means of determining a certain orientation of the light emission axes of the light sources 21 of the light-emitting system 20. The fact is that in general, the invention is about realizing a main orientation of emission by making appropriate choices in respect of the design of the light-emitting system 20. This does not necessarily involve adapting the orientation of the light emission axes of the light sources 21 to certain requirements, although this is a practical option. An alternative or additional option is the option of taking measures which are aimed at determining the way in which light is outcoupled from the light-emitting system 20, which can be done, for example, by making appropriate choices in respect of a surface structure of a slab 24 of transparent material as may be part of the light-emitting system 20 at a light-emitting side thereof.

[0057] Notable aspects of the invention can be summarized as follows. In the context of anti-biofouling, an arrangement 1 is provided which comprises an object 10 and a light-emitting system 20 arranged on at least a main surface 11a, 11b of the object 10. The light-emitting system 20 includes a plurality of light sources 21 configured to emit anti-biofouling light in an activated state thereof. Further, the light-emitting system 20 is configured to emit the anti-biofouling light in a direction away from the object 10. The light sources 21 are arranged in the light-emitting system 20 in at least two different light-emitting groups 22, each light-emitting group 22 being configured to emit the anti-biofouling light in a respective main direction of emission 23 and the main directions of emission 23 of at least two light-emitting groups 22 having different spatial orientations when viewed on an unfolded and flattened area of the main surface 11a, 11b where the at least two light-emitting groups 22 are located. In this way, it is achieved that the area that is reached by the anti-biofouling light during operation of the anti-biofouling arrangement 1 can be adjusted to particular requirements, which may be requirements as to where the presence of anti-biofouling light should be avoided and/or requirements as to where the presence of anti-biofouling light should be ensured despite complicating factors such as structural irregularities.