EP3680164A1

EP3680164A1 - System and method for irradiating a surface with anti-biofouling light

Info

Publication number: EP3680164A1
Application number: EP19150784.7A
Authority: EP
Inventors: Roelant Boudewijn HIETBRINK; Eduard Matheus Johannes Niessen; Antonius Adrianus Petrus SCHUDELARO; Merijn Wijnen
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2019-01-08
Filing date: 2019-01-08
Publication date: 2020-07-15

Abstract

In the context of anti-biofouling, a system (1) is provided that is configured to emit anti-biofouling light to a surface (21). The system (1) comprises a radiation unit (10) including at least two light-emitting areas (34, 35) which are both/all configured to emit anti-biofouling light in an activated state thereof, wherein the arrangement of the at least two light-emitting areas (34, 35) with respect to each other in the radiation unit (10) is variable. In particular, the at least two light-emitting areas (34, 35) of the radiation unit (10) may be displaceable and/or reorientable with respect to each other. Consequently, it is possible to arrange the at least two light-emitting areas (34, 35) in such a way with respect to each other that the shape/contour of a surface (21) to be subjected to an anti-biofouling action can be followed, in an accurate/close fashion if so desired.

Description

FIELD OF THE INVENTION

In the first place, the invention relates to a system for irradiating a surface with anti-biofouling light, the system being configured to emit anti-biofouling light.
In the second place, the invention relates to a combination of a marine structure such as a ship and a system as mentioned, wherein the system has a function in irradiating at least a portion of an exterior surface of the marine structure, such as a ship's hull, with anti-biofouling light.
In the third place, the invention relates to a method for irradiating a surface with anti-biofouling light, comprising the steps of providing a radiation unit of the system as mentioned, positioning the radiation unit with respect to the surface, and operating the radiation unit so as to emit anti-biofouling light to at least a portion of the surface.
In the fourth place, the invention relates to a computer program product comprising code to cause a processor, when the code is executed on the processor, to execute the method as mentioned.

BACKGROUND OF THE INVENTION

Various structures that are temporarily or permanently exposed to an aqueous environment are prone to biofouling. For instance, in a marine environment (including both seawater and freshwater), ships, oil rigs, pipelines, support structures for sea-based wind turbines, structures for harvesting tidal/wave energy, etc. are subject to organisms growing on them, especially in areas that are temporarily or permanently exposed to water. As a result, the drag of ships increases, the moving of parts can be hampered, and filters can become clogged. In respect of the influence of biofouling on the drag of ships, it is noted that biofouling can involve an increase of up to 40% in fuel consumption.
In general, biofouling is the accumulation of microorganisms, plants, algae, small animals and the like on surfaces. According to some estimates, over 1,800 species comprising over 4,000 organisms are responsible for biofouling. Hence, biofouling is caused by a wide variety of organisms, and involves much more than an attachment of barnacles and seaweeds to surfaces. Biofouling is divided into micro fouling that includes biofilm formation and bacterial adhesion, and macro fouling that includes the attachment of larger organisms. Due to the distinct chemistry and biology that determine what prevents them from settling, organisms are also classified as being hard or soft. Hard fouling organisms include calcareous organisms such as barnacles, encrusting bryozoans, mollusks, polychaetes and other tube worms, and zebra mussels. Soft fouling organisms include non-calcareous organisms such as seaweed, hydroids, algae and biofilm "slime". Together, these organisms form a fouling community.
As mentioned in the foregoing, biofouling creates substantial problems. Various solutions have been developed to address these problems. For instance, robots exist that are designed to scrape biofouling from the hulls of vessels. Another solution involves irradiating a surface that is subject to biofouling with ultraviolet light. In general, ultraviolet light of type C, i.e. UV-C light, is known for being effective when it comes to anti-biofouling so that good results may be achieved.
KR20150015962A discloses a system that may be used for the purpose of irradiating a surface of a ship's hull with ultraviolet light. In an embodiment, the system comprises a movable radiation unit that includes a buoyant body for generating buoyancy, a propelling body mounted on the buoyant body for generating a driving force for moving the buoyant body, and a light-emitting part comprising a plurality of UV LEDs arranged on a substrate that is embedded in a transparent and fluid-tight cover. The dimensions of the light-emitting part are relatively small with respect to a ship's hull, and the movable radiation unit is moved around the hull so as to perform an anti-biofouling action on successive submerged portions of the hull. In the process, the radiation unit is moved through the water surrounding the hull at a close distance from the hull by means of the propelling body. It is possible for the radiation unit to be equipped with wheels, in which case the radiation unit can be made to contact the hull and to move along the hull by means of the wheels. The wheels are typically provided on the buoyant body so as to be outside of the light-emitting part of the radiation unit.
As mentioned, the dimensions of the light-emitting part of the movable radiation unit of the system known from KR20150015962A are relatively small with respect to a ship's hull. In this way, it is possible for the radiation unit to let the light-emitting part follow the generally curved shape/contour of the hull when the radiation unit is moved with respect to the hull. In principle, it is possible to use a larger light-emitting part, but in such a case, a situation in which certain sections of the light-emitting part are significantly closer to the hull than certain other sections of the light-emitting part cannot be avoided. Thus, when the dimensions of the light-emitting part would be chosen so as to be larger, an uneven distribution of anti-biofouling light on the hull would be obtained as a result thereof. However, when use is made of a light-emitting part that is small in comparison to the hull, it would be necessary to have more than one light-emitting part in the known system, which may necessitate having more than one radiation unit in the system, and/or to let the light-emitting part emit light of high intensity in order to achieve the anti-biofouling effects as desired to a sufficient extent.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an anti-biofouling system that is very well capable of performing an effective anti-biofouling action on a surface such as a ship's hull, and that is designed to alleviate the above-mentioned issue of needing to restrict the dimensions of a light-emitting part in order to avoid an uneven distribution of anti-biofouling light on the surface, so as to avoid an associated need to increase the number of light-emitting parts and/or the intensity of the light to be emitted to the surface for the purpose of guaranteeing the anti-biofouling effects as desired. In view thereof, the invention provides a system for irradiating a surface with anti-biofouling light, the system i) being configured to emit anti-biofouling light, and ii) comprising a radiation unit including at least two light-emitting areas which are both/all configured to emit anti-biofouling light in an activated state thereof, wherein the arrangement of the at least two light-emitting areas with respect to each other in the radiation unit is variable.
In general, a surface subject to biofouling is not necessarily entirely planar/flat, but may instead comprise planar/flat portions of different orientations, be curved in one or more directions, etc. According to the invention, a system that is configured to irradiate a surface with anti-biofouling light is equipped with a radiation unit in which at least two light-emitting areas are present, in a variable arrangement with respect to each other in the radiation unit. It may particularly be so that the at least two light-emitting areas of the radiation unit are displaceable and/or reorientable with respect to each other in the radiation unit, and the system may comprise means which are suitable for displacing and/or reorienting the light-emitting areas with respect to each other in the radiation unit so as to enable a situation in which a shape/contour of a surface to be irradiated with anti-biofouling light can be accurately followed, either in a stationary positioning or during movement of the system's radiation unit and the surface with respect to each other. Any suitable kind of mechanism may be provided for the purpose of setting the arrangement of the light-emitting areas of the radiation unit with respect to each other. Such a mechanism may be controlled on the basis of information about the surface's shape/contour, which information may be preprogrammed or obtained in real-time by means of a detection system.
The respective light-emitting areas of the radiation unit may be planar or have any other suitable shape. It may be practical for the radiation unit to comprise two slabs of transparent material and a number of discrete light sources embedded in each of the two slabs, each of the slabs having a light emission surface from which light is emitted when electric power is supplied to the light sources. According to the invention, it is advantageous if the two slabs of material are movable with respect to each other, so that it is possible to adapt the arrangement of the slabs with respect to each other for the purpose of closely following the shape/contour of a surface to be irradiated with anti-biofouling light.
The anti-biofouling light may be ultraviolet light, particularly ultraviolet light of the UV-C type, which does not imply that other types of anti-biofouling light are not covered by the invention as well. Further, any suitable type of light source may be used in the system according to the invention. For example, the light-emitting areas of the radiation unit can be associated with at least one layer of material that can be activated to emit light, or with at least one discrete light emitter such as an LED. In any case, in a general sense, it may be so that each of the at least two light-emitting areas is associated with at least one light source that is configured to generate anti-biofouling light to be emitted from the respective light-emitting area.
Examples of objects having surfaces to be subjected to an anti-biofouling action by means of the system according to the invention include ships and other vessels, marine stations, sea-based oil or gas installations, buoyancy devices, support structures for wind turbines at sea, structures for harvesting wave/tidal energy, sea chests, underwater tools, etc. In this respect, it is noted that the invention also relates to a combination of a marine structure such as a ship and the system according to the invention, wherein the system has a function in irradiating at least a portion of an exterior surface of the marine structure, such as a ship's hull, with anti-biofouling light. In general, it is noted that the invention is not only suitable to be applied in a context of objects for use in seawater, but involves advantages in respect of any object for use in any type of water that is known to contain biofouling organisms.
The at least two light-emitting areas of the radiation unit may be interconnected, wherein the light-emitting areas may be provided in a configuration in which they are adjacent to each other. As already mentioned in a general sense, the system according to the invention may comprise a mechanism that is configured to vary the arrangement of the at least two light-emitting areas of the radiation unit with respect to each other, which will hereinafter be referred to as position setting mechanism. For example, a position setting mechanism having arms may be used, wherein the arrangement of the light-emitting areas with respect to each other in the radiation unit is varied by moving at least one of the arms. Further, the system may comprise a displacement mechanism that is configured to move the at least two light-emitting areas of the radiation unit with respect to a surface. This option is particularly advantageous when the dimensions of an area composed of the light-emitting areas are (much) smaller than the dimensions of a surface to be irradiated with anti-biofouling light, as in such a case, coverage of the entire surface may be realized by moving the light-emitting units from one position with respect to the surface to another. It may be very practical if the entire radiation unit is movable with respect to the surface.
According to a feasible option, it may be so that at least the radiation unit comprises a flexible structure, wherein the at least two light-emitting areas of the radiation unit are areas of the flexible structure. Examples of a flexible structure include a foil, a net, and a flexible grid. The flexible structure may be designed so as to enable a situation in which the flexible structure is wrapped around at least a portion of the surface to be irradiated with anti-biofouling light. The flexible structure may have any suitable shape, such as the shape of a sheath, wherein it depends on the shape/contour of the surface with which the system according to the invention is to be used which shape of the flexible structure can actually be qualified as suitable. The system according to the invention may comprise a structure-shaping mechanism that is configured to flex the flexible structure so as to allow the flexible structure to follow a shape/contour of a surface, wherein the at least two light-emitting areas of the radiation unit may be areas of a piece of foil that is engaged by the structure-shaping mechanism, for example. Alternatively, the radiation unit may comprise a body that is configured to move along a surface by rolling on the surface, the flexible structure being included in the body. Such a radiation unit may generally be shaped like a ball, for example.
In case the radiation unit comprises a flexible structure, such a structure may alternatively be used for moving the at least two light-emitting areas of the radiation unit for the purpose of varying the arrangement of the at least two light-emitting areas with respect to each other in the radiation unit, namely by flexing whenever it is intended to realize another arrangement of the at least two light-emitting areas. It is practical if the flexible structure also has a function in supporting the least two light-emitting areas, so that there is no need for having a separate mechanism to that end. The at least two light-emitting areas may be of any suitable design and may be rigid.
According to another feasible option, it may be so that the radiation unit comprises at least two segments which are hingably connected to each other, wherein the at least two light-emitting areas of the radiation unit are areas of the respective at least two segments. The segments may be rigid and may be coupled to each other by means of flexible joints, for example. It may be very practical if the radiation unit comprises a plurality of the segments, and if the segments are arranged in a caterpillar track configuration. In such a case, the radiation unit may comprise a displacement mechanism that is configured to impose movement on the segments in the caterpillar track configuration so as to allow the radiation unit to contact a surface and to move along such a surface by means of the segments in the caterpillar track configuration.
In case it is desirable to have a certain distance between the respective at least two light-emitting areas of the radiation unit and a surface under all circumstances, so that direct contact between the light-emitting areas and the surface is avoided, it is advantageous if the system according to the invention comprises a distance guard that is configured to guarantee a minimum distance between the light-emitting areas and the surface. An advantage of having a certain distance between the light-emitting areas on the one hand and the surface on the other hand is that an area of the surface that is covered by the anti-biofouling light is larger than when the light-emitting areas are on or very close to the surface.
A distance guard for guaranteeing a minimum distance between the light-emitting areas on the one hand and the surface on the other hand may be included in the radiation unit. An example of such a distance guard includes at least one volume body such as an air-filled pocket or a silicone-filled pocket at an appropriate location on the radiation unit.
As suggested earlier, the system according to the invention may particularly be designed for use in an aqueous environment. It may therefore be advantageous if the system comprises a floatation device that is configured to allow at least the radiation unit to float in an aqueous environment, wherein the floatation device may comprise one or more floatation bodies, for example. By having a floatation device in the system, it is possible to put and keep the radiation unit at an appropriate place with respect to the surface or at least a portion thereof so as to allow the radiation unit to subject the surface or at least a portion thereof to an anti-biofouling action.
Further, the invention relates to a method for irradiating a surface with anti-biofouling light, comprising the steps of providing a radiation unit of the system according to the invention, i.e. the system comprising the radiation unit including the at least two light-emitting areas which can be put in different arrangements with respect to each other, positioning the radiation unit with respect to the surface, and operating the radiation unit so as to emit anti-biofouling light from the at least two light-emitting areas thereof to at least a portion of the surface, wherein the step of positioning the radiation unit with respect to the surface comprises setting the arrangement of the at least two light-emitting areas with respect to each other in the radiation unit in dependency of a shape/contour of the at least a portion of the surface.
Still further, the invention relates to a computer program product comprising code to cause a processor, when the code is executed on the processor, to execute the method as defined and described in the preceding paragraph. Hence, one aspect of the operation of the processor is setting the arrangement of the at least two light-emitting areas with respect to each other in dependency of a shape/contour of a surface to be irradiated with anti-biofouling light.
The above-described and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of embodiments of a system comprising a radiation unit including at least two light-emitting areas which are both/all configured to emit anti-biofouling light in an activated state thereof, wherein the arrangement of the at least two light-emitting areas with respect to each other in the radiation unit is variable. The description of the various embodiments is in the context of subjecting a ship's hull to an anti-biofouling action. Particulars of these embodiments are disclosed and explained for the purpose of enhancing understanding of the invention; in no way is the invention limited to these embodiments. The ship's hull is one out of many possible examples of a surface to be subjected to an anti-biofouling action with anti-biofouling light.

BRIEF DESCRIPTION OF THE DRAWINGS

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 shows a front view of a radiation unit of a system according to a first embodiment of the invention,
Fig. 2 diagrammatically shows a side view of the radiation unit shown in Fig. 1,
Fig. 3 illustrates how the radiation unit shown in Figs. 1 and 2 is used for the purpose of subjecting submerged portions of a ship's hull to an anti-biofouling action,
Fig. 4 illustrates basic aspects of the design of a radiation unit of a system according to a second embodiment of the invention,
Fig. 5 illustrates basic aspects of the design of a radiation unit of a system according to a third embodiment of the invention,
Fig. 6 illustrates basic aspects of the design of a radiation unit of a system according to a fourth embodiment of the invention, and
Fig. 7 illustrates basic aspects of the design of a radiation unit of a system according to a fifth embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention is in the context of anti-biofouling, and Figs. 1-3 relate to a system 1 according to a first embodiment of the invention, which is particularly designed to subject a submerged surface to an anti-biofouling action in order to avoid formation of biofouling deposits on the surface. In Figs. 1 and 2, a front view and a side view, respectively, of a radiation unit 10 of the system 1 are shown, in a diagrammatic fashion. Fig. 3 serves to illustrate use of the system 1 with a ship 20 for the purpose of irradiating portions of the ship's hull 21, wherein both the radiation unit 10 and the ship 20 are shown in a simplified fashion, and wherein the radiation unit 10 is shown at two possible positions with respect to the ship 20. For the sake of illustration, the radiation unit 10 is shown at a larger scale than the ship 20.
The radiation unit 10 of the system 1 is designed so as to be movable through water. The radiation unit 10 comprises a floatation body 11 and a propelling mechanism 12 arranged on the floatation body 11. Within the framework of the invention, instead of the floatation body 11 and the propelling mechanism 12 as shown, other mechanisms may be used for enabling the radiation unit 10 to move through water and to float in the water at a certain position with respect to the ship 10 for a certain period of time before moving on to another position. Further, the radiation unit 10 comprises two segments 31, 32 which are hingably connected to each other. Each of the segments 31, 32 includes a number of light sources 33 which are configured to generate anti-biofouling light in an active state thereof. In the following, it is assumed that the light sources 33 are UV-C LEDs, which does not alter the fact that other suitable types of light source may be used as well. Each of the segments 31, 32 comprises a light-emitting area 34, 35 that is associated with the UV-C LEDs 33 and that is thereby configured to emit UV-C light during operation of the UV-C LEDs 33. The segments 31, 32 may comprise material that is transparent to the UV-C light and that may have a structural function in embedding the light sources 33, for example, or supporting the light sources 33 in another way. A practical example of the transparent material is a silicone material. For the purpose of providing the UV-C LEDs 33 with the necessary power, any suitable type of power source or power generating arrangement may be used in the system 1. For example, it may be practical to have a battery pack in the radiation unit 10.
The assembly of the two segments 31, 32 is hingably connected to the floatation body 11. The radiation unit 10 is equipped with a position setting mechanism 40 for varying the orientation of the segments 31, 32 with respect to the floatation body 11 and with respect to each other. The position setting mechanism 40 may be designed to act at the position of the hinge between the segments 31, 32 and the hinge between the floatation body 11 and the assembly of the segments 31, 32 and/or to act at the position of the segments 31, 32. For example, as can be seen in Fig. 2, the position setting mechanism 40 may comprise extendable and retractable arms 41, 42 engaged with the respective segments 31, 32, the arms 41, 42 extending from a support 43 that is fixedly connected to the floatation body 11. In any case, in the shown example, it is possible to vary the orientation of the segments 31, 32 with respect to each other, and to also with respect to the floatation body 11. On the basis thereof, it is possible to adapt the orientation of the segments 31, 32 and thereby the orientation of the light-emitting areas 34, 35 in dependence on the shape/contour of the hull 21 so as to have high anti-biofouling effectiveness on the hull 21 by limiting variation of the traveling distance of the anti-biofouling light and ensuring that the traveling distance is generally shorter than an acceptable maximum.
Operation of the system 1 involves moving the radiation unit 10 towards the hull 21, activating the UV-C LEDs 33, putting the radiation unit 10 in the vicinity of a portion of the hull 21 with the light-emitting areas 34, 35 facing the hull 21, and adjusting the orientation of the segments 31, 32 if necessary to enable the light-emitting areas 34, 35 to follow the shape/contour of the portion of the hull 21 as close as possible. In this respect, it is noted that at the left side of Fig. 3, the radiation unit 10 is shown at a position where the hull 21 has a substantially vertical orientation, whereas at the right side of the figure, the radiation unit 10 is shown at a position where the hull is partially vertical and partially inclined with respect to the vertical. Fig. 3 serves to illustrate how the configuration of the radiation unit 10 can be adapted to the appearance of a local portion of the hull 21. At the left side of Fig. 3, the radiation unit 10 is shown in a condition in which both segments 31, 32 are held in a substantially vertical orientation, and at the right side of Fig. 3, the radiation unit 10 is shown in a condition in which the segment 31 that is directly connected to the floatation body 11 is held in a substantially vertical orientation while the other segment 32 is held in an orientation that is inclined with respect to the vertical. It is clear that if the segments 31, 32 would not be reorientable with respect to each other, it would not be possible to have high effectiveness of the anti-biofouling action by closely following the shape/contour of the hull 21 at all positions on the hull 21, so that other measures would need to be taken, such as increasing light intensity or reducing size of the area from which anti-biofouling light is emitted.
It is practical if the system 1 comprises a processor (not shown) for controlling i) movement and positioning of the radiation unit 10 with respect to the hull 21, so that the radiation unit 10 may follow a track for eventually covering the entire submerged portion of the hull 21, i.e. the portion of the hull 21 that is prone to biofouling, and ii) the orientation of the light-emitting areas 34, 35 through orientation of the segments 31, 32. In the shown example, the first control aspect can be achieved when the processor is configured to control operation of the propelling mechanism 12, and the second control aspect can be achieved when the processor is configured to control operation of the position setting mechanism 40 for varying the orientation of the segments 31, 32 with respect to the floatation body 11 and with respect to each other. The system 1 may further comprise a detection system (not shown) for providing the controller with information about the local appearance of the hull 21 at the position of a portion that is faced by the light-emitting areas 34, 35, and possibly other information that may be useful for the purpose of operating the system 1 such that the radiation unit 10 is moved around the hull 21 in an efficient manner and the light-emitting areas 34, 35 are made to closely follow the shape/contour of the hull 21 in the process.
A combination of a processor and a detection system may also be used for maintaining a certain minimum distance between the radiation unit 10, particularly the respective light-emitting areas 34, 35 thereof, and the hull 21. Alternatively, or additionally, the radiation unit 10 may be equipped with a mechanical mechanism that is configured to guarantee a minimum distance between the respective light-emitting areas 34, 35 of the radiation unit 10 and the hull 21. In this respect, an option of having pockets 13 filled with a suitable medium such as air or silicone at appropriate places on the radiation unit 10 is illustrated in Figs. 1 and 2.
In general, it may be advantageous for the radiation unit 10 of a system according to the invention that is intended to be used in an underwater environment to include one or more floatation bodies 11. The option of having at least one floatation body 11 is therefore applicable to the systems 2, 3, 4, 5 to be discussed in the following with reference to Figs. 4, 5, 6 and 7, respectively, although this is not explicitly/separately shown in those figures.
Fig. 4 relates to a system 2 according to a second embodiment of the invention. In the figure, a local outline of a portion of a ship's hull 21 is diagrammatically shown. Further, a radiation unit 10 of the system 2 is diagrammatically shown. The radiation unit 10 is designed so as to be movable on the hull 21 and is provided with wheels 14 to that end. For the purpose of imposing movement on the radiation unit 10, a propelling mechanism 12 as shown in respect of the system 1 according to the first embodiment of the invention may be used, but alternatively, or additionally, it is also possible for the radiation unit 10 to include a motor for making the wheels 14 rotate, for example. The radiation unit 10 comprises a flexible piece of foil 36 and a position setting mechanism 40 for holding the piece of foil 36. The flexible piece of foil 36 is designed to emit anti-biofouling light and may include or be associated with one or more light sources (not shown).
When the system 2 is used for the purpose of subjecting the hull 21 to an anti-biofouling action, the light sources are activated and the radiation unit 10 is rolled over the hull 21 so as to move from one portion of the hull 21 to another. In the process, the piece of foil 36 is flexed according to the shape/contour of the hull 21, so that the anti-biofouling action is performed in the most effective fashion. Thus, during operation of the system 2, various portions of the flexible piece of foil 36 are moved with respect to each other as necessary for adapting the appearance of the piece of foil 36 to the shape/contour of the hull 21 each time the radiation unit 10 has moved to a new portion of the hull 21.
The position setting mechanism 40 as used for holding the piece of foil 36 may be of any suitable design. It may be advantageous if during operation, the flexible piece of foil 36 is held against the portions of the hull 21 to be irradiated with the anti-biofouling light, so as to contact those portions in their entirety. In such a case, the appearance of the flexible piece of foil 36 is adapted to the shape/contour of a portion of the hull 21 that is faced by the piece of foil 36 simply by placing the piece of foil 36 against the portion. Nevertheless, within the framework of the invention, it is also possible that the flexible piece of foil 36 is held at a distance from the hull 21 at all times, and that the position setting mechanism 40 is controlled to act on the piece of foil 36 so as to let the piece of foil 36 follow the shape/contour of the respective portions of the hull 21, which does not necessarily need to take place in the most accurate fashion but rather on the basis of general shape/contour aspects of the hull 21 in order to save on control power.
For the sake of completeness, it is noted that the concept of having a flexible piece of foil 36 and adapting the appearance of the piece of foil 36 to a local shape/contour of the hull 21, either by placing the piece of foil 36 against the hull 21 or by manipulating the foil 36 while keeping the foil 36 at a distance from the hull 21, is independent of the measures aimed at enabling movement of the radiation unit 10 with respect to the hull 21. For example, it is not necessary for the radiation unit 10 to be equipped with wheels 14. In case the position setting mechanism 40 that is used for holding the flexible piece of foil 36 is actively controlled in the process of setting the appearance of the piece of foil 36, it may be advantageous to apply both a processor and a detection system, wherein the detection system may be used for providing the processor with relevant information.
Fig. 5 relates to a system 3 according to a third embodiment of the invention. In the figure, a radiation unit 10 of the system 3 is diagrammatically shown. The radiation unit 10 is generally shaped like a cylinder having a substantially circular circumference and includes a flexible sleeve of foil 36 and a body 44 having two interconnected end pieces arranged on opposite sides of the sleeve of foil 36, an structure for interconnecting the end pieces extending through the interior space of the sleeve of foil 36. During operation of the system 3, anti-biofouling light is emitted from the radiation unit 10 at the position of the flexible sleeve of foil 36.
The radiation unit 10 may comprise a plurality of light sources 33, in which case the flexible sleeve of foil 36 can be associated the light sources 33. In this respect, it is noted that it is not necessary that light sources 33 are arranged so as to cover the entire flexible sleeve of foil 36. If the anti-biofouling light is generated in an interior unit that is dimensioned to cover the entire length of the flexible sleeve of foil 36 and only a portion of the periphery of the sleeve of foil 36, it is advantageous if such a unit is arranged in the radiation unit 10 so as to be movable with respect to the sleeve of foil 36. By having a relatively small interior unit for generating the anti-biofouling light, less power is needed for operating the system 3.
The radiation unit 10 is designed so as to be capable of rolling over the hull 21 during operation. In the process, the flexible sleeve of foil 36 is locally flexed upon encountering the hull 21 in the rolling movement of the radiation unit 10, whereby the sleeve of foil 36 is enabled to closely contact the hull 21. Within the framework of the invention, the system 3 may comprise any suitable type of mechanism for the purpose of imposing the movement as desired on the radiation unit 10.
Fig. 6 relates to a system 4 according to a fourth embodiment of the invention. In fact, Fig. 6 illustrates an alternative to the use of the flexible piece of foil 36 explained earlier with reference to Fig. 4. Instead of the flexible piece of foil 36, it is possible to use a chain-like arrangement 37 made up of a number of segments 45 which are hingably connected to each other, and which are held in an appropriate position setting mechanism 40. The segments 45 may be rigid. In any case, each segment 45 has a light-emitting area 38 for facing the hull 21.
During operation, the radiation unit 10 is moved with respect to the hull 21, and the orientation of the segments 45 with respect to each other is adapted to local shape/contour aspects of the hull 21. As is the case with the flexible piece of foil 36, this may be done either by letting the segments 45 contact the hull 21, in which case the orientation of the respective segments 45 is dictated by the hull 21, or controlling the position setting mechanism 40 to vary the orientation of the respective segments 45 so as to have a configuration of the chain-like arrangement 37 that involves high effectiveness of an anti-biofouling action to be performed on the hull 21, for various positions on the hull 21.
Fig. 7 relates to a system 5 according to a fifth embodiment of the invention. In fact, Fig. 7 illustrates a very advantageous configuration of the chain-like arrangement 37 shown in Fig. 6, namely a configuration in which the chain-like arrangement 37 is shaped like a closed loop, whereby use of the chain-like arrangement 37 as a caterpillar track is enabled. In this way, a compact and robust radiation unit 10 is obtained, which is designed to move over the hull 21 by means of the chain-like arrangement 37 in the caterpillar track configuration. The fact that the chain-like arrangement 37 does not only have a function in imposing movement on the radiation unit 10 but also includes light-emitting areas 38 is an advantageous concept in the context of the invention. In the system 5, any suitable type of mechanism may be used to drive the chain-like arrangement 37, which may in practical cases comprise driven caterpillar track wheels 46.
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.
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.
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.
The terms "comprise" and "include" 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" or "include" may in respect of an embodiment mean "consist of', but may in another embodiment mean "contain/have/be equipped with at least the defined species and optionally one or more other species".
Notable aspects of the invention can be summarized as follows. In the context of anti-biofouling, a system 1, 2, 3, 4, 5 is provided that is configured to emit anti-biofouling light to a surface 21. The system 1, 2, 3, 4, 5 comprises a radiation unit 10 including at least two light-emitting areas 34, 35, 38 which are both/all configured to emit anti-biofouling light, wherein the arrangement of the at least two light-emitting areas 34, 35, 38 with respect to each other in the radiation unit 10 is variable. In particular, the at least two light-emitting areas 34, 35, 38 of the radiation unit 10 may be displaceable and/or reorientable with respect to each other. In the system 1, 2, 3, 4, 5 according to the invention, it is possible to arrange the at least two light-emitting areas 34, 35, 38 in such a way with respect to each other that the shape/contour of a surface 21 to be subjected to an anti-biofouling action can be followed, in an accurate/close fashion if so desired, so that effectiveness of an anti-biofouling action on a surface 21 does not need to be lower in cases of surfaces which are not entirely planar/flat, wherein particularly light intensity does not need to be increased in such cases.

Claims

System (1, 2, 3, 4, 5) for irradiating a surface (21) with anti-biofouling light, the system (1, 2, 3, 4, 5) being configured to emit anti-biofouling light, and comprising a radiation unit (10) including at least two light-emitting areas (34, 35, 38) which are both/all configured to emit anti-biofouling light in an activated state thereof, wherein the arrangement of the at least two light-emitting areas (34, 35, 38) with respect to each other in the radiation unit (10) is variable.
System (1, 2, 3, 4, 5) according to claim 1, wherein the arrangement of the at least two light-emitting areas (34, 35, 38) with respect to each other in the radiation unit (10) being variable comprises the at least two light-emitting areas (34, 35, 38) being displaceable and/or reorientable with respect to each other in the radiation unit (10).
System (1, 2, 3, 4, 5) according to claim 1 or 2, wherein the at least two light-emitting areas (34, 35, 38) of the radiation unit (10) are interconnected.
System (1, 2, 3, 4, 5) according to any of claims 1-3, comprising a position setting mechanism (40) that is configured to vary the arrangement of the at least two light-emitting areas (34, 35, 38) of the radiation unit (10) with respect to each other.
System (1, 2, 3, 4, 5) according to any of claims 1-4, comprising a displacement mechanism (12, 14, 37) that is configured to move the at least two light-emitting areas (34, 35, 38) of the radiation unit (10) with respect to a surface (21).
System (2, 3) according to any of claims 1-5, wherein at least the radiation unit (10) comprises a flexible structure (36), and wherein the at least two light-emitting areas (34, 35, 38) of the radiation unit (10) are areas of the flexible structure (36).
System (2) according to claim 6, comprising a structure-shaping mechanism (40) that is configured to flex the flexible structure (36) so as to allow the flexible structure (36) to follow a shape/contour of a surface (21).
System (3) according to claim 6, wherein the radiation unit (10) comprises a body (44) that is configured to move along a surface (21) by rolling on the surface (21), and wherein the flexible structure (36) is included in the body (44).
System (1, 4, 5) according to any of claims 1-5, wherein the radiation unit (10) comprises at least two segments (31, 32, 45) which are hingably connected to each other, and wherein the at least two light-emitting areas (34, 35, 38) of the radiation unit (10) are areas of the respective at least two segments (31, 32, 45).
System (5) according to claim 9, wherein the radiation unit (10) comprises a plurality of the segments (45), and wherein the segments (45) are arranged in a caterpillar track configuration.
System (1, 2, 4) according to any of claims 1-10, comprising a distance guard (13) that is configured to guarantee a minimum distance between the respective at least two light-emitting areas (34, 35, 38) of the radiation unit (10) and a surface (21).
System (1) according to any of claims 1-11, comprising a floatation device (11) configured to allow at least the radiation unit (10) to float in an aqueous environment.
Combination of a marine structure such as a ship (20) and a system (1) according to any of claims 1-12, wherein the system (1) has a function in irradiating at least a portion of an exterior surface of the marine structure, such as a ship's hull (21), with anti-biofouling light.
Method for irradiating a surface (21) with anti-biofouling light, comprising the steps of providing a radiation unit (10) of the system (1, 2, 3, 4, 5) according to any of claims 1-12, positioning the radiation unit (10) with respect to the surface (21), and operating the radiation unit (10) so as to emit anti-biofouling light from the at least two light-emitting areas (34, 35, 38) thereof to at least a portion of the surface (21), wherein the step of positioning the radiation unit (10) with respect to the surface (21) comprises setting the arrangement of the at least two light-emitting areas (34, 35, 38) with respect to each other in the radiation unit (10) in dependency of a shape/contour of the at least a portion of the surface (21).
Computer program product comprising code to cause a processor, when the code is executed on the processor, to execute the method according to claim 14.