WO2005007976A1

WO2005007976A1 - System for limitation of water pollution

Info

Publication number: WO2005007976A1
Application number: PCT/NL2004/000535
Authority: WO
Inventors: Anne Max Duursma
Original assignee: Max Cargo B.V.
Priority date: 2003-07-23
Filing date: 2004-07-23
Publication date: 2005-01-27
Also published as: EP1664443A1; NL1023983C2

Abstract

According to the present invention there is provided a system for limiting the spread of a contamination, such as an oil-slick, over a water surface. The system comprises at least one elongate, flexible curtain-like screen. The system further comprises, at least in use, a number of spreaders which can be or are fastened to the screen. In use the spreaders spread the curtain-like screen so that it extends partly above and partly below the surface of the surface water A system according to the invention can have a much lower weight than heretofore, and the utility and manoeuvrability are thereby improved. Because the weight of a screen can be much lower than that of previously used rigid and closed flaps or aprons, the buoyancy to be produced by floats no longer has to be so high either, and simple measures can be taken to bring about good stability to prevent the system tipping over.

Description

SYSTEM FOR LIMITATION OF WATER POLLUTION The present invention relates to a system for limiting the spread of a contamination such as oil over a water surface. Such systems are per se generally known, wherein a floating body is used which is oriented horizontally in use and a closed flap or apron is hung thereon which extends vertically in the surface of the water. The flap or apron serves to stop the spread of the contamination, and heretofore has always been given for this purpose a closed and considerably rigid form. In the known systems ballast weights can be suspended from the flap or the apron to make it extend downward. The known systems, and particularly those considered suitable for use in open sea, are very heavy, particularly due to the use and the weight of the closed, rigid, thick flaps or aprons and the buoyancy which has to be generated as a result by the floats. A weight of 40 kg per running metre is certainly not unusual. The buoyancy of the known systems is therefore also high, and a known system can have a buoyancy of at least 750 kg per running metre. The combination of weight and buoyancy does however result in the drawback that the stability of the known systems is extremely low, particularly under the influence of current and wave action. The known systems can hereby easily overturn or tip over and thereby immediately lose the intended functionality of stopping the spread of contamination. In addition, the high weight and large dimensions of the known systems are a considerable hindrance in setting out or taking these systems into use at the location of a contamination. In many countries this contravenes current legislation on working conditions and the permitted weight which may be handled by personnel. As a consequence complex installations are required on board ships used for setting out the known systems, but these are practically unavailable. The present invention has for its object to obviate, or at least alleviate, said drawbacks of the known art. A system is provided for this purpose which comprises: at least one elongate, flexible curtain-like screen; and with, at least in use, a number of spreaders which can be or are fastened to the screen, and which in use spread the curtain-like screen so that it extends partly above and partly below the upper surface of the surface water. A system according to the invention can have a much lower weight than heretofore, and the utility and manoeuvrability are thereby improved. Because the weight of a screen can be much lower than that of the previously used closed flaps or aprons, the buoyancy to be produced by floats no longer has to be so high either. In a particularly favourable embodiment, the system according to the invention can have the feature that the spreaders comprise floats. Because the spreaders form an integral part of the floats, and vice versa, a considerable simplification of systems according to the invention is realized compared to other embodiments, wherein individual new spreaders are arranged in addition to known floats. The spreaders are preferably inflatable, so that the systems for the purpose of transport thereof can be extremely compact. In the situation mounted on the screen, the spreaders preferably extend substantially transversely of the longitudinal direction of the screen. They then thus have a substantially vertical orientation, so that they react to wave action in a manner comparable to a buoy, which results in an advantageous stability. A weight can further be arranged on the side of at least some of the spreaders which is directed downward during use. The stability is hereby improved even further. The screen can be rolled up and rolled out. This results in advantageous manner in a configuration which is easy to transport and easy to bring into and take out of use. The screen preferably comprises a fine-mesh web for allowing through water and/or wind and for holding back contamination. This is a considerable contribution toward further weight reduction, and the stability is simultaneously increased because the elements, and in particular the wind, have no effect on the screen, or at least much less of one. The system preferably further comprises coupling means for mutually connecting at least two screens. The screens can thereby be easily coupled when being set out. At least some of the spreaders can herein comprise the coupling means. This is particularly advantageous in respect of the number of components in the system, since one spreader at a time can be arranged simultaneously on two screens so as to connect the two screens. In one embodiment with the spreaders fixed to a screen, the spreader can comprise or form the coupling means in each case on one outer end of the screen. The screen preferably further has sufficient strength to be towed through the water during use, for instance with a boat. It is thus possible to position and displace the screens accurately with the boat, and it is also possible here to displace the contamination so as to facilitate clearing thereof. The invention will be described hereinbelow in detail with reference to the annexed drawings which show a preferred embodiment of the invention, and in which: figure 1 shows a perspective view of the use of a system according to the present invention; and figure 2 shows a detail of figure 1.

Figure 1 shows a view of the manner in which a system 1 according to the invention is used in limiting the spread of a contamination, here an oil leakage 2 from a ship 3. A boat 4 is utilized here to place or position the system 1. Loaded onto boat 4 is a number of rolls 5 with an elongate, flexible, curtain-like screen 6. Spreaders 7 are pre-arranged on screen 6, or these spreaders are arranged on screen 6 when the screen is unrolled from rolls 5 for setting out thereof. Spreaders 7 serve in any case to hold the screen upright, with a part of the height thereof under the water surface 8 and the remaining part thereof above water surface 8, as shown in figure 2. Without spreaders 7 the screen 6 would not remain standing in the position shown in figure 2, because it is not sufficiently rigid to do so. This is because it is a curtain-like screen. Screen 6 is a fine-mesh web which can allow through wind and water and holds back thicker substances such as the oil pollution 2. Screen 6 is unrolled from boat 4 from one of the said rolls 5 and is strong enough to be towed through the water using the boat. Screen 6 is thus not only curtain-like and preferably a fine-mesh web, but is also made from a sufficiently strong material to enable it to be towed by boat 4. In the embodiment shown in figure 2, spreaders 7 are also floating bodies. These can be made from solid material with a sufficient buoyancy but, in order to save space during transport, spreaders 7 are preferably inflatable, although provisions are then necessary on boat 4 for inflating the spreaders 7. Spreaders 7, which spread screen 6 in substantially vertical direction, are provided for this purpose with inflating valves 8 which also serve for deflation of spreaders 7 after use. In order to enhance the stability of the system, weights 9 can be arranged on screen 6 or on (selected) spreaders, or be arranged when screen 6 is placed in the water. In the embodiment shown in figure 2, weights 9 are suspended from all spreaders 7 with a chain connection 10, but it will also be found possible to use any other type of connection. Figure 2 also shows that system 1 here comprises two screens 6 and 6'. The ends of screens 6 and 6' directed toward each other are arranged on one of the spreaders 7 with coupling means (not shown) , which spreader is also designated for distinguishing purposes with reference numeral 11. When spreaders 7 must be arranged on the screens during rolling out of screen 6 or 6', the coupling means can engage both screens 6 and 6' simultaneously. Alternatively, when spreaders 7 are already pre-arranged fixedly on the screens, a free end without a spreader 7 of one of the screens 6 and 6' can be connected to the spreader 7 on the outer end of the other of the screens 6 and 6¹ directed toward the one of the screens 6 and 6' using coupling means other than or possibly the same as those with which spreaders 7 are already fixedly pre-arranged on screens 6 and 6'. Now that in the foregoing a specific embodiment of a system according to the present invention has been described and shown in the annexed drawings, it must be noted that the invention is by no means limited to this explicit embodiment, but is on the contrary limited only by the definitions of the appended claims. Several alternatives to the specific features shown in the drawings have thus already been noted in the foregoing. Also added thereto here is that spreaders can also be used which have a horizontal orientation during use to spread the screens between the floats. The weights can be incorporated in the spreaders, for instance at the bottom of the interior of hollow inflatable floating bodies which also serve as spreaders. Weights can also be suspended from the underside of the screens themselves or be there incorporated in the screens themselves, for instance in the form of a plumb line. The coupling means can be formed in random manner, for instance as hooks, clamps, wires threaded through the web meshes from which the screens can be formed, etc. these coupling means do not therefore have to correspond with the spreaders and/or floats but may also be embodied separately thereof.

Claims

1. System for limiting the spread of a contamination such as oil over a surface water, comprising: at least one elongate, flexible curtain-like screen; and with, at least in use, a number of spreaders which can be or are fastened to the screen, and which in use spread the curtain-like screen so that it extends partly above and partly below the upper surface of the surface water.

2. System as claimed in claim 1, wherein the spreaders comprise floats.

3. System as claimed in claim 1 or 2, wherein the spreaders are inflatable.

4. System as claimed in claim 1, 2 or 3, wherein in the situation mounted on the screen, the spreaders extend substantially transversely of the longitudinal direction of the screen.

5. System as claimed in claim 4, wherein a weight is arranged on the side of at least some of the spreaders which is directed downward during use.

6. System as claimed in any of the foregoing claims, wherein the screen can be rolled up and rolled out.

7. System as claimed in claim 1 or 6, wherein the screen comprises a fine-mesh web for allowing through water and/or wind and for holding back contamination.

8. System as claimed in any of the foregoing claims, further comprising coupling means for mutually connecting at least two screens.

9. System as claimed in claim 8, wherein at least some of the spreaders comprise the coupling means.

10. System as claimed in any of the foregoing claims, wherein the screen has sufficient strength to be towed through the water during use, for instance with a boat.