The present invention relates to reducing level variations of water surface in conjunction with a water intake opening of oil collecting equipment and, particularly, to reducing the influence of waves that have on influence on the water intake opening of a floating vessel or device.

Known in prior art oil collecting equipments there are solutions in which oil mixed up with water is conveyed through the water intake opening of the vessel to the collecting equipment. The collecting equipment acts to separate the oil from the water, and thereafter the water is removed from the vessel through an outlet opening.

In practice, the influence of waves, that is to say the level variations of water surface, has, however, proven problematic. In order that the amount of oil recovered by a collecting device would be as big as possible, the stream of water from the water intake opening to the collecting equipment should be as smooth as possible.

Known from GB publication 1 441 281 is a non-return valve whose curved shutter member disposed in a container is made of a floating material, and thus moves in dependence on the fluid level. However, this kind of structure is not functional, for example, to reduce the influence of waves.

Known in prior art from GB publication 2 075 855 is also a device for recovering oil from the water surface. However, this solution lacks the shutter member, which is why the solution is not suited, for example, for reducing the influence of waves.

Still, a float controlled shutter valve for oil skimming equipment is disclosed in GB 1 450 111 A.

It is an objective of this invention to solve the problem referred to above and to provide a regulator having as simple and reliable a structure as possible and enabling compensation of the level variations of water surface in conjunction with the water intake opening. This goal is achieved by the regulator as defined in independent claim 1.

The invention utilizes a float that floats together with the water surface and regulates the shutter member by the effect of the level variations of water surface. This enables one to achieve a smooth stream of water from the water intake opening using relatively cost-effective and simple equipment.

In the regulator of the invention, the float uses two parts arranged one upon the other at a distance from each other, the slit between them forming a flow path to the water intake opening. As in a structure like this, the float is arranged to be buoyant in such a depth that just the upper part thereof is partly above water level, a surface layer of certain thickness can be separated from the wavy water and introduced into the water intake opening. This kind of structure is very advantageous in conjunction with an oil collector because in practice, the oil to be collected is concentrated specifically in the surface layer.

In one preferred embodiment of the regulator of the invention, rotatable cylinders are used as parts of the float that are rotated in opposite directions so that the water that comes into contact with the cylinder surfaces flows though the opening between the cylinders toward the flow-through opening. A solution of this kind makes the separation and recovery of the surface layer even more effective than before.

Preferred embodiments of the regulator of the invention are apparent from attached dependent claims 2 - 9.

In the following section, the invention will be described by way of example in greater detail with reference to the attached drawings, in which

• Fig. 1 illustrates a first preferred embodiment of the regulator of the invention; and
• Figs. 1 - 4 illustrate the regulator of Fig. 1 in operation.

Fig. 1 illustrates the first preferred embodiment of the regulator 1 of the invention. In the embodiment as shown in Fig. 1, the regulator 1 is attached to an enclosure 2 that can be attached to the hull of a vessel. In that case, the water flows through the regulator into the enclosure 2 via the open front wall thereof, and further through an opening 3 in the enclosure 2 into the vessel via the water intake opening disposed in the hull of the vessel. Therefore, for example, during oil spill response, it is possible to supply the oil-water mixture floating on the water surface to the oil collector arranged inside the hull of the vessel.

The regulator includes a float 4, which in the embodiments of the figures consists of two parts 5 and 6, which in this example both consist of cylinders. Each cylinder can be one-piece, or alternatively consist of several "discs" connected to one another. The cylinders 5 and 6 are arranged one upon the other along parallel axes. The horizontal axes of rotation of the cylinders are mounted with bearings 7 on the end pieces 8 arranged at the opposite ends of the cylinders.

In the embodiments of the figures, the end pieces 8 consist of plates that have been pivotally connected 9 to the enclosure 2. Due to the hinges 9, the cylinders 5 and 6 of the float 4 can move vertically with respect to the enclosure 2 as the water level varies. The cylinders 5 and 6 and the end plates 8 define between them a flow channel through which the water can flow into the enclosure 2 via the nearly wholly open front wall thereof and further from the enclosure via the opening 3 into the water intake opening of the vessel.

The regulator 1 shown in Fig. 1 is designed to be used specifically for conveying water to the water intake opening of an oil collector mounted within the hull of a vessel. In that case it is preferred that the float truly consists of two parts, whereby the float 4 can be so dimensioned that it is floating in a desired depth and "skims" a layer of certain thickness from the water surface to be conveyed to the water intake opening. In such an application, it is also preferred that the parts specifically consist of the cylinders 5 and 6 as shown in the figures, which can be rotated into opposite directions so that the water-oil mixture that comes into contact with them flows toward the water intake opening. In other connections in which it suffices that the float solely moves the shutter member of the regulator 1 it is possible to use a one-piece float that also in this case can consist of a rotatable cylinder.

Figs. 2 - 4 illustrate the regulator 1 of Fig. 1 in operation, whereby the enclosure 2 is shown sectioned. The figures show the operation of the regulator as the water level varies by the effect of waves so that in the situation of Fig. 2, the regulator is disposed on a wave crest; in the situation of Fig. 3 in the middle depth; and in the situation of Fig. 4 on a wave trough.

The float 4 has been so dimensioned that during use the lower cylinder 6 remains underneath the water surface and about a fourth of the upper cylinder 5 is disposed underneath the water surface. In Figs. 3 - 5, the water surface is depicted with a line 13. By the effect of waves, the water level varies, whereby the float 4 moves vertically. This is made possible by the hinges 9 between the end pieces 8 and the enclosure 2, about which hinges the end pieces turn together with the float 4.

Connected to the end pieces 8 is also a shutter member 11 disposed between the upper cylinder 5 and the enclosure 2, consisting of a plate in this embodiment. The aforementioned shutter member 11 moves vertically together with the end pieces. In conjunction with the wave crest as shown in Fig. 2, as well as in conjunction with the middle depth as shown in Fig. 3, the shutter member 11 is disposed in such a place that from underneath thereof, between the cylinders 5 and 6, water can flow into the enclosure 2 via an opening 14 and further via the opening 3 into the water intake opening. In connection with the wave trough as shown in Fig. 4, the shutter member 11 has, however, moved downward to such an extent that its lower edge has reached the wall 12 arranged in the lower edge of the opening 14 of the enclosure. In that case, the shutter member 11 and the front edge 12 together shut the flow path. In this manner, backflow from the enclosure is prevented.

In conjunction with oil spill response it is especially important that the backflow from the water intake opening is prevented. Thus, the shutter member should prevent at least this kind of backflow possibly occurring on the wave trough. Excessive stream of water on the wave crest can also impede the operation of the collector, but it is, however, not so harmful as the backflow. To provide a more uniform stream, it is preferable to manufacture the enclosure as shown in the figures so as to be as big as possible in capacity so that the amount of water will suffice also during that time when the shutter member 11 has shut the flow path to the water intake opening.

The regulator 1 includes an engine or engines that are used to rotate the cylinders 5 and 6 into opposite directions during use. This has been illustrated by arrows in Figs. 2 - 4. Thus, water flows via the opening defined in the vertical direction by the cylinders toward the opening 14 of the enclosure 2. The regulator 1 also includes scrapers 15 that are in contact with the surface of the cylinders, or at least very close to their surface, and thus due to the rotating movement of the cylinders, the scrapers remove the dirt that stuck to the surface of the cylinders.

In the above figures one has by way of example supposed that the regulator has been arranged in conjunction with a separate enclosure, from which water is introduced via the water intake opening of the vessel to the oil collecting equipment installed in the hull of the vessel. However, the regulator of the invention can also be utilized in other connections, for example, so that there is no separate enclosure; instead the regulator has been arranged directly in conjunction with the water intake opening. In that case, a water intake opening of a vessel or e.g. the water intake opening of a self-floating oil combating device can come into question.

It must be understood that the above description and the figures relating to it are only intended to illustrate the present invention. Various variations and modifications of the invention will be apparent to a person skilled in the art without departing from the scope of the invention said down by appended claims.