FIELD OF THE INVENTION

The invention relates to a brush wheel, and particularly to a brush wheel for collecting oil from a surface of water. The present invention further concerns a method for collecting oil from a surface of water.

BACKGROUND OF THE INVENTION

A skimmer of a brush wheel type for collecting oil from a surface of water is disclosed for example in US 4555338 A, WO 2006/1 13784 A2 and WO 2007/059606 A1 .

A problem with the known brush wheels is that the oil collecting efficiency from water having blocks of ice floating on the surface of the water is poor because oil tend to stick to the blocks of ice and not to the bristles of the brush wheel.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a brush wheel and a method for collecting oil so as to solve the above problem.

The object of the invention is achieved by a brush wheel and a method for collecting oil which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on the idea of providing a brush wheel for collecting oil from a surface of water, the brush wheel comprising protrusions for contacting with ice floating on the surface of water and moving the ice in the direction of rotation when the brush wheel is rotated.

An advantage of the brush wheel of the invention is that the protrusions push the oily blocks of ice under the surface of water thus making the oil disengage the blocks of ice and gather on the surface of water. Then the oil floating on the surface of water can be collected to the bristles of the brush wheel and further to a waste oil container. Ability to collect oil from water having ice enables using the brush wheel in arctic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

Figure 1 is a schematic side view of a brush wheel according to an embodi- ment of the invention in operation; and

Figure 2 is a schematic cross section of a brush wheel according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a brush wheel for collecting oil from a surface of water, the brush wheel comprising an annular brush part 30 comprising bristles 31 extending away from the center of annulus 32 of the annular brush part 30, wherein the brush wheel further comprises protrusions 33 for contacting with ice floating on the surface of water and moving the ice in the direction of rotation R when the brush wheel is rotated.

In other words the brush wheel further comprises protrusions 33 for contacting with ice floating on the surface of water and pushing ice under the surface of water when the brush wheel is rotated. The brush wheel is rotated about the center of annulus 32 of the annular brush part 30. Preferably ice is in form of pieces of ice.

According to an embodiment at the protrusions 33 are arranged evenly along the perimeter of the annular brush wheel. Preferably the shape of the protrusion is such that the protrusions 33 are able to move the ice regardless of the direction of rotation R of the brush wheel. In other words the brush wheel can be used in oil collecting systems where the brush wheel is rotated in either di- rection.

Rotation of the brush wheel in direction opposite of the normal operation direction of rotation may be needed for cleaning the brush wheel.

According to an embodiment the protrusions 33 are pins arranged radially to the annular brush part 30.

According to an embodiment the annular brush part 30 comprises at least two annular brush sections 34 arranged coaxially. According to an embodiment the protrusions 33 are plate parts arranged between the annular brush sections 34. The annular plate parts can be attached to the frame 10, to the annular brush part 30 or to the annular brush sections 34.

According to an embodiment the annular brush part 30 comprises an annular plate 35 arranged between the annular brush sections 34, wherein the protru- sions 33 are comprised in the annular plate 35. Preferably the annular plate 35 comprises an outer edge extending away from the center of annulus 32 of the annular plate 35, and the outer edge is shaped so that protrusions 33 are provided to the annular plate 35. The annular plate 35 can be attached to the frame 10 or to the annular brush part 30.

According to an embodiment the annular brush part 30 comprises several annular brush sections 34 and several annular plates 35 arranged alternately between the annular brush sections 34.

Preferably the thickness of the plate parts or the annular plate 35 is such that the plate is able to withstand the contact with ice without permanent defor- mation. According to an embodiment the thickness of the plate parts or the annular plate 35 is 2 to 5 mm.

According to an embodiment the protrusions 33 extend 1 to 8 cm further from the center of annulus 32 of the annular brush part 30 than the bristles 31 . By extending further than the bristles 31 , the protrusions 33 protect the bristles 31 from the ice and are able to move the ice before the ice contacts the bristles 31 .

According to an embodiment the protrusions 33 are made from rubber or metal. According to an embodiment the protrusions 33 are made from steel. Preferably the pins are made from metal, such as steel.

According to an embodiment the brush wheel comprises heating means 40 for heating at least part of the brush wheel. According to an embodiment the brush wheel comprises heating means 40 for heating the protrusions 33. Heating the at least part of the brush wheel prevents accumulation of ice on the surfaces of the brush wheel.

According to an embodiment the brush wheel comprises a frame 10 and an axis 20 supporting the frame 10, wherein annular brush part 30 is supported by the frame 10 and arranged coaxially with the axis 20. The axis 20 is arranged concentric with the center of annulus 32 of the annular brush part 30 and the brush wheel is rotated about the axis 20. According to an embodiment the brush wheel comprises steam channeling means 41 for channeling steam via the axis 20 to the annular brush part 30. Steam generated outside the brush wheel is led through the steam channeling means 41 to the annular brush part 30. The steam channeling means 41 has at least partly been arranged inside the axis 20. In other words steam generated outside is fed through the axis 20 and the steam channeling means 41 to the annular brush part 30. Preferably the steam is arranged to heat the protrusions 33.

According to an embodiment the brush wheel comprises water channeling means 42 for channeling water from the annular brush part 30 via the axis 20. Water formed from melting ice is collected through the water channeling means 42 and led to outside of the brush wheel. The water channeling means 42 has at least partly been arranged inside the axis (20). In other words water formed from melting ice is collected through water channeling means 42 and led through axis 20 to outside of the brush wheel. Preferably the water collection is at least partly powered by a vacuum generated to the water channeling means 42.

The invention also relates to a method for collecting oil from a surface of water comprising ice, the method comprising

providing a brush wheel as defined above at least partly submerged in water;

rotating the at least partly submerged brush wheel;

pushing ice floating at least partly on the surface of water and contacting the brush wheel to under the surface of water using protrusions 33 comprised in the rotating brush wheel, for separating oil from ice to the surface of water; collecting oil to the bristles 31 of the rotating brush wheel; and

scraping oil from the bristles 31 of the rotating brush wheel.

According to an embodiment the method further comprises spraying water or steam on ice before pushing ice contacting the brush wheel under the surface of water. Spraying water or steam on ice improves separation of oil from the ice. Water can be sprayed on ice continuously, periodically or when required. According to an embodiment the method further comprises heating at least part of the brush wheel. According to an embodiment the method further comprises heating the protrusions 33.

The invention also relates to a method for collecting oil from a surface of water comprising ice, the method comprising

providing a brush wheel an annular brush part 30 comprising bristles 31 extending away from the center of annulus 32 of the annular brush part 30; and protrusions 33 for contacting with ice floating on the surface of water and moving the ice in the direction of rotation R when the brush wheel is ro- tated; wherein the brush wheel is at least partly submerged in water;

rotating the at least partly submerged brush wheel;

pushing ice floating at least partly on the surface of water and contacting the brush wheel to under the surface of water using protrusions 33 comprised in the rotating brush wheel, for separating oil from ice to the surface of water; collecting oil to the bristles 31 of the rotating brush wheel; and

scraping oil from the bristles 31 of the rotating brush wheel.

According to an embodiment the method further comprises spraying water or steam on the ice before pushing ice contacting the brush wheel under the surface of water.

According to an embodiment the method further comprises heating at least part of the brush wheel. According to an embodiment the method further comprises heating the protrusions 33.