GB2206814A

GB2206814A - Oil skimmers

Info

Publication number: GB2206814A
Application number: GB08713584A
Authority: GB
Inventors: Michael Charles Foulds
Original assignee: Vikoma International Ltd
Current assignee: Vikoma International Ltd
Priority date: 1987-06-10
Filing date: 1987-06-10
Publication date: 1989-01-18
Also published as: GB8713584D0

Abstract

An oil skimmer comprises a rotary shaft 2 carrying oil-collecting discs 3, 4, 5 and scrapers (not shown) which remove oil from the discs. To assist flow of floating oil 7 towards the discs, impeller blades 8,9 are provided on the shaft and/or on the discs. In Figs. 3 to 5 the blades bridge the gap between two adjacent discs. <IMAGE>

Description

OIL SKIMMERS The invention relates to oil skimmers.

Various kinds of oil skimmer have been widely used for picking up oil from the surface of water. Among the most effective of such oil skimmers are those of the rotating disc and scraper kind wherein a disc, which is probably one of a plurality of discs, is rotated about a horizontal axis and is immersed in the oil coated water for a portion of its diameter. Oil on the surface of the water engages and clings to the side faces of the disc, is lifted clear of the water by the rotation of the disc and is removed from the disc by scrapers which bear against the side surfaces of the disc. The scrapers may for example guide the oil scraped off the disc to a removal trough. The water may for example be open water, such as a sea or estuary, or may be provided in a container, for example, in a factory or refinery.If the water is open then the discs may be supported thereon by floats, if it is provided in a container then the liquid level in the container may be controlled by floats and the discs supported at a set position with respect to the container.

Our British patent 1 554 458 discloses an oil pick-up device having at least three sets of discs with each set comprising at least three discs each of which is associated with a scraper or scrapers with each of the sets being mounted on a separate, straight, rotatable shaft, all the shafts lying substantially in a single plane and defining a substantially closed area and the rotation of the discs causing oil adhering to the discs to be transported into the closed area.

One problem which can arise in the use of rotating disc oil skimmers is that of bringing the oil into juxtaposition with the discs so that it can adhere thereto. Generally where the oil exists as a continuous layer on the surface of the water it will be drawn towards the discs by removal of oil in contact with the discs but particularly where the oil is in isolated patches it may not adequately be drawn towards the discs.

According to the invention in a rotating disc oil skimmer means are provided to cause movement of oil on the surface of water towards a disc or discs of the skimmer.

Such means may comprise impeller means which are rotated by rotation of a shaft on which the disc or discs are mounted. The impeller means may comprise blades mounted on the shaft and/or impeller members secured to the side faces of the disc or discs.

The blades and/or impeller members are preferably so dimensioned and positioned that in operation of the device radially outer portions of the blades or impeller members are, upon rotation of the shaft, caused to be submerged a small distance into the oil floating on the surface of the water.

Thus the blades or impeller members act at and just below the surface of the oil coated water.

In one particularly advantageous embodiment of the invention the discs are provided as pairs of discs slightly spaced apart with the blades or impeller members bridging between the two discs of the pair adjacent a shaft on which the discs are mounted.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Figure 1 is an elevation of one embodiment of a disc skimmer according to the invention; Figure 2 is a sectional view taken on line II-II of Figure 1; and Figures 3, 4 and 5 show a perspective view, a front view and a side view of another embodiment of a disc skimmer according to the invention.

Referring to the drawings and firstly to Figures 1 and 2, a disc skimmer has a rotary portion generally indicated at 1 and comprising a shaft 2 which can be driven for rotation and which mounts discs 3, 4 and 5 for rotation therewith. Scraper means (not shown) are provided for removing oil adhering to the discs 3, 4, 5 in known manner.

The device advantageously operates immersed in water 6 with a surface layer 7 of oil thereon, that is to say partially submersed. to the level indicated in the drawings.

To assist movement of the oil 7 towards the discs 3, 4, 5, impeller members are provided. The impeller members may comprise blades 8 provided on the shaft 2 and projecting generally radially outwardly therefrom, for example as shown for approximately one third of the distance between the periphery of the shaft and the circumference of the disc, and/or projections 9 provided on the side faces of the discs 3, 4, 5. The impeller members 8 and 9 will cause, upon rotation of the shaft 2 and the discs 3, 4, 5, movement of the surface layer of the oil and/or the water towards the discs 3, 4, 5 thereby to enhance oil pick-up by the discs 3, 4, 5.

For example the discs may be between 275mm and lmm in diameter and may rotate at between 10 to 40 r.p.m. The impeller members 8 and 9 should not interfere with the action of the oil scrapers since these act generally only on the radially outer part of the discs.

In the embodiment of Figures 3, 4 and 5, the blades 8 of the embodiment of Figures 1 and 2 are omitted and the projections 9 bridge the gap between a pair of parallel discs 10 and 11. A scraper 12 has two long tongues 3, 14 which act on the outer faces of the discs 10 and 11 and a short tongue 15 which acts on the two inner faces of the discs 10 and 11.

Claims

1. A rotating disc oil skimmer including means provided to cause movement of oil on the surface of water towards a disc or discs of the skimmer.

2. A rotating disc oil skimmer according to claim 1, in which said means comprise impeller means which are rotated by rotation of a shaft on which the disc or discs are mounted.

3. A rotating disc oil skimmer according to claim 2, in which the impeller means comprise blades mounted on the shaft and/or impeller members secured to the side faces of the disc or discs.

4. A rotating disc oil skimmer according to claim 3, in which the blades and/or impeller members are so dimensioned and positioned that in operation of the device radially outer portions of the blades or impeller members are, upon rotation of the shaft, caused to be submerged a small distance into the oil floating on the surface of the water.

5. A rotating disc oil skimmer according to claim 3 or claim 4, in which the discs are provided as pairs of discs slightly spaced apart with the blades or impeller members bridging between the two discs of the pair adjacent the shaft on which the discs are mounted.

6. A rotating disc oil skimmer substantially as hereinbefore described and illustrated with reference to the accompanying drawings.