流出油吸引回収時の粘性の影響

抄録

During recovery of spilled oil, floating oil is contained with a barrier and the oil layer is thickened and removed. When the contained oil is recovered, the aim is to increase the recovery rate and to reduce the water content in the recovered oil-and-water mixture. When the recovered water is discharged after separation through the oily water separator on board, oil content has to be at or below 15 ppm. To make it easy to separate oil from water, the oil should be recovered with low water content. Oil recovery with no water content is ideal, but when the oil layer becomes thin, recovered oil contains a large amount of water.
In this study, oil was suctioned from above the surface of the oil layer to reduce water content in the recovered oil-and-water mixture. Even if air was sucked in with the oil, the air could be easily separated. When the suction inlet was located near the interface between the oil layer and the water, the water content increased; the influence of the clearance between the suction inlet and the oil layer surface and the influence of the oil viscosity were investigated experimentally.
In the low-viscosity case, at a clearance of 4 mm and using a vacuum cleaner, the oil was recovered well with low water content. In the case of high-viscosity oil, at a clearance of 3-4 mm and using a high-vacuum pump, oils could be recovered well with low water content.