Basic study on recovery of spilled oil in the sea by the use of buckets

摘要

Oil spilled from the oil tanker Nakhodka was recovered using buckets lowered from grab dredgers and self-propelled grab barges. This method of oil recovery was effective, but one problem was the large volume of seawater collected in buckets together with the oil. To resolve this problem the model bucket with holes in the bottom was designed and laboratory experiments were conducted. It was found that when the bucket filled with seawater and oil was raised, the water flowed through the holes first and then the oil flowed through the holes with a time lag that depended on the viscosity of the oil and size of the holes. The relationship between kinetic viscosity and passage of the oil through the holes was theoretically estimated, and these results were agreed well with the experimental results.