Author(s)

T. Kumagai, A. Katoh, T. Tanaka, M. Muraoka & J. Sadaki

Abstract

Hydrodynamic characteristics of an air-suction system of oil spilled in the marine environment T. Kumagai1, A. Katoh1, T. Tanaka1, M. Muraoka1 & J. Sadaki2 1 Department of Mechanical Engineering, Science University of Tokyo, Noda City (278-8510), Japan 2 Faculty of Technology, University of Tokyo, Bunkyou-ku (113-8654), Japan Abstract The hydrodynamic characteristics of air-suction system of oil are studied experimentally in order to suck oil with less quantity of water. The air-suction system of oil is set up with a high-speed air-fan, a separating box of oil from water, various types of inlets and transporting pipes. The tested inlets are a straight inlet, a Bell mouth and a contracted inlet. It is concluded that the Bell mouth realizes the desirable suction of oil with slight quantity of water at H/Di 0.3 for the mineral oil with the kinematic viscosity of 2000 cSt, where Di and H denote the inlet diameter and the height of inlet from the water level respectively. 1 Introduction The countries such as Japan, which need imports of mineral oils as the major energy source, are daily faced with a danger of oil spill caused by accidents of oil-tankers. It was remembered that the oil-spill accident caused by a sinking of Russian tanker \“Navotka” (1997) in Japan sea had given us miserable effects for several years after the accidents [l]. From a long-range viewpoint, the oil pollution in the marine environment seems to be recovered naturally by microbiological activities. However from a viewpoint of short-range viewpoint, the oil spill accident causes significant effects on the marine environment. Thus it is regarded as the best operation to remove oil as soon as possible just after spilt in the marine environment [2]. It is considered to be the best way to suck oil directly by using water-jet pumps [3]~[7] or air-suction systems, if the ratio of

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