Abstract
The discharge into the sea of chemical substances or tank washings contains such substances should be prohibited to protect marine environment from pollution produced by ships. Using much water to wash the tank is a burden to a shipping service and it needs heavy cost and much fuel for the incineration. Therefore a method of the reduction of the wash water is considered The washing with a water jet is studied experimentally. As the result, concerning the water jet nozzle scanning pitch, the scanning order and the residue viscosity, the relation of the wash water quantity and the content of the residue in washing discharge is obtained When the pitch angle of water jet nozzle is small and the scanning is done repeatedly from above to bottom, the quantity of washing water can be reduced.
