Abstract
After unloading chemical cargos transported by chemical tankers, the discharge of the cargo residues or tank washings containing such chemical substances is prohibited according to the pollution categorization to protect marine environment from pollution produced by ships. To reduce the cargo residue quantity, stripping or straw piping devices have been developed.
In this study the residue quantity at the tank well and in the piping, the adhering quantity on the tank surface and in the piping, and the vapor quantity in the tank and the piping are investigated by the past reports on board test. There are a few ships, the residue quantity in the well or in the piping of which is reduced less than one liter in the case of the straw piping equipment and the stripping equipment are settled.
One liter of the residue is small compared to the vapor quantity or adhering quantity in the tank. To reduce the discharge quantity of chemical cargos from ships furthermore, the recovery of the vapor and adhering quantity demands deliberation.
