METHOD OF CLEANING SHIPBOARD FUEL TANKS Russian patent published in 2004 - IPC

FIELD: operation of ships; chemical cleaning of shipboard fuel tanks before repair of ship. SUBSTANCE: proposed method includes successive operations of washing shipboard tanks by means of detergent solution, accumulating and settling of washing detergent solution in settler and final washing of tanks. Detergent compound contains petroleum fuel with surfactant added to it. Content of water in detergent compound is increased in the course of operation of each subsequent tank. Final washing of each tank is effected by means of use of aqua emulsion taken from settler; first, emulsion is fed to tank to be washed in the amount of 0.5-3.0% of volume of tank, after which it is pumped to accumulator wherefrom aqua emulsion is fed for final washing under pressure built-up by means of hose system; if necessary aqua emulsion may be pumped from tank to accumulator for the second time. Upon completion of final washing, aqua emulsion is returned to settler by means of standard system and may be used for final washing of subsequent tank. After final washing of last tank, aqua emulsion is utilized by mixing it with fresh fuel and burning in shipboard power plant. EFFECT: avoidance of contamination of water area; reduced labor consumption. 1 dwg