CORROSION COMMENTARY

CORROSIVE EMULSIONS AT SEA. Furnace oil fuel burnt in marine boilers is liable to form stable emulsions when contaminated with sea‐water. Such emulsions cause a number of troubles, chief of which are corrosion of tubes and slagging of refractories, making frequent refining of furnaces necessary, due to the salt contained in the sea‐water. The stability of the emulsions varies considerably with the source of the oil fuel, but if conditions of emulsification are sufficiently severe, stable emulsions can be made with practically any furnace fuel oil. British ships which put salt water ballast into fuel tanks are required by law to use an oily water separator when deballasting, but the oil recovered from such a separator can contain as much as 30% by weight sea‐water.