Abstract: A vapor degreasing method and apparatus wherein a second cooling coil is used to prevent escape of solvent or solvent vapor from a degreaser. Gaseous refrigerant from the second coil can be released to the freeboard space above the solvent vapor zone to provide a barrier layer.

Abstract: Toxic heavy metal ions are removed from water by electrochemical replacement as the water flows through a tandem bed of (a) activated zinc and then (b) magnesium alloyed with a minor amount of manganese to inhibit corrosion. The zinc is activated by contact with a noble metal salt. Preferably, fine granules of zinc and Mg/Mn are used. Clogging is prevented by intermittent vacuum degassing of the beds. The activated zinc and the Mg/Mn advantageously are prepackaged and stored in cartridges which become part of the processing column. The Mg/Mn cartridge has a non-reactive atmosphere of e.g., argon, retained by frangible or soluble barriers that hermetically seal the ends of the cartridge. The barriers are torn away or dissolved by the initial water flow when the cartridge is installed. System scale-up is simplified by a "half-length" concept characteristic of the present invention.

Abstract: A coating for protecting steel from corrosion is a mixture of an organic solvent and binder, powdered magnesium, and a passivating agent which has a pH greater than about 8 when in contact with water. Steel covered with the coating is cut or welded by the application of heat sufficient to melt the magnesium and underlying steel. In some embodiments, the pyrolysis products of the coating create an odor which warns of the build-up of nitrogen oxides produced by typical welding and coating operations.