Process and apparatus for cleaning and/or coating metal surfaces using electro-plasma technology

An apparatus for cleaning or coating an electrically conducting surface of a workpiece, the apparatus including:

• a chamber comprising one or more porous chamber dividers that separate the chamber into multiple sections, one section being adapted to receive an aqueous electrolyte, another section comprising a perforated anode plate which forms an outer wall of the chamber;
• means for converting the aqueous electrolyte into a foam;
• a heated screen located in the one section of the chamber which adds thermal energy to the aqueous electrolyte so that the temperature thereof can be controlled and the aqueous electrolyte is converted into the foam;
• and
• means for sealing the region of a working gap formed between the anode plate and the surface of the workpiece, thereby forming a sealed treatment zone adapted to be filled with foam delivered through the perforated anode plate.

An apparatus for cleaning or coating a workpiece having an electrically conducting surface to be treated, the apparatus comprising:

• (i) at least two opposed anode assemblies suitably disposed with respect to the surface to be treated, thereby forming a working gap between each anode assembly and the surface,
• (ii) means for sealing each working gap to form a sealed treatment zone between the anode assemblies, each anode assembly comprising
• an anode which is in communication with a chamber adapted to receive an electrically conductive medium;
• means for supplying the electrically conductive medium to the chamber, and
• means for converting the electrically conductive medium into a foam;
• (iii) means for moving the workpiece through the treatment zone;
• (iv) means for opening and closing the treatment zone;
• and
• (v) means for controlling supply and removal of foam from the treatment zone so that the treatment zone is filled with foam during treatment.