Method and arrangement for internally coating a tube by reactive deposition from a gas mixture activated by a plasma

摘要

Tubes, consisting of an electrically insulating material such as SiO2, are internally coated by reactive deposition form a gas mixture passing through the tube. The deposition is activated by a plasma reciprocally moving along within the tube. The plasma is formed in the tube by high-frequency electric energy capacitively applied to the gas phase by means of two flames which impinge upon the outside of the tube at two longitudinally spaced sites. The sites are reciprocally moved along the tube during the reactive deposition. A high-frequency generator is electrically connected to the burners generating the flames. An apparatus for coating tubes comprises a gas supply system, burners for generating a plasma and means for moving the burners.