Method and apparatuses for plasma treatment

摘要

A method and an apparatus for plasma treatment of gas, particularly for transformation, passivation and stabilization of polluting and toxic admixtures and for applications of plasma treated gas in plasma treatment of surfaces at gas pressures exceeding 100 Torr are disclosed. A flowing gas (1) to be treated is passed through a hollow cathode (2) provided with a counter electrode (5) and a hollow cathode discharge plasma (3) is generated by a generator (4) connected to the hollow cathode (2). The flowing gas (1) undergoes interactions with oscillating electrons (6) in the hollow cathode discharge plasma being generated in the gas. The interaction of the hollow cathode discharge plasma with inner walls (8) of the hollow cathode is controlled and the inner walls should have a temperature below its melting point, whereby the inner walls can provide a catalytic effect. The inner walls may also release wall species (9) promoting plasma-chemical reactions in the hollow cathode discharge plasma. The flowing gas is then exhausted as a transformed gas (10) after being treated in the hollow cathode discharge plasma and may also be used for treatment of surfaces. A gas to be treated may also be mixed with an auxiliary gas (7) for obtaining a suitable mixing of gas, whereby the auxiliary gas intensifies an ultraviolet radiation and/or plasma-chemical reactions.