Apparatus for treating materials with plasma

An apparatus for treating materials with plasma, comprising:

• a microwave generator;
• a waveguide;
• and
• a tubular torch comprising an upstream section, a central section, a downstream section, and at least one inner tube, an intermediate tube, and an outer tube arranged coaxially, each having an upstream end and a downstream end,
• wherein said outer tube extending from said upstream section at least up to said central section of said torch and defines a plasma containment chamber in said central section of the torch;
• wherein the longitudinal axis of said torch is aligned with the electric field operatively generated in said waveguide;
• wherein said inner tube, said intermediate tube, and said outer tube of said torch are removably mounted at their upstream ends via fixing and centering means in said upstream section of said torch;
• wherein said waveguide is connected to said microwave generator and to a hollow body of said central section of the torch, said hollow body having a cavity in which there are defined an upstream side and a downstream side, each provided with a circular hole for housing said outer tube of the torch, said plasma containment chamber being defined in the outer tube;
• wherein the downstream end of said intermediate tube is aligned with said upstream side of said cavity of said hollow body, or extends for a portion beyond said side upstream side of said cavity;
• wherein the downstream end of said inner tube is aligned with the downstream end of said intermediate tube, or is arranged upstream of the downstream end of said intermediate tube;
• wherein said downstream section of said torch comprises a secondary treatment zone defined in said outer tube downstream of said plasma containment chamber, ending with an exhaust opening.