High performance induction plasma torch with a water-cooled ceramic confinement tube

An induction plasma torch comprising:

• a tubular torch body including a machined cylindrical inner surface having a first diameter;
• a plasma confinement tube (a) made of ceramic material having a high thermal conductivity, and (b) including a first end, a second end, and a machined cylindrical outer surface having a second diameter slightly smaller than said first diameter;
• the plasma confinement tube being mounted within said tubular torch body, and the cylindrical inner and outer surfaces being coaxial to define between said inner and outer surfaces a thin annular chamber of uniform thickness;
• a gas distributor head mounted on the torch body at the first end of the plasma confinement tube for supplying at least one gaseous substance into said confinement tube, said at least one gaseous substance flowing through the plasma confinement tube from its first end toward its second end;
• an induction coil coaxial with said cylindrical inner and outer surfaces, embedded in the torch body, and supplied with an electric current for inductively applying energy to said at least one gaseous substance flowing through the plasma confinement tube in order to produce and sustain a high temperature plasma in said confinement tube;
• and
• means for establishing a high velocity flow of cooling fluid in the thin annular chamber, the high thermal conductivity of the ceramic material forming the confinement tube and the high velocity flow of cooling fluid both contributing in efficiently transferring heat from the plasma confinement tube, heated by said high temperature plasma, into the cooling fluid to thereby efficiently cool said confinement tube.