| 摘要 |
1,223,323. Induction plasma generators. HUMPHREYS CORP. 13 June, 1968 [21 June, 1967], No. 28083/68. Heading H5H. An induction plasma generator has a single gas inlet 24 leading to an annular chamber 98 from which an annular sheath of plasma forming gas issues to plasma chamber 102; the arrangement being such that the velocity is uniform about the circumference. The generator comprises a housing 20 provided with a main aperture 60 and a smaller diameter coaxial aperture 66. The main aperture 60 comprises two coaxial bores 62, 64. A gas distributer 70 is located in bore 62, bearing against shoulder 68 and an annular coolant distributer 80 is mounted in bore 64, an O-ring 88 being located in a recess formed between the tapered end of coolant distributer 80 and the flat end of gas distributer 70. A quartz plasma confining tube 22 having the same inner diameter as gas distributer 70 is received in an annular seat 90 of the gas distributer. The annular chamber 98 is defined between the continuous walls of gas distributer 70 and quartz tube 22 and the outer wall of a cylindrical plug 32 sealed into aperture 66. Gas enters an annular recess 72 in the gas distributer from whence it is injected by equispaced radial ports 74 into annular chamber 98. The housing 20 is secured by screws 58 to a plate 16, the gas distributer 70 and coolant distributer 80 being thereby accurately located in the housing and the quartz tube 22 being held firmly against seat 90 by O-ring 88. A second plate 14 carrying a pancake induction coil 34 is secured by screws 56 to plate 16. A water cooled probe 30 for introducing material to be heated is secured to plug 100. Coolant flows from earth terminal 52 through a passage 128 in a radial extension 10 to the inner end of coil 34 and through the coil 34 and a connector 120 to input terminal 124. Water also flows through a flexible conduit 130 connected to extension 10, the coolant distributer structure 80 to cool quartz tube 22, flexible conduit 132 to the inlet 108 of annular probe coolant channels, through the coolant channels 106, 112 and probe outlet 108, and conduit 134 to connector 120. The generator is supported by the extension 10. A radiation shield 54 of copper fits over the end of quartz tube 22. In an alternative arrangement the lower plate 14 is dispensed with and the pancake coil is replaced by a helical coil, the coil being supported by a supply terminal and the housing 20 being secured to a cantilever arm carried by the supply terminal. Argon and oxygen may be used for plasma gases. Metal and refractory materials may be worked or chemical reactions may be effected in the resultant plasma. |
