| 摘要 |
<p>A head for a plasma arc cutting torch includes a swirl 222 located between the nozzle 212 and the electrode 216, through which plasma fuel gas is introduced into the nozzle. The plasma fuel gas is introduced directly into the plasma formation zone or plenum 228 beyond the junction 238 between the nozzle body and cone end 214 thereby avoiding change in direction within the conical end 214 of the nozzle 212 before the plasma formation zone 228. <??>The external taper of the wall 252 of the swirl 222 is complementary to the internal taper 248 of the nozzle 212 and the internal taper of the wall 254 of the swirl 222 is complementary to the external taper 214 of the electrode 216. The hollow tapered swirl 222 so formed is fitted in the hollow nozzle 212 to abut the inner taper 248 of the nozzle; and the electrode 216 is fitted in the hollow swirl 222 to abut the inner taper 254 of the swirl to centre the electrode within the nozzle. <??>A method of centering an electrode in the nozzle of a plasma arc torch head is also disclosed. <IMAGE></p> |
