| 摘要 |
<p>Semi-conductor rods are purified by zone melting in protective atmosphere using a coil surrounding the rod which is clamped at both ends to rotating shaft. The shaft is sealed by circular oil fitted seals, these being pressed against the shaft by the pressure of the oil. This is maintained by air supply and should be 0.5 atm. above the max. pressure inside chamber. Device is useful for crucibleless zone melting operations, during which wide pressure variations can occur, preventing shaft sealing problems. The seal described can deal with all conditions from vacuum to high positive pressure.</p> |
