| 摘要 |
<p>In the representative embodiment described in the specification, an electron beam furnace (10) has an evacuation system (25) which maintains the interior of the furnace at a pressure in the range from about 50 microns Hg to 300 mcirons Hg. The relatively high pressure reduces degassing time from a cold start, suppresses volatilization of constituents of metal being refined, and causes volatilized metal to condense in powder form on a condensing screen. A vibrator (27) assists in removing the powder from a condensing screen (26). Each electron beam gun (17, 19, 23) has a series of compartments which are individually evacuated to maintain the pressure in the compartment containing the cathode at a level less than about 1 micron Hg.</p> |
