| 摘要 |
PURPOSE:To accomplish the title desulfurization in high efficiency at low cost by heating treatment of a graphite sheet with itself as an exothermic body in a high-frequency induction heating system. CONSTITUTION:A graphite sheet 3 is gradually moved in the arrow a direction through a space between heat resistant, non-electrically conductive partition plates 4,4 made of e. g. ceramic. A high-frequency voltage is then applied from a high-frequency electric source 1 via a current transformer 2 on a high-frequency coil 5 provided externally in proximity to the partition plates 4. Thereby a field current is generated in the graphite sheet 3 to make instantaneous heating and cooling. In this case, the heating temperature is pref. >=1400 deg.C. It is preferable that high-frequency coil 5 be divided into plural parts and the sheet 3 treated at lower temperatures ca.1000-1300 deg.C in the former half and at higher temperatures 1400-1700 deg.C in the latter half, i.e. in a multi- stage temperature-raising manner over heating zones H1-H3 etc. Furthermore, it is preferable that e.g. N2 gas be allowed to flow in the arrow c direction between the partition plates 4,4 to prevent the graphite sheet 3 from oxidation as well as to quickly expel the sulfur-contg. gas generated out of the system. Thus, the objective desulfurization of the graphite sheet 3 can be accomplished in high efficiency. |
