double electrode direct current arc furnace

例句：

1. 1. The double-electrode DC arc furnace is used for melting refractory metals.
   双极直流电弧炉用于熔炼难熔金属。
2. 2. In the double-electrode DC arc furnace, the molten metal flows through a channel to cool and solidify.
   在双极直流电弧炉中，熔融金属通过一个通道流动以冷却和固化。
3. 3. The double-electrode DC arc furnace is an essential tool in the metallurgical industry.
   双极直流电弧炉是冶金工业中不可或缺的工具。