low-frequency electric furnace

例句：

1. 1. This low-frequency electric furnace is used to melt metals.
   这个低频电炉用于熔化金属。
2. 2. The low-frequency electric furnace is an important tool in the metallurgical industry.
   低频电炉是冶金工业中一个重要的工具。
3. 3. Low-frequency electric furnaces are more energy-efficient than traditional furnaces.
   低频电炉比传统炉子更节能。