炉

1. Origins, structure, and basic meaning

• Structure: 炉 (ろ) is a hearth or furnace for burning fuel or melting metal. It appears as a fuel destination and work equipment.
• Basic usage: A craftsperson adds charcoal to a hearth; a factory melts metal in a large furnace.

2. Common pitfalls and similar expressions

• Hearth fueled with charcoal and industrial melting furnace
  • 炉に is destination for fuel; 炉で is work setting. Size and purpose select “hearth” or “furnace.”