furnace jacket

例句：

1. 1. The furnace jacket had to be replaced after the fire.
   火灾后，炉子外套必须更换。
2. 2. The engineer inspected the furnace jacket before starting the new project.
   工程师在开始新项目前检查了炉子外套。
3. 3. The furnace jacket was designed to protect the workers from the heat and smoke.
   炉子外套设计用来保护工人免受热量和烟雾的伤害。