nailhead
n. 钉头;钉头状装饰
例句
In the long-term operation of atmospheric and vacuum heat furnace that use vacuum heavy oil as fuel, thesurface of nailhead furnace tube in the convection chamber was seriously deposited.
以减压渣油为燃料的常减压加热炉在长期生产运行过程中, 对流室钉头炉管表面结垢严重。