hot primary air

• 一次热空气

hot primary air的用法和样例：

例句

1. The research in flux is mainly to change the original double hot dip coating technique, and change the first hot-dip galvanizing into electrolyzing flux.
   对于助镀剂的研究主要是改变原有的双热浸镀工艺，改第一次热浸镀锌为电解助镀。