unburned coal in fly ash

• 飞灰可燃物

unburned coal in fly ash的用法和样例：

例句

1. After retrofitting,the boilers combustion is stable and the combustible matter in fly ash is reduced,with the boilers efficiency improved.
   改造后的锅炉燃烧稳定，飞灰可燃物降低，提高了锅炉效率。