adj.無(wú)塵的；無(wú)灰的

Three symbols rose from the dust. 三個(gè)神諭從封塵的土中浮起。

An air curtain was designed according to the jet theory of fluid mechanics and the role and feature of air curtain to separate dust in a fully mechanized face. 根據(jù)流體力學(xué)射流理論，分析了空氣幕在綜采工作面隔離粉塵的作用，并根據(jù)綜采工作面應(yīng)用空氣幕隔塵的特點(diǎn)，設(shè)計(jì)了空氣幕。