补风口：采用铝合金百叶窗，表面环氧树脂喷涂。
Secondary air tuyere : aluminum alloy shutter , the surface was electro-sprayed by epoxy resin .
铝合金防雨百叶窗，采用阶梯式的页片设计更有利于雨水渗漏。
Aluminum rainproof shutter , using the type design is more advantageous to plates of water leakage .
铝合金百叶窗