水泥窑过渡带用低导热多层复合砖研究(Ⅰ):多层复合结构的设计

摘要

为减少水泥窑的过度散热和安全运行隐患,采用工作层(硅莫砖,厚0.140 m)、保温层(轻质莫来石,厚0.035 m)、隔热层(含ZrO2的陶瓷纤维板,厚0.025 m)的3层复合设计方法,研究了低导热多层复合砖的保温层的结合界面方式和受力分析,并计算了该复合砖的综合热导率.结果表明:多层复合砖的工作层和保温层的结合界面采用正弦曲面结合方式,保温层和隔热层的结合界面采用135°坡形结合方式的设计,可使复合砖中间层(保温层)的应力集中较少;多层复合砖的综合热导率由原来使用非复合砖(即硅莫砖)的2.74 W·m-1·K-1降低到1.50 W·m-1·K-1.将该多层复合砖实际应用于水泥窑过渡带时,使水泥窑筒体外壳温度比采用非复合砖的降低了50 ～ 70℃.%In order to restrain thermal loss and potential safety hazards in cement kilns,a design of three layers,namely a working layer (mullite-SiC brick,0.140 m in thickness),a thermal preservation layer (light weight mullite,0.035 m in thickness),and a thermal insulation layer (ceramic fiber board containing ZrO2,0.025 m in thickness),was adopted to research the boundary combination method and strain distribution of the thermal preservation layer of low thermal multi-layer conductivity bricks,and the overall thermal conductivity was calculated.The results show that sinusoidal shaped boundary combination between the working layer and the thermal preservation layer,slope-shape with angle of 135 degrees between the thermal preservation layer and the thermal insulation layer can relieve the strain concentration.The comprehensive thermal conductivity of the multi-layer composite brick decreases from the original mullite-SiC brick 2.74 W · m-1 · K-1 to 1.54 W · m-1 · K-1.When applied this composite mullite in the transition zone of a cement kiln,the temperature of the kiln shell lowered by 50-70 ℃ than using normal bricks.