无机膜除尘器对水泥厂窑尾烟气脱硫机理研究

【作者】 艾浩；

【导师】 陶文亮；

【作者基本信息】 贵州大学 ， 材料学， 2008， 硕士

【摘要】 本文是针对在水泥厂回转窑窑尾安装的无机膜除尘器进行除尘试验的基础上,通过分析实际烟尘的特性,研究无机膜除尘器在回转窑窑尾烟气脱硫的机理。这一项研究无论是在膜科学理论还是在工程应用方面均是一项积极而有益的工作尝试,其研究工作为无机膜在气固分离和烟气脱硫领域更广泛的应用提供了有价值的参考。由于无机膜是一种惰性膜,不会参与脱硫反应的进行。所以,本文采用化学分析方法和XRD衍射分析方法对无机膜除尘器进出口粉尘的成分进行了分析;利用烟气自动分析仪对进出口的烟气特性进行了检测,在试验的工况为:进口烟气流量是22.4 L/min,进口SO₂质量浓度1700 mg/m³,进口粉尘的质量浓度为31.54g/m³,烟气入口温度为50℃,烟气的相对湿度为0.7下,无机膜除尘器具有2.0%～5.7%的脱硫效率,在此基础上对无机膜除尘器烟气脱硫的机理进行分析。通过分析掌握了无机膜除尘器的脱硫机理是烟气中携带的粉尘吸附在无机膜管内壁上,其中的潜在碱性物质在烟气中蒸汽的作用下被激活而释放出Ca（OH）₂等碱性物质,碱性物质与SO₂发生化学反应,进而产生脱硫效果。由于脱硫反应的过程是气固反应,所以本文采用气固反应的收缩核模型,同时将反应的区域晶粒化,在此基础上通过引进分形维数来纠正使用收缩核模型时由于粉尘颗粒形状不规则而导致对脱硫效率的分析误差。利用改进的模型来分析SO₂的浓度、烟气的相对湿度、烟气的温度及钙硫比等对脱硫效率的影响。通过这些重要影响因素的分析发现:无机膜除尘器内控制脱硫反应过程进行的环节主要是二氧化硫气体通过灰层的扩散阻力。无机膜除尘器入口二氧化硫气体的浓度、和烟气的温度相对于相对湿度及Ca/S摩尔比对脱硫效率的影响要小。相对湿度对无机膜除尘器脱硫效率的影响最为显著。更多还原

【Abstract】 In this article, by analyzing the characteristics of the actual dust to research the flue gas desulphurization mechanism of inorganic membrane filter at the kiln tail of cement plant, it is on basis of the experimental of its remove dust. This work is a positive and beneficial research in the theory of membrane science and its application, the research work provide a valuable reference in the field of gas-solid separation and the flue gas desulphurization for its more widely application.The membrane is an inert inorganic, it doesn’t take part in desulphurization reaction. In the research, by using chemical analysis methods and XRD pattern analysis methods to analyze the dust of inorganic membrane filter’s inlet and outlet, and the gas by automatic flue gas analyzer. There is 2.0%～5.7% of desulphurization efficiency under these conditions that the gas flow rate is 22.4 L/min, the mass concentration of SO₂ is 1700 mg/m³, the mass concentration of dust is 31.54 g/m³,the gas temperature is 50℃and relative humidity is 0.7.In according these to study the gas desulphurization mechanism of inorganic membrane filter.The results show that the gas desulphurization mechanism of inorganic membrane filter is dust carried by gas is absorbed in inorganic membrane, including the potential alkaline substances in the steam activation and release Ca（OH）₂, alkaline material and SO₂ result in the chemical reaction, produce desulphurization efficiency. The desulphurization process is gas-solid reaction, the paper using gas-solid reaction shrinking core model, and also the regional grain of reaction. On this basis induce the fractal dimension to rectify shrinking core model because the dust particle shape is not a spherical lead to the error of desulphurization efficiency. By using the improved model to do a contrastive analysis of the concentration of SO₂, the relative humidity of gas, the temperature, sulfur and calcium’s ratio to research the desulphurization efficiency. Through these important factors’ analysis found: the mainly control desulphurization process is sulfur dioxide gas through the ash layer diffusion resistance in inorganic membrane filter. The inlet’s the concentration of sulfur dioxide gas, and the gas temperature compared to the relative humidity and Ca/S’s effect is small in desulphurization efficiency. Relative humidity is the most important factor to impact the inorganic membrane filter’s desulphurization efficiency.更多还原