摘要
通过污泥干燥实验,研究了污泥干燥过程中的形貌变化,考察了泥层厚度、温度、风速对污泥干燥特性的影响,并引入薄层干燥模型,采用MATLAB对污泥干燥的动力学过程进行模拟。结果表明：污泥中网络状的絮体结构不利于水分的蒸发;在泥层厚度为0.4 mm,将污泥含水百分比20%作为干燥终点时,干燥过程为恒速干燥,能够有效地降低干燥时间;提高温度和风速,可以提高污泥水分的表面蒸发速率,减少干燥时间;Page模型比其他模型更适合本次污泥干燥分析。应用Fick扩散模型,得到在温度50~70℃、泥层厚度0.4~2.0 mm条件下有效扩散系数的变化范围为1.13×10^-9~8.90×10^-9m^2/s,并得到了有效扩散系数随厚度、温度变化的关系式。
Through the municipal sludge drying experiments,morphology change of sludge drying process was studied. The sludge drying characteristics were investigated on the effects of the sludge thickness,temperature and wind speed. And the thin layer drying model was used to simulate the dynamic process of sludge drying by MATLAB. The results showed that when the thickness was at 0. 4 mm and moisture content of sludge was at 20%,constant drying happened in the drying process.Increasing the temperature and wind speed could improve the surface evaporation rate of sludge moisture,and reduce the drying time. The Page model was more suitable to simulate the sludge drying course. Using Fick diffusion model,the variation range of the effective diffusion coefficient was 1. 13 × 10^-9~ 8. 90 × 10^-9m^2/s,and the relationship between the effective diffusion coefficient with the thickness and temperature was obtained.
出处
《环境工程》
CAS
CSCD
北大核心
2016年第10期103-107,共5页
Environmental Engineering
基金
水体污染控制与治理科技重大专项(2010ZX07319-002)
关键词
城市污泥
薄层干燥
动力学模型
有效扩散系数
municipal sludge
thin layer drying
dynamic model
effective diffusion coefficient
