污泥干燥特性及其模型求解  

DRYING CHARACTERISTICS AND THE MODEL SOLVING OF SLUDGE

作　　者：程诚[1] 黄亚继[1] 袁琦[1] 杨高强[1] 

机构地区：[1]东南大学能源热转换及其过程测控教育部重点实验室能源与环境学院,南京210096

出　　处：《环境工程》2013年第S1期585-589,680,共6页Environmental Engineering

摘　　要：相同质量污泥(3.0±0.01)g在85~145℃下进行恒温干燥实验,得到污泥干燥过程中含水率、干燥速率等变化规律,采用多元线性回归对实验数据进行分析,得到污泥干燥动力学模型。结果表明:污泥在干燥过程中经历加速、恒速和降速3个阶段,3个阶段的分界点固定在污泥失重率为10%和65%处而不随干燥温度的变化而变化;在同一干燥温度下,饼状污泥的干燥速率大于球状污泥;Logarithmic干燥模型MR=a·exp(-kt)+b在各干燥温度下均最适宜表述污泥干燥过程,其参数a、b与干燥温度T呈二次多项式关系,参数k与干燥温度T呈一次线性关系;饼状污泥的有效扩散系数D eff在9.21×10-6~2.22×10-5m2/min,球状污泥的有效扩散系数D eff在6.55×10-6~1.37×10-5m2/min。且随着干燥温度的上升,有效扩散系数D eff呈上升趋势。在相同干燥温度下,饼状污泥的有效扩散系数大于球状污泥。The sludge with constant weight( 3. 0 ± 0. 01) g was dried at constant temperature from 85 to 145℃. The change law of moisture content and drying rate were got during sludge drying. Drying dynamic model was obtained by multiple linear regression. Results are as follows: sludge drying process includes acceleration phase,constant-rate phase and falling-rate phase. Demarcation points of the three phases,which fix at 10% and 65%,and are not changed with the drying temperature. The drying rate of cake sludge is higher than that of spherical sludge at the same temperature; Logarithmic model is best fitted for the process of sludge drying. There is a quadratic nonlinear relationship between the parameter( a and b) and drying temperature. The relationship between parameter k and drying temperature is linear; The effective diffusion coefficient D eff of cake sludge is in the range of 9. 21 × 10-6m2/min to 2. 22 × 10-5m2/min,and that of spherical sludge is of 6. 55 × 10-6m2/min to 1. 37 × 10-5m2/min. Both of them increase with the temperature elevating. The effective diffusion coefficient D eff of cake sludge is bigger than that of spherical sludge at the same temperature.

关 键 词：污泥 干燥特性 形状 模型求解 有效扩散系数 

分 类 号：X703[环境科学与工程—环境工程]