摘要
采用薄层干燥的方式对嘉兴市某污水处理厂的脱水市政污泥在不同厚度和温度下的干燥特性进行实验研究,并通过引入薄层干燥模型,对薄层市政污泥干燥过程进行模拟分析。结果表明:厚度越小或干燥温度越高,污泥干燥速率越快。当温度从70℃上升到130℃时,最大干燥速率从0.02587 g·(g·min)^(-1)上升到0.08158 g·(g·min)^(-1);从节能角度考虑,温度过高会导致有更多的能量消耗在污泥干质上,不利于能量的有效利用;Midilli模型很好地描述了市政污泥含水率的变化与时间的关系;应用Fick扩散定律推导出70~130℃下薄层市政污泥干燥的水分有效扩散系数变化范围为5.96×10^(-9)~3.24×10^(-8) m^(2)·s^(-1),并利用Arrhenius方程建立有效扩散系数与温度的关系,得到薄层市政污泥水分扩散的活化能为31.32 kJ·mol^(-1)。
The drying characteristics of dewatered municipal sludge from a municipal wastewater treatment plant in Jiaxing City at different thicknesses and temperature were experimentally studied.Furthermore,the simulation analysis of its drying process was performed by thin layer drying models.The results showed that the drying rate of the sludge became larger with the decrease of thickness or drying temperature.The maximum drying rate increased from 0.02587 g·(g·min)^(-1) to 0.08158 g·(g·min)^(-1) when the temperature rose from 70℃to 130℃.In the view of energy saving,higher temperature led to more energy consumption,which was detrimental to the effective utilization of energy.Midilli model could describe the relationship between the change of moisture content in the sludge and time well.The effective diffusion coefficients for the thin layer drying of municipal sludge ranged within 5.96×10^(-9) and 3.24×10^(-8) m^(2)·s^(-1).The relationship between effective diffusion coefficient and temperature was established by Arrhenius equation.The activation energy of moisture diffusion for the thin layer of the sludge was 31.32 kJ·mol-1.
作者
冯金钻
陶乐仁
黄理浩
谷志攀
吴生礼
FENG Jinzuan;TAO Leren;HUANG Lihao;GU Zhipan;WU Shengli(School of Energy and Power Engineering/Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;College of Civil Engineering and Architecture,Jiaxing University,Jiaxing 314001,China)
出处
《能源研究与信息》
CAS
2021年第1期10-16,共7页
Energy Research and Information
基金
上海理工大学科技发展项目(2019KJFZ201)。
关键词
市政污泥
干燥
模拟
有效扩散系数
活化能
municipal sludge
drying
simulation
effective diffusion coefficient
activation energy
