氧化钙和木屑预调制污泥的低温干化特性研究

Study on low-temperature drying characteristics of premodified sludge with calcium oxide and sawdust

热泵干化是一种低碳节能的污泥干化方法,其运行温度一般不超过70℃。为提升污泥在低温条件下的干化速率,采用实验研究加数据分析方法,研究了空气温度、风速和添加剂比例对污泥低温干化特性的影响。实验结果表明,当空气温度在50~70℃,风速为0.5~1.7 m/s时,提高空气温度、风速和增大添加剂比例均可以提高污泥干化速率,CaO和木屑预调制污泥比纯污泥的平均和最大干化速率分别提高了14.2%和25.7%。通过双因素方差分析(ANOVA)表明,干化温度比干化风速对污泥干化的影响更大。通过非线性拟合,构建温度和风速变化对污泥干化过程的动力学模型,为低温条件下污泥干化提供数据基础。

Heat pump drying is a low-carbon and energy-saving sludge drying method.The operating temperature of heat pump is generally no more than 70℃.In order to improve the drying rate of sludge at low-temperature,the ef⁃fects of air parameters and additives on sludge drying characteristics at low-temperature were studied by experimen⁃tal research and data analysis methods.Experimental results showed that when the air temperature was 50-70℃and the air velocity was 0.5-1.7 m/s,increasing the air temperature,air velocity and the additive ratio could acceler⁃ate the drying process of sludge.The average and maximum drying rates of CaO and sawdust premodified sludge were increased by 14.2%and 25.7%,respectively,compared with pure sludge.Two-way analysis of variance(ANOVA)showed that drying temperature had a greater impact on sludge drying than air velocity.Through nonlinear curve fitting,the dynamic model of sludge drying process with temperature and air velocity changes was con⁃structed,which provided a data basis for sludge drying under low-temperature conditions.