流化床中污泥干燥特性

以湿污泥为原料在气固流动流化床干燥器内进行了污泥干燥特性的实验研究,考察流化风速、送风温度、联合干燥热量配比的变化对干燥强度、干燥热效率及平均传热系数的影响。实验结果表明,流化床污泥干燥最佳流化风速为1.48 m/s左右;随着流化风温的升高,干燥强度和干燥热效率逐渐增大,但增幅减小;单独的加热管干燥和流化风干燥的干燥热效率均较低,分别为33%和45%左右。在相同总输入热量下,随着内置加热管输入热量的比重越来越大,干燥热效率、干燥强度和平均传热系数均先增大后减小。

Drying characteristics of sludge in a fluidized bed

An experimental investigation on the drying characteristics of wet sludge was carried in a bubbling fluidized bed. The effects of fluidized wind speed, air supply temperature and combined drying heat ratio on drying strength, drying thermal efficiency and average heat transfer coefficient were investigated. The results show that the best fluidized wind speed by fluidized bed drying is about 1.48 m/s. With the air supply temperature increasing, drying strength and drying thermal efficiency both increase, but the growth extent decreases. The thermal efficiency of separate heating tube drying and fluidized wind drying are relatively lower, respectively about 33% and 45%. Drying thermal efficiency, drying strength and average heat transfer coefficient all increase and then decrease with the increasing proportion of built-in heating pipes heat input for the same total heat input.