颗粒状污泥的干燥特性及表观变化

对3种不同质量等级的污泥颗粒（2.5、5和10 g）在100、200、300、400和500℃下进行恒温干燥实验,通过观察污泥的失重特征和表观形态的变化,深入研究了污泥干燥过程、失重速率的变化规律.结果表明,污泥在100～200℃下的干燥过程分为加速阶段、恒速阶段和降速阶段,而在300～500℃下并没有真正的恒速阶段,...

Drying Characteristics and Apparent Change of Sludge Granules During Drying

Three different weight grades of sludge granules (2.5, 5, 10 g) were dried at constant temperature of 100, 200, 300, 400 and 500 degrees C, respectively. Then characteristics of weight loss and change of apparent form during sludge drying were analyzed. Results showed that there were three stages during sludge drying at 100-200 degrees C: acceleration phase, constant-rate phase, and falling-rate phase. At 300-500 degrees C, there were no constant-rate phase, but due to lots of cracks generated at sludge surface, average drying rates were still high. There was a quadratic nonlinear relationship between average drying rate and drying temperature. At 100-200 degrees C, drying processes of different weight grade sludge granules were similar. At 300-500 degrees C, drying processes of same weight grade of sludge granules were similar. Little organic matter decomposed till sludge burning at 100-300 degrees C, while some organic matter began to decompose at the beginning of sludge drying at 400-500 degrees C.