添加CaO脱水污泥的微波干燥特性

Microwave drying characteristics and kinetic model of thin-layer dehydrated sludge with CaO addition

采用薄层干燥实验法对添加Ca O的脱水污泥进行微波干燥研究,考察了污泥的干燥特性,并引入干燥曲线对实验数据进行数值分析。结果表明,添加Ca O能减少污泥的干燥时间。污泥微波干燥过程主要分为升速干燥、恒速干燥和降速干燥3个阶段,且恒速干燥阶段所占的比例较大。数学模型分析发现,Page模型能更好地拟合薄层污泥的微波干燥过程。

The drying process plays an important role in sewage sludge disposal. The thin-layer drying method, with CaO addition, was adopted to investigate the microwave drying characteristics of dehydrated sludge. The addition of CaO could reduce the sludge drying time. The parameters studied were the various thick- nesses （2, 4, and 8 mm） and the operating power （150, 300, 450, and 600 W）. Drying curves and drying rate curves were used to describe the drying process. The drying rate increased as the output power increased and the sludge thickness decreased, with the constant speed drying stage accounting for a larger proportion. The mathematical modeling showed that the Page model had superior prediction ability.