[关键词]
[摘要]
分别在 462 W、 595 W、 700 W 微波功率下, 对不同含水率的疏浚底泥进行微波干燥试验, 微波干燥过程经历了 加速干燥、 恒速干燥和降速干燥阶段, 试验结果表明底泥的干燥速率、 含水率及温度变化符合典型干燥特征曲线。 通过分析不同因素对疏浚底泥微波干燥特性的影响, 发现含水率下降曲线受底泥初始含水率的影响不大, 低功率 ( 462 W) 下含水率下降趋于平缓, 高功率(595 W、 700 W) 下含水率急剧下降; 含水率和微波功率对底泥温度的影响 主要体现在恒温和继续升温阶段, 对预热升温阶段影响较小; 相同干燥条件下, 底泥温度的最大值与功率大小成正 比, 与含水率成反比例关系; 与红外干燥相比, 微波干燥大幅度地减少了干燥时间。单位能耗分析表明, 合适的微波 功率可减少能耗约 9%~ 26%。
[Key word]
[Abstract]
The microwave drying experiments were performed on the dredged sediments with different moisture contents under the microwave output powers of 462, 595, and 700 W respectively. The microwave drying process included increased speed dr2 ying, constant speed drying, and reduced speed drying process. T he results showed that the drying speed, moisture content, and temperature variation of dredged sediment agree with the typical drying characteristics curve. Effects of different factors on the microwave drying characteristics were discussed and unit energy consumption( UEC) was calculated. The initial moisture con2 tent of sediment had little influence on the variation of moisture content, which decreased gently at a lower output power of 462 W and decreased sharply at higher output powers of 595 W and 700 W. T he effects of moisture content and microwave power on the sediment temperature were more obvious during the constant speed and reduced speed periods while not obvious during the increased speed period. U nder the same drying condition, the maximum temperature of sediment was proportional to the micro2 wave power whereas inversely proportional to the moisture content. Compared with infrared drying, microwave drying reduced the drying time significantly. Proper microwave power can reduce U EC by 9% to 26%.
[中图分类号]
[基金项目]
2013 年安徽省住房城乡建设科学技术计划项目( 2013YF234)