紫花苜蓿低温干燥特性试验研究

Study on Low Temperature Drying Characteristics Experiment of Alfalfa

研究了干燥温度在40～80℃范围内的紫花苜蓿干燥过程,并分析不同干燥因素:热风温度、流速、苜蓿初始密度及苜蓿初始含水率对其干燥速率的影响。结果表明,干燥温度及热空气流量是影响苜蓿干燥速率的重要因素,高温高流量干燥效果最好。但低温情况下,气流的影响在干燥后期效果不明显。苜蓿初始含水率和堆放密度对干燥速率的大小、恒速干燥阶段的持续时间及干燥速率变化率有影响:密度大,相应干燥速率下降。

Temperature ranged from 40℃ -80℃ drying experiments of alfalfa were performed to determine the effect of the drying air temperature, air velocity, initial density and initial moisture content. Result showed that drying air temperature and air velocity are the important factors during drying process, the high temperature and high air velocity, the high drying rate, however, it is no difference during the late period of drying process in low temperature, high air velocity. The initial density and initial moisture content of alfalfa influence the decline of drying rate and the lasting time of constant rate drying period.