苜蓿茎秆压扁系数对水分散失的影响研究

Water loss of alfalfa stem affected by flattening coefficient

为深入研究苜蓿压扁系数与含水率变化的关系,以苜蓿晾晒过程中主茎杆为对象,用研制的压扁间隙性能试验台,对不同部位段苜蓿主茎杆进行不同压扁系数条件下的含水率变化对比试验,研究不同压扁程度对紫花苜蓿茎秆不同部位的水分散失规律影响。结果表明:温度25℃,相对湿度50%RH,光照度11 000lx条件下,压扁系数55%的苜蓿茎秆内不同部位段的含水率变化较一致。在苜蓿压扁晾晒过程中增加压扁的程度虽然可以增加干燥速度,但茎秆不同部位的水分散失速度对压扁程度的敏感度不同。靠近根部的茎秆对不同的压扁系数都比较敏感,其水分散失速度随压扁系数的减小明显的逐步增大。压扁系数70%以上的轻度压扁不能显著加快茎秆中上部的干燥速度。

To study the relationship between flattening coefficient and the moisture content changes of alfalfa main stem,a flattening testing device was designed,which provides adjustable spacing between the flattening rolls.Different parts of the main stem segments under different moisture content and flattening coefficients were tested.The water loss laws of alfalfa stems affected by different condition levels to different parts were studied.The results showed that：Under the conditions of temperature 25 ℃,relative humidity 50% RH,11 000 lx light illumination and 55% flattening coefficient conditions,moisture content changes in different parts of stem were basically the same;Although,the drying speed of alfalfa stem could be increased by using greater flattening coefficient in alfalfa field drying,and the stem water loss sensitivity was different in different parts by using different flattening coefficients.The stem closer to the root was more sensitive to different flattening coefficients,and its water loss rate was gradually significant increased with the decrease of flattening coefficients.The drying speed of the upper stems was not significantly speed up using flattening coefficient more than 70%（slightly flattening）.