烤烟烘烤过程风机频率对叶温和烟叶变黄失水的影响

Influence of Fan Frequency on Leaf Temperature,Yellowing and Dehydration during Tobacco Bulk Curing

研究烤烟烘烤过程风机频率对叶温和烟叶变黄失水的影响,以期为风机频率的筛选提供理论依据。设置全程30 Hz、全程40 Hz和全程50 Hz 3个档次的风机频率,测定不同温度下的叶温不均匀度、烟叶的颜色参数和失水指标,分析叶温不均匀度和变黄失水协调程度的关系。结果表明,各温度下叶温不均匀度最小的频率为30 Hz(36℃)、40 Hz(38℃)、50 Hz(42℃)、50 Hz(48℃)、40 Hz(54℃)、30 Hz(68℃)。在烟叶变黄方面,取样温度36—42℃时,30 Hz的变黄程度和黄蓝值最高;取样温度48—68℃时,50 Hz的变黄程度、亮度值和黄蓝值最高。在烟叶失水方面,取样温度38—48℃时,50 Hz的失水程度最高;取样温度38—68℃时,30 Hz的厚度收缩率最高;横向卷曲度和卷曲度先减小后增大,整体上以50 Hz最高。各温度下变黄失水协调程度最好的频率为30 Hz(36℃)、40 Hz(38℃)、50 Hz(42—68℃)。叶温均匀是烟叶变黄失水较协调的特征,可以将烘烤过程中叶温不均匀度的高低作为筛选各温度下风机频率的重要依据。

In order to provide a theoretical basis for the screening of fan frequency,influence of different fan frequency on leaf temperature,yellowing and dehydration during tobacco bulk curing was studied.The fan frequencies of 30 Hz,40 Hz and 50 Hz in the whole process were set,and the non-uniformity of leaf temperature,color parameters and water loss index of tobacco leaves at different temperatures were measured,and the relationship between non-uniformity of leaf temperature and yellowing dehydration coordination was analyzed.The results showed that the frequencies of the minimum leaf temperature unevenness at each temperature were 30 Hz(36℃),40 Hz(38℃),50 Hz(42℃),50 Hz(48℃),40 Hz(54℃),30 Hz(68℃).In terms of yellowing of tobacco leaves,the yellowing degree and yellow-blue value of 30 Hz were the highest when the sampling temperature was 36—42℃,and the yellowing degree,brightness value and yellow-blue value of 50 Hz were the highest when the sampling temperature was48—68℃.In terms of water loss of tobacco leaves,the water loss degree of 50 Hz was the highest at the sampling temperature of 38—48℃;the thickness shrinkage rate of 30 Hz was the highest at the sampling temperature of 38—68℃;the horizontal curling degree and vertical curling degree first decreased and then increased,and overall reached the maximum at 50 Hz.The best frequencies of yellowing and dehydration coordination at each temperature were 30 Hz(36℃),40 Hz(38℃),and 50 Hz(42—68℃).The uniformity of leaf temperature is a relatively coordinated feature of tobacco leaves turning yellow and losing water.The degree of non-uniformity of leaf temperature during the curing process can be used as an important indicator for screening the frequency of fans at different temperatures.