蚕茧干燥工艺中相对湿度的控制及与茧层含水率关系的研究

Studies on the Control of Relative Humidity During Drying Process of Silkworm Cocoon and Relationship With Water Contents of the Cocoon Shells

研究认为 :蚕茧干燥中室内相对湿度峰值不出现在临排气前的 82℃时段 ,而是位于鲜茧进灶 10min左右的 70℃附近 ;在现行干燥设备及控湿条件下 ,等速干燥阶段空气相对湿度基本符合干燥工艺要求 ,但减速干燥阶段则相差较大 ,应进行人工补湿。对茧层含水率的测定分析认为 ,预热段加温速度会对茧层含水率产生影响 ,快速加温有利于缩短杀蛹时间 ,维持较适当的茧层含水率。但生产上以中速偏快加温方式 (加温速度 1 0～ 1.2℃ /min)为宜。茧层含水率高低与灶内空气相对湿度的大小有密切联系 ,二者相关系数达 0 8312 ,且相对湿度 2 0 %及以上时与 10

The result of this study indicates that the peak value of relative humidity in the drying chamber appears at the period of 70℃,10 minutes after the fresh cocoon was got into the drying chamber,instead of the period of 82℃ before the ventilation.Under the current drying and humidity controlling conditions,the relative air humidity can basically meet with the demands of drying process at the even rate drying stage ,but not meet with the demands of moisture at the decreasing rate stage.The moisture defficiency can be worked out by artificial adding moisture.The sampling results of water contents of cocoon shell showed:the rate of temperature increasing will affect the water content of the cocoon shells during early heating period,the high speed of temperature increasing process can be beneficial to shorten the period of pupa killing which can keep water content of cocoon shell at a relative levels.However, the middle speed or above 1.0～ 1.2 ℃/min will be suitable in practice and the low speed of temperature increasing should be avoided;the status of water contents of cocoon shells is closely correlated with the conditions of relative air humidity in the drying chamber,the correlation coefficient reach up to 0.831 2.The differences between relative humidity above 20% and below 10% are significant statistically.