胡萝卜太阳能低温吸附干燥特性与干燥模型研究

Study on Characteristics and Model of Solar Low-temperature Adsorption Drying for Fresh Carrot

以新鲜胡萝卜为研究对象,采用太阳能低温吸附干燥系统为试验设施,探讨干燥温度、相对湿度、干燥介质流速、载样量、胡萝卜切片厚度对胡萝卜太阳能低温吸附干燥特性的影响。结果表明,胡萝卜太阳能低温吸附干燥过程可以分为3个阶段:调整、恒速、降速干燥阶段;其中干燥温度对胡萝卜干燥的速率影响最显著,如50℃比10℃节时达59.7%,各因素对胡萝卜干燥的影响的主次顺序为干燥温度>相对湿度>干燥介质流速>切片厚度>载样量;采用数学软件选用3种模型对试验数据进行计算拟合,胡萝卜干燥数学模型与Page模型拟合程度最高,胡萝卜太阳能低温吸附干燥数学表达式为MR=exp(-0.011666 t^1.62715);此模型的建立为脱水胡萝卜太阳能低温吸附干燥的生产应用提供理论支撑。

By taking fresh carrot as the research object and by using the solar low-temperature adsorption drying(SLAD)system developed by our unit as the experimental facility,the effects of different factors including drying temperature,relative humidity,drying medium flow rate,sample load and material thickness on SLAD characteristics and mathematical model for fresh carrot were investigated in this paper.The results show that the SLAD process of carrot can be divided into three stages:adjustment,constant rate and reduced rate drying processes;Among those factors,the effect of drying temperature on drying rate of fresh carrot was most significant,for example,the drying rate at 50℃was 59.7%more than that at 10℃,the order of priority of the effects of the factors on carrot drying was:drying temperature>relative humidity>drying medium flow rate>material thickness>sample load;Three models selected by mathematical software were used to perform calculation fitting for the experimental data,and the degree of fit of mathematical model for carrot drying with Page model was highest.The mathematical expression of SLAD for fresh carrot was MR=exp(-0.011666 t1.62715).The establishment of this model provides a theoretical support for application of SLAD of dewatered carrot in production.