萝卜丝薄层干燥试验及其数学模型的建立

萝卜丝干燥是萝卜加工的重要环节。利用薄层干燥试验台，进行萝卜丝的薄层干燥试验，探讨热风温度、风速对干燥速率的影响。结果表明，萝卜丝干燥具有典型物料干燥的升温、等速、降速3个阶段，热风温度对干燥速率的影响比风速对干燥速率的影响显著。用BP神经网络建立萝卜丝干燥的数学模型，并与Page模型的模拟结果进行对比。结果表明，用BP神经网络预测的含水率比精度明显高于Page模型。

Experimental Study on Thin Layer Drying of Turnip Strips and Establishment of Mathematical Model

The experimental drying of turnip strips were car ried out in a thin-layer drying test rig and the effects of temperature and flo wrate of hot air on the drying rate were investigated. The experimental results show that the turnip strips drying appears three typical periods, the rising tem perature, the constant drying rate and the falling one. The temperature of hot a ir has a bigger effect on drying rate than air flowrate. A mathematical model of turnip strip drying based on BP neural network was established. Through fitting the measuring moisture ratio of some wind temperature and airflow speed using B P neural network model and traditional Page model respectively, we concluded tha t the moisture ratio predicted by a BP neural network model was more accurate th an that predicted by the Page model.