真空干燥动力学实验平台的设计及测试

真空干燥既能保证干燥后物料品质, 又能提高干燥速率, 且具有干燥温度低, 温差热应力小和适用于热敏性物料干燥等优点。相对于传统热风干燥, 作为热敏性作物的稻谷采用真空干燥可以有效降低爆腰率和提高发芽率。为研究稻谷真空干燥动力学特性, 设计搭建了可准确控制相对压力、温度并实时测量质量的干燥动力学实验平台。该平台包括真空控制模块、温度控制模块、质量称量模块、实时数据采集与控制模块以及数据处理模块。对实验平台的真空控制、温度控制和质量测量性能进行测试分析, 结果表明该平台能够实现相对压力和温度的准确控制并实现干燥数据的实时精确采集。

Design and Evaluation of Test Platform for Study on Vacuum Drying Kinetics

The test platform was designed, constructed and evaluated for experimental study of vacuum drying kinetics of paddy rice, a heat sensitive bio-material.When it comes to low burst-rate and high germination-rate, the vacuum drying outperforms the conventional hot air drying.The lab-built test platform comprised the units of pumping, heating with thermostat control, is-situ weighing of mass, real-time data acquisition/processing, various electronics sensing/control and a self-developed control program package based on Lab VIEW and MATLAB software.The test results included:a relative pressure range of-90~0.0 k Pa, a mass range of ≤ 200 g with a precision of±0.01 g and a temperature range of 23℃ to 110℃ with an accuracy of ±1℃.We suggest that the newly-developed test platform may be of some basis and technological interest in study on vacuum drying kinetics of crop seeds, including but not limited to paddy rice, wheat, soy bean and cotton.