过热蒸汽干燥对玉米裂纹率的影响及其工艺优化

Effects of superheated steam drying on stress-crack index of maize and its process optimization

为降低高温快速干燥后玉米裂纹率,分别以热风和过热蒸汽为干燥介质,农户田间玉米为供试材料,对比研究在不同干燥温度、风速、缓苏温度条件下玉米裂纹率和裂纹表现形式的变化规律。结果表明,在相同的工艺参数条件下过热蒸汽干燥后玉米裂纹率均低于热风干燥且具有较好的裂纹表现形式,优化后工艺参数为过热蒸汽温度150℃、风速3 m/s、缓苏温度50℃。玉米过热蒸汽干燥及缓苏操作可以提升干燥效率的同时保证较低的玉米裂纹率,具有较大的开发价值。

To reduce the stress-crack index of maize after fast drying at high temperature, respectively with hot air and superheated steam as drying medium, maize as tested materials, comparative study of stress-crack index and forms regulation of maize in different drying temperature, velocity and tempering temperature, the optimum craft for maize superheated steam drying were studied. The results showed that superheated steam drying stress-crack index of maize were lower than that of the hot air drying and with a better crack form under the condition of the same parameters. The optimum craft were as follows ： superheated steam temperature 150 ℃, velocity 3 m/s, tempering temperature 50 ℃. Maize with superheated steam drying and tempering operation could improve drying efficiency and ensure lower stress-crack index and had a great value for development.