石墨烯低温远红外辐射干燥稻谷干燥特性与品质研究

Drying Characteristics and Quality of Paddy under Low Temperatures and Far-infrared Drying Conditions of Graphene

为研究稻谷的石墨烯低温远红外干燥特性及其对稻谷干燥品质的影响,以辐射温度、排粮流量和除湿风量为影响因素,以整精米率和应力裂纹指数增值为评价指标,用自制的循环式石墨烯低温远红外干燥机进行稻谷干燥试验,通过BBD(Box-Behnken设计)响应面法,分析了低温远红外干燥对稻谷干燥品质的影响以及工艺参数优化。结果表明:影响稻谷干燥特性和品质的最主要因素是辐射温度,其次是排粮流量和除湿风量。随着辐射温度的升高,稻谷干燥速率和应力裂纹指数增值逐步增大,整精米率则逐步降低。与同温度的热风干燥相比,石墨烯低温远红外干燥平均干燥速率和干燥品质均有显著提高。经优化后,稻谷最佳石墨烯低温远红外干燥工艺条件为:辐射温度43℃、排粮流量4 kg/min、除湿风量193 m^(3)/h,此时应力裂纹指数增值为9,整精米率为79.75%,稻谷干燥品质最佳。这说明利用石墨烯低温远红外干燥稻谷,可以明显提高干燥速率并改善稻谷干燥品质。

In order to study the graphene low temperature far-infrared drying characteristics of paddy and its influence on the drying quality of rice,the IR temperatures,grain flow and dehumidification air volume were used as influencing factors,and the head rice rate and additional stress crack index were used as evaluation indexes.A self-made circulating graphene low temperature far-infrared drying machine was used to carry out paddy drying tests.The effect of low temperature far-infrared drying on paddy drying quality and the optimization of process parameters were analyzed.The results showed that the most important factors affecting the drying characteristics and quality of paddy were IR temperature,followed by grain flow and dehumidifying air volume.With the increase of IR temperature,the drying rate and additional stress crack index of paddy were increased gradually,while the percentage of head rice was decreased gradually.Compared with hot air drying at the same temperature,the average drying rate and drying quality of graphene low temperature far-infrared drying were significantly improved.After optimization,the optimal low temperature far-infrared drying conditions for paddy were as follows:IR temperature was 43℃,grain flow rate was 4 kg/min,dehumidification air volume was 193 m^(3)/h,stress crack index increment was 9,head rice rate was 79.75%,and paddy drying quality was the best.The results showed that using graphene to dry paddy at low temperature and far-infrared can significantly increase the drying rate and improve the drying quality of paddy.