高水分稻谷分程干燥工艺及效果

针对中国南方地区稻谷收获季节需及时干燥高水分稻谷的市场需求较大和粮食干燥机的保有量较少、干燥机的使用效率受气候条件影响的技术现状,将收获的稻谷分为较高水分干燥过程和较低水分干燥过程。当稻谷含水率高于18%时,采用56～85℃的干燥介质,降水速率为0.90～2.94%/h;当稻谷含水率小于等于18%时,采用50～58℃的干燥介质,降水速率为0.49～0.93%/h。在2次干燥过程之间,采用通风仓暂存。现场试验表明,与恒温干燥工艺相比较,分程干燥工艺在保证稻谷烘后品质的条件下,可缩短干燥时间约12.8h,平均降水速率提高0.7%/h,一个收获期内可使干燥机处理量增加225%,提高干燥机的使用效率152%,且总干燥成本降低5%,有助于又好又快地进行高水分稻谷的干燥。

Separating-process drying technology and efficiency for paddy with high moisture content

According to greater market demand that high moisture content paddy must be dried in time during the harvest in south of China and less stock of grain dryer as well as the use efficiency of dryer was affected by the climatic conditions, harvested paddy was divided into drying process of higher moisture content and lower moisture content. When the moisture content of paddy was higher than 18% and the air temperature was 56-85℃ , the drying rate was 0.90-2.94%/h. When the moisture content of paddy was lower or equal to 18%, air temperature should be 50-58℃ and the drying rate should be 0.49-0.93%/h. The technology of ventilation and temporary storage was applied during the two drying processes. Spot testing showed that the technique of separating-process drying could reduce the drying time about 12.8h and enhance the average drying rate 0.7%/h, and improve drying quality. Compared with constant temperature drying, the application of the technology could increase capacity 225% in a period of harvest and the use efficiency 152% of the dryer, meanwhile cut down total drying costs 5%. So it is possible for high moisture content paddy to be dried quickly and well.