水稻混流干燥工艺的试验研究

Experimental study on continuous mixed-flow drying technology for rice

混流式粮食干燥机是当前中国应用最广泛的粮食干燥机机型，但由于水稻干燥的特殊性，横流循环干燥机基本上是水稻干燥的唯一机型，这造成国内粮食干燥机的利用率普遍不高。为了充分提高现有混流式干燥机的利用率，利用移动式混流粮食干燥机进行了稻谷的干燥试验。研究了不同的风温、不同的干燥缓苏比对稻谷爆腰率及降水速率的影响规律。研究结果表明：稻谷混流干燥过程中应有必要的缓苏。当干燥缓苏比一定时，烘干温度与爆腰率增值存在线性关系；当烘干温度一定时，干燥缓苏比与爆腰率增值存在线性关系;采用混流干燥机干燥稻谷时热风温度可以高于横流干燥机5～10℃，降水速率最高可达1．3％／h。

Mixed flow grain dryer is one of the most widely used grain dryers in China. Because of the characteristics of rice drying, the cross-flow recirculating dryer is the only one type of rice dryer basically. It is why the utilization ratio of grain dryer is not high generally in China. In order to improve the utilization ratio of mixed flow grain dryer, a great number of tests on rice drying have been carried out with movable mixed flow grain dryer. The effects of different heat-air temperatures, different ratios of drying time to tempering time on rice fissure ratios and moisture removal rate of the dryer were studied. The results show that the tempering time is necessary on mixed flow drying of rice. Given the ratio of drying time to tempering time, the relationship between drying temperature and the increment of rice fissure ratio is linear. Given the heat-air temperature, the relationship between the increment of fissure ratio and the ratio of drying time to tempering time is linear too. The drying air temperature applied in mixed flow dryer is 5-10℃higher than that in cross flow dryer, and the fastest moisture removal rate is 1.3%/h.