Experimental study on continuous mixed-flow drying technology for rice

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.