Study On Rotary Ventilation Cylinder Drying Characteristics And The Impact Of Different Drying Methods On Rice Quality

Currently,wet grain processing,quality assurance and storage loss are common problems in rural areas.In this case,the Academy of State Administration of Grain designed a new type of drying granary for farmers—rotary ventilation cylinder.In this paper,based on the study of the drying characteristics of rice in rotary ventilation cylinder,the effects of rotary ventilation cylinder drying,natural drying and mechanical drying on the quality of rice were studied.The following conclusions were drawn:(1)Using mechanical ventilation for drying rice in a rotary ventilation cylinder,it takes 28 days to reduce the moisture of 9.80 tons rice from 23.11%to 13.81%,the average daily precipitation is 0.33%,and the unit precipitation energy consumption is3.47kW?h/(1%?t).During drying,the inner layer of rotary ventilation cylinder had fast precipitation velocity and the outer layer is slow.The whole water showed uniform distribution—gradient distribution—uniform distribution trend.At the end of drying,the moisture in the whole cylinder was uniform distributed.During the drying period,the highest total number of fungal spores was 4.02×10~5/g,indicating that the rice in the rotary ventilation cylinder was within a safe level,which verified the feasibility of the rotary ventilation cylinder for grain precipitation.(2)By using the auxiliary heating device to do rice drying test in the rotary ventilating cylinder,it takes 13 days to reduce the moisture of 10.00 tons rice from 19.85%to 13.03%,the average daily precipitation is 0.52%,and the unit precipitation energy consumption is7.62kW?h/(1%?t).During drying,the inner layer of rotary ventilation cylinder had rapid precipitation and the outer layer is slow.The highest total number of fungal spores was3.42×10~5/g,which was within safe level.At the end of drying,the moisture gradients of the inner and outer layers of rice are larger,and evenness of the precipitation is worse than the mechanical ventilation rice drying.(3)By natural drying,it takes 28 days to reduce the moisture of 1.60 tons rice from23.11%to 14.38%,and the average daily precipitation is 0.31%.During drying process,the highest total number of fungal spores was 6.75×10~5/g,which was close to the fungal hazards level.Mechanical drying reduced the moisture of 10.0 tons rice from 23.11%to13.80%for a total of 5h,the drying size was 9.31%,the drying capacity was 18.62 t/h,and the drying rate was 1.86%/h.The variation coefficient method was used to comprehensively compare the quality of rice treated with three different drying methods.The scores were 0.7503 for rotary ventilation cylinder,0.5274 for natural drying,and0.3328 for mechanical drying,indicating that the quality of rice after rotary ventilation cylinder drying was the best.(4)After different drying methods,rice was subjected to storage tests under 5temperature conditions.The results showed that the germination rate of rotary ventilation cyinger drying rice and natural drying rice was on the rise,and mechanically drying rice had almost no change.Head rice yield showed a downward trend.The higher the temperature,the greater the drop of head rice yield;Amylose increased slightly in fluctuation;The fat acidity showed a gradual upward trend,and the higher the temperature,the faster the increase;the taste value showed a gradual decline,and the higher the temperature,the faster the decline.Under the condition of 25°C,comparing quality changes of rice dried by three different methods after 120d,the results show that the drying treatment of rotary ventilation cylinder can keep the quality of rice during storage and slow down its aging speed.