اثر خشك كردن چندمرحله اي بر بازده تبديل و مدت زمان خشك كردن شلتوك كبري تجددي طلب

The Effect of Multi Pass Drying on Milling Yield and Drying Time of Paddy

in this study, the Khazar variety has been used. The statical analysis was carried out using factorial experiment by Completely Randomized Design (CRD) with three replications. The factors were initial moisture content of paddy in two level (16.3%± 0.7 and 20.5%± 1.5 in wet basis) and drying method in three level (one, two and three pass drying). The percentage of brown rice, head rice, broken rice and drying time were analyzed. In the first year, paddy with moisture content 19.6%, the single pass drying had 39.3% head rice (minimum amount) and three pass with 42.9% had maximum head rice.The maximum head rice was obtained with the two and three pass methods, and the minimum percent of head rice was associated with the single pass method in paddy with moisture content 15.70%. The result of second year showed that multi pass (three) drying with 56,6% maximum and single pass with 52.7% minimum amout of head rice were obtained when moisture content paddy was 21.80%. The minimum and maximum head rice were obtained in single and three pass drying method with 52.5% and 55.8% respectively for initial moisture content of paddy 16.20%. The result of this study showed that drying procedure was not significant on milling yield. The multi pass procedure was more efficient and economic because the dryer was used only when the kernel surfaces were relatively moist, as a result of tempering. In conclusion for Khazar variety with moisture content of 19.0-22%, three pass was an appropriate method and with moisture content of 15.5-17.0%, the method of two pass drying was recommended.