بررسي اثر دماي هواي ورودي بر بازده حرارتي خشك كن هاي بستر ثابت شلتوك

Investigation of effective air temperature in batch dryers on thermal efficiency of paddy rice

Considering the importance of the International trade in todayʹs life, the incorporation of cost of fuel consumption in the price of agricultural products is inevitable. In the process of paddy rice production the optimization of fuel consumption in dryers is matter of concern. An investigation has been conducted in order to study the fuel consumption in drying the Khazar paddy rice variety under two thermal levels of 35 and 65 °C air temperature using a laboratory dryer with a known drying efficiency. Result of this study shows that the various parameters such as entrance air temperature, moisture content (>14%) and the specific thermal difference between paddy rice and water have considerable impact on the thermal efficiency of drying process. Increasing the dryer temperature, causes the reduction in the time of drying from 10 to 4hours and increase in the adsorbed heat in paddy rice moisture, while the discharging air temperature decreases at both 35 and 65°C air temperature levels. The average thermal efficiency at both 35 and 65°C air temperature levels were 36.5 and 26.27%, respectively. As the moisture content of the paddy rice changes from 44 to 15% at 35 °C, and from 41 to 25% at 65°C air temperature the thermal efficiency also decreases.