Evaluation of The Drying Process of Paddy Rice with a Biogas Continuous Rotary Dryer

Abstract

A rotary drum dryer was designed and developed for drying paddy rice. A novel design thermal unit is designed and fabricated to provide the heat energy required for drying process. This thermal unit can be operated using liquid petroleum gas (LPG) or biogas as a renewable resource. Most of artificial drying systems contaminate the dried material by the exhaust gases and negatively affect the germination ratio. The advantage of this new thermal unit is that the exhaust gases are vented from the chimney and only clean hot air contacts the dried material. Also, a novel technique is used for transporting dried material depends on the venturi theory where the phenomenon of fluidized bed occurs and partial grain drying process happens. A set of preliminary experiments were conducted to arrive at suitable blower speed, hot air velocity and rotary drum speed. The main drying process happened in the rotary drum dryer where a great disturbance of dried material happened due to stirring and air velocity combined effects. The results showed that the air velocity of 10 m/s and feeding rate of 75 kg/cycle had the greatest effect on drying rate and lowest effect on specific energy consumption. Also, the rotary drum speed of 10 rpm was suitable regarding the drying rate and specific energy consumption at feeding rate of 75 kg/cycle. This drying system incurred a lower cost per kilogram compared to other methods.

The Mathematical Modeling, Diffusivity, Energy, and Enviro-Economic Analysis (MD3E) of an Automatic Solar Dryer for Drying Date Fruits

“…It is critical to eliminate moisture from the product using heat to ensure safe storage, avoid marketing degradation within a set duration, ease processing, and permit product transportation [2,6]. Sun drying is the traditional way of drying agricultural goods in many developing countries, including Egypt, and entails spreading the produce on an open floor or field under the sun for a certain period until the required moisture content is obtained [7][8][9]. However, this approach is prone to contamination by dust, dirt, sand particles, and insects [10,11].…”