Design charts for in-store paddy drying under hot and humid climates

• Main Authors: Somchart Soponronnarit(King Mongkut's Institute of Technology Thonburi, Bangkok (Thailand). School of Energy and Materials), Pairoj, W.(King Mongkut's Institute of Technology Thonburi, Bangkok (Thailand). School of Energy and Materials), Adisak Nathakaranakule(King Mongkut's Institute of Technology Thonburi, Bangkok (Thailand). School of Energy and Materials), Somchai, C.(King Mongkut's Institute of Technology North Bangkok, Bangkok (Thailand). School of Energy and Materials)
• Format: Publication
• Language: English
• Published: Bangkok (Thailand) 1997
• Subjects: Chemicophysical properties; Design; Deterioration; Drying; Heat; Humidity; Mathematical models; Methods; Oryza sativa; Quality; Rice; Storage; Yields

Product quality, drying capacity and energy consumption have to be taken into consideration in a drying system design. Long period in-store drying of paddy may cause the deterioration fo product due to successive fungi, yellowing and dry matter loss. Determination of appropriate air flow rate and thickness of grain bed is usually a time-consuming process. The objectives of this paper are thus to develop the design charts for in-store paddy drying under tropical climates and to investigate appropriate design drying parameters. A near equilibrium drying model was developed. Effects of heat and moisture liberated from respiration process were included to improve accuracy of the model. Comparative results between experiment and simulation showed that they were in good agreement. Then simulation results under various conditions were used to construct four quadrant charts. From them, minimum specific air flow rates for different bed thickness (cubic m/min-cubic m of grain) which corresponded to the dry matter loss of 0.5 percent and 0.75 percent could be found. Other relevant parameters such as pressure drop, specific energy consumption and drying time could also be obtained from the charts.