Development and optimization of a solar greenhouse dryer for drying rice

Drying of rice is especially problematic in monsoon climates areas such as the Philippines where there is much precipitation during the harvest period. In the Philippines “highway dryers” are used, which are long stretches of mats laid alongside rural roads where wet paddy is spread out to dry in the open sun in sufficiently thick layers, raking the grain while drying to continuously mix it. This traditional practice can allow for grain germination and cracking, undesirable microbiological development and reduced overall product quality.

In response, the present study will propose a low-cost solution involving solar drying to reduce drying time and ensure a secure drying process. Different prototypes will be tested design based on the greenhouse concept in combination with natural and forced convection principles. Advanced simulation studies using Computation Fluid Dynamics (CFD) will provide additional in-depth understanding of the thermodynamics involved in the process, like mass balances, airflow and moisture transfer rates are required for further development of the dryer into a commercial product that will benefit farmers and drying service providers.