GREENHOUSE SOLAR DRYER FOR DRYING ANDROGRAPHIS PANICULATA HERB

Abstract

This work presents an experimental performance of a greenhouse solar dryer for drying Andrographis paniculata herb. The dryer consists of a polycarbonate sheet covered on a concrete floor. The dryer is 9 m in width, 24 m in length and 4 m in height. Nine 15-W DC fans powered by two 50-W PV modules were used to ventilate the dryer. The dryer was used to dry 15 batches of Andrographis paniculata herb to investigate its performance. For each batch, 50 kilograms of Andrographis paniculata herb were dried in the dryer. Results obtained from the experiments showed that drying temperatures varied from 32^๐C to 65^๐C. In addition, the drying time for drying Andrographis paniculata herb was 1 day, compared to 3 days required for natural sun drying. Andrographis paniculata herb dried in the dryer were completely protected from rain and high-quality Andrographis paniculata herb were obtained. In addition, a neural network model was also studied. They are divided into two types: Type 1 (5:10:5:1) and Type 2 (5:10:5:3:2:1). The variables used in the model are solar radiation intensity, air temperature, air relative humidity, and airflow rate. Numerical solutions were obtained using C⁺⁺ programming. The results showed that the moisture content of Andrographis paniculata herb calculated from the model was consistent with the measurement results. Type 1 (RMSD) was 5.2% and R² was 0.9715, and Type 2 (RMSD) is 4.5% and R² is 0.9822.