Study of Large-scale Solar Dryers Equipped with Monitoring and Control Systems for Banana Drying

Abstract

This paper presents a study on the field performance of 18 large-scale greenhouse solar dryers equipped with remotely controlled monitoring and control systems. The dryers were built for the dried banana producers in Phitsanulok province in Thailand. These dryers were equipped with monitoring and control systems that allowed remote monitoring of operation parameters such as the drying air temperature, drying air relative humidity, and the weight and images of the bananas being dried through a mobile phone. In addition, the on-off controls of the LPG burners and AC fans were also controlled via a mobile phone. To investigate the performance of each dryer, 1200 kg of peeled bananas was dried in it. Bananas dried inside the dryers dried much faster than those dried outside the dryers that were under ambient conditions. Remote control of the monitoring and control systems using a mobile phone, facilitated a more convenient and efficient utilization of the dryers. An economic analysis of the dryers was also carried out. The results showed that the drying cost was 49 THB/kg, the payback period (without subsidy) was 4.88 years, and the internal rate of return was 16%.