Indirect solar dryer with a single compartment for food drying. Application to the drying of the pear

This work presents the experimental results relating to agri-food drying in an indirect solar dryer with a single compartment. This compartment has four facades. Which consist of: glazed cover above and aluminium walls at the bottom and an air layer bounded by them. The drying chamber is under the aluminium walls. The layers of glass, air and walls subjected to the solar flux act as an absorber and play an important role to enhance the heat transfer in the drying chamber. The designed dryer is a single compartment with a south-oriented roof. Moreover, this roof has two inclined surfaces with optimal angles of 50 and 34 from the horizontal plane to absorb the maximum solar irradiation during the year. This dryer is made up in the solar energy and environmental laboratory of the Faculty of Sciences of Rabat city (longitude: 649'57', latitude: 3400'47'). After this choice, the study presents the thermal and economic performances of the designed dryer. Firstly, in terms of thermal performance, the experimental tests show that the relative humidity inside the dryer can decrease by up to 10% compared to an external relative humidity between 70 and 90%, and the average temperature inside the dryer was 50 C, in comparison to the average ambient temperature is 25 C. These thermal performances allowed the pear to dry just after 24 h. Secondly, in terms of economic cost, this new design of the solar dryer is less expensive than conventional two-compartment solar dryers and encourages its use by the local producer.

Automated summary

This study presents the experimental results of an indirect solar dryer with a single compartment. The unique design of the dryer enhances heat transfer and drying efficiency, resulting in decreased relative humidity and faster drying time for agricultural products. The cost-effective nature of this dryer makes it an attractive option for local producers.