Open Access

ARTICLE

Design and Development of a Forced-Convection Solar Dryer: Application to Beetroot Cultivated in Béchar, Algeria

Benali Touhami¹, Bennaceur Said¹, Atouani Toufik¹, Lammari Khelifa², Ouradj Boudjamaa², Bounaama Fateh², Belkacem Draoui², Lyes Bennamoun^3,*

1 Laboratory for the Development of Renewable Energies and Their Applications in Saharan Areas (LDREAS), Faculty of Exact Science, University of Tahri Mohamed Béchar, P.O. Box 417, Béchar, 08000, Algeria
2 Laboratory of Arid Zones Energetic-(ENERGARID), Faculty of Technology, University of Tahri Mohamed Béchar, P.O. Box 417, Béchar, 08000, Algeria
3 Department of Mechanical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada

* Corresponding Author: Lyes Bennamoun. Email:

(This article belongs to the Special Issue: Recent Advance and Development in Solar Energy)

Energy Engineering 2026, 123(2), 17 https://doi.org/10.32604/ee.2025.073329

Received 16 September 2025; Accepted 27 November 2025; Issue published 27 January 2026

Abstract

The aim of this study is to design, build, and evaluate an indirect forced convection solar dryer adapted to semi-arid climate, such as that of Béchar situated in the west south region of Algeria. The tested drying system consists of a flat-plate solar collector, an insulated two-chamber drying unit, and an Arduino-controlled device that ensures uniform temperature distribution and real-time monitoring using DHT22 sensors. Drying tests were conducted on locally grown beet slices at air temperatures of 45°C, 60°C, and 80°C, with a constant air velocity of 1.2 m/s and a mass flow rate of 0.0027 kg/s. The collector reached a maximum temperature of 65°C, with thermal efficiencies ranging from 20% to 35%. In these conditions, the drying times were cut down to 200–300 min, and the beet’s moisture content dropped to 0.47, 0.27, and 0.24 g/g dry matter, respectively. The experimental data were fitted to several empirical models, including the logarithmic model. The modelled results showed strong agreement with the experimental ones (correlation coefficients r = 0.9919–0.9989; standard errors SE = 0.017–0.043; root-mean-square errors RMSE = 0.016–0.027). The results demonstrate that the system operates efficiently and consistently, making it suitable for the sustainable drying of agricultural and medicinal products in arid climates.

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