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Abstract: Solar dryers use free and renewable energy sources, reduce drying losses (as compared to sun drying) and show lower operational costs than the artificial drying, thus presenting an interesting alternative to conventional dryers. This work proposes to study the feasibility of a solar chimney to dry agricultural products. To assess the technical feasibility of this drying device, a prototype solar chimney, in which the air velocity, temperature and humidity parameters were monitored as a function of the solar incident radiation, was built. Drying tests of food, based on theoretical and experimental studies, assure the technical feasibility of solar chimneys used as solar dryers for agricultural products. The constructed chimney generates a hot airflow with a yearly average rise in temperature (compared to the ambient air temperature) of 13 ± 1 °C. In the prototype, the yearly average mass flow was found to be 1.40 ± 0.08 kg/s, which allowed a drying capacity of approximately 440 kg.

Keywords: Solar chimney; Solar drying; Technical feasibility

by André G. Ferreira 1, Cristiana B. Maia 2, Márcio F.B. Cortez 3 and Ramón M. Valle 3
1. Departamento de Ciências Exatas e Tecnologia, Centro Universitário de Belo Horizonte, Av. Professor Mário Werneck, 1685. Buritis, Belo Horizonte, Minas Gerais, CEP 30455-610, Brazil; Tel.: +55 31 3498 0196; fax: +55 31 3378 9294
2. Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500 – Coração Eucarístico, Belo Horizonte, Minas Gerais, CEP 30535-901, Brazil
3. Departamento de Engenharia Mecânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627 – Campus Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brazil

Solar Energy via Elsevier Science Direct www.ScienceDirect.com
Volume 82, Issue 3; March, 2008; Pages 198-205
http://dx.doi.org/10.1016/j.solener.2007.08.002