<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Vegetable drying is an energy consuming procedure despite the fact that it is the most efficient way to preserve agricultural products. This study investigates a new way to dry good quality garlic at lower cost. Thin garlic layer was submitted to free convection airflow at air drying temperature of 40 °C, 50 °C, and 60 °C. Using the slope method, effective diffusivity coefficient was determined at each drying temperature during the first and second falling drying rate periods. Considering the former, it increased with increasing temperature. In relation to latter, it decreased with the temperature increase. However, at low drying temperatures, process keeps on going to very low moisture content; and it develops to an asymptotic value at high temperatures, indicating that shrinking at high temperature prevents evaporation of some residual moisture. Considered separately, these temperatures do not reflect the conditions met in solar drying, since in solar systems, air temperature increases during the day with increasing solar radiation. Therefore, characterization of garlic drying by means of step temperature varying – the first hour of drying at 40 °C; the second hour of drying at 50 °C, and the remaining time of drying at 60 °C – might better correspond with conditions under solar drying and result in better understanding of the process.</p></abstract>

Vegetable drying is an energy consuming procedure despite the fact that it is the most efficient way to preserve agricultural products. This study investigates a new way to dry good quality garlic at lower cost. Thin garlic layer was submitted to free convection airflow at air drying temperature of 40 °C, 50 °C, and 60 °C. Using the slope method, effective diffusivity coefficient was determined at each drying temperature during the first and second falling drying rate periods. Considering the former, it increased with increasing temperature. In relation to latter, it decreased with the temperature increase. However, at low drying temperatures, process keeps on going to very low moisture content; and it develops to an asymptotic value at high temperatures, indicating that shrinking at high temperature prevents evaporation of some residual moisture. Considered separately, these temperatures do not reflect the conditions met in solar drying, since in solar systems, air temperature increases during the day with increasing solar radiation. Therefore, characterization of garlic drying by means of step temperature varying – the first hour of drying at 40 °C; the second hour of drying at 50 °C, and the remaining time of drying at 60 °C – might better correspond with conditions under solar drying and result in better understanding of the process.

Improved Procedure for Natural Convection Garlic Drying

Acta Technologica Agriculturae

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

{"article-title":"Improved Procedure for Natural Convection Garlic Drying"}

Vegetable drying is an energy consuming procedure despite the fact that it is the most efficient way to preserve agricultural products. This study investigates...

Improved Procedure for Natural Convection Garlic Drying

Published Online: Jun 05, 2020

Page range: 92 - 98

DOI: https://doi.org/10.2478/ata-2020-0015

Keywords
free convection airflow, stepwise increasing temperature, solar drying, effective diffusivity

© 2020 Amor Bouhdjar et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Improved Procedure for Natural Convection Garlic Drying

Published Online: Jun 05, 2020

Page range: 92 - 98

DOI: https://doi.org/10.2478/ata-2020-0015

Keywordsfree convection airflow, stepwise increasing temperature, solar drying, effective diffusivity

© 2020 Amor Bouhdjar et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
free convection airflow, stepwise increasing temperature, solar drying, effective diffusivity