Effect of aeration strategy on moisture removal in bio-drying process with auto-controlled aeration system

• Published in: Drying technology Vol. 40; no. 10; pp. 2006 - 2020
• Main Authors: Park, Jae-Ram, Lee, Dong-Hoon
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 12.07.2022; Taylor & Francis Ltd
• Subjects: Aeration; aeration strategy; Air flow; auto-controlled aeration system; Bio-drying; Drying; Evaporation; Exhaust gases; Flow rates; Flow velocity; Gas temperature; mechanically sorted residue; Moisture effects; Moisture removal; Temperature gradients; Vertical distribution
• ISSN: 0737-3937; 1532-2300
• DOI: 10.1080/07373937.2021.1912080

Moisture removal during bio-drying with an auto-controlled aeration system was investigated under four combined aeration strategies for a set range on exhaust gas temperature and air-flow direction. The exhaust gas temperature was kept stable within the set range by varying the air-flow rate under upward aeration, although there was a horizontal temperature gradient in the waste layer, irrespective of air-flow direction. This aeration system enhanced drying performance such that 74.7% of initial moisture weight was removed for 14 days, on average. Moreover, inversion of the air-flow direction induced as much uniformity of the vertical moisture distribution as turning the waste matrix. We evaluated moisture removal in the bio-drying process in terms of performance and efficiency and confirmed that the air-flow rate significantly affected both indicators. To achieve rapid and efficient moisture removal during bio-drying, it is important to control the air-flow rate in response to the exhaust gas temperature to fully utilize metabolic heat for evaporation.