Evaluation on microwave drying of waste paper towel with multi-magnetron and mode stirrer. Issue 7 (3rd May 2021)

• Record Type: Journal Article
• Authors: Zhang, H. S.; Chen, M. Q.; Fu, B. A.; Li, Q. H.
• Is Part Of: Drying technology. Volume 39:Issue 7(2021)
• Page Start: 882
• Page End: 895
• Publication Date: 2021-05-03
• Subjects: Paper towel -- microwave drying -- kinetics -- multi-magnetron -- mode stirrer -- uniformity; Drying -- Periodicals; Desiccation; 660.28426
• DOI: 10.1080/07373937.2020.1728306
• Languages: English
• ISSNs: 0737-3937

Abstract

Abstract: The thin-layer drying performance for a typical solid waste (paper towel) was evaluated at hot air temperatures of 90–130 °C (0.5 m/s air velocity) and microwave powers of 200–800 W in a bench-scale microwave combined convective drying setup. Influences of hot air and radiation modes (multi-magnetron and mode stirrer) on the temperature distribution uniformity were examined. The effective moisture diffusivities of sample during pure hot air drying ranged from 6.07 × 10 −9 to 1.31 × 10 −8 m 2 /s, while those for pure microwave drying were from 3.54 × 10 −8 to 1.52 × 10 −7 m 2 /s. The apparent activation energy of sample in pure hot air drying was estimated as 23.17 kJ/mol, while that for pure microwave drying was 22.64 W/g. The effective moisture diffusivities of sample in combined drying ranged from 5.71 × 10 −8 to 2.05 × 10 −7 m 2 /s. The heating uniformity for microwave was improved effectively by the combined drying. The application of the mode stirrers and multi-magnetron radiation modes further improved the microwave heating uniformity. Midilli model can well describe moisture content of paper towel over time.