Performance Evaluation of Indirect Solar Dryer under Passive and Active Modes during Drying Beetroot Slices

Abstract

In the present work, the drying characteristics of beetroot slabs, thermal and performance characteristics were estimated and analyzed in passive (mode-A) and active (mode-B) indirect solar dryers (ISD). The conventional mode-A dryer was updated with a diverging duct that comprises direct current fans run by photo-voltaic panels to make the mode-B dryer. In mode-B, the drying time of 16.67 and 42.31% is saved compared to mode-A and open sun drying (OSD), respectively, to achieve a final moisture content of 0.057 from 7.7535 kg/kg of dry basis. The Two-term exponential model was observed to be a perfect fit model for beetroot slices in both modes of ISD and OSD, respectively. The improvements in drying rate, dryer and collector efficiencies and specific moisture extraction rate in mode-B over mode-A are found to be 19.97, 19.18, 8.34 and 14.23%, respectively. It is found that mode-B has better thermal and performance properties than mode-A.

Acknowledgements

The authors indebted to the Department of Mechanical Engineering, NIT Warangal, India for supporting the project in finance which is referred as: NITW/MED/Head/2015/408 dated 3^rd Dec. 2015.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Vishnuvardhan Reddy Mugi

Vishnuvardhan Reddy Mugi is presently working as an Assistant Professor in the Department of Mechanical Engineering, B V Raju Institute of Technology Narsapur, India. He graduated in Mechanical Engineering from RGUKT R K Valley, India in 2014. He completed his Master of Engineering in Energy Engineering and Management from NIT Calicut, India in 2017. He obtained his Ph.D. from NIT Warangal, India in 2023. He is working in the area of solar drying, renewable energy, thermal energy storage, biodiesel production, etc. He has 25 SCI publications and conference papers.

Mulatu Chake Gilago

Mulatu Chake Gilago is a Ph.D. student in the Mechanical Engineering Department at the National Institute of Technology Warangal, India, under the supervision of Dr. V. P. Chandramohan. He is also a staff member in Mechanical Engineering Department at Wachemo University, Ethiopia. He received his M.Sc. degree in Materials Science from Hawassa University, Ethiopia. He is currently researching experimental investigation of solar dryers.

Velayudhan Parvathy Chandramohan

Velayudhan Parvathy Chandramohan is presently working as a Professor in the Department of Mechanical Engineering, National Institute of Technology Warangal, India. He graduated in Mechanical engineering from Manonmaniam Sundaranar University in 2001, completed his Master of Engineering in Thermal Power Engineering from Annamalai University in 2002 and MBA Project Management in 2009. He obtained his Ph.D. from IIT Delhi, India in 2012. His research interests are computational fluid dynamics, convection and conduction heat transfer, drying and simultaneous solution of heat and mass transfer, solar energy, solar updraft tower and solar vortex plant. He has more than 150 publications in international reputed journals, book chapters and conferences. He is handling a lot of sponsored research projects from various funding sources. He got various awards such as a Gold medal for ME (Thermal Power) and Dr. S. Sathik prize from Annamalai University, DST-SERB Empowerment Scheme Award 2016, and ScienceDirect TOP 25 Hottest Articles award. He is serving as editorial board member and reviewer in various reputed journals in his field of expertise. ORCID: 0000-0002-8680-8363

Valasingam Suresh Babu

Valasingam Suresh Babu is presently working as a Professor and Head of the Department in the Department of Mechanical Engineering, National Institute of Technology Warangal, India. He graduated in Mechanical Engineering from JNTU College in 1995, completed his Master of Engineering in Design Engineering from IIT Delhi, India in 1996. He obtained his Ph.D. from IIT Delhi, India in 2013. His research interests are machine dynamics, analysis of mechanism, composite material, functional graded materials, condition monitoring and fault diagnosis. He has more than 50 SCI publications and conference papers.