Experimental investigation of drying kinetics of green chilli and okra using indirect solar dryer with evaluation of dryer performance

Abstract

In this study, green chillies and okra were dried using an indirect type solar dryer ITSD dryer and their drying kinetics were evaluated. The initial moisture content (MC) of green chilli was 8.3984 kg/kg of dry basis (db) and it was reduced to final MC of 0.2218 kg/kg of db. Also, MC of okra reduced from 10.1234 to 0.3348 kg/kg of db. The efficiency of solar air collector and the drying efficiency were estimated during the drying of green chilli and okra. The activation energy was found to be 32.484 and 25.330 kJ/mol and effective moisture diffusion coefficient was found to be 1.464 × 10⁻⁹ and 5.1798 × 10⁻⁹m²/s for green chilli and okra, respectively. The surface transfer coefficients (both heat and mass) of green chilli and okra were estimated. Uncertainty analysis was performed on all the measured and derived drying parameters.

KEYWORDS:

• Drying kinetics
• solar air collector
• drying rate
• activation energy
• surface transfer coefficients

Acknowledgements

The authors would like to thank Department of Mechanical Engineering, National Institute of Technology Warangal, India for funding this project. The project approval number is: NITW/MED/Head/2015/408. The author acknowledges with thanks the support received by way of proof reading from Dr. M.R. Vishwanathan, Assistant Professor of English, Head, Humanities and Social Science Department, NIT Warangal, India.

Disclosure statement

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

Additional information

Funding

This work was supported by National Institute of Technology Warangal: [Grant Number NITW/MED/Head/2015/408].