Mango leather (Aam Papad) drying in hybrid greenhouse solar dryer with evacuated tube collector and finned drying tray: drying behavior and economic analysis

ABSTRACT

Mango is primarily produced in India, and being a seasonal fruit, its pulp is dried to make mango leather so that it can also be enjoyed in the off-season. Traditionally, it is dried under the open sun, which takes more time to dry, and quality gets compromised due to direct exposure to dirt, direct sunlight, birds, pests, and microbes. Hence, its drying behavior is analyzed in a standalone hybrid greenhouse solar dryer (HGSD) operating in active mode. An evacuated tube collector (ETC) is attached to the dryer for high room air temperature and high drying rate. An aluminum drying tray having fins is fixed over copper tubes of a heat exchanger. The copper tubes get fixed in the finned slots of the drying tray, which increases the heat exchange between tray and tube. Experimentation is performed under three conditions: dryer with a collector, dryer without a collector, and open sun drying (OSD). The drying time in the dryer with the collector is 4 hours, 7 hours less than the dryer without the collector and OSD, respectively. The average convective heat transfer coefficient (CHTC) for the dryer with and without the collector is 0.11 W/m²°C and 0.08 W/m²°C, respectively, while in OSD, it is 0.07 W/m²°C. The economic analysis of the dryer shows that the payback time is 0.25 years only; hence, the large amount invested on the dryer is recovered in very less time and the profit can be enjoyed for the remaining time.

KEYWORDS:

• Mango leather
• solar collector
• heat transfer coefficient
• greenhouse
• hybrid dryer

Highlights

• The drying behavior of mango leather inside the novel hybrid greenhouse solar dryer is studied.

• The evacuated tube collector and heat exchanger are integrated with the greenhouse solar dryer to increase the drying rate and operational time of the dryer.

• The developed dryer is completely dependent on solar energy and will replace the traditional OSD or other conventional source drying methods practiced for mango product drying.

• The economic analysis of the novel hybrid dryer is also shown in this article to show the economic viability of the developed dryer.

Acknowledgments

The authors are thankful to All India Council of Technical Education (AICTE), New Delhi, for providing the fund through the RPS project (File No.: 8-24/FDC/RPS(policy-1)/2019-20) to develop the experimental setup and carry out the experiment.

Disclosure statement

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

Nomenclature

Table

Table

Additional information

Funding

This work was supported by the All India Council for Technical Education [File No.: 8-24/FDC/RPS(policy-1)/2019-20].