chamber for drying the product and simultaneously the desiccant bed
receives solar radiation directly and through the reflected mirror. In
the off-sunshine hours, the dryer is operated by circulating the air inside
the drying chamber through the desiccant bed by a reversible fan. The
inclusion of reflective mirror on the desiccant bed increases the drying
potential by 20%. The useful temperature rise of about 10 °C was
achieved with mirror, which reduced the drying time by 2 and 4 h for
green peas and pineapple, respectively. Also, the pick-up efficiency,
drying rates and average dryer thermal efficiency were relatively higher
when compared to solar drying and desiccant integrated drying.
Uniform drying in all the trays was achieved with good quality in
terms of color and microbiological decay when compared to solar
drying. Taste of the dried pineapple was found to be satisfactory. The
desiccant material is stable even after continuous operation for more
than a year. The dryer can be used for drying various agricultural
products. It can reduce drying time and improve the quality of the
dried product.