Physical, frictional and thermal properties of turmeric rhizomes

Abstract

It is important to study the engineering properties to design the dryers. The present investigation aimed to design a rotary dryer, so that some physical and thermal properties of fresh and dried turmeric rhizomes of PTS 10 variety were studied with a moisture content range between 410 to 7% (d.b.). The size of the turmeric decreased as the moisture decreased from 410 to 7% (d.b.). The bulk and true density was decreased with decrease in moisture content. The porosity was increased from 39.14 o ± 1.16 to 46.34° ± 3.5 with decrease in moisture content. The coefficient of friction of turmeric rhizomes was decreased as the moisture content decreased. The thermal conductivity and specific heat was decreased from 0.2532 to 0.13 W m-1 K-1 and 3.9 to 1.01 kJ kg-1K-1, respectively whereas the thermal diffusivity increased from 9.26 x 10-8 to 1.9 x 10-7 m2s-1 as the moisture content decreases.