Determination of thermal properties of ambient and cryoground black pepper

Abstract

The effects of temperature (-40 C to 55 C) and particle size (71-492μm) on thermal properties of black pepper ground at ambient and cryogenic conditions were investigated. The specific heat decreased non linearly whereas the thermal conductivity and thermal diffusivity increased non linearly with the increase in temperature range of black pepper powder for different grades of both grinding conditions. The specific heat at ambient conditions varied from 2.3× 104-2.2× 104 J/kg-K, 2.5× 104-2.3× 104 J/kg-K and 2.2× 104-2.1× 104 J/kg-K and at cryogenic conditions it varied from 3.03× 104-2.9× 104 J/kg-K, 3.2× 104-3.2× 104 J/kg-K and 3.24× 104-3.20× 104 J/kg-K, for three grades I, II, III respectively. The thermal conductivity varied from 0.044-0.061 W/mK, 0.043-0.059 W/mK and 0.041-0.076 W/mK at ambient conditions while in cryoground conditions it varied from 0.046-0.078 W/mK, 0.045-0.077 W/mK and 0.045-0.067 W/mK at different grades. The thermal diffusivity varied from 38.79× 10-8-58.69× 10-8 m2/s, 39.57× 10-8-58.56× 10-8 m2/s and 45.37× 10-8-85.59× 10-8 m2/s in ambient conditions and during cryo conditions varied from 28.94× 10-8-49.37× 10-8 m2/s, 27.41× 10-8-46.74× 10-8 m2/s and 27.72× 10-8-42.36× 10-8 m2/s, respectively at different temperature and grades