IJSRP, Volume 7, Issue 12, December 2017 Edition [ISSN 2250-3153]
Abeyrathna R.M.R.D., Amaratunga K.S.P.
Chili, a potential cash crop in the world is considered as one of the most important spices due to its multiple uses and vital role in most of the cuisines. Traditional drying systems use direct sunlight or indirect heating sources and hence difficult to control the drying conditions. Convective drying systems use hot air and because of high temperature, volatile compounds tend to remove from the product leading to a quality reduction. Use of dehumidified air for drying has been suggested as one of the solutions as drying can be done at relatively lower temperatures while preserving the volatile compounds. In this study, a heat pump drying (HPD) system was designed, evaluated and then validated to be used as an alternate method of drying chili in the industry level. Weight and the bulk density of the evaluated sample were 8,000 kg and 98 kg/m3 respectively. The Specific Moisture Removal Rate (SMER) value of the evaluated HPD system was 1.027 kg/kWh. The moisture content of chili was reduced from 10.8% to 5.05% (wet basis) within three hours. The relative humidity of the dehumidified room was reduced to 8% from 55% and the temperature of the dehumidified room increased from 29°C to 41°C within three hours. Average water condensed rate was 5.2kg/h. Results suggested that the developed heat pump drying system has performed well serving its purpose and hence it can be concluded that the established closed cycle heat pump drying system can be effectively used to dry chili in industrial level.