THERMODYNAMIC EVALUATION OF A LOW-PRESSURE FISH DRYER

Abstract

Fish products are major sources protein supplements for human nourishment composing of low - fat diet cherished by consumers for health wise consequence. Quite substantial amount of this products during harvest cum handling are lost to spoilage due to lack of short time drying technology systems and untimely removal of moisture content amidst activities of bacteria. The inappropriate and inadequate processing methods must be eliminated by providing advance short time drying outfits to assist the local processors to stall the activities of bacteria orchestrating fish spoilage. To meet this short time drying needs and increase fish storability and shelf life for overall good productivity, an indigenous affordable vacuum dryer was conceived and developed locally. The unit was fabricated using locally sourced materials and was tested on water cans and cat fish samples.  A constant vacuum head of 3.6 KPa was attained at pumping rate of 320 l/hr, at observed temperature range of 38 and 42^oC, energy and power level of 498.6 KJ and 13.6W with an effective moisture diffusivity 8.41×10^-7m²/s and 2.05×10^-7m²/s were recorded for the fish samples; gutted and un-gutted respectively dried within 10 hours. Total moisture content removal efficiency of 85% was attained This method of drying was very effective in drying the fish samples but still requires further optimization studies to scale up the unit for commercial purpose.