Modelling Kinetics of Extruded Fish Feeds in a Continuous Belt Dryer

Abstract

Feed is the major inputs in aquaculture production which affects the development growth of aquaculture in the African continent. Extruded fish feeds are dried to desire moisture content to increase the shelf life. Conventional method of drying fish feeds had gained attention recently in Nigeria in order to reduce high cost of producing fish feeds. However, this method is still grossly underutilized. Extrude floating fish feed was dried using continuous belt dryer at drying air temperature from 60°C to 100°C at an interval of 10°C, velocity of air using for drying from 0.8 m s-1 to 1.0 m s-1 at an interval of 0.1 m s-1 using a constant linear belt speed of 50 m s-1. Various moisture contents gotten at different conditions were changed to ratio of the dried extrudates moisture so as to obtain curves of drying by plotting the ratio of moisture against time. The dried extrudates behaviour was determined by fixing the drying curves with five well known models. Model with high determination coefficient and low reduced chi-square, low standard error, low value of least square and low standard deviation error (SEE) was used as best model. Midilli et al model was found suitable in describing the behaviour of extruded fish feed during drying. The temperature of air used for drying was discovered to have a major influence on the drying kinetics of the extruded fish feeds based on the conditions of this experiment.