Drying of Fish Press-Cake with Superheated Steam in a Pilot Plant Impingement System

Abstract

Drying tests for pine sawdust and mackerel press-cake with hot air and with superheated steam were carried out in a pilot impingement cylindrical dryer. Wet particles move axially along the dryer, adjusting the inclination of the equipment, whereas hot gases circulate in cross-flow against the particles, forming a corotational impingement front. Feed rate and residence time of solids were studied experimentally as a function of dryer inclination for hot air and superheated steam as drying media. Drying rates and heat and mass transfer coefficients were found to increase at shorter residence times and higher gas temperatures. Dried mackerel press-cake with superheated steam resulted in a product with high moisture removal and very low losses of the valuable omega-3 fatty acids.