DRYING METHOD AND APPARATUS

摘要

The invention relates to a method of drying a biodegradable material, such as a plant or animal product, comprising: a. Pre treating the material to reduce enzymatic degradation and / or microbial, particularly bacterial, attack; and b. Subjecting the material to drying conditions. It also relates to a process for drying oily fish, such as salmon and other pelagic species, comprising: i) Pre treating the material to reduce the oil content of the material; and ii) Subjecting the material to drying conditions. These and other drying processes are preferably conducted in a drying apparatus (10) of the invention. The closed loop drying apparatus (10) comprises a drying chamber (24) having a floor (70), a ceiling (72), two end walls (74; 76) and two side walls (78; 80). Incorporated towards the ceiling, and running substantially the whole length of the ceiling is some ducting (32). Located at one end (74) of the drying chamber (24) are two dehumidifying units (18) each comprising an expansion chamber (26), a compressor (28) and a heat exchanger (30). Mounted externally to the drying chambers are two external heat exchangers (20) which are operatively linked with the dehumidifying unit. In one embodiment ammonia is removed by diverting a proportion of the drying gas out of the drying chamber, through a scrubber and back into the closed loop apparatus. It also relates to a method of drying a food or animal product, particularly fish waste, and to the product obtained by the method.