GB747363A - Method and apparatus for the processing of fish - Google Patents

Abstract

747,363. Animal food. HILLER, S. Dec. 22, 1953 [Oct. 15, 1953], No. 35574/53. Class 5 (2). Fish meal is prepared by cooking and partially dehydrating fish to an intermediate moisture content wherein there is no visible excess moisture and the fish is fibrous in character, pressing and then further dehydrating, the cooking and partial dehydration being effected by continuously conveying the fish in a closed circuitous path with simultaneous agitation. 25-40 per cent is the specified intermediate moisture content. Oil is separated from the press effluent and the aqueous phase of the effluent is added to the pressed fish before further dehydration. In operation, raw fish is cooked and partially dehydrated in a dehydrator 2 provided with a discharge 4 through which the fish passes to a hopper 6, then a press 7. Effluent passes to a collector 8 and is discharged through an outlet 9. A mixer 11 breaks up the press cake which is further dried by hot air from a pipe 12, and also in a drier 16. The dehydrator (Fig. 2) comprises side by side cylindrical chambers 21 connected by a duct 22 at each end. Heat is applied both externally and internally of the fish mass, externally by means of steam jackets 23 around each chamber, and internally by means of hollow steam shafts 32 and hollow screw flights 29 of screws 28, steam being admitted through inlet pipes 33 and 36. At the ends of the dehydrator, the screw flights of the screws are offset relative to each other, thereby conveying the fish in a closed circuitous path.