Process for making extruded cattle manure pellets
AssigneeS.A.F. Societe Agricole et Fonciere S.A.
InventorHugo Imhof
Life of this patent
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Abstract
Cattle manure is mixed and batches are separately brought into the form of a coherent substantially homogeneous pulp with a moisture content between 50 and 55% by weight, by heating with exhaust gases, drying in an oven, admixing dry material, and spraying dry material with liquid manure recuperated from the waste materials. The pulp is chopped and immediately thereafter extruded to form frangible strands, sections of which are allowed to break off, without cutting, and to further break by dropping onto a conveyor. Breakage into pellets is completed, without the use of a conventional pelletizing drum involving compression of the pellets, in a vibrated fluidized bed where the pellets are superficially dried to a non-tacky state, drying being completed in further non-vibrated fluidized beds.
Claims17
A process for pelletizing cattle manure into pellets suitable for use as soil fertilizer comprising:
- providing a substantially homogeneous coherent pulp of said cattle manure with a moisture content of from 45 to 60% by weight;
- chopping said pulp until it is sufficiently fine to be extruded;
- horizontally extending by extrusion said pulp immediately after chopping to form unsupported elongated frangible strands sufficiently long to break off under their own weight thereby causing said strands to break into elongated sections;
- providing means defining a receiving surface beneath the falling strand sections so that the falling strand sections strike the receiving surface and further break into smaller sections upon impact;
- and
- mechanically vibrating said smaller strand sections in a fluidizied bed, maintained by supplying a raising stream of hot gas, to further break said smaller strand sections into pellets and at least superficially dry the pellets.
Dependencies are inferred from the claim text.