SYSTEM FOR SEPARATING MILL STARCH TO OBTAIN A PROTEIN-RICH PRODUCT AND A STARCH-RICH PRODUCT

摘要

A system and process are provided for obtaining a protein-rich product and a starch-rich product from the mill starch fraction of a corn wet milling process, the system comprises a first separation zone containing at least two protein separation stages and a second separation zone containing a plurality of starch washing stages, each of the stages comprises a plurality of hydrocyclones arranged in parallel within a housing, each hydrocyclones comprises a vortex member, a conical member and a apex member; a counter current stream of wash water is introduced through the system adjacent the penultimate stage of the starch washing stages and the mill starch fraction is fed under pressure successively through the protein separation stages such that the mill starch fraction is separated into a protein-rich stream and a starch enriched stream; the protein-rich stream is discharged through the vortex members and the starch-enriched stream is discharged through the apex members; a pressure differential .DELTA.P is maintained across each of the protein separation stages at at least about 100 p.s.i.; a protein-rich stream is removed from the last stage of the protein separation stages; and a starch-enriched stream discharged from the apex member of the second of said protein separation stages is delivered to the mill starch fraction feed means such that the stream is combined with the mill starch fraction; the starch enriched stream discharged from the apex member of the first of the protein separation stages is fed under pressure successively through the plurality of starch washing stages such that the lighter, slower settling materials are discharged through the vortex members of the hydrocyclones and the heavier, faster settling materials are discharged through the apex members of the hydrocyclones. the faster settling materials consisting essentially of an increasingly enriched starch stream; the lighter, slower settling materials discharged from the starch separation zone are recirculated to be combined with the mill starch fraction; the pressure differential .DELTA.PW across each of the successive starch washing stages is maintained at at least about 80 p.s.i.; and, the enriched starch stream is removed from the last stage of the starch washing stages.