METHOD OF EXTRACTING FROM A STARCH SUSPENSION OF NATIVE STARCH, FRACTIONATED BY SIZE OF STARCH GRANULES

摘要

FIELD: starched industry.;SUBSTANCE: method of extracting starch suspension of native starch, sized to size starch granules, comprising crushing raw material into a mush, feeding of mash into collector, filtration for separation of large particles of mash, separation of pulp in hydro cyclones into unrefined suspension and mixture of pulp and juice, dilution of unrefined starch suspension with water, its refining on an arc sieve with excess product outlet and filtered starch suspension, its supply to hydro cyclones for condensation, dehydration of condensed suspension till achievement of specified moisture content of starch and its drying. Obtained starch suspension after refining is subjected to fractionation process differing by starch granule size prior to its thickening. Separation is carried out in several steps. First, the suspension is directed to sieve separation, which enables to release granules with size of more than 50 mcm using sieve plants VS-4, Sh5-PSL-200, RZ-PSL-100, CLS-100, CLS-200, BSS-100, Sh5_PSB-9, PSU-100, PSU-200, BSK-200 with metal sieves having holes of round or square cells with dimensions of 150 mcm, 100 mcm and 50 mcm at temperature of not more than 30 °C at average capacity of sieves from 1,500 to 4,000 kg/h. Then it is separated in hydro cyclone unit with suspension flow rate – up to 2,500 m³/h, cylindrical part diameter – up to 2,000 mm, conical part angle from 10° up to 160°, feeding hole diameter is up to 420 mm, drain hole diameter is up to 520 mm for granules separation in 30–50 mcm size range. For separation of granules in the size range of 10–30 mcm, filtering on membrane filters with pump operating frequency from 35 to 50 Hz with pressure at output of 4 atm to obtain fractions in size range from 10 mcm to 30 mcm and with pressure of 18 atm and with temperature of filtered starched suspension of not more than 40 °C when producing fraction smaller than 10 mcm.;EFFECT: invention enables to develop a highly efficient, cheap and environmentally safe method of extracting starch suspension of native starch, classified by size of granules.;1 cl, 1 dwg, 1 tbl, 3 ex