The fifth step in making cornstarch
Starch sieving
After grinding the crushed corn, corn paste is obtained, and sieving can be used to separate the starch from the coarse and fine residues. Commonly used sieving equipment include hexagonal sieve, flat shaking sieve, curved sieve and centrifugal sieve.
Sieve starch sieve hole should be decided according to the type of screening equipment and starch quality requirements. Hexagonal sieve cleaning coarse slag sieve diameter of 0.6 mm, fine slag sieve diameter of 0.12 mm, flat shaking sieve screening coarse slag sieve with 7 × × No. double material nylon, sieve fine slag sieve with 12 × × No. double material nylon, curved sieve cleaning coarse and fine slag using six levels of 120 ° curved sieve, sieve length of 1.6 m, the first level of curved sieve slit width of 0.05 mm, the remaining levels of sieve slit width of 0.075 mm; centrifugal sieve rotor sieve plate screen hole is 2 × 0.24 mm. It is generally operated continuously with four stages.
Sieving coarse and fine slag need clear water, according to 100 kg of dry material, sieving coarse slag need 230 ~ 250 liters, fine slag need 10 ~ 130 liters, water temperature of 45 ~ 55 ℃, containing 0.05% sulfur dioxide, pH is about 4.3 ~ 4.5 is appropriate.