Corn Starch

Corn purification aims to remove impurities such as iron, sand, stones, and stems from corn, improving raw material quality and protecting production equipment. Raw materials are cleaned using round sieves, magnetic separators, and air separators to obtain clean corn for the soaking process.

Sulfur dioxide is prepared by burning sulfur, which is then absorbed by process water to form sulfurous acid for soaking and softening corn.

The purpose of corn soaking is to soften the corn through physical and chemical actions, so as to alter the endosperm structure and physicochemical properties, break the component connections within the kernels, and finally leach out the soluble substances and minerals.

Corn crushing involves breaking whole corn kernels into various components and extracting corn germ through multiple grinding processes. The selected "primary mill" and "secondary mill" are both degerming mills. After primary and secondary crushing, the germ is fully separated from the endosperm after the secondary crushing and separation process. During crushing, the starchiness of the endosperm is broken into fragments, releasing some starch. Wet corns are introduced into the primary degerming mill, where most of the germ is separated. The crushed corn syrup then is transferred to the primary germ hydrocyclone, where the germ flows out from the top to the germ washing system, and the underflow enters the secondary degerming mill. The further crushed slurry flows into the secondary germ hydrocyclone, where the germ flows out to the primary germ hydrocyclone, and the underflow enters the pin mill.

The purpose of fine grinding is to feed the twice-crushed slurry into a fine grinder to separate the still-connected seed coats and endosperm under the action of high-speed impact. The selected equipment for fine grinding is a pin mill. The ground slurry then enters the fiber washing process.

The purpose of fiber washing is to separate the seed coats and endosperm from the finely ground slurry through washing. The obtained fibers are separated from the starch milk and proteins in the pressure curved sieves and fiber washing tanks through the action of washing water. The fibers are introduced into a multi-stage washing system, while the mixed starch milk and proteins, collectively known as crude starch milk, are transferred to the crude starch milk tank, and then pumped to the next stage of starch milk refining.

The crude starch separated from the upstream curved sieve of fine grinder and fiber washing curved sieve is first treated with desanders and rotary filters to remove impurities, and then introduced to a gluten separator. The underflow from the gluten centrifugal separator is sent to a washing and separation hydrocyclone for further refining.

The soaking liquid generated during corn soaking contains some solids. It is concentrated into corn syrup in the evaporation system, which is then dried with fiber to produce feed. Heating and concentration utilize waste steam from the tube dryer, achieving "zero steam consumption" in corn syrup production.

The refined starch milk is dehydrated and dried using a scraper centrifuge and pneumatic drying, with the finished starch being transported to the packaging workshop.

The dilute gluten separated from the top flow of the main separator is concentrated by the separator and then dehydrated using a vacuum drum filter or plate-and-frame filter press. The obtained filter cake is sent to a tube dryer for drying, and the dried protein is transported to the packaging workshop.