Complete engineering
Turn-key Project of Corn Starch Plant
Release Time:
2025-04-21
Corn is processed into corn starch through procedures such as cleaning, soaking, coarse crushing, germ separation, fine grinding, fiber separation, protein separation, dehydration, drying, screening, and packaging; meanwhile, by-products such as corn germ, corn protein powder, and corn pulp are produced.
Corn starch has a wide range of uses and is an important basic raw material in industries such as food, papermaking, textiles, pharmaceuticals, and fermentation. Its by-product, corn germ, can be pressed to extract high-quality corn germ oil, while corn fiber, corn protein powder, and corn pulp are important raw materials for the feed and fermentation industries.
Our company has decades of experience in corn starch processing technology design, equipment manufacturing, installation and commissioning, and personnel training, and can provide users with customized turnkey complete project services.
The raw grain cleaning in the corn starch workshop is a crucial part of the entire production process. Corn raw materials contain impurities such as hemp rope, cob cores, corn silk, corn husks, straw, metal objects, stones, soil clumps, and dust. First, multi-layer screening is used: the upper screen has holes slightly larger than corn kernels to remove large impurities, the lower screen has holes slightly smaller than corn kernels to remove small impurities, then the material enters a vertical suction duct to remove light impurities; next, the material passes through a magnetic separator to remove magnetic metal impurities. Finally, the corn enters a grain cleaning destoner to remove heavy impurities.
Soaking is the pre-treatment step in the entire corn starch processing flow. The soaking solution is water with 0.1%-0.2% sulfur dioxide or sodium bisulfite added, with pH controlled between 3.0-4.0 and temperature controlled between 48°C-55°C. After countercurrent soaking for 36-48 hours, the moisture content of the corn kernels rises to 40%-45%, swelling and softening them, breaking down the protein matrix network, facilitating subsequent crushing, germ extraction, protein and starch separation, maximizing starch extraction rate, and laying the foundation for recovering high value-added by-products (germ, corn pulp, fiber).
The soaked corn and water (process water) are mixed in a certain ratio and fed into the degerminator mill. The corn kernels are impacted between two discs (fixed and rotating), crushed into about 4-6 segments by shearing and friction, and the germ is completely separated. The crushed slurry then enters the germ cyclone washer under certain pressure, where centrifugal force separates the germ from the endosperm; the endosperm then enters the secondary degerminator mill, and the slurry from this mill re-enters the secondary germ cyclone to complete germ separation.
The slurry after germ separation enters fine grinding (needle mill) for further pulverization, thoroughly dissociating protein, starch granules, and fiber flakes to form a suspension. Then the suspension is sprayed onto the curved screen surface of a pressure curved sieve, forming a thin layer flow; fibers are retained and slide off along the screen surface; starch milk passes through the screen gap, achieving separation of the two. Multi-stage combinations can be used to minimize starch residue before fiber discharge.
Starch and protein (gluten) separation is based on their different physical properties. Starch granules have a density of 1.5-1.6 g/cm³ and particle size of 5-25 μm; protein (gluten) granules have a density of 1.1-1.3 g/cm³ and particle size of 1-3 μm. The main equipment is a disc centrifuge, assisted by a group of cyclones (9-12 stages), achieving starch concentration not less than 20 Be°.
In the corn starch processing, the main product is starch; by-products include protein powder, fiber, germ, etc.
Common equipment for dehydrating starch milk includes vacuum drum filters and horizontal scraper centrifuges; either can be chosen to dehydrate starch milk with a concentration of 18-22 Be° to wet starch with moisture content of 38%-42%.
Corn protein powder (gluten powder) dehydration is generally done using plate and frame filter presses or decanter centrifuges. Plate and frame filter presses can dehydrate the protein powder suspension to wet cakes with moisture content below 60%.
Corn fiber (bran) and corn germ dehydration equipment mostly use screw presses, which mechanically press to reduce moisture content to below 65%.
The drying step in corn starch processing mainly aims to dry starch (moisture 38%-42%), wet protein powder (moisture below 60%), wet fiber (moisture below 65%), and wet germ (moisture below 65%) to below 14% moisture for safe storage and sale.
Corn starch drying equipment usually uses airflow dryers; protein powder (gluten) drying equipment can use airflow or tube bundle dryers; germ drying mostly uses fluidized bed dryers; fiber drying mostly uses tube bundle dryers or disc dryers.
Main equipment for corn starch packaging includes finished product silos, inspection sieves, packing machines, and palletizers.
Finished product silos are generally made of stainless steel as vertical silos; the number of silos can be set according to production rhythm to save logistics costs.
Inspection sieves are key equipment for controlling finished product particle size; the sieve path and mesh configuration are scientifically designed based on processing capacity and finished product particle size requirements.
Packing machines (weighing) come in various specifications, enabling seamless connection from small packages to ton packages; in terms of automation, multi-station free combinations can be realized.
Palletizers come in various styles and models for customer selection; manual stacking is also possible.
Automation control is an important way to improve production efficiency, stabilize product quality, and reduce energy consumption and labor costs in corn starch processing. By detecting parameters such as temperature, pressure, flow, and humidity during the production process (on-site), the PLC (programmed logic controller) performs logical calculations and issues commands to control actuators such as variable frequency motors, pneumatic valves, and flow regulators, achieving reasonable workshop operation parameters, high product yield, stable quality, automatic sequential start and stop of equipment, and centralized management of plant-wide data.
