Main technological processes of cassava starch
(1) Raw material preparation
Raw materials are the material basis of production, and the quality of raw materials is directly related to the quality of products. The raw materials of cassava starch factory include fresh cassava and dried cassava chips.
After fresh cassava is harvested, the soil, roots, whiskers and woody parts should be removed promptly and stacked on a clean ground to avoid mixing iron blocks, nails, stones, wood and other debris. It is required to harvest the cassava on the same day, enter the factory on the same day, and process it on the same day. , to ensure the freshness of raw materials, thereby improving the extraction rate and product quality.
Dried cassava chips should be dry, not moldy, not spoiled, and free of insects to ensure product quality.
(2) Raw material transportation
Using potato collectors and conveyors to transport cassava from the storage yard to the cleaning machine is required to ensure the normal supply of raw materials for the process. During the transportation process, special precautions should be taken to prevent iron blocks, nails, stones, wood and other debris from being mixed in. If any debris is found, it should be picked out in time.
The GX-850 drum cleaning machine is used, which is divided into rough washing area, bathing area and clean washing area. The cassava raw materials roll forward with the rotation of the cylinder wall, and are sprayed, rinsed, bathed, ground, cleaned and peeled with water as the medium (water distribution is 1:4). It is required to remove the sediment through cleaning, and the peeling rate reaches more than 80%, and then it is sent to the crushing process.
The function of disintegration is to destroy the tissue structure of cassava, so that the tiny starch granules can be disintegrated and separated from the cassava roots.
The 6wsJ-45 flying hammer crusher is used. This machine relies on high-speed operation to make the hammer fly up and work with the hammer, partition plate, sieve plate, etc. to hammer, file and cut the continuously fed cassava in the machine. , squeeze, thereby disintegrating the cassava, causing the starch granules to be continuously separated, and using water as the medium (water distribution is 1:1), the disintegrated cassava is processed into starch puree. At present, the secondary disintegration process is commonly used in order to disintegrate the cassava tissue more fully and finely, so that the starch granules are separated more thoroughly, which is more beneficial to improving the extraction rate.
It is required that the starch puree after primary crushing passes through a sieve opening of about 8.0mm, and the starch puree after secondary crushing passes through a sieve opening of 1.2-1.4mm.
Stirring is an essential link in processes such as crushing, screening, bleaching, sand removal, separation, and dehydration. Its function is to: store original pulp and whey; balance the concentration of whey; adjust the pH value of whey to promote starch separation; avoid starch precipitation, etc.
However, the stirring time needs to be mastered. If the stirring time is too long, the whey may become sour and liquefied, reducing the viscosity and starch recovery rate.
The dilute starch slurry after crushing and stirring needs to be screened to separate the starch milk and fiber. At the same time, the starch milk needs to be screened to remove fine residue, and the fiber needs to be treated with detergent to recover starch. Through screening, the purpose of separating and purifying starch is achieved.
At present, 120 pressure curved screen and vertical centrifugal screen are mainly used. The two are used in conjunction, that is, the curved screen is used to screen and wash fibers, and the vertical centrifugal screen is used to finely screen to remove fine residue. Multiple screening or countercurrent washing processes are generally adopted.
It is required that through puree screening and washing, the starch content of potato residue (dry basis) is less than 35%, and the free starch content is less than 5%; the fiber impurity content of the whey is less than 0.05%; the whey concentration reaches 5 to 6 Bé.
Bleaching is an important step in ensuring the quality of cassava dried flake starch products. Its function is to: adjust the pH value of the milk to control microbial activity, fermentation and saccharification; accelerate the separation of starch and other impurities; bleach the outer layer of starch granules to keep the starch granules white for a long time.
(8) Sand removal
According to the principle of specific gravity separation, the starch slurry is pumped into the vortex with a pressure pump, the sand is removed by the bottom flow, and the top flow passes through the slurry to achieve the purpose of sand removal. After sand removal, not only impurities such as fine sand can be removed, but also the disc separator can be protected.
The function of separation is to separate insoluble proteins and residual soluble proteins and other impurities from the starch milk slurry, so as to achieve the purpose of washing, refining and concentrating the starch milk.
At present, disc separators are commonly used to wash, refine and concentrate starch slurry. It separates water, starch and yellow pulp protein according to their different specific gravity. Generally, two disc separators are used in series, and the first input pulp concentration is required to be 5-6Bé, and the output pulp concentration is 20-22Bé.
After the separation process, the concentrated whey still contains a lot of water, so it must be dehydrated to facilitate drying.
At present, scraper centrifuges are mostly used for dewatering by the overflow method. It is required that the moisture content of wet starch after dehydration is less than 38%.
The wet starch dehydrated by the scraper centrifuge is transported to the air flow dryer for drying. The steam pressure is controlled at 0.8Mpa. It is required that through drying, the moisture content of the finished starch should be around 13.5%.
(12) Packing and storage
It is required that the number of bags is sufficient, the bags are sewn firmly, and they are put into storage in a timely manner.
Henan Huatai starch production supplier will give you the best solution according to your needs, different capacity cassava starch production, tapioca starch solution, any need please email to [email protected]