Sweet potato, also known as sweet potato, sweet potato, hawthorn, red glutinous rice, etc., is an excellent material for starch processing. The production process of sweet potato starch is based on the fact that the starch is insoluble in cold water and the specific gravity is greater than that of water. With a lot of water, the special effect of the machine is used to separate the starch from the water suspension.
The technical process of starch equipment is divided into: transportation - cleaning - crushing - separation - sand removal - concentration - dehydration - drying - air-cooled packaging.
First, starch equipment cleaning
The role of cleaning: the first is to remove the sand from the outer skin of the sweet potato, and wash away the skin of the sweet potato roots. For the starch as the material to be produced, the fresh sweet potato or sweet potato chips are cleaned to ensure the quality of the starch. The cleaner the clean, the better the quality of the starch.
Second, the starch equipment is broken
The role of disintegration: sweet potato starch is mainly stored in the roots of the meat, and only a few are stored in the endothelium. The intention of disintegration is to arrange the layout of the damaged sweet potato so that the fine starch granules can be smoothly separated from the roots. The starch released from the cell, called free starch; remains in the residual internal cells called the linked starch.
Destruction is one of the most important processes in the processing of fresh potatoes. It is related to the flour extraction rate of fresh potatoes and the quality of starch. The need for destruction lies in: 1. The starch equipment breaks the cells of fresh potatoes as much as possible, releasing more Free starch granules; 2. Starch equipment is easy to separate. It is not expected that the skin residue is too fine, and the skin residue is too fine to be detrimental to the separation of the starch from other ingredients, and the difficulty of separating the fine residue.
Third, the starch equipment is separated
Sweet potato slag is a slender fiber, the volume is larger than the starch granules, the swelling coefficient is also larger than the starch granules, and the specific gravity is lighter than the starch granules. The raw pulp to be disintegrated is treated with water as the medium, and the panning and pressureless percolation are selected. Kneading the technique of sequential multi-stage circulation. The pure panning removes the starch from the fiber; the non-pressure percolation allows the slurry to pass through the mesh hole and the fine residue remains on the net; the dried starch makes the starch slurry contained in the potato residue Filter out further.
Fourth, starch equipment sand removal and concentration
The specific gravity of mud and sand is greater than that of water, and is greater than the specific gravity of starch granules. According to the principle of specific gravity separation, the use of cyclone to remove sand can reach a more ambitious role. The specific gravity of the yellow pulp is close to water, and it is lighter than the specific gravity of the starch granules. The shape is palm shape. The longer the processing cycle is, the more the glue function is. The sieving screen sticks to the starch granules, which is extremely difficult to separate, so the demand material is fresh. The technical process is short and timely.
Five, starch equipment dehydration
The wet starch directly from the flow cell usually has a moisture content of about 55%, and the concentrated slurry of the hydrocyclone is usually separated from the concentrated milk slurry by 20 waves, and needs to be dehydrated again to improve the boring power and save energy.
After the solid phase and the liquid phase are separated, a large amount of water is thrown out from the filter cloth empty space on the screen, and the moisture content of the wet powder is less than 40%, so as to reach the need of saving heat energy, improving output value and quality.
Six, starch equipment is boring
At present, the airflow that is usually used in the starch factory is boring (also known as sudden and boring). The whole technical moment is completed in a while, so the internal moisture of the starch granules has not been gelatinized and has been boring, so there is no appearance of gelatinization or degradation.
The turbulence of the airflow is a concurrent and boring process, that is, the cocurrent process of the wet powder material and the hot air flow, which consists of two processes of heat transfer and mass transfer. When the wet starch touches the hot air, the hot air transfers the heat energy to the surface of the wet starch and then from the outside to the inside. This process is the heat transfer process; at the same time, the moisture in the wet starch is liquid or from the inside of the material. The gaseous state is dispersed to the surface of the starch, which is dispersed from the outer surface of the starch through the gas film into the hot air. This is a mass transfer process. That is, the high-temperature airflow and the wet starch are uniformly exchanged in the dry tube to make the dry starch powdery, and after cooling, it can be packed into the warehouse.