Process flow Potatoes → Cleaning → Grinding → Potato residue separation → Precipitation → Drying → Coarse starch operation points (1) Grinding: Select potatoes with high starch content, sort out rotten and diseased potatoes, put them into the washing tank, and add water Use a stick to stir to clean the potato cubes. The washed potato pieces are put into a grater and ground while adding water. They are ground into starch slurry and flow into the receiving tank. (2) Separation: Use coarse and fine flat sieves twice to sift out the potato residues in the starch slurry, or put the starch slurry into a cloth bag, tie the bag mouth, put it into the trough, and step on it with your feet to make the starch flow out of the bag. If the hole overflows, add water to the potato residue and then step on it.
(3) Precipitation: Put the starch milk into the sedimentation tank, stir it thoroughly, and let it stand for more than 5 hours, then the starch will precipitate on the bottom layer. The upper clarified liquid is removed to separate the starch. If the starch separated at one time has many impurities, you can add water to the washing tank, stir, let it sit for a few hours, and then remove the above clarified liquid. Repeat this washing process 3 to 4 times. After finally letting it stand, the upper layer will be the skin, the middle layer will be starch, and the lower layer will be silt. Scrape off the impurities on the upper layer and take out the middle starch layer, which is the wet starch. (4) Drying: Cut the wet starch blocks into small pieces, then spread them on a bamboo sieve or a shallow wooden tray, and dry them in the sun until the starch blocks break when touched. You can also dry them manually.