Selecting process in wheat flour mill
In the wheat flour mill cleaning process, the impurities sorting out which are not different from the wheat in the raw materials by the difference in length or grain shape is called selection. The impurities to be removed from selected equipment are usually barley, oats, hazelnuts, and mud. Among these impurities, barley and hazelnuts are edible, but their ash, color and taste have an adverse effect on the product. Therefore, when the product is a higher grade flour, it is necessary to set a selection in the cleaning process.
Because the particle size and suspension speed of such impurities are similar to those of wheat, it is difficult to remove by means of screening, stone removal, etc. Therefore, selection is an important means to clean up some impurities. Commonly used selection equipment includes a indented cylinder machine and a spiral selection machine.