How does a flour mill treat the outer layer of the grain?

发布时间：2026-04-17 点击次数：

　As raw grain for flour mills is subject to contamination by impurities during the daily processes of harvesting, drying, transport and so on, it is necessary for the flour mill to treat the surface of the raw grain to prevent these contaminants from being mixed into the finished product and compromising its quality. So, how exactly does a flour mill treat the surface of the raw grain?

　　Firstly, within the entire milling process, cleaning should ideally be scheduled after screening and stone removal, as this effectively prevents excessive impurities from causing significant wear to the sieve plates later on.

Secondly, surface cleaning in the milling process can be divided into two stages. The first stage takes place before wheat is moistened; as the grain has a low moisture content and is prone to breakage, it is subjected to gentle, light beating. The second stage involves more vigorous beating after the wheat has been moistened.

　　Furthermore, during flour mill operation, combining threshing equipment with suction systems can enhance cleaning efficiency.

The flour content and particle size distribution of the feedstock entering the flour mill are determined by the design of the high-level flat screens, sieve frames and mesh configurations. If the feedstock entering the flour mill does not meet requirements, improvements should be made in this regard. The feedstock must be distributed evenly across the full width of the sieve surface. If this is not the case, first check the horizontal alignment of the sieve body; then adjust the feed gates. In principle, the gate openings should be uniform, but they can be adjusted according to how widely the material is distributed across the sieve surface—reducing the opening where material is concentrated and increasing it where there is less.