Research on water-saving cleaning technology based on rough–fine-washing separation for wheat

Wheat flour is a necessity in our daily life. Wheat with impurities and pesticide residues will seriously affect the quality of wheat flour, and thereby wheat cleaning before milling is essential for the whiteness, purity, ash, pesticide residues, and other important indicators of flour. Wheat washing could refine wheat and remove stones with the dissolution and flushing of water, and meanwhile there are some shortcomings about the current wheat washing: fresh water consumption and pollution to the environment. For conserving fresh water and the environment, a novel water-saving cleaning technology based on rough–fine-washing separation has been proposed and investigated. In this, there are no chemical additives added in cleaning and no secondary pollution to the grain. And this can also bring us more safe food and reduced the pollution to the environment. In this paper, the principle of rough–fine-washing separation is first shown. Next, an experimental approach based on rough–fine-washing separation is developed. With the help of water-cycling system, the effective reuse for water is achieved. In order to verify the washing effect and the water-saving effect, the comparative experiments were done. The results show that the measurement values about cleaning effect are not reduced when the water consumption is only 1/3 of the traditional wheat washing. As the same time, the pollution to the environment is reduced radically with smaller water consumption, and the production cost of enterprises is significantly reduced with the decrease of water consumption.