In grain processing, the rice mill is one of the important mechanical equipment. According to different processing techniques, rice milling machines can be classified into white rice milling machines and brown rice white rice milling machines. The difference between them lies in that the rice mill (commonly known as the agricultural rice mill) is an iron roller or iron rod sand roller type rice mill that directly grinds rice into white rice. This model has a simple structure, is easy to operate and maintain, and is low in price, making it very suitable for use in rural areas. The husking machine is generally a sand roller type rice milling machine, which is only suitable for processing clean brown rice with the husk removed. It needs to be combined with rice husk machines, rice husk separators and other rice processing equipment. The investment scale is relatively large and is mainly used for grain processing enterprises.

There are many factors that affect the threshing effect of a rice mill, and it is often the result of the combined action of multiple factors. To sum up, the main factors include raw grain factors, human factors, objective factors, etc. Apart from the factors of the machine itself, the raw grain has a significant impact on the test results. The selection of raw grains is an important step in the inspection or testing of rice mills. The quality of the raw grains will directly affect the test results, especially the technical parameters of the finished rice. Therefore, in the process of grain purchase, there are strict inspection standards for raw grains. The inspection items mainly include particle shape: The particle shape of rice refers to the surface shape of the particles. According to their length-to-width ratio, there are long particle shapes and round particle shapes (tending to be round). Swelling rate: Swelling refers to one or more crisscrossing cracks on the brown rice grains. Moisture content: The moisture content of rice directly affects the working condition of the rice milling machine. This is related to the toughness of the rice husk, the binding force between the brown rice bran and the endosperm, the damage resistance of the endosperm, the difficulty of grinding, and whether the loose powder can be discharged in time. Keratin rate: Rice endosperm has a high keratin rate (commonly known as vitreous body), a compact structure, and high compressive strength, so it is less likely to produce broken rice during processing. Uniformity: The uniformity of rice refers to the consistency of the surface shape, particle shape, size and moisture content of the rice. Impurity content: According to the provisions of GB 1350-2009, the impurity content of any grade of rice of any variety should be less than (or equal to) 1.0%. However, the reality is that the sources of raw grains are rather diverse, and the impurity content generally exceeds the standard, with some even reaching 3% to 4%. This will directly affect the output, power consumption per ton, productivity and other performance indicators of the rice mill.

A good rice mill can retain over 70% of the germ in fresh rice. All kinds of nutrients, especially vitamins, inorganic salts and dietary fiber, are much richer than those in precisely processed refined white rice. The nutritional value of the germ is very high, accounting for only about 2% of the mass of the rice germ, while its nutritional value makes up more than 50% of the rice. It is rich in vitamin B and dietary fiber. All kinds of vitamin B play a crucial role in the daily growth and health of the human body. Dietary fiber cannot be digested and absorbed by the human body as a nutrient, but its impact on human health should not be underestimated.