growing in south of China area normally have more buckwheat seeds and mud, less sand and high moisture. Usually not considering wheat washer, considering enhance threshing wheat, removing buckwheat and destone in dry way. Wheat growing in north of China normally contain more sand and marl, less buckwheat seeds and low moisture. To clean up this kind of wheat, should strengthen the suction, destone and wheat washing process, generally not consider buckwheat removing equipment. Wheat growing in Spring area have high moisture, more sand and wild grass seeds. To process this kind of wheat, should strengthen the screening, selection and destone process; low temperatures in winter, wheat should have procedure of preheating and moisture adjusting.  
Wheat infected with smut, ergot and scab has a great influence on human health. Therefore, we must pay high attention to the cleaning. The infection of scab and smut of wheat, wheat should be strengthened, broken by a serious pest and weaken the wheat, and strengthen the screening and winnowing, in order to achieve effective cleaning. When wheat contains ergot, it can be cleaned effectively by gravity classifier.
Insect pests of wheat should be killed by the impact machine, and strengthen the screening and suction, remove insects and insects fragments. The grain length of wheat, such as wire worm disease, is shorter than that of normal wheat grain, but its width is similar. It is difficult to remove by screening, and it is more effective to remove with grain separator.   

In China's varieties kinds of wheat, soft wheat more than hard wheat, in the processing of hard wheat,  need to add more water and moisture wheat time.
Factory size and type of milling flours

Under normal circumstances, the factory scale larger, the production of high precision flour higher, the relative clean-up process to be better. The small-scale processing factory have low  precision of flour requirements , Suffer the investment conditions and plant space constraints limit, the relative clean-up process is simple, in this case, you can choose a compact, with a variety of functions and better combination of cleaning equipment , To ensure that the basic clean-up process and the necessary clean-up road. 

Requirements for establishing wheat cleaning process
(1)Each process is complete, the number of cleaning equipment is appropriate, the process sequence is reasonable.
(2)In accordance with the "first easy after difficult, first inorganic after organic" principle to arrange the process sequence
(3)to the large harm and much content impurity, such as sand, buckwheat seeds, wheat scab etc. should strengthen cleaning.
(4)The process should be flexible in order to adapt to the change of impurities in raw materials
(5)There should be perfect water regulation facilities to ensure the moisture content of the incoming wheat to meet the process requirements.
(6)There should be perfect wheat processing facilities, so that the quality index of wheat into the mill can basically meet the quality requirements of the finished flour.
(7)Serial, standardized, universal and efficient advanced cleaning equipment should be used as much as possible.
(8)In order to ensure environmental sanitation and improve the efficiency of impurity removal,the design of air dust removal system should be reasonable.