How can the flour mill match the "high square screen" to produce high yield and good flour!

Ash content is an index to measure the processing accuracy of flour, and the quality of flour can be directly evaluated by ash content. In the production of universal flour, ash should be said to be a reference index. The level of ash can not directly evaluate the quality of a flour, but more importantly, it depends on the internal quality and use effect of flour (that is, the rheological characteristics of dough and the operability in the process of processing finished products). In the production of instant noodle flour, ash is a hard index for flour grading. If the ash content exceeds the standard, the supplied flour will be deducted or degraded, degraded or even rejected. Therefore, it is particularly important to control the ash content of flour and maximize the yield of flour under the premise of ensuring the qualified ash content. This is directly related to the reputation and economic benefits of the flour mill. How to control and reduce ash content has always been a subject that our milling workers are constantly exploring. Based on years of practical work experience, the author summarizes some effective methods for reference. The main factors affecting ash content are: ① the ash content of processed wheat itself is too high; (2) The milled wheat is not thoroughly cleaned, which leads to the impurities that should be removed being mixed into the wheat; (3) Improper moisture regulation leads to excessive breaking of bran into flour during milling; (4) Low flow rate of screening equipment or long screening process, resulting in dry screening, and fine chaff is mixed into flour; ⑤ The screen of the high square sieve is too thin or broken, and the silk-stringing phenomenon of the high square sieve will also mix too much chaff in the flour; ⑥ Too many new toothed rollers are replaced at the same time, the shearing effect of grinding teeth is too strong, and too much chaff is mixed into flour during production; ⑦ The technical parameters of the grinding roller are unreasonable, and the bran is easily broken and mixed with flour during operation; When the flour yield is too high, the bran content in flour increases. This paper mainly expounds the technical transformation measures and experience of how to reduce ash in recent years from the aspects of technology, equipment and operation. 1 improve the process 1) improve the cleaning process. Some people in our industry think that the current process is perfect and needs no improvement. Therefore, many flour mills always design the cleaning process in a fixed mode-3 screens, 2 dozen, 3 demagnetization and 2 moistening. The author thinks that the design of flour mill should be eclectic according to the actual situation in order to be innovative. Through the practice of production management and technical transformation in recent years, the author summarizes some effective measures to reduce ash. ① Three-leaf pressure beater is the last beater for cleaning raw wheat. The advantages are as follows: the equipment pressurizes wheat while mixing with water, which destroys the surface water tension of wheat, increases the water permeability and shortens the wetting time, which is very beneficial when the temperature is low in winter. Beating wheat with three-leaf pressure water hammer can also enhance the beating effect in the cleaning process and effectively remove the tough skin from wheat grains, because this skin is most likely to be peeled and ground by the mill and broken into flour during grinding. It should be pointed out that in the production process, the pressure door of the equipment should be properly adjusted. Excessive pressure in the machine will not only increase the impact on wheat, destroy the tough fiber layer in wheat seeds, and make wheat bran more fragile in the milling process, but also increase the workload of equipment and power consumption. ② Wheat cleaning adopts wheat brushing machine and air suction separator. The former can remove the dust in the abdominal ditch of wheat and brush off part of the skin at the same time, while the latter can further remove the shriveled grains and moth-eaten grains in wheat, because such grains can not only increase the flour yield, but also introduce more impurities and increase the ash content. ③ It is best to spray water before grinding. Because instant noodle manufacturers have strict requirements on flour moisture (generally not more than 14.0%), and the wear is also very low when the temperature is low in winter, it is required that the moisture content is very low when grinding. We know that the low moisture content and the low ash content in grinding are a pair of contradictions, so we must use water spraying, because wheat is put in a clean wheat cabinet 15-30 minutes before grinding begins. Water is only absorbed by wheat epidermis but not endosperm, so the water content of flour will not increase, which not only ensures the integrity of bran, reduces the ash content of flour, but also increases the water content of bran, thus improving its economic benefits. 2) Improve the milling process. The modern milling technology is 4B7M2S2T, and the contact length of the grinding roller of the front center milling cutter is lengthened. 200 /d mill, 1M can be equipped with 3 pairs of rollers, 300/d mill and 1M can be equipped with 4 pairs of rollers. Due to the widening of the road ahead, it is not only beneficial to produce good flour in advance, but also beneficial to improve the output. In the use of powder cleaning machine, more attention is paid to the intensive classification of materials, the scope of powder cleaning is widened, and even repeated powder cleaning is adopted. Some measures to improve product quality in recent years are introduced as follows. ① Change the direction of materials and make full use of powder cleaner to make materials more pure. If the screen of the pre-grading screen is encrypted in order to purify the material, it will inevitably affect the flour yield of high-quality flour. If the material on the pre-classification screen is changed, the pure wheat core can be recovered by the flour cleaner to avoid pushing back the good material and ensure the flour yield of high-quality flour. For example, 1M is graded to1t.