Dmitruk E.A., Ilchuk V.B., Vereshchinsky A.P., Cherny A.A., Kharchenko E.I.

“Rules for organizing and maintaining the technological process at flour mills” [1] recommend carrying out the grinding process on four torn and six to eight grinding systems (Table 1). The specific load on the roller line is 80-100 kg/cm•day, the specific load on the screening surface is 750-1300 kg/m²•day. It is known that today there are mills with reduced technological schemes, while the grinding process is carried out on four torn and five to seven grinding systems with the production of both two and three grades of flour, including the highest grade. Thus, in the city of Baryshevka there is a mill with a capacity of 100 tons per day, which has four grinding systems, five grinding systems, three sieve systems and two grinding systems. The average yield of premium flour is 45%, first grade – 30% and bran – 25%. The average specific load on the roller line is 71.4 kg/cm•day, on the screening surface – 1328 kg/m²•day, which falls within the load limits defined by the “Rules…”

Table 1. Product yield rates for reduced technological schemes, %.

Grinding product Grinding using reduced technological schemes
two-grade single-grade
The flour of everything,
75 78 72 85
highest grade
first grade 55 – 65 40 – 50 72
second class 10 – 20 28 – 38 85
feed flour 3 6
bran 19.1 19.1 19.1 12.1
waste of categories I and II 2.2 2.2 2.2 2.2
Waste of category III with mechanical losses 0.7 0.7 0.7 0.7
Total 100 100 100 100

In the grain cleaning department, grain is cleaned and prepared in accordance with the “Rules for organizing and maintaining the technological process at flour mills” with two degrees of grain conditioning and grain surface treatment.

At the same time, the technological process of grinding grain can be carried out on two torn and two grinding systems without using a sieve process. This technological process was carried out at a mill with a capacity of 30 tons/day in the city of Ovidiopol. The technological process uses a dismembrator with variable speed, which allows you to adjust the degree of grinding of intermediate grinding products.

Dismembrators are structurally similar to entolators, the distinctive thing is that a rotor with fingers rotates in the housing, while the second rotor is fixedly fixed.

The grain cleaning department includes a separator, a destoner, an automatic grain moistening system and two debranders produced by OLIS (Odessa), which are installed after the grain has been dampened to clean the grain surface and peel it. Debranders allow you to remove the shell in an amount of up to 8%.

The study of technological processes at this mill showed that the extraction of flour after the roller mill of the first torn system (sieve passage 49/52PA) is 14%, the whiteness of the flour is 52.9 units.< /p>

To reduce the load on the sieving surface of the second torn system, a sifter manufactured by OLIS was installed. Flour extraction after the roller machine of the second torn system is 16% and whiteness is 53.2 units.

Flour extraction after the roller machine of the first grinding system is 34% with a whiteness of 69.3 units. Extraction of flour after the roller machine of the second grinding system is 66% with a whiteness of 55 units.

The first and second tearing systems have threaded rollers, and the grinding ones have micro-rough rollers.

The study of the technological process was carried out during the processing of wheat grain with a natural content of 776 g/l and an initial moisture content of 13.5%.

A study of the balance of the grinding department showed that the yield of premium flour is 53.14%, first grade – 20.27% and bran – 26.58%.

The specific load on the roller line is 100 kg/cm•day, the specific load on the screening surface is 1822 kg/m²•day.

The loads on individual systems are shown in Table 2. Such flour yields and quality are ensured mainly due to the efficient operation of debranders, which, along with surface treatment of the grain, make it possible to remove part of the shell and, as a consequence, this leads to a reduction in the duration of the grinding process. The absence of the enrichment process does not significantly affect the yield and quality of the finished product.

Table 2. Actual loads on grinding process systems, kg/h.

System Values
II dr.s. 510
1 RUR 584
2 r. s. 405

Based on the above data, it is possible to revise the technological processes of grain grinding, which are given in the “Rules…”. By supplementing the technological processes of grain grinding in industrial mills with effective grain surface treatment, it is possible to reduce not only the number of grinding systems, but also the number of sieving systems, which will immediately affect not only the reduction of energy costs for grain processing, but also reduce operating costs.

Research of the technological process at the mill, which has three torn and three grinding systems, with a capacity of 30 tons/day (Vinnitsa region, Litinsky district, Borkov village) shows that With such a reduced technological scheme, a yield of premium flour of 58-64% is possible, but with the enrichment of intermediate grinding products. At this mill, a roller machine Rb-VS-185×250 is installed in front of the first tearing system, which is used for grain flattening. Grain flattening is an effective technological operation not only in terms of energy consumption [2], but also in terms of flour production technology with an appropriate gap between the rollers.

Along with the roller machines, standard R3-BER entolators are installed on the grinding systems. The operating efficiency of the “roller machine – entolator” system is given in Table. 3.

Low extraction of flour after entolator by 2 r.s. due to the fact that there is little load on this system.

Table 3. Efficiency of the “roller machine – entolator” system on grinding systems 1 and 2.

Indicator System
1 rub. 2 rubles
to the machine after the machine after entolator to the machine after the machine after entolator
Pass sieve No. 43 15.40 50.70 74.19 23.26 48.52 52.50
Flour extraction, % 35.30 23.49 25.26 3.98
Motor load, kW 6.85 1.25 6.85 1.25
kW % flour 0.19 0.05 0.27 0.31
Flour whiteness, units 51.8 65.1 60.5 36.0 48.7 48.3

During the research, grain with a natural content of 796 g/l and a glassiness of 61% was processed.

This enterprise pays great attention to the quality of grain sent for production. For this purpose, grain fractionation by size is used. By passing a 2.4×20 mm sieve, the fine grain fraction, about 6%, is selected, which allows increasing the quality indicators of the grain. Nature of the fine fraction – 719 g/l; puny grains in the fine fraction account for 3.7%; broken – 33.6%; seeds of other crops – 0.18%; barley – 0.01%; fine grain – 62.5%.

The use of grain fractionation, peeling and flattening before the torn process, in the grinding process, the use of an entolator with optimal specific loads makes it possible to improve the technical and economic indicators of processing grain into flour.

  • 1. Rules for organizing and conducting the technological process at boron mills. – K.: VIPOL, 1998. – 146 p.
  • 2. Improving the technology of grinding wheat and rye in the USSR and abroad. Maksimchuk B.M., Sibiryakov B.A., Skryabin V.A., Kosteltseva N.N., Nikiforova I.A., Cyxapev A.V. Review information, series: Flour and cereal industry. – M.: TsNIITEI Minzaga USSR, 1981. – pp. 1-40.

Published based on materials
“Grain storage and processing”
scientific-practical journal
№2 (116) February 2009

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