Flour Production Process

Each company receives, processes, stores and supplies grains to be processed. The grain, received at the procurement facilities, contains weed seeds, grans of other crops, organic and mineral impurities, damaged, bad kernels etc. Presence of the above impurities worsens grain quality. Therefore, one of the important conditions for both securing quantitative and qualitative safety of the grain and improving the quality and output of the finished products is efficient grain cleaning.

Grain cleaning is important. It is carried out partially in the agricultural and partially in the elevator industry. The focus of the procurement facilities is on cleaning grain from the impurities that are hard to remove. The purpose of cleaning is to ensure the required grain quality, and, consequently, the quality of flour and cereal. However, the existing «dry» grain cleaning techniques do not enable to achieve the required grain quality indices at procurement facilities as well as in the mill preparatory departments and cereal production shops. It is equally significant for the procurement and processing facilities. The procurement companies suffer considerable economic losses while supplying consumers with low quality grain.

Wheat, similarly to other grain crops, is subject to numerous diseases, which lead to lower yield and its worse quality. During grain processing mineral dust and microorganisms get into the finished product, causing its high bacterial count. The flour and cereal become unstable while shipping and storing. At the same time the development of microbial flora is so intensive that these products go bad (bacterially) being shipped, which does not allow using them in food manufacturing, especially for babies. One of the most widespread bacteria at flour mills and bread baking facilities is Bacillus mesentericus.

Recently it has been accepted that rain is not washed before milling, but only humidified. Therefore, while milling grains the Bacillus mesentericus gets into the flour. Under favourable conditions these bacteria multiply fast. The optimal conditions for the development of the Bacillus mesentericus spores are the temperature of about 40 ºС, moisture, medium, low acidity. These cells cannot bear heating to 80°С, whereas the spores remain revivable at 120 °С. Therefore, bacteria die when baking bread, while their spores stay revivable.

To prevent the spread of Bacillus mesentericus it is required to take certain measures at all stages – starting with soil, grain and finishing with bread. To improve grain, flour and bread condition and to prevent the Bacillus mesentericus development in bread it is necessary to follow the instructions in the «Guidelines on storing food and feed grains, oil seeds, flour and cereals», the «Rules of arranging and operating elevator process», and the «Rules of arranging and operating the process at mills».

However, one of the most efficient techniques, removing the above drawbacks, is the use of washer KVD-1. Washers, besides impurity separating machines, are the initial stage of the complex water and heat treatment of grain in the process of hydroseparation, sweating and wetting. Our thorough development of the modes for each stage of water and heat treatment generally determine changes in the respective grain processing properties.

The essential hydroseparation of the grain mix is in the flotation chamber, where impurities are actually removed.

The final stage of the washer operation is grain dehydration. In the washer centrifugal column moisture is separated as a result of grain hydroextracting and air drying.

KVD washers have been successfully operated at a number of flour mills in Ukraine and the Russian Federation. For example, at a mill with the capacity of 70 tons grain per day the following parameters were achieved while grain cleaning per separator passage and the washer.

Ash content decreases to 0,03 %. Water flow is 500 … 750 liters per 1 ton grain depending on the rate of the grain contamination. Humidifying rate of 2 … 6 % is regulated by the loading spout. Water pressure is up to 2 atmospheres. A single screw conveyor machine capacity is up to 3,7 t/h.

The use of the washer enables to reduce the set of grain cleaning machines. Therewith, first class flour output is 70…72% with the standard whiteness and ash content. The use of the washer leads to lower capital and operational expenses.