Ensuring the effective operation of mills in the cold season.

   Technical Director of "OLIS, Ph.D. Vereshchynsky A.P.

      With the coming cold season in most mills are visible problems associated with a decrease in the quality and yield of flour. The main reason for this decline is a violation of the temperature conditions necessary for the effective conduct waterthermal  grain handling. 
      As you know, waterthermal processing of grain, also known as air-conditioning, along with cleaning, form the basis of training in wheat quality grinding. In the process of conditioning under the influence of moisture and heat directionally changing the physical and mechanical properties of grain. Shell becomes more robust and resilient, and endosperm loses its strength and becomes friable. Such changes are a result of grinding flour contributes to increasing output and reduce its ash content, improve whiteness. As a result of biochemical processes that accompany the air conditioning in the flour produced better quality of gluten, increases the activity of enzymes. 
     The vast majority of mills in the simplicity of implementation and efficiency of applying the method of cold air conditioning. Wheat moistened to the desired moisture content and sent to a bunker for conditioning. During the time specified with conditioning, and must occur above, useful changes. When implementing this method uses a natural biological capacity of the grain to germinate, that occur under certain conditions. Therefore, to ensure the effectiveness of such conditioning grain must contain 15,5-17,0% moisture, and its temperature must be below 18 degrees. With the onset of cold weather, arriving at the mill the grain is characterized by low temperatures and poor moisture absorption during hydration. It is particularly difficult to get, in such circumstances, moisturize dry, and vitreous seeds. Often this grain were forced to send conditioning with deliberately low humidity, which does not meet the required conditions of effective air conditioning. In the cold grain moisture slowly penetrates the endosperm, which can sometimes compensate for the increase of time of conditioning. However, even in the presence of sufficient moisture absence of the necessary amount of heat can not start the second activation of the embryo to grow without which full air conditioning is not possible. 
      At many mills the water, which hold moisture, heated to a temperature of 60-70 degrees, which is undoubtedly a useful exercise. However, due to the small required flow even very hot water can heat the grain no more than a few degrees. For a complete solution to this problem, moisture is necessary to heat not only water but also the grain. Recommended heating temperature of the grain is 20-25 degrees. 
      For heating grain during conditioning, we developed a heater PZ, which is already several years successfully implemented and operated at the mills of various capacities. Heater consists of a hopper, one or more heating sections and the extraction device. Heating section is a construction shaft type with a rectangular cross-section 1000h1000mm length 2000mm. The heating element is made of straight segments of pipe connected to the coil, welded joints which are located outside the mine. Housing section is provided with manholes for access into and lids, closing zippers heating pipes. The venting device includes the construction of the final crater excluding the education section of the heating of stagnant zones, as well as the gateway to the feeder drive. All exterior heating element heater insulated. As the coolant is water which is heated in a boiler of any type and fed through a heating element in a closed circuit. One heating section is designed for productivity of 1500 kg / h. If necessary, increase the productivity of the required number of sections mounted in series, making them vertically with the help of flanged joints. 
      Grain to be heated and served in a hopper and gravity in bound mode passes through the heating section, washing pipe heating element. As a result of contact with the hot surface of the grain is heated. Release of grain from the apparatus and carried out through exhaust funnel and gateway feeder extraction device. To automatically adjust the grain filling heater provides level sensors associated with the control unit output airlock feeder. To control the grain temperature heater is equipped with several electronic thermometers. 
      As practice shows operating heaters PZ grain in Ukraine and Russia described the use of the heater allows the grain to ensure the work of the mill in winter, without compromising the quality and yield of flour. Moreover, even if using an electric boiler and heating the grain at 15 degrees, energy consumption will be about 8 kW per ton of processed grain.

 

 

Fig.1 Grain heater  PZ

 

Fig.2 The heating section of the grain heater  PZ