FLAT SIEVE SEPARATORS WITH ANNULAR PNEUMATIC SEPARATION DUCT

The search for the optimal variant of the structural ar-rangement of flat-screen separators by centrifugal-air sepa-rators with annular pneumatic separation ducts is a promis-ing direction in the development of new equipment. This will significantly improve the technological performance of grain cleaning plants. It may be considered a promising direction for such research. Therefore, it is necessary to look for new options for the layout of grain cleaning ma-chines to increase their technological efficiency. Several variants of technological schemes for the operation of ex-isting flat-sieve separators with a centrifugal-air separator with an annular pneumatic separation ducts are proposed. The technological process of the modernized grain clean-ing plant based on the A1-BIS-100 plantis described. The main parameters of the gravity transporting device are de-termined; they fully ensure the operability of the modern-ized plant.

Modeling of Aerodynamic Separation of Preliminarily Stratified Grain Mixture in Vertical Pneumatic Separation Duct

The productivity of most grain cleaning machines seems to be directly related to the efficiency of vertical pneumatic separation ducts. Nevertheless, improvement is accompanied by an increase in the load of the vertical duct, the design of which is limited by the width of the grain cleaning machines. This requires an increase in the thickness of the layer of grain mixture that enters the working area of the duct, which significantly worsens the conditions of separation of its components under the action of airflow. Particles of light impurities are unable to separate due to their retention by the grain medium. This reduces the quality of cleaning and requires appropriate scientific and technical solutions. The application of preliminary stratification of the granular mixture while increasing the concentration of light impurities in the top layer of the mixture seems to be a prospective method. The positive effect of the previous stratification on the intensity of redistribution of light impurity particles in the working zone has been theoretically considered and experimentally confirmed. Mathematical models were obtained to determine the trajectory of discussed particles, taking into account the previous stratification of mixtures, and the corresponding dependences were established. The influence of the initial coordination of the introduction of the particles of lightweight impurities, their sizes and densities, and technological and structural parameters of operation of the pneumatic separation duct were taken into account in the studies. The intensification of the process of cleaning grain from lightweight impurities in the working zones of pneumatic separation ducts of grain cleaning machines is theoretically substantiated.

Optimization of hammer grinder for white lupine “Dega” processing

Исследования проведены в 2019 году в лаборатории «Технология и техника мукомольно-крупяного производства» ВНИИ зерна и продуктов его переработки – филиала ФГБНУ «ФНЦ пищевых систем им. В. М. Горбатова» РАН. В качестве объекта исследований использовали зерно белого люпина сорта Дега. Эксперименты по изучению условий измельчения зерна проводились на лабораторной молотковой дробилке с регулируемой частотой вращения ротора. Рассматривалось влияние влажности зерна, скорости молотков и диаметра отверстий рабочего сита дробилки на выход крупки и содержание в ней недоруша (зёрен и частиц с остатками оболочки, крупных частей неотвеянной оболочки). Использование простой технологической схемы обрушения зерна белого люпина на базе молотковой дробилки позволило получить до 70% крупки с повышенным содержанием белка и низким содержанием клетчатки. С ростом скорости молотков и уменьшением диаметра отверстий рабочего сита дробилки выход крупки снижался, что объяснимо ростом доли мелкой фракции, которая отвеивается при пневмосепарации. Крупка представляет из себя частицы ядра с недорушем, а относы являются смесью дроблёной оболочки с мучкой — мелкой фракцией дробленого ядра. Основная доля мучки ядра была сосредоточена во фракции меньше 1,5–2,0 мм, в которой содержится больше белка. Данная фракция составляла около половины массы относов или около 15% от массы зерна. Наличие недоруша в крупке повышало содержание в ней клетчатки и снижало содержание белка. С ростом влажности и диаметра отверстий рабочего сита дробилки содержание недоруша возрастало, а при росте скорости — падало. При фиксированной влажности содержание недоруша можно снизить за счёт повышения скорости удара (увеличения числа оборотов) или уменьшения диаметра отверстий рабочего сита дробилки, но и тот и другой метод повышают энергозатраты. При возрастании скорости удара росла и производительность. The research was conducted in 2019. Hammer grinder with adjustable rotor speed was used to crush the grain of white lupine “Dega”. The effects of grain water content, crushing speed and sieve size were analyzed on grain crushing and hulling as well as the proportion of unhulled grain. This technology resulted in up to 70% of crushed hulled grain rich in protein but poor in fiber. Increase in hammer speed and decrease in sieve size negatively affected the proportion of crushed grain due to the high content of fine fractions discarded further via pneumatic separation. Crushed hulled grain is normally combined with unhulled grain. The mixture of crushed hulls and fine particles of crushed grain are to be separated. Most of the bran was found in the fraction of 1.5–2.0 mm containing more protein. This fraction amounted to 15% of grain mass and 50% of the mass to be discarded. Unhulled grain mixed with crushed hulled grain increased fiber content in the mixture but reduced protein concentration. Higher grain water content and larger sieve size increased the amount of unhulled grain, while higher hammer speed decreased its fraction. Higher hammer speed as well as smaller sieve size reduce the content of unhulled grain but increased energy costs under constant grain water content. Increase in hammer speed improved the capacity of the grinder.

Environmentally friendly automated line for recovering aluminium and lithium iron phosphate components of spent lithium-iron phosphate batteries

Lithium iron phosphate (LFP) batteries contain metals, toxic electrolytes, organic chemicals and plastics that can lead to serious safety and environmental problems when they are improperly disposed of. The published literature on recovering spent LFP batteries mainly focuses on policy-making and conceptual design. The production line of recovering spent LFP batteries and its detailed operation are rarely reported. A set of automatic line without negative impact to the environment for recycling spent LFP batteries at industrial scale was investigated in this study. It includes crushing, pneumatic separation, sieving, and poison gas treatment processes. The optimum retaining time of materials in the crusher is 3 minutes. The release rate is the highest when the load of the impact crusher is 800 g. An air current separator (ACS) was designed to separate LFP from aluminium (Al) foil and LFP powder mixture. Movement behaviour of LFP powder and Al foil in the ACS were analysed, and the optimized operation parameter (35.46 m/s) of air current speed was obtained through theoretical analysis and experiments. The weight contents of an Al foil powder collector from vibrating screen-3 and LFP powder collector from bag-type dust collector are approximately 38.7% and 52.4%, respectively. The economic cost of full manual dismantling is higher than the recovery production line. This recycling system provides a feasible method for recycling spent LFP batteries.

DEVELOPMENT OF THE OPTIMAL DESIGN OF A CYCLONE APPARATUS WITH A FLUIDIZED BED FOR THE PROCESS OF METALS PNEUMATIC SEPARATION IN THE COMPOSITION OF INDUSTRIAL WASTE

Recycling of techno genic waste accumulated in recent years in Uzbekistan is currently a pressing problem. In this regard, this paper examines the issue of studying the process of enrichment of man-made waste in a cyclone with a fluidized bed. To conduct the experiment on experimental advanced devices with extended zones five types of samples of techno genic waste with the limits of 0.072÷0.078mm, 0.064÷0.070mm, 0.057÷0.063mm, 0.046÷0.055mm and 0.041÷0.044mm have been prepared. Nomograms have been obtained using mathematical models to determine particle size limits, which ensure good separation. Experiments have been carried out on the separation of techno genic waste in three structures of a cyclone with a fluidized bed: cylindrical, cylindrical with one extended zone and cylindrical with two extended zones. The best results are obtained in a fluidized bed machine with one extended zone. The following results were obtained for a sample with a 0.041÷0.044 mm limit size: the number of Mo increased 40 times, Ag increased 20 times, Mn increased 2.5 times, Cu increased 1 time, Ti increased 6.6 times, Ni decreased 125 times and the number of Si in the selected sample decreased from 20% to 12%.

The Process of Separation of Husked Soybean in Oblique Airflow

The study concerns an evaluation of the effect of selected parameters on the course of horizontal pneumatic separation of unsorted husked soybean and the process efficiency. The efficiency of the process of isolating endosperm fraction from husks and other impurities was evaluated by determining the separation efficiency indicator η. It was shown that increased moisture content of the mixture results in a significant decrease in the η indicator. For example, with the 2.2% increase of moisture content (from W1 = 10.1% to W2 = 12.3%), the separation efficiency indicator decreased, on average, by 6.8%. The value of the η indicator rose with the increased velocity of the airstream, but the amount of valuable fraction that is picked up by the airstream is higher as well. It was found that, when the air velocity increased from V1 = 7.8 m·s−1 to V2 = 10.5 m·s−1 (for the moisture content W1 = 10.1% and W4 = 15.7%), the increment in the efficiency was the highest and reached 14.9–34.3%. A parametric model of the separation process of fragmented mixtures of biological origin was developed based on the analysis of the obtained results observation undertaken. This model can be used in designing and carrying out operations of separation into particular size fractions and cleaning of various feed mixtures, or in determining parameters of the movement of specific mixture components within pneumatic channels.

Recovery of Cenospheres and Fine Fraction from Coal Fly Ash by a Novel Dry Separation Method

Aluminosilicate microspheres are a valuable fraction of coal fly ash with diverse applications due to their low density. Currently, there is no efficient and ecologically rational method of cenosphere recovery from fly ash. A combination of dry methods for the recovery of both fine ash particles and aluminosilicate microspheres from coal fly ash is presented. It is comprised of fluidised bed separation followed by screening and pneumatic separation in a free-fall air chamber. Fluidised bed separation was assisted by a mechanical activator to prevent agglomeration. This step reduced the portion of material that required further treatment by 52–55 wt.%, with the recovery of microspheres exceeding 97%. Then, the concentrates were individually subjected to pneumatic separation. The final separation product for the fly ash containing 0.64 wt.% cenospheres was a cenosphere concentrate that constituted about 17 wt.% of the initial fly ash. The recovery of cenospheres was around 81%. Usage of a combination of dry methods allowed for maintaining almost 83 wt.% of the raw material in its dry form. Furthermore, the produced fly ash grain fractions could be used for different industrial purposes.

SUBSTANTIATION OF OPTIMUM PARAMETERS OF PNEUMATIC SEPARATION OF CRUSHED OIL SEEDS

С целью обоснования оптимальных параметров сепарирования рушанки семян подсолнечника, рапса и тыквы воздушным потоком исследованы особенности сепарирования рушанки в промышленном аэросепараторе в стендовых условиях и проведено моделирование процесса. Разработана адекватная математическая модель движения частиц рушанки в стесненных условиях. Проведен численный эксперимент, представленный в виде криволинейных траекторий частиц при различных скорости воздуха, скорости витания и других параметрах. Рассчитаны оптимальные параметры пневмосепарирования рушанки масличных семян. При сепарировании рушанки семян подсолнечника фракций недоруша (максимальная скорость витания лузги 4,5 м/с), сечки (средняя скорость витания лузги 3,1 м/с) и мелкой сечки (минимальная скорость витания лузги 1,8 м/с) скорость воздуха следует поддерживать соответственно в интервалах 7,5–8, 5–6 и 3–4 м/с при скорости поступающих частиц в пневмосепарирующий канал не более 1,1 м/с. При сепарировании рушанки семян рапса сходовой фракции с сита диаметром 1,8 мм (максимальная скорость витания плодовой оболочки 4,45 м/с) скорость вертикального воздушного потока необходимо поддерживать в интервале 6–7 м/с, при этом скорость поступающих частиц в зону сепарирования должна быть не более 0,8 м/с. Сепарирование рушанки тыквенных семян (скорость витания оболочки 3,8–5,2 м/с) в вертикальном воздушном потоке целесообразно проводить с его скоростью в интервале 6–7 м/с при скорости поступающих частиц в зону сепарирования не более 1,1 м/с. For the purpose of substantiation of the optimal separation parameters of sunflower, rapeseed and pumpkin crushed seeds by air flow, the features of separation of crushed seeds in an industrial air separator in bench conditions were studied and the process was modeled. The adequate mathematical model of movement of crushed seeds particles in constrained conditions has been developed. A numerical experiment presented as curved particle paths at different air velocity, soaring velocity and other parameters was performed. Optimal parameters of pneumatic separation of oil seeds are calculated. When separation of crushed sunflower seeds fractions incompletely crushed (maximum soaring velocity husk 4,5 m/s), medium crushed (average soaring velocity husk of 3,1 m/s) and small crushed (minimum soaring velocity husks 1,8 m/s) air velocity should be maintained respectively in the range of 7,5–8, 5–6 and 3–4 m/s when the velocity of the incoming particles in aspiration channel is not more than 1,1 m/s. When separating of the crushed rapeseed from a sieve with a diameter of 1,8 mm (the maximum soaring velocity of the fruit shell is 4,45 m/s), the velocity of vertical air flow must be maintained in the range of 6–7 m/s, while the velocity of incoming particles in the separation zone should not be more than 0,8 m/s. Separation of the crushed pumpkin seeds (the soaring velocity of the shell is 3,8–5,2 m/s) in a vertical air flow is advisable to carry out with its velocity in the range of 6–7 m/s at the velocity of incoming particles in the separation zone of no more than 1,1 m/s.