SUBSTANTIATION OF OPTIMUM PARAMETERS OF PNEUMATIC SEPARATION OF CRUSHED OIL SEEDS

2020 ◽  
Author(s):  
В.В. ДЕРЕВЕНКО ◽  
А.В. ДИДЕНКО ◽  
Г.А. ГЛУЩЕНКО ◽  
Г.Х. МИРЗОЗОДА ◽  
А.В. ЖУПЛЕВ
Keyword(s):  
Separation Zone ◽  
Air Flow ◽  
Air Velocity ◽  
Oil Seeds ◽  
Optimal Separation ◽  
Optimum Parameters ◽  
Pneumatic Separation ◽  
Pumpkin Seeds ◽  
Constrained Conditions ◽  
Particle Paths

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.

scholarly journals Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

2021 ◽  
Vol 13 (9) ◽  
pp. 4748
Author(s):  
Edwin Villagran ◽  
Carlos Bojacá ◽  
Mohammad Akrami
Keyword(s):  
Latin American ◽  
Crop Yields ◽  
Numerical Study ◽  
Air Flow ◽  
Research Work ◽  
Flow Patterns ◽  
Soil Conditions ◽  
Air Velocity ◽  
The Hours ◽  
Microclimatic Conditions

The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 °C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out.

Temperature Distribution of Hot Air Flow in Heating Zone for Drying Application

2014 ◽  
Vol 627 ◽  
pp. 153-157
Author(s):  
Nawadee Srisiriwat ◽  
Chananchai Wutthithanyawat
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Power Supply ◽  
Air Flow ◽  
Heating Zone ◽  
Velocity Control ◽  
Rectangular Duct ◽  
Air Velocity ◽  
Hot Air ◽  
Set Up

The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.

Resistance of Pumpkin Seeds to Air Flow

1979 ◽  
Vol 22 (6) ◽  
pp. 1414-1416 ◽  
Author(s):  
C. B. Akritidis ◽  
A. J. Siatras
Keyword(s):  
Air Flow ◽  
Pumpkin Seeds

scholarly journals Automobile Radiator’s Engineering and Analysation

2020 ◽  
Vol 9 (5) ◽  
pp. 554-558
Keyword(s):  
Flow Rate ◽  
Heat Dissipation ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Cooling Fan

The shape of a radiator cover is crucial either in determining the pattern of air flow or in increasing the same through the radiator core thereby increasing the thermal efficiency, thus making it a necessity to understand it. Moreover the parts circumjacent to the core namely the upper tank, lower tank, cooling fan, fins, tubes, etc promote the air flow rate. Also it is to note that the air flow rate of discharge gases from radiator core is one of the prime factors in determining the automobile cooling system. Initially factors such as temperature, pressure, air flow rate that affect the performance are obtained in order to derive out the entities of operation. One of the observations that can be made through this paper is that as the volume of the coolant increases, the rate of heat dissipation increases, also parameters like inlet temperature and volume flow rate of coolant, air velocity, temperature drop and drop in pressure of coolant are factors that contribute in radiator performance evidently.

Air Flow Analysis in Square Duct Bend

2014 ◽  
Vol 695 ◽  
pp. 622-626 ◽  
Author(s):  
Mohamad Nor Musa ◽  
Mohd Nurul Hafiz Mukhtar
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Cross Section ◽  
Air Flow ◽  
Flow Analysis ◽  
Maximum Velocity ◽  
Maximum Pressure ◽  
Air Velocity ◽  
Square Duct ◽  
Inlet Velocity

This paper present new result for experimental analysis of air flow velocity and pressure distributions between two ducts bend: (1) 90° duct bend with a single turning vane having 0.03m radius and (2) 90° duct bend with double turning vane, in 0.06 × 0.06 m duct cross section. The experiment used five different Reynolds numbers chosen between the ranges 1 ×104 and 6×104. Each experiment has four point measurements: (1) point 1 and point 2 at cross section A-A and (2) point 3 and point 4 at cross section B-B. The first experimental study used single turning vane radius 0.03m with inlet air velocity from 2.5m/s to 12.2m/s. And for the second experiment that used square turning vane with 0.03m radius. In experiment 2, the inlet air velocity also start from 2.5m/s to 12.2m/s. From analysis results, the pressure drop in experiment 1 is higher than experiment 2. As example the maximum pressure drop at 7.5m/s inlet air velocity between point 1 and 3 was found to be 71.6203 Pa in experiment 1 as compared to 61.8093 Pa in experiment 2. The velocity after duct bend is greater when using double turning vane compare used single turning vane as maximum velocity at point 3 in experiment 2 compare to velocity at point 3 in experiment 1 that is 55.677× 10-4 m/s and 54.221× 10-4 m/s. The velocity at duct wall is equal to zero. When increase the value of Reynolds number or inlet velocity, the maximum velocity and total pressure also increase. For example in experiment 1 at point 1, the velocity is 48.785 × 10-4 m/s at Reynolds number 1 ×104 and velocity 65.115×10-4 m/s at Reynolds number 12.2 ×104 . Velocity flow in duct section are lower than inlet velocity. In experiment 1, the inlet velocity is 2.5m/s meanwhile the maximum velocity in the duct section at point 2 is 73.075×10-4 m/s that is much more lower than inlet velocity.

Numerical Modeling of Air Flow in a Cabinet Dryer Equipped by Deflector Plates

2019 ◽  
Vol 15 (10) ◽  
Author(s):  
Omid Reza Roustapour ◽  
Hamid Reza Gazor ◽  
Kazemi Farzin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Modeling ◽  
Air Flow ◽  
Outlet Temperature ◽  
Governing Equations ◽  
Air Velocity ◽  
Drying Time ◽  
Elapsed Time ◽  
Quadrilateral Elements ◽  
Simulation Results

AbstractIn this study, air deflector plates were used in order to increase the air elapsed time in the chamber. The air flow pattern was simulated using computational fluid dynamics. The geometry of the chamber was produced in 2D and meshed by triangular and quadrilateral elements, boundary conditions were defined and the governing equations solved. Modeling of flow without any deflectors depicted the air flowed to the chamber conducted to the outlet without any distortion. Air vortices were generated when the deflectors defined in model. To evaluate the influence of deflectors on drying period, constructed plates installed in the dryer chamber and melon slices were dried when deflectors used or not. Simulation results showed magnitude of the air velocity was increased and temperature uniform distribution developed on the surface of trays. The outlet temperature was also decreased up to 10 % and drying time reduced to 22 % when the deflectors were employed.

scholarly journals Modelling particle movement in conical guide of seeder pneumatic pipe

2020 ◽  
Vol 175 ◽  
pp. 12019
Author(s):  
Vladimir Zaitsev ◽  
Artem Kravtsov ◽  
Vladimir Konovalovi
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Air Flow ◽  
Force Analysis ◽  
Particle Movement ◽  
Air Velocity ◽  
Finite Element Calculations ◽  
Calculation Results ◽  
Case Part ◽  
Good Agreement

In the course of the study, methods for ensuring the centeringof particlesofbulkmaterialintheairflowmovinginthepneumaticductofthe seeder were investigated. To solve this problem, it is proposed to use a conical confusor. The aim of the study was to obtain the functional dependences of the movement of particles in a conical airflow guide (confusor) for the conditions of transportation of the sown particles on the basis of force analysis and to identify the nature of the movement of the sownparticlesinataperingairflow.Duringthestudy,todescribethemotion of particles in a vertical tapering pipe, a system of expressions was substantiated. The developed mathematical model of particle motion in a conical air flow, implemented in the MathCAD mathematical package, allowscalculatingboththeparticletrajectoryandthevelocityparametersof the air flow and the particles to be sown. The digital calculation results in the MathCAD program are in good agreement with the finite element calculations. The magnitude of the error in air velocity is less than 1%. The differences in the velocities of the transported particles in the calculation options do not exceed 7%. The installation of a conical guide helps tofocus the flow of particles in the central part of the narrowed air line. In this case, part of the particles in the central part of the guide will retain the initial longitudinaltrajectory.Theangleattheapexoftheconeandtheparameters of the particles affect the speed and angle of the tangent contact of the particle with theguide.

scholarly journals Three-Dimensional CFD Modelling and Analysis of the Thermal Entrainment in Open Refrigerated Display Cabinets

2008 ◽  
Author(s):  
Pedro Dinis Gaspar ◽  
L. C. Carrilho Gonc¸alves ◽  
R. A. Pitarma
Keyword(s):  
Air Temperature ◽  
Mass Flow ◽  
Air Flow ◽  
Three Dimensional ◽  
Food Products ◽  
Ambient Air ◽  
Air Velocity ◽  
Air Curtain ◽  
Numerical Predictions ◽  
Thermal Entrainment

This study presents a three-dimensional Computational Fluid Dynamics (CFD) simulation of the air flow pattern and the temperature distribution in a refrigerated display cabinet. The thermal entrainment is evaluated by the variations of the mass flow rate and thermal power along and across the air curtain considering the numerical predictions of abovementioned properties. The evaluation on the ambient air velocity for the three-dimensional (3D) effects in the pattern of this type of turbulent air flow is obtained. Additionally, it is verified that the longitudinal air flow oscillations and the length extremity effects have a considerable influence in the overall thermal performance of the equipment. The non uniform distribution of the air temperature and velocity throughout the re-circulated air curtain determine the temperature differences in the linear display space and inside the food products, affecting the refrigeration power of display cabinets. The numerical predictions have been validated by comparison with experimental tests performed in accordance with the climatic class n.° 3 of EN 441 Standard (Tamb = 25 °C, φamb = 60%; νamb = 0,2 m s−1). These tests were conducted using the point measuring technique for the air temperature, air relative humidity and air velocity throughout the air curtain, the display area of conservation of food products and nearby the inlets/outlets of the air mass flow.

scholarly journals Protection from microbial contamination in a room ventilated by a uni-directional air flow

1969 ◽  
Vol 67 (1) ◽  
pp. 95-106 ◽  
Author(s):  
O. M. Lidwell ◽  
A. G. Towers
Keyword(s):  
Microbial Contamination ◽  
Air Flow ◽  
Regional Hospital ◽  
Airborne Bacteria ◽  
Settling Rate ◽  
Air Velocity ◽  
Experimental Room ◽  
Flow Lines ◽  
Hospital Board ◽  
Different Parts

SUMMARYExperiments have been carried out on the extent to which movement of persons in a room ventilated by a horizontally directed uniform air velocity can transport airborne bacteria from one position to another. More than 107 particles approximately 13 μ in diameter (settling rate in air about 1 ft./min.) carrying spores of Bacillus subtilis var. niger were liberated in each experiment and the numbers reaching the different parts of the room were estimated by those recovered on exposed settling plates. At air velocities of 35 ft./min. and over, no particles could be certainly found to have moved against the direction of air flow except into areas actually entered by persons, and the numbers found in these areas were between 100 and 1000 times less than would have been expected in rooms turbulently ventilated with the same volume of air. There was some transport of particles transversely across the air-flow lines but at 4 ft. distance from the area where movement of persons was taking place the numbers had fallen substantially below 1/100 of those to be expected in a turbulently ventilated room.The results recorded at an air velocity of 22 ft./min. were significantly less satisfactory.Our thanks are due to the N.W. Metropolitan Regional Hospital Board, to the Hospital Management Committee of St Charles' Hospital, London, W10, and especially to the hospital engineer for accommodating the experimental room and facilitating its operation.

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