scholarly journals MATHEMATICAL MODEL OF MOTION OF A FOREST SEED MATERIAL PARTICLE IN THE OPERATING CHANNEL OF SEPARATOR

2021 ◽  
Vol 11 (1) ◽  
pp. 123-131
Author(s):  
Vladimir Zelikov ◽  
Vyacheslav Kozlov ◽  
Aleksey Skrypnikov ◽  
Evgeniy Izvekov ◽  
Elena Kozlova
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Flow Rate ◽  
Magnetic Force ◽  
Air Flow ◽  
Air Flow Rate ◽  
High Quality ◽  
Seed Material ◽  
Seed Mixture ◽  
Hereditary Properties

Preparation of high-quality seed material for the needs of forest seed stations aimed at the reproduction of forests with seeds with improved hereditary properties requires the use of special seed cleaning machines. The use of such seeds with improved hereditary properties will provide an increase in the productivity, quality and sustainability of plantations. Seed material of different species has features of surface and shape, taking into account these differences, various machines and installations have been developed and widely used. The need to use special machines for magnetic cleaning is caused by the impossibility of high-quality separation of seed material. Analysis of modern technical means of seed preparation showed that the idea of combining air and magnetic cleaning deserves special attention. During pneumomagnetic separation, various forces act on a particle of the seed mixture, the magnitude and direction of which change depending on the design parameters of the working body of the inductor and the position of the particle of the seed mixture in the magnetic field of the inductor. It is possible to study the movement of a particle in the operating channel, as well as to construct a mathematical model, by making some assumptions, the result of which makes it possible to study in theory the influence of design and technological parameters on the separation process of forest seed, as well as to determine the regularities of the process of pneumomagnetic separation. Based on the results of the analysis of the movement trajectories of the seed mixture, curves of the movement of particles are plotted at various values of the magnetic force in the working channel, and graph is presented that illustrates the possibility of carrying out the process of pneumomagnetic separation depending on the ratio of the air flow rate and magnetic force acting on the particle. It has been determined that the process of pneumomagnetic seed cleaning can be effectively carried out at an air flow rate of 3.5 ÷ 5.2 m/s, and a magnetic force of 3.4 × 10-6 ÷ 8 × 10-6N. It is necessary to create a magnetic field induction in the range of 0.115 ÷ 0.177 T in order the magnetic force to have such a value in the working channel.

scholarly journals Modelling of air flow rate in significantly flattened rounded rectangular ventilation ducts

2018 ◽  
Vol 180 ◽  
pp. 02082 ◽  
Author(s):  
Kazimierz Peszynski ◽  
Jan Novosád ◽  
Emil Smyk ◽  
Lukasz Olszewski ◽  
Petra Dančová
Keyword(s):  
Mathematical Model ◽  
Velocity Profile ◽  
Flow Rate ◽  
Cross Sections ◽  
Air Flow ◽  
Air Flow Rate ◽  
New Model ◽  
Ventilation Ducts ◽  
Air Flow Velocity ◽  
New Phenomena

Paper presents new mathematical model for air flow velocity distribution in rounded rectangular ducts and its experimental verification. In papers [1, 2] an mathematical model based on modified Prandtl equation for power power-law velocity profile was determined. It works very well for smaller cross sections. During the study of larger cross sections new phenomena in flowing air have been observed, it forced the search for a new model. The new model is based on a rounded rectangular division into two parts: slot and rounded square.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Modeling and optimization of radish root extract drying as peroxidase source using spouted bed dryer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Air Flow ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Air Flow Rate ◽  
Spouted Bed ◽  
Radish Root

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

Method to Determine an Optimal Air-Flow Rate in Solar Collectors

1979 ◽  
Vol 3 (6) ◽  
pp. 357-362
Author(s):  
H. C. Hewitt ◽  
E. I. Griggs
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Solar Collectors ◽  
Air Flow Rate

Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

2003 ◽  
Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Air Flow ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Process Data ◽  
Cfb Boiler ◽  
Flow Rates ◽  
Load Change ◽  
Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

scholarly journals Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Hasan Alimoradi ◽  
Madjid Soltani ◽  
Pooriya Shahali ◽  
Farshad Moradi Kashkooli ◽  
Razieh Larizadeh ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Pso Algorithm ◽  
Outlet Temperature ◽  
Air Flow Rate

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction.

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