scholarly journals Experimental study of convective dryer with centrifugal fluidized bed

Vestnik IGEU ◽  
2021 ◽  
pp. 5-13
Author(s):  
A.A. Nadeev ◽  
A.V. Barakov ◽  
D.A. Prutskikh ◽  
V.Y. Dubanin ◽  
A.M. Naumov
Keyword(s):  
Mass Transfer ◽  
Moisture Content ◽  
Fluidized Bed ◽  
Hydraulic Resistance ◽  
Heat Mass Transfer ◽  
Experimental Plant ◽  
Working Chamber ◽  
Fluidizing Agent ◽  
Centrifugal Fluidized Bed ◽  
Dispersed Material

Nowadays, the units with a fluidized bed hold a special place among all heat-mass transfer plants currently used in industry. First of all, it is due to the highly developed surface of interaction between the fluidizing agent (air) and dispersed materials in such units, their low hydraulic resistance, relatively simple design and small sizes. At the same time, the units with a centrifugal fluidized bed, which is formed in an annular channel of the working chamber when a fluidizing agent is added under the fixed angle, are of particular interest. Currently, a limited number of experimental and theoretical studies of hydrodynamics and heat-mass transfer in a fluidized bed are known. Besides, these studies were carried out mainly in respect to regenerative heat exchangers and absorbers. In this regard, such studies in respect to the devices for other purposes, such as dryers, seem to be relevant. The results of these studies are the scientific backgrpund for development of an engineering calculation methodology of such units and their design. The study has been carried out based on an experimental plant using means for measuring temperature, relative air humidity, differential pressure, air velocity, and moisture content of solids. A TPM 148 PID controller has been used as a secondary device. Experimental data have been recorded in MasterSCADA SCADA system. Data processing has been carried out using interpolation by cubic splines. The article describes in detail an experimental plant that allows carrying out a full factor experiment to study the hydrodynamic and thermal parameters of a convective dryer with a centrifugal fluidized bed. The article presents the results of a preliminary series of experiments in which silica gel is used as a dispersed material. As a result of visual observations over the dispersed material in the working chamber, the values of the minimum and maximum speed of the drying agent have been determined. The grafic relationship of the hydraulic resistance of the working chamber and the height of the material layer are obtained depending on the speed of the drying agent and the mass of the material, as well as the temperature and moisture content of the material and the drying agent depending on the drying time. The results obtained make it possible to determine the design and operational parameters of the centrifugal fluidized bed drying plant and select a fan to supply the drying agent.

scholarly journals Simulation and Analysis of Plug Flow Fluidized Bed Dryer

2020 ◽  
Vol 9 (7) ◽  
pp. 805-811
Keyword(s):  
Mass Transfer ◽  
Moisture Content ◽  
Heat And Mass Transfer ◽  
Fluidized Bed ◽  
Plug Flow ◽  
Small Scale ◽  
Outlet Temperature ◽  
Drying Process ◽  
Fluidized Bed Dryer ◽  
Hot Air

Today many industries now use the dryer as a part of grain-drying process even during wet and dry seasons. This helps in reducing spoilage and wastage of paddy. Mostly the available industrial dryers are expensive to purchase and to maintain its smooth functioning. This study therefore is a step to design a simple Plug flow fluidized dryer that can lead to introduce small scale dryers to paddy process industry. The Plug flow fluidized bed dryers are designed and fabricated in this study consists of the drying chamber, hot air distributer plate, hot air inlet and exit system, paddy entry and exit system, fluidization chamber unit with temperature control unit and the centrifugal fan. The evaluation of dryer is based on drying time and reduction in moisture content and outlet temperature of paddy on quality parameters. Dryer dimensions are very important to analyze heat and mass transfer analysis of the Plug flow fluidized bed drying process of paddy grains. It was found d that heat and mass transfer properties of paddy grains in fluidized bed dryer was decreases as the time of drying passes and very rapid at the start of drying. The model present here predicts about dryer dimensions along safe zone of rough rice moisture content with other parameters. Simulation results show a good agreement between the simulation model and the existing simulation models

EXPERIMENTAL RESEARCH ON MASS TRANSFER IN A CENTRIFUGAL FLUIDIZED BED DRYER

1998 ◽  
Vol 17 (9) ◽  
pp. 1845-1857 ◽  
Author(s):  
G. F. Chen ◽  
W. Wang ◽  
H. Van ◽  
X. Z. Wang
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Experimental Research ◽  
Fluidized Bed Dryer ◽  
Centrifugal Fluidized Bed

Heat and Mass Transfer of Drying Particles in a Fluidized Bed

2010 ◽  
Author(s):  
J. Bruchmu¨ller ◽  
B. G. M. van Wachem ◽  
S. Gu ◽  
K. H. Luo
Keyword(s):  
Mass Transfer ◽  
Moisture Content ◽  
Heat And Mass Transfer ◽  
Fluidized Bed ◽  
Particle Temperature ◽  
Mixing Efficiency ◽  
Coffee Bean ◽  
Transfer Coefficients ◽  
Quality Properties ◽  
On Line

In this study, the heat transfer and drying process of arabica coffee beans in a batch fluidized bed roaster has been studied. Herein, the discrete element method (DEM) has been used and modified to account for resolved 1D temperature and moisture content profiles within each single coffee bean. This approach has the strength to provide much more information on the global (fluidization, mixing) and local (particle data) level compared to existing coffee roaster models. Therefore, the product quality can be evaluated on-line by many more specific criteria beyond the averaged global particle temperature and moisture content. Instead, information of every single particle is available which includes heat and mass transfer coefficients, its local position inside the bed, collision forces, etc. Furthermore, the overall roaster performance is based on e.g. fluidization stability, mixing efficiency or uniformity of quality properties among all particles. More data are presented to account for a broader coffee bean roasting evaluation. Modeling results are in good agreement with experimental data.

scholarly journals Multistage Shelf Devices with Fluidized Bed for Heat-Mass Transfer Processes: Experimental Studies and Practical Implementation

2021 ◽  
Vol 11 (3) ◽  
pp. 1159
Author(s):  
Mykola Yukhymenko ◽  
Artem Artyukhov ◽  
Ruslan Ostroha ◽  
Nadiia Artyukhova ◽  
Jan Krmela ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Fluidized Bed ◽  
Heat Mass Transfer ◽  
Structural Parameters ◽  
Experimental Studies ◽  
Shelf Space ◽  
Interphase Heat Transfer ◽  
Transfer Processes ◽  
Mass Transfer Processes

The article deals with the theoretical description and experimental study of the hydrodynamic and heat transfer properties regarding the operation of multistage gravitational devices of the fluidized bed with inclined perforated shelves. The peculiarities of the work and the implementation field of the multistage shelf units are described. A theoretical model to define the solubilizer’s velocity above the perforation holes, in the above-shelf space of the device and in the outloading gap, as well as the residence time of the dispersed phase at the stage (perforated shelf contact) of the device is presented. The results of experimental studies regarding the influence, made by the structural parameters of the perforated shelf contacts, on the distribution pattern of single-phase and gas-dispersed flows in the workspace of the device, on the intensity of interphase heat transfer are presented. The conditions to create active hydrodynamic operating modes of multistage gravitational shelf devices, which provide higher efficiency of heat-mass transfer processes, and with lower gas consumption and hydraulic resistance compared to typical fluidized bed devices, are proved. Peculiarities regarding the implementation of heat-mass transfer processes in multistage devices are described using heat treatment and drying processes as examples.

scholarly journals Substantiation of a rational method for drying granules in a fluidized bed and the hydrodynamic regime of their interaction with a fluidizing agent

Vestnik MGTU ◽  
2021 ◽  
Vol 24 (3) ◽  
pp. 287-298
Author(s):  
A. A. Nugmanova ◽  
I. Y. Aleksanian ◽  
A. H.-H. Nugmanov ◽  
Y. A. Maksimenko ◽  
R. A. Khaybulov
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Gas Flow ◽  
Wheat Gluten ◽  
Rational Method ◽  
Hydrodynamic Regime ◽  
Hydrodynamic Characteristics ◽  
Fluidizing Agent ◽  
State Of Rest ◽  
The Given

Gluten is produced from wheat grains and is used in the food industry as an improver in flour baking properties. On the basis of a comparative analysis of the methods of dehydration of frozen granules of wheat gluten with a surface dry crust, a rational method of drying them in a fluidized bed has been selected. In the process of calculating units with a fluidized bed, its hydrodynamic parameters have been determined: loss of the pressure of the fluidizing agent; the speed at the transition of the bed from the state of rest to the pseudo-boiling mode; layer porosity; the rate of entrainment of particles in unrestricted conditions roughly corresponding to the rate of soaring, at which a single particle is in equilibrium in the gas flow. During the dewatering operation, the rate of entrainment of the granules varies; therefore, it is advisable to use the passing fluidization mode depending on the decrease in their moisture content. In the variant of the active hydrodynamic regime in the drying unit, the dehydration procedure is intensified without a noticeable decrease in the economic efficiency of its functioning and high quality indicators of the finished product with the given final moisture are provided, which is due to the specific conditions of contact of the granules with the coolant. For granules with a moisture content of 0.19 kg/kg, the values of hydrodynamic characteristics have been determined: the area of critical pseudo-boiling rates is 4.1-5.5 m/s; the carryover rate of the fines is 12.5-14.5 m/s. As a result of the study, the choice has been substantiated in favor of drying the studied granules in a fluidized bed due to the prevalence of its advantages over the dehydration of the object in drum dryers.

INVESTIGATION ON HYDRODYNAMICS OF FLUIDIZED BED AS A COMPONENT DETERMINING HEAT AND MASS TRANSFER

1974 ◽  
Author(s):  
N. B. Kondukov ◽  
L.I. Frenkel ◽  
M. B. Kliot ◽  
B. V. Pankov ◽  
V. S. Potapochkin ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Fluidized Bed
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