scholarly journals Mechanical and thermal segregation of milli-beads during contact heating in a rotary drum. DEM modeling and simulation.

2018 ◽  
Author(s):  
Aline Mesnier ◽  
Maroua Rouabah ◽  
C. Cogné ◽  
Roman Peczalski ◽  
Séverine Vessot-Crastes ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Standard Deviation ◽  
Operating Conditions ◽  
Contact Heat ◽  
Segregation Index ◽  
Dem Simulation ◽  
Contact Heating ◽  
Particulate Solid ◽  
Rotary Drum ◽  
Horizontal Drum

The flow mechanics and heat transfer phenomena within a bed of milli-metric size spherical beads rotated and heated by contact in a horizontal drum were simulated by means of commercial discrete element software EDEM. Mono-dispersed and bi-dispersed beds (two particle sizes or two particle densities) were considered. The mechanical segregation index (standard deviation of local bed compositions) and the thermal segregation index (standard deviation of beads temperatures) were calculated for the different types of bed and same operating conditions. The thermal segregation was found to be enhanced by mechanical segregation and was much stronger for bi-dispersed beds than for monodispersed one.   Keywords: rotating drum; particulate solid; segregation; contact heat transfer; DEM simulation. 

scholarly journals Mixing of Bi-Dispersed Milli-Beads in a Rotary Drum. Mechanical Segregation Analyzed by Lab-Scale Experiments and DEM Simulation

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1166
Author(s):  
Aline Mesnier ◽  
Roman Peczalski ◽  
Guilhem Mollon ◽  
Séverine Vessot-Crastes
Keyword(s):  
Discrete Element ◽  
Front Side ◽  
Discrete Elements ◽  
Simulation Data ◽  
Segregation Index ◽  
Dem Simulation ◽  
Rotary Drum ◽  
Horizontal Drum ◽  
Dem Model ◽  
Discrete Elements Method

Mechanical flow and segregation phenomena within a bed composed of milli-metric size spherical beads rotated in a horizontal drum were investigated. The beads population was bi-dispersed, with two kinds of binary (half by half) compositions: a bi-size bed with two different sizes and a bi-density bed with two different densities. The distributions of the beads were observed optically on the front side of the bed by means of a lab-scale drum prototype. Different numbers and lengths of peripheral straight baffles were tested as well as different drum filling ratios. The photographical data were processed to obtain the front layer mechanical segregation index. This experimental index was compared to the simulated one, obtained by means of commercial discrete element software EDEM. The simulations were corroborated by the experiments provided that the friction coefficients of the discrete elements method (DEM) model were correctly adjusted. The global segregation index was also calculated from simulation data for all considered cases and its values were lower and less sensitive to baffles’ configurations than those for the front layer.

Heat Transfer Model in a Rotary Drum During the Fermentation Process

2020 ◽  
Vol 77 (1) ◽  
pp. 151-160
Author(s):  
Norazaliza Mohd Jamil ◽  
Aainaa Izyan Nafsun ◽  
Abdul Rahman Mohd Kasim
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Transfer Coefficient ◽  
Fermentation Process ◽  
Transfer Model ◽  
Kutta Method ◽  
Contact Heat ◽  
Contact Heat Transfer ◽  
Runge Kutta Method ◽  
Rotary Drum

A new mathematical model describing heat transfer during the fermentation process in a rotary drum is proposed. The model includes representations of the kinetic reactions, the temperature of the solid bed, and physical structures within the rotary drum. The model is developed using five ordinary differential equations and was then solved using the Runge-Kutta method embedded in MATLAB software. A reasonable behaviour for the temperature profile to the fermentation process is achieved. The results show that the mass of the solid bed, contact heat transfer coefficient, and the wall temperature has a significant effect on the fermentation process in a rotary drum.

Performance Evaluation of a Thermal Energy Storage

2013 ◽  
Vol 291-294 ◽  
pp. 642-647 ◽  
Author(s):  
Mohamed Gadalla ◽  
Saad Ahmed
Keyword(s):  
Heat Transfer ◽  
Direct Contact ◽  
Air Conditioning ◽  
Operating Conditions ◽  
Contact Heat ◽  
Transfer Rates ◽  
Contact Charging ◽  
Contact Heat Transfer ◽  
Charging Mode ◽  
Transfer Method

The direct contact heat transfer technique gives better heat transfer rates. In this paper, the operation of a simple system was simulated under different operating conditions. During the charging mode of the operation, refrigerant R134a is injected into water stored in an evaporator to exchange directly heat with the water and form clathrates. Later, the clathrate is used to cool water which is used for air-conditioning purposes. Direct contact charging and/or discharging eliminate the necessity of a heat exchanger inside the storage tank and leads to an effective heat transfer method. The results indicate that the performance of the system depends on the refrigerant type, compressor speed and the mass flow rate of the refrigerant.

Hydrodynamic Features of Contact Heat-Transfer Packing Devices

1997 ◽  
Vol 28 (4-6) ◽  
pp. 393-397
Author(s):  
N. Yu. Koloskova ◽  
V. V. Dubrovskaya ◽  
V. V. Orlyanskii
Keyword(s):  
Heat Transfer ◽  
Contact Heat ◽  
Contact Heat Transfer
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