Experimental and numerical study on a bubbling fluidized bed with wet particles

AIChE Journal ◽  
2016 ◽  
Vol 62 (6) ◽  
pp. 1970-1985 ◽  
Author(s):  
Tianyu Wang ◽  
Yurong He ◽  
Tianqi Tang ◽  
Wengen Peng
Author(s):  
Sanjib K. Das Sharma ◽  
Ratan Mohan

Numerical study of the influence of tube-bank on the hydrodynamics of a freely bubbling fluidized bed is relatively less reported in the literature. In this paper, results obtained from CFD study of a two dimensional gas-solid fluidized beds with horizontal tube-bank are compared with the published experimental data (Hull et. al., 1999). A 2-D bed, 1 m high and 0.2 m wide with tubes of diameter 0.026 m was taken for the calculations. Two different tube arrangements of staggered and inline pitch with center-to-center distance of 0.05 m were considered. Air was used as the fluidizing medium and ballotini glass (diameter: 230 mm and density: 2723 kg/m3) was the fluidized material. Air velocities used were 0.15 m/s and 0.187 m/s. The Eulerian-Eularian Two-Fluid CFD model was employed for modeling the momentum equations for both the gas and the solid phase with kinetic theory modification for the solid phase to account for the inter-particle interactions. Hydrodynamic features, such as, bubble size and bubble rise velocity and their variation with height within and outside the tube bank showed good agreement with the data of Hull et al.(1999)


2019 ◽  
Vol 142 (2) ◽  
pp. 1087-1096
Author(s):  
Mohamed Sobhi Alagha ◽  
Botond Szucs ◽  
Pal Szentannai

AbstractIn this article, numerical investigations on mixing and heat transfer of solid refused fuel (SRF) particles in a bubbling fluidized bed are carried out. The numerical model is based on the Eulerian–Eulerian approach with empirical submodels representing gas–solid and solid–solid interactions. The model is verified by experimental data from the literature. The experimental data include SRF vertical distribution in SRF–sand mixtures of different sand particle sizes ($$d_{\mathrm{pm}} = 654,810$$ d pm = 654 , 810 and 1110 $$\upmu$$ μ m) at different fluidization velocities ($$u/u_{\mathrm{mf}} = 1.2$$ u / u mf = 1.2 –2.0). We proposed magnification of drag force exerted by the gas on SRF particles based on Haider and Levenspiel (Powder Technol 58(1):63–70, 1989) drag coefficient. The proposed model shows good agreement with the experimental data at high fluidization velocities ( $$u/u_{\mathrm{mf}} = 1.5$$ u / u mf = 1.5 –2.0) and poor predictions at low fluidization velocities ($$u/u_{\mathrm{mf}} = 1.2$$ u / u mf = 1.2 –1.5). Heat transfer results showed that the present model is valid and gives good agreement with the experimental data of wall–bed heat transfer coefficient.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Yurong He ◽  
Wengen Peng ◽  
Tianyu Wang ◽  
Shengnan Yan

A modified discrete element method (DEM) was constructed by compositing an additional liquid-bridge module into the traditional soft-sphere interaction model. Simulations of particles with and without liquid bridges are conducted in a bubbling fluidized bed. The geometry of the simulated bed is the same as the one in Müller’s experiment (Müller et al., 2008). A comparison between the dry and the wet particular systems is carried out on the bubble behavior, the bed fluctuation, and the mixing process. The bubble in the dry system possesses a regular round shape and falling of scattered particles exists while the bubble boundary of the wet particles becomes rough with branches of agglomerates stretching into it. The mixing of the dry system is quicker than that of the wet system. Several interparticle liquid contents are applied in this work to find their influence on the kinetic characteristic of the wet particle flow. With an increase of liquid content, the mixing process costs more time to be completed. Symmetrical profiles of the velocity and granular temperature are found for two low liquid contents (0.001% and 0.01%), while it is antisymmetrical for the highest liquid content (0.1%).


2016 ◽  
Vol 36 (1) ◽  
pp. 1-10 ◽  
Author(s):  
F. Zinani ◽  
C. G. Philippsen ◽  
M. L. S. Indrusiak

2015 ◽  
Author(s):  
Marcelo José Alba ◽  
Flávio Clareth Colman ◽  
Luíz Mário de Matos Jorge ◽  
Alexandre Marconi de S. Costa ◽  
Paulo Roberto Paraíso

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