scholarly journals A Fast and Improved Tunable Aggregation Model for Stochastic Simulation of Spray Fluidized Bed Agglomeration

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7221
Author(s):  
Abhinandan Kumar Singh ◽  
Evangelos Tsotsas

Agglomeration in spray fluidized bed (SFB) is a particle growth process that improves powder properties in the chemical, pharmaceutical, and food industries. In order to analyze the underlying mechanisms behind the generation of SFB agglomerates, modeling of the growth process is essential. Morphology plays an imperative role in understanding product behavior. In the present work, the sequential tunable algorithm developed in previous studies to generate monodisperse SFB agglomerates is improved and extended to polydisperse primary particles. The improved algorithm can completely retain the given input fractal properties (fractal dimension and prefactor) for polydisperse agglomerates (with normally distributed radii of primary particles having a standard deviation of 10% from the mean value). Other morphological properties strongly agreed with the experimental SFB agglomerates. Furthermore, this tunable aggregation model is integrated into the Monte Carlo (MC) simulation. The kinetics of the overall agglomeration at various operating conditions, like binder concentration and inlet fluidized gas temperature, are investigated. The present model accurately predicts the morphological descriptors of SFB agglomerates and the overall kinetics under various operating parameters.

Author(s):  
Juliana G Rosa ◽  
R. F. Nascimento ◽  
K. Andreola ◽  
O. P. Taranto

Acacia gum is an important food emulsifier that presents poor instant properties which can be improved by fluidized bed agglomeration. This study investigated the influence of drying conditions on particle growth kinetics using an in-line particle size monitoring by spatial filter velocimetry. The drying conditions varied according to the binder flow rate and the fluidizing air temperature. The particle growth kinectis showed drying conditions dependence. At mild drying conditions the growth rate and the process yield were higher. The in-line particle size monitoring was useful to observe the influence of the drying conditions on the growth kinetics.Keywords: fluidized bed agglomeration; acacia gum; particle growth kinectis; in-line monitoring.  


Author(s):  
Gerd Strenzke ◽  
Ievgen Golovin ◽  
Maximilian Wegner ◽  
Stefan Palis ◽  
Andreas Bück ◽  
...  

Agglomeration is a particle formulation process in which at least two primary particles are combined to form a new one. The growth of agglomerates depends on interactions of particles covered with wet spots that generated by depositions of binder droplets. This work experimentally compares the influence of external feed rate and sprayed binder content on product properties and process stability with internal separation at different drying conditions. Due to the identification of parameters a populations balance model (PBM) is developed. The PBM includes the agglomeration kernel function, which characterizes the kinetics, i.e. the rate at which primary particles build agglomerates. Keywords: spray fluidized bed agglomeration; drying; continuous process; internal separation; population balances


Author(s):  
Antonio Cammarota ◽  
Riccardo Chirone ◽  
Fabrizio Scala

The fluidized bed combustion of a biomass residue (olive husk) common in the Mediterranean area has been investigated in a bench scale reactor. The focus of the study was the high propensity of this fuel to give rise to bed agglomeration problems during combustion, as a consequence of the high alkali content of the ash. Bed agglomeration characteristic times as well as temperature and pressure gradients were measured at different operating conditions. In addition, a diagnostic tool based on the measurement of the dynamic pressure signal inside the bed was tested for its capability to predict the bed agglomeration onset.


2012 ◽  
Vol 550-553 ◽  
pp. 2936-2940
Author(s):  
Xing Yong Liu ◽  
Hu Yang ◽  
You Cheng Wang ◽  
Zhuo Xu Deng

The particle concentration signals of silicon powder in the fluidizing gas i.e. air under different operating conditions were determined. The diameter of silicon particles, operating velocity, radial distance and axial distance are used as input vector; the mean value of particle concentration signal in the silicon power fluidized bed is used as a target vector. The RBF neural network is applied to build the predicted model of the mean value in silicon power fluidized bed. The result shows that the prediction of mean value through the RBF neural network is prior to that by BP neural network, and its error is less than 0.2%.


2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).


Author(s):  
İlyas Atalar ◽  
Abdullah Kurt ◽  
Furkan Türker Saricaoğlu ◽  
Osman Gül ◽  
Hüseyin Gençcelep

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1681
Author(s):  
Yixiang Yuan ◽  
Qinghua Zeng ◽  
Jun Yao ◽  
Yongjun Zhang ◽  
Mengmeng Zhao ◽  
...  

Aiming at the problem of the narrow combustion stability boundary, a conical swirler was designed and constructed based on the concept of fuel distribution. The blowout performance was studied at specified low operating conditions by a combination of experimental testing and numerical simulations. Research results indicate that the technique of the fuel distribution can enhance the combustion stability and widen the boundary of flameout within the range of testing conditions. The increase of the fuel distribution ratio improves the combustion stability but leads to an increase in NOx emission simultaneously. The simulation results show the increase of the fuel distribution ratio causes contact ratio increase in the area of lower reference velocity and gas temperature increase. The increased contact ratio and temperature contribute to the blowout performance enhancement, which is identical to the analysis result of the Damkohler number. The reported work in this paper has potential application value for the development of an industrial burner and combustor with high stability and low NOx emission, especially when the combustion system is required to be stable and efficient at low working conditions.


2020 ◽  
Vol 6 ◽  
pp. 275-285
Author(s):  
Jurarat Nisamaneenate ◽  
Duangduen Atong ◽  
Anun Seemen ◽  
Viboon Sricharoenchaikul

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