Navegando por Assunto "Fluidized bed"

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Acesso aberto (Open Access)
Interação CFD-DEM em fluidização: aplicação para o setor mineral
(Universidade Federal do Pará, 2013) CASTELO BRANCO JÚNIOR, Alan Mota; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The particle fluidization process is widely used in the industry, mainly due to the high heat and mass transfer rates between the phases. The coupling between the Computational Fluid Dynamics (CFD) and the Discrete Element Method (DEM) has become attractive for the simulation of fluidization, because in this case the particles movement is analyzed in a more direct way than in other types of approaches. The main problem with the CFD-DEM coupling is the high demand for computational capacity in order to track the movement of all the particles in the system, what it leads to the use of some strategies to reduce the simulation time which in case of incorrect usage can prejudice the results. The present work deals with the application of the CFD-DEM coupling in the analysis of alumina fluidization, which is an important problem for the mineral sector. It were analyzed several parameters capable of influencing the results and the simulation time like the time steps, the drag models, the particle size distribution, the spring constant, the usage of representative particles bigger than the actual particles, etc. The DEM model used was the Linear Spring Dashpot model (LSD). All the simulations were carried out with the software ANSYS FLUENT 14.5 and the results obtained were compared with experimental data and the data available in the literature. These results allowed to verify the capability of the Linear Spring Dashpot Model for predicting the global behavior of alumina beds and reducing the simulation time, since the model parameters are defined adequately.
Acesso aberto (Open Access)
Recobrimento de pimenta-do-reino (piper nigrum l.), em leito de jorro, com suspensão polimérica de amido de mandioca, plasticizada com etanol
(Universidade Federal do Pará, 2024-12-13) QUEIROZ, Nian Iury Ferrão; REGO, José de Arimatéia Rodrigues do; http://lattes.cnpq.br/4163468898377462; HTTPS://ORCID.ORG/0000-0003-0891-6438; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
This study aimed to evaluate the black pepper coating technique using a fluidized bed, focusing on its applicability in the food industry. The research explored the optimization of operational parameters, such as suspension flow rate, temperature, and blower flow rate, using the response surface methodology within a Box-Behnken design. The goal was to improve the efficiency of the coating process, ensuring uniform distribution of the coating over the black pepper grains. This study investigated the fluid dynamic and physicochemical behavior of black pepper seeds coated with a cassava starch-based biofilm, applying the spouted bed process. The seeds were classified in group D of the Geldart classification, indicating good fluidization potential and excellent flowability, facilitating the coating process. The sphericity of the seeds (0,98) and their density (1,45 g/cm³) directly influenced their behavior in the bed, allowing minimal fluidization at a velocity of 38,32 cm/s and a pressure drop of 7,13 cmH2O. The molecular interaction between the starch and ethanol generated biofilms with flexibility and mechanical strength. However, ethanol's volatility requires control during the drying process to maintain the biofilm's quality. The spouted bed process proved efficient for coating application, and the desirability function analysis indicated that the established criteria were satisfactorily met. The results confirm the technical feasibility of applying biopolymer coatings to black pepper seeds, contributing to the development of biodegradable alternatives aligned with environmental demands