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Abstract

An engineering application case study on a two-fluid flow model for the control of industrial drying operations is reported. The mathematical model of this process was numerically solved by a computer code developed in FORTRAN language and was validated through data taken from PVC drying performed in an industrial continuous fluidized-bed dryer. The predicted steady-state outlet temperature and PVC moisture content values agree with the real data observed on the industrial plant. This model was also used to predict the temperature and concentration profiles inside the dryer as a function of time as a response to the disturbances and variations on the PVC water content at the dryer inlet.

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... Tacidelli et al. [4] presented a model to control the PVC drying processes. In response to variations and disturbances of initial PVC moisture content, concentration and temperature profiles were predicted with time using the model. ...
... For grids consisting of 42,560 (original) and 238,340 (reduced) cell volumes in setup A and 61,855 (original) and 319,280 (reduced) cell volumes in setup B, the maximum difference in the calculated flow fields of air velocity, density, pressure, temperature, and vapor mass fraction was observed to be smaller than 5%. The gas outlet boundary condition is selected as a pressure outlet and Equation (9) calculates the turbulent kinetic energy and its dissipation rate [4] : ...
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The multistage drying system is one of the novel methods that has small specific energy consumption (SEC) compared to the conventional single drying systems. Rotary and fluidized bed dryers are the conventional drying systems of suspension-grade polyvinyl chloride (S-PVC). This article describes the energy consumption characteristics of a two-stage pneumatic fluidized bed drying system for drying of S-PVC. Computational Fluid Dynamics is used to anticipate the hydrodynamics and drying mechanisms with Eulerian–Lagrangian and Eulerian–Eulerian approach in the pneumatic dryer and fluidized bed dryer, respectively. The experimental study is accomplished using spiral pneumatic and a fluidized bed dryer. The investigation of the SEC and influence of a two-stage drying system on S-PVC drying has been set as the main target. The result shows that by using the two-stage pneumatic-fluidized bed drying in certain conditions, the SEC is reduced up to 8255 kJ/kg and an average of 5260 kJ/kg compared with fluidized bed single-stage drying.
... Existem alguns trabalhos na literatura voltados à modelagem cinética e otimização do processo de secagem de PVC (Araujo et al., 2010;Tacidelli et al., 2012). Outros trabalhos são voltados à modelagem da fluidodinâmica do secador. ...
... As condições reais de operação do secador industrial estão disponíveis em Tacidelli et al. (2012). Utilizou-se a estratégia de falso transiente, que consiste em resolver as equações com o termo transiente, no entanto sem forçar a convergência completa para cada instante de tempo, até atingir o estacionário. ...
... Abdel-Jabbar et al. (2002) presented a model to simulate the dynamic behavior of a continuous well-mixed fluidized bed dryer by combining the drying kinetics for diffusioncontrolled system and residence time density function. Only one study on the mathematical modeling of an industrial plug-flow fluidized bed drying process under dynamic conditions has been published by Tacidelli et al. (2012). The proposed model was based on the two-fluid model consists of the gas and particulate phases. ...
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