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Hidrociclones são equipamentos usados em processos de separação óleo-água. São considerados eficientes, compactos, seguros, de simples construção e manutenção, e baixo custo, quando comparados a outros equipamentos de semelhante aplicação. Diante disso, este trabalho tem como objetivo analisar numericamente o processo de separação da mistura óleo-água em um hidrociclone, quanto ao seu aspecto fluidodinâmico. Para a solução numérica das equações governantes utilizou-se o software Ansys CFX. Resultados dos campos de pressão e fração volumétrica da fase óleo, e do desempenho de separação do equipamento são apresentados e analisados. Dos resultados obtidos verificou-se que as maiores pressões ocorrem próximo as paredes e entrada do equipamento, que as maiores frações volumétricas do óleo ocorrem na região central e próximo a saída do hidrociclone, e que este equipamento apresentou uma eficiência de separação superior a 99,8%.

This paper presents a mathematical model and numerical solution to describe the drying of ceramic hollow bricks in a tunnel dryer of cross flow type on an industrial scale. The model is based on mass and energy balances written for a differential volume located in an arbitrary position of the solid material and include the condensation of water. To get the numerical solution of the governing equations the finite volume method and the "upwind" interpolation scheme for the convective terms are used. To validate the methodology, numerical and experimental results for the moisture content and the temperature of brick during the drying on an industrial scale are compared and a good correlation was obtained. Results of moisture content and temperature of the product, temperature, relative humidity and humidity ratio of drying air as a function of drying time and bed length of the dryer are presented and analyzed.

In this work, modeling of continuous and intermittent drying of oblate spheroidal bodies is presented. The model considers the liquid diffusion as the only process of mass transfer inside the body, constant diffusion coefficient and equilibrium conditions at the surface of the solid. The diffusion equation is described in the oblate spheroidal coordinates system, for the two- dimensional case discretized using the finite volume method and fully implicit formulation. Based on the literature, experimental data of the properties and physical dimensions of lentil grains were used in the all simulation. Several processes of intermittent drying for the lentils were simulated: using a same time of tempering (time of rest), beginning in different drying time and for two or more intervals (time steps) along the process. For a same useful time of use of the dryer, it was observed that the intermittent drying always increases the efficiency of the process. Another outstanding result is the improvement of the final quality of the product due to the absence of great moisture content gradients inside of the product during the drying process.