No abstract

West Indian cherry, widely known as acerola in Latin America, is a fruit rich in vitamin C and other bioactive compounds. In Brazil, the largest producer of acerola in the world, the processing of this fruit results in large amounts of waste or residues. A method that allows these residues to be reused is drying. However, acerola residue has low flowability in spouted beds due to its low density and high moisture content. Therefore, in this study, soybean was used as an auxiliary material to maintain the stability of the fluid dynamics and the characteristics of the food end product. Because this process involves a mixture of solids of different sizes, shapes and densities, particle segregation may occur. This article reports on a study of the fluid dynamics of the mixture of acerola residue and soybean in a spouted bed, operating with different mass fractions of residue and different static bed heights. Particle segregation was analysed, allowing for the quantification of the effect of the initial concentration of acerola residue on the degree of miscibility. The content of phenolic compounds, flavonoids and ascorbic acid, as well as the moisture and mixture indices at different drying times, were also quantified.

Numerical simulation using computational fluid dynamics (CFD) technique associated with experimental verification is a useful tool for analysis of gas-solid multiphase flows. Simulations of the spouted bed fluid dynamic using two-dimensional computational grids were accomplished in our previous works with good results. In this article, the patterns of solids and gas flows in a spouted bed were numerically simulated using the three-dimensional (3D) Eulerian multiphase model. The minimum spouted condition was identified by the simulated solids volume fraction and pressure profiles. The simulated results show good agreement with experimental data and higher accuracy when compared with 2D simulations.La simulation numérique par CFD associéeà des vérifications expérimentales est un outil utile pour l'analyse desécoulements multiphasiques gaz-solides. Des simulations de la dynamique des fluides en lit jaillissant utilisant des maillages bidimensionnels ontété effectuées dans nos travaux antérieurs avec de bons résultats. Dans cet article, les profils d'écoulement de solides et de gaz dans un lit jaillissant ontété simulés de manière numériqueà l'aide d'un modèle multiphasique eulérien tridimensionnel (3D). La condition de jaillissement minimale aété déterminée par les profils de fraction de volume des solides et de pression simulés. Les résultats simulés montrent un bon accord avec les données expérimentales et une plus grande précision lorsqu'ils sont comparés aux simulations bidimensionnelles.

The mechanical extraction of the bixin from Bixa orellana seeds using a spouted bed was investigated in this work. The experimental program was divided into two main steps. In the first step, a two-level factorial experimental design was used to analyze the influence of the main process variables on the mechanical extraction responses. The second step of the experiment was carried out to evaluate the effect of the distance between the draft tube and the conical base (h t ). Computational fluid dynamic technique was used to understand seed flow and the effect of h t on the mechanical extraction process. The results obtained showed that the presence of the draft tube was the variable that most strongly affected the powder extraction. The best condition for the bixin extraction from B. orellana seeds was the one when the draft tube was positioned at 4 cm from the air inlet.