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-During the pneumatic conveying of plastic pellets, it has been observed that materials with similar physical characteristics may develop a substantial difference in pressure drop. In this work, the pressure drop in a particle-laden 2.7 meter long horizontal channel with circular cross-section is presented from an experimental perspective. Experiments are carried out for cylindrical polystyrene beads with an average diameter of 3.2 mm and mass loadings of 0.06 to 0.11 (kg particles/kg gas). The air mass flow rate was studied in the range from 0.085 kg/s to 0.170 kg/s. The pressure drop curve is shown as a function of air velocity and particle load. Response surface methodology showed high statistical significance for air velocity, particle load and their cross-relation.

The project on heat transfer surfaces in agitated vessels is based on the determination of the heat exchange area, which is necessary to abide by the process conditions as mixing quality and efficiency of heat transfer. The heat transfer area is determined from the overall heat transfer coefficient (U). The coefficient (U) represents the operation quality in heat transfers being a function of conduction and convection mechanisms. The determination of U is held from the Nusselt's number, which is related to the dimensionless Reynolds and Prandtl's, and from the fluid's viscosity relation that is being agitated in the bulk temperature and the viscosity in the wall's temperature of heat exchange. The aim of this chapter is to present a summary for the literature concerning heat transfer in agitated vessels (equipped with jackets, helical coils, spiral coils, and vertical tube baffles) and also the many parameters of Nusselt's equation for these surfaces. It will present a numerical example for a project in an agitated vessel using vertical tube baffles and a 45°pitched blade turbine. Subsequently, the same procedure is held with a turbine radial impeller, in order to compare the heat transfer efficiencies.

The transport of heavy oil in tubes is energy intensive since the oil viscosity can reach values of 10 500 000 cP. This study focuses on the transport of oil in a piping system by an annular flow of oil wrapped with water, since this alternative reduces head loss. The piping system was comprised of horizontal tubes, curves, and vertical tubes. The assumptions for the CFD simulation were the following: 3D geometry, turbulent flow, and isothermal system as well as incompressible, steady‐state, and transient flow. A mesh convergence study was carried out. The residue for pressure and velocity dropped at least three orders of magnitude. The inter‐phase‐slip Algorithm (IPSA), algebraic slip model (ASLP), scalar equation method (SEM), and Phoenics models were applied to calculate the interaction between the phases. Turbulence was modelled with default k‐ϵ and k‐ω models and the LES strategy by using a Smagorinsky sub‐grid scale model. The density profiles generated in the CFD simulation were compared with experimental data and a resemblance was observed. The transient simulation showed a swirling flow that was experimentally observed, which was a result of synergy of multiphase flow, horizontal tube, curve, and vertical tube.

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There are several correlations used to predict the external heat transfer coefficient in tanks equipped with vertical tube baffles in batch operations, but little information concerning the external heat transfer coefficient in steady state operations. The objective of the present article is to experimentally determine a correlation of the external heat transfer coefficient based on the model proposed by Sieder and Tate (Ind. Eng. Chem. 1936, 1429–1435) in a steady flow rate in a vessel equipped with a radial impeller, turbine type, with six flat blades. The study was carried out in a 50 dm3 working capacity acrylic vessel, fitted with vertical tube baffles made of copper, in which water and sucrose solutions at mass concentrations of 20% and 50% were heated. Heating temperatures varied from 28 to 45 °C, whereas the rotations varied from 90 to 330 rpm. From the Nusselt, Reynolds, and Prandtl similarity parameters, a correlation was obtained which yielded excellent results of the observed data–a maximum deviation of 21% between the observed and predicted data for the external heat transfer coefficient. In addition, one could also observe that the radial impeller raises the heat transfer to as much as 70% compared to the axial impeller for the same study conditions.

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