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This paper presents the thermal analysis and mathematical modeling of a discontinuous agitation reactor. A data acquisition phase was implemented in terms of operation and utility of the agitation reactors. Subsequently, the concepts of thermodynamics, fluid mechanics, heat transfer and matter transport were applied to perform the respective thermal analysis and thus, determine the energy contained and transferred in the fluids used. In addition, a mathematical model was deduced in the EES software to examine its behavior, taking into account the operational variables subjected to various types of fluids. Finally, the physical-chemical environment of the reactor was simulated to validate the calculated data and compare them with the experimental values, relating the geometry of the equipment to the performance conditions and the specifications of the final product. [ABSTRACT FROM AUTHOR]

Previous scientific research has not focused on downdraught beehive kilns, which are the most used in the Colombian brick (ceramic) industry. Hence, in the present paper, an analytical mathematical model is developed in order to simulate the exhaust gas behavior. To do so, gas combustion and heat and mass transfer to the products and the walls are modelled within the kiln. The obtained model is validated by experimental data. Finally, with the experimental data acquired in the discharge duct and chimney, a heat recovery system is proposed to make use of the residual energy. [ABSTRACT FROM AUTHOR]

Friction StirWelding is a process used for joining metals, mainly of low melting temperature, such as aluminum alloys. Studies involving the tool used in this welding process, focusing mainly on quantifying the effect of geometry on the final properties of the welded joint. In this paper it was studied the effect of the tool geometry in the heat dissipation, using computer simulation, specifically the module CFX of Ansys®14.5. They were considered three tool geometries, each built in a modular way with three parts: Collet Chuck, Shank and Implant. The virtual assembly was subjected to simulation models for the calculation of temperature and heating time. The models were evaluated, considering as welding parameters: Welding Speeds of 100, 150, 200 and 250 mm.min-1 and Rotation Speed of 700, 800, 900 and 1000 rpm. For the calculation it was assume that the temperature reached on the implant (Shoulder and Pin) were 500°C, in a welding time of 1 hour. The results allow to improve the tools design with a shorter shank and allows to confirm the effectiveness of using fins on the shank for greater heat dissipation, being more effective the use of Fins Displaced towards the insert in comparison with System with Fins on the Rod Center. [ABSTRACT FROM AUTHOR]

This research work shows different numerical schemes for 1D flow heat exchanger calculations based on Finite Volume Methods (FVM). The method allows calculating heat exchanger, flows in pipes, among other, where besides to appear pressure drops due to the flow field, a heat transfer can be presented with the environment, or another fluid. The general proposed method uses energy conservation, momentum conservation and mass conservation equations. Such equations are integrated throughout the heat exchanger, that along with the equations of state, and the equations that allow evaluating certain empirical parameters, constituting a system of nonlinear equations to solve. This paper describes a comparison of time consumption where sequential and simultaneous heat exchanger calculations are performed. The results show the most convenient calculation method obtained in this study that present the lowest error and time consumption is the sequential method when a constant wall temperature is assumed. [ABSTRACT FROM AUTHOR]