Uso de fluidodinâmica computacional para a análise do tempo de residência em reatores tubulares utilizando líquido como fluído de trabalho

Abstract

The use of computational fluid dynamics has become, over the years, an incredible tool for the optimization of equipment in various industrial sectors. The improvement of equipment will impact on the conversion rate of the chemical species of the process in question, which it will cause the increase of the profit that comes from this process. Flows with piston and pulse type feeds were interpreted in a tubular reactor from which they are evaluated using computational fluid dynamics techniques. The studies were carried out maintaining a constant mass flow of 1.2 kg/s of water at the entrance of the plug flow reactor and having throughout the tests changes in the velocity profiles of the feed, therefore was analyzed the characteristic of the residence time distribution for a given case, which is determined by the injection of an inert tracer. Seven simulations were carried out, the first simulation presented stationary type feeding, and the second simulation presented feeding with variable flow and the five last simulations were fed with variable flow but with an angle of 30 in the entrance of the reactor, changing the operating frequency of the pump in each case. The use of the pulse-shaped feed with angle at the entrance ensured the formation of perpendicular vortices to the axis, condition that can decrease the residence time of the species involved according to the results found.