DECAT - Departamento de Controle e Automação
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/490
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2 resultados
Resultados da Pesquisa
Item Study of the electricity consumption reduction of a compressed air system : the case of a steelmaking company.(2017) Silva, Washington Luís Vieira da; Souza, Leonardo Carvalho Oliveira de; Bortolaia, Luis Antônio; Paula, Milton Realino de; Leal, Elisângela MartinsThis work aims to reduce the energy consumption and thus increase the availability of blast furnace compressors of a steelmaking company, located in Alto Paraopeba region in Minas Gerais state, Brazil, through the elimination of waste points in the compressed air distribution. In order to develop this work, an ultrasound test in the compressed air line was performed to identify and quantify leaks in the flow. Once the leaks were identified, they were eliminated through corrective maintenance and improvements, and then the energy consumption scenarios before and after the improvements were compared. As a result, the average monthly electricity consumption in the reporting period decreased by 57.2%. In addition, one compressor was set aside in stand-by condition, as in the original plant. Thus, one can prove the efficiency in eliminating of waste points in compressed air distribution, since the reduction of energy consumption is important for the company to remain competitive, as the cost of electric energy affects the final price of the final products.Item Numerical analysis of the liquid ejection due to the gaseous jet impact through computational fluid dynamics.(2018) Araújo, Hiuller Castro; Rodrigues, Eliana Ferreira; Leal, Elisângela MartinsMetal droplets generated by an impinging jet, play an important role in metal refining processes, mainly in oxygen steelmaking, where the droplets are ejected into the slag phase. Since the available interfacial area of droplets is very high in this process, the generated droplets enhance the rates of heat transfer and chemical reactions. Therefore, knowledge of the metal droplet generation rate, size distribution and residence time in the slag are of industrial relevance. In this work, the isothermal, transient flow of an incompressible air jet impinging onto an air/water interface at room temperature has been simulated to obtain a better understanding of the droplet ejection phenomenon. The interface was tracked throughout time using the volume of fluid (VOF) technique. The governing equations formulated for mass and momentum conservation and the k-e turbulence model are solved in the axisymmetric computational domain using the commercial code FLUENT. The droplet ejection rates calculated with computational fluid dynamics model are compared to experimental data reported in literature, showing partial agreement, being the incompressibility assumption the probable reason for the deviation observed, which was as far pronounced as the great jet velocity. Nevertheless, the model presented shows itself as a relatively good starting point for the construction of more complex ones (with less simplifying assumptions) which should be able to offer a means to increase the understanding of the droplet ejection phenomena.