Dissertações em Engenharia de Infraestrutura e Desenvolvimento Energético (Mestrado) - PPGINDE/NDAE/Tucuruí

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9401

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Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Cálculo de ar induzido pela queda livre de materiais granulares via CFD
(Universidade Federal do Pará, 2021-12-17) LIMA, Leandro Ferreira Borba; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The proposal of the work consists of presenting an analysis method via ANSYS-Fluent using the DDPM tool (Dense Discrete Phase Model) of the integrated Eulerian multiphase model, a better understanding of the flow of granulated material with the adjacent induced air due to the drag provided by the free-falling particles, which result in the generation and propagation of dust, avoid simulations with materials where particle density and diameters are variable. The use of this analysis tool will make it possible to improve and improve de dusting projects in industries that work with granular materials that emit dust. The simulations carried out were compared with other computational methods and practical experiments, in addition to previous theoretical formulas.
Acesso aberto (Open Access)
Desenvolvimento de túnel de vento para avaliação de bicos de pulverização no abatimento de poeira
(Universidade Federal do Pará, 2024-12-20) SANTOS, Danilo Silva; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Mining is extremely important economically and socially for the industry, especially iron ore, but along with its benefits, it also has environmental impacts generated in different ways, such as dust. This inconvenience has caused disruptions to mining enterprises, such as production shutdowns and heavy fines, as well as problems for people who work in the companies and surrounding communities, due to health problems associated with inhaling dust and dirt from the environments, making them unhealthy and devalued. Dust control mechanisms have been widely studied and one of these is dust control using spraying of suppressant solutions. Studying the efficiency of spray nozzles has become of great importance and bench tests act as efficient means of understanding the mechanism of dust abatement from minerals. Research has been common to use wind tunnels. Thus, a tunnel was built capable of evaluating 5 different nozzles and their efficiencies in suppressing pellet feed and sinter feed at two speeds and different water pressures. It was concluded that the tunnel is capable, through the methodology used, of evaluating and comparing the best nozzle, demonstrating that it is an important tool in consolidating this knowledge in the Fluid Dynamics and Particulates Laboratory.
Acesso aberto (Open Access)
Desenvolvimento de um túnel para secagem e emissão de minério em condições ambientais controladas
(Universidade Federal do Pará, 2021-12-15) SILVA, Artur José Cunha da; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
A dust emission is present in the various stages of the mineral industry, from extraction in mines to ship loading in ports. Transport in train wagons, storage in stockpiles and handling are three major sources of particulate emissions into the atmosphere. Suspended dust does not only affect the local environment, as the wind transports the particulates and brings disturbances to urban centers close to railway networks and ports. Larger particles are deposited on surfaces, outperforming visual surfaces, and smaller, unresearched particles with a size between 10 and 2.5μm are easily inhaled and lodge in lung tissue, potentially causing irritation or necrosis. Dust emission is enhanced by local atmospheric conditions, which cause the evaporation of surface moisture from the wet ore, breaking the liquid bridges that keep the particles linked together. Aiming at studying the dynamics of drying ore, a drying tunnel was designed and built, comprising a wind tunnel, cooling, heating and humidification equipment that are interconnected by a supervision and control system. The use of the bench for drying studies using sinter feed is known to be satisfactory, as the temperature remained stabilized at the setpoint during the drying time, reflecting the good calibration of the temperature PID controller. Moisture and ore mass were automatically measured using a scale and a capacitive moisture sensor positioned in the test section of the bench. The constant rate and descending rate drying curves only in the lightest weather conditions. The biggest limitations and variations were observed only in the period with decreasing drying rate, showing the influence of environmental conditions on the drying dynamics. Therefore, this work leaves as a contribution the preparation tunnel for future research and an experimental database for the calibration of numerical models and models of mathematical models for prediction prediction.
Acesso aberto (Open Access)
Experimento em escala de emissão de poeira no processo de empilhamento
(Universidade Federal do Pará, 2022-03-25) CASTRO, Maycon Magalhães; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662; MACHADO, Luis Paulo Silveira; http://lattes.cnpq.br/0702289670734922; https://orcid.org/0000-0003-1587-3632
Dust emission can lead to health problems, explosion risk, material segregation and environmental pollution. Therefore, it is necessary to understand the parameters related to dust generation to improve particulate emission control techniques. Dust reduction based on spray spraying is the main method to prevent and control dust emission in ore stacking. Dust suppression techniques at conveyor belt transfer points can be subdivided into material spraying and trapping of fugitive particles. To analyze the parameters associated with dust generation during ore stacking, a scaled conveyor bench was developed for dust suppression tests via water spray. This installation is equipped with spray nozzles whose relative location on the belt can be adjusted and the speed of the conveyor can also be controlled. The spray jet is provided by a set of spray module and flow divider, allowing the variation of the system pressure and with the possibility of using suppressors, which can increase the efficiency of particle capture. Dust suppression performance is analyzed by monitoring strategic points with the highest dust emission. The results of this investigation show that dust generation increased as the drop height increased, it was observed that the region close to the pile emits a higher concentration of dust, due to the impact of the material flow on the stacking surface, in compared to the front region of the flow. The results after using the spray on the belt showed that the highest drop height (1600 mm) emitted the highest concentration of particles (3192.72 μg/m3) after spraying, on the material, the dust concentration reduced by about almost 70%, showing the efficiency of spray humidification. It was also observed that PF has a higher critical humidity than that of SF, as well as that it emits a higher concentration (1116.52 μg/m3) compared to Sinter feed (848.14 μg/m3), making it evident that by as it is a material with a smaller granulometry, the pellet feed tends to emit a higher concentration of particulates when handled.

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