Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/15264 http://doi.org/10.14393/ufu.di.2016.37 |
Resumo: | Ball mills are used in several industrials sectors, such as cement, food and mining industries. Inside a ball mill, the comminution is performed by the grinding media movement and their interaction with the material to be broken. In this work, the grinding media dynamics in a ball mill with lifters was studied experimentally by the analysis the transitional phenomena between cascading, cataracting and centrifuging. In order to assess the end-walls effect in the behavior ball charge, both transitions were investigated for one, two or three layers of balls in the axial direction. The end-wall effect did not significantly influence the transitions between regimes. The centrifuging critical rotation speeds noted experimentally were compared to the centrifuging speeds given by literature equations which take into account some systems variables. These equations could not correctly predict the occurrence of centrifuging in a ball mill with lifters. Therefore, a centrifuging equation was adjusted for the steel-chrome balls used in this work. Coupled with experimental work, the grinding media dynamics was studied by simulations in computational fluid dynamics (CFD), using the commercial software FLUENT® and the Eulerian approach. The influence of boundary conditions in the walls was investigated by analysis the different values of specularity coefficient, considering the difficultly of measuring this parameter. It was found the influence of the specularity coefficient on the movement of grinding media simulation in ball mill. The values of this parameter that had greater physical consistency with the experimental observations are between 0,40-0,20. This observation confirms the required careful in the assignment of the boundary condition in the wall, especially the equipment is simulated in small scales and even though the end-wall effect was not observed in experimental study. Moreover, the grinding media movement was assessed for values of the ball restitution coefficient and it was not observed considerable differences. |
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2016-06-22T18:41:56Z2016-06-022016-06-22T18:41:56Z2016-02-12MACHADO, Marcela Vieira Caixeta. Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola. 2016. 99 f. Dissertação (Mestrado em Engenharias) - Universidade Federal de Uberlândia, Uberlândia, 2016. Disponível em: http://doi.org/10.14393/ufu.di.2016.37https://repositorio.ufu.br/handle/123456789/15264http://doi.org/10.14393/ufu.di.2016.37Ball mills are used in several industrials sectors, such as cement, food and mining industries. Inside a ball mill, the comminution is performed by the grinding media movement and their interaction with the material to be broken. In this work, the grinding media dynamics in a ball mill with lifters was studied experimentally by the analysis the transitional phenomena between cascading, cataracting and centrifuging. In order to assess the end-walls effect in the behavior ball charge, both transitions were investigated for one, two or three layers of balls in the axial direction. The end-wall effect did not significantly influence the transitions between regimes. The centrifuging critical rotation speeds noted experimentally were compared to the centrifuging speeds given by literature equations which take into account some systems variables. These equations could not correctly predict the occurrence of centrifuging in a ball mill with lifters. Therefore, a centrifuging equation was adjusted for the steel-chrome balls used in this work. Coupled with experimental work, the grinding media dynamics was studied by simulations in computational fluid dynamics (CFD), using the commercial software FLUENT® and the Eulerian approach. The influence of boundary conditions in the walls was investigated by analysis the different values of specularity coefficient, considering the difficultly of measuring this parameter. It was found the influence of the specularity coefficient on the movement of grinding media simulation in ball mill. The values of this parameter that had greater physical consistency with the experimental observations are between 0,40-0,20. This observation confirms the required careful in the assignment of the boundary condition in the wall, especially the equipment is simulated in small scales and even though the end-wall effect was not observed in experimental study. Moreover, the grinding media movement was assessed for values of the ball restitution coefficient and it was not observed considerable differences.Os moinhos de bolas são utilizados em diversos setores industriais, como indústrias de cimento, alimentícias e de mineração. No interior de um moinho de bolas, a cominuição é realizada pelo movimento dos corpos moedores e sua interação com o material a ser moído. Neste trabalho, a dinâmica dos corpos moedores em um moinho de bolas com suspensores foi estudada experimentalmente através da análise das transições entre os regimes de cascateamento-catarateamento e catarateamento-centrifugação. A fim de avaliar o efeito das paredes frontal e traseira sobre o movimento dos corpos moedores, ambas as transições foram investigadas para uma, duas e três camadas de esferas dispostas axialmente. O efeito de parede não influenciou significativamente as transições entre os diferentes regimes. As velocidades críticas de centrifugação verificadas experimentalmente foram comparadas com as velocidades previstas por equações da literatura que levam em consideração variáveis do sistema. Essas equações não puderam prever satisfatoriamente a ocorrência da centrifugação em um moinho de bolas com suspensores e, deste modo, foi ajustada uma equação de previsão da centrifugação para as esferas do caso em estudo. Aliado aos estudos experimentais, a dinâmica dos corpos moedores foi estudada por simulações em fluidodinâmica computacional (CFD) por meio do software comercial FLUENT® e utilizando a abordagem Euleriana. A influência da condição de contorno na parede foi investigada através da análise de diferentes valores de coeficiente de especularidade, tendo em vista a dificuldade de medida experimental deste parâmetro. Foi constatada a influência do coeficiente de especularidade sobre a simulação do movimento dos corpos moedores no moinho de bolas, sendo que os valores desse parâmetro que apresentaram maior coerência física com as observações experimentais estão entre 0,40 e 0,20. Isso comprova a cautela requerida quando da especificação da condição de contorno na parede, sobretudo se o equipamento for simulado em escalas reduzidas, mesmo que o efeito de parede não tenha sido observado no estudo experimental. Além disso, o movimento das esferas foi avaliado para valores do coeficiente de restituição das esferas e não foram verificadas diferenças consideráveis.Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMestre em Engenharia Químicaapplication/pdfporUniversidade Federal de UberlândiaPrograma de Pós-graduação em Engenharia QuímicaUFUBREngenhariasFluidodinâmica computacionalMoinho de bolasCorpos moedoresCatarateamentoCentrifugaçãoCFDCoeficiente de especularidadecoeficiente de restituiçãoBall millGrinding mediaCataractingCentrifugingSpecularity coefficientRestitution coefficientCNPQ::ENGENHARIAS::ENGENHARIA QUIMICAMoinhos e trabalhos em moinhosEstudo experimental e numérico da dinâmica de corpos moedores em moinhos de bolainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisDuarte, Claudio Robertohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4708473P5Barrozo, Marcos Antonio de Souzahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787095J7Ataide, Carlos Henriquehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787952H6Santos, Dyrney Araújo doshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4264374A0http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4490993A1Machado, Marcela Vieira Caixetainfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFUTHUMBNAILEstudoExperimentalNumerico.pdf.jpgEstudoExperimentalNumerico.pdf.jpgGenerated Thumbnailimage/jpeg1266https://repositorio.ufu.br/bitstream/123456789/15264/3/EstudoExperimentalNumerico.pdf.jpgde1ecdf5e88c04eaa3d31487c8823a29MD53ORIGINALEstudoExperimentalNumerico.pdfapplication/pdf4800738https://repositorio.ufu.br/bitstream/123456789/15264/1/EstudoExperimentalNumerico.pdf16e3746af70e8a994bdbc778a9cb64d1MD51TEXTEstudoExperimentalNumerico.pdf.txtEstudoExperimentalNumerico.pdf.txtExtracted texttext/plain174536https://repositorio.ufu.br/bitstream/123456789/15264/2/EstudoExperimentalNumerico.pdf.txt2b6e695aa9160e5318b4ca4a1e4ba491MD52123456789/152642020-09-21 20:12:29.933oai:repositorio.ufu.br:123456789/15264Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2020-09-21T23:12:29Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.por.fl_str_mv |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
title |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
spellingShingle |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola Machado, Marcela Vieira Caixeta Fluidodinâmica computacional Moinho de bolas Corpos moedores Catarateamento Centrifugação CFD Coeficiente de especularidade coeficiente de restituição Ball mill Grinding media Cataracting Centrifuging Specularity coefficient Restitution coefficient CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA Moinhos e trabalhos em moinhos |
title_short |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
title_full |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
title_fullStr |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
title_full_unstemmed |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
title_sort |
Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola |
author |
Machado, Marcela Vieira Caixeta |
author_facet |
Machado, Marcela Vieira Caixeta |
author_role |
author |
dc.contributor.advisor-co1.fl_str_mv |
Duarte, Claudio Roberto |
dc.contributor.advisor-co1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4708473P5 |
dc.contributor.advisor1.fl_str_mv |
Barrozo, Marcos Antonio de Souza |
dc.contributor.advisor1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787095J7 |
dc.contributor.referee1.fl_str_mv |
Ataide, Carlos Henrique |
dc.contributor.referee1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787952H6 |
dc.contributor.referee2.fl_str_mv |
Santos, Dyrney Araújo dos |
dc.contributor.referee2Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4264374A0 |
dc.contributor.authorLattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4490993A1 |
dc.contributor.author.fl_str_mv |
Machado, Marcela Vieira Caixeta |
contributor_str_mv |
Duarte, Claudio Roberto Barrozo, Marcos Antonio de Souza Ataide, Carlos Henrique Santos, Dyrney Araújo dos |
dc.subject.por.fl_str_mv |
Fluidodinâmica computacional Moinho de bolas Corpos moedores Catarateamento Centrifugação CFD Coeficiente de especularidade coeficiente de restituição |
topic |
Fluidodinâmica computacional Moinho de bolas Corpos moedores Catarateamento Centrifugação CFD Coeficiente de especularidade coeficiente de restituição Ball mill Grinding media Cataracting Centrifuging Specularity coefficient Restitution coefficient CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA Moinhos e trabalhos em moinhos |
dc.subject.eng.fl_str_mv |
Ball mill Grinding media Cataracting Centrifuging Specularity coefficient Restitution coefficient |
dc.subject.cnpq.fl_str_mv |
CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
dc.subject.autorizado.none.fl_str_mv |
Moinhos e trabalhos em moinhos |
description |
Ball mills are used in several industrials sectors, such as cement, food and mining industries. Inside a ball mill, the comminution is performed by the grinding media movement and their interaction with the material to be broken. In this work, the grinding media dynamics in a ball mill with lifters was studied experimentally by the analysis the transitional phenomena between cascading, cataracting and centrifuging. In order to assess the end-walls effect in the behavior ball charge, both transitions were investigated for one, two or three layers of balls in the axial direction. The end-wall effect did not significantly influence the transitions between regimes. The centrifuging critical rotation speeds noted experimentally were compared to the centrifuging speeds given by literature equations which take into account some systems variables. These equations could not correctly predict the occurrence of centrifuging in a ball mill with lifters. Therefore, a centrifuging equation was adjusted for the steel-chrome balls used in this work. Coupled with experimental work, the grinding media dynamics was studied by simulations in computational fluid dynamics (CFD), using the commercial software FLUENT® and the Eulerian approach. The influence of boundary conditions in the walls was investigated by analysis the different values of specularity coefficient, considering the difficultly of measuring this parameter. It was found the influence of the specularity coefficient on the movement of grinding media simulation in ball mill. The values of this parameter that had greater physical consistency with the experimental observations are between 0,40-0,20. This observation confirms the required careful in the assignment of the boundary condition in the wall, especially the equipment is simulated in small scales and even though the end-wall effect was not observed in experimental study. Moreover, the grinding media movement was assessed for values of the ball restitution coefficient and it was not observed considerable differences. |
publishDate |
2016 |
dc.date.accessioned.fl_str_mv |
2016-06-22T18:41:56Z |
dc.date.available.fl_str_mv |
2016-06-02 2016-06-22T18:41:56Z |
dc.date.issued.fl_str_mv |
2016-02-12 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
MACHADO, Marcela Vieira Caixeta. Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola. 2016. 99 f. Dissertação (Mestrado em Engenharias) - Universidade Federal de Uberlândia, Uberlândia, 2016. Disponível em: http://doi.org/10.14393/ufu.di.2016.37 |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufu.br/handle/123456789/15264 |
dc.identifier.doi.pt_BR.fl_str_mv |
http://doi.org/10.14393/ufu.di.2016.37 |
identifier_str_mv |
MACHADO, Marcela Vieira Caixeta. Estudo experimental e numérico da dinâmica de corpos moedores em moinhos de bola. 2016. 99 f. Dissertação (Mestrado em Engenharias) - Universidade Federal de Uberlândia, Uberlândia, 2016. Disponível em: http://doi.org/10.14393/ufu.di.2016.37 |
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https://repositorio.ufu.br/handle/123456789/15264 http://doi.org/10.14393/ufu.di.2016.37 |
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por |
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Universidade Federal de Uberlândia |
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Programa de Pós-graduação em Engenharia Química |
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UFU |
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BR |
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Engenharias |
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Universidade Federal de Uberlândia |
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