Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional
Autor(a) principal: | |
---|---|
Data de Publicação: | 2023 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/17462 |
Resumo: | Conventional transfer chutes are equipment used to change the solids flow direction in transporting systems that use conveyor belts. During operation, the solid transported by the upper conveyor belt enters the chute and falls, from where it is directed to the lower conveyor belt, changing its flow direction. A patent from Vale S.A company describes the adaptation of the transfer chute as an industrial drying unit, consisting of feeding hot air in the base of the equipment, which rises and exchanges heat and mass with the falling wet ore. One of the main advantages of the adapted equipment is the implementation of a moisture reduction process for iron ore concentrates in an equipment already installed on the production line. However, since it is a new technology, many aspects of its operation are unknown. The objective of this work was to simulate by computational fluid dynamics (CFD) the operation of the drying chute, referring to a unit installed in the pelletizing plant of São Luís/MA, analyzing and evaluating the momentum, heat, and mass transport phenomena involved. It was decided to experimentally obtain a correlation for the mass transfer coefficient (K), which is a key simulating parameter to be implemented in the CFD simulations for greater precision in describing the iron ore drying rate. The procedure for obtaining and validating the correlation for K was initially executed in a laboratory-scale dryer called FB-2. Thin layer drying experiments were carried out for various conditions of air temperature (50 °C ≤ Tf ≤ 90 °C) and air velocity (2.5 m/s ≤ uf ≤ 4.5 m/s). From these data, a correlation for K was obtained and implemented in CFD simulations of the FB-2 equipment. The validation procedure showed an excellent agreement between the experimental and simulated data for the variation of the dimensionless moisture with time. Afterwards, in order to obtain a correlation for a range of conditions closer to those of the drying chute, a new dryer (GR-1) was designed and constructed. In this dryer, for an air temperature of 140 °C and an air velocity of 15 m/s, a drying time of about 6 s was required to reduce the iron ore moisture by two percentage points (wet basis). From experimental data collected in the GR-1, a correlation for K was obtained for another range of air temperatures (100 °C ≤ Tf ≤ 140 °C) and air velocities (5 m/s ≤ uf ≤ 15 m/s), implemented in CFD simulations of the GR-1 equipment and validated against the experimental data. Finally, CFD simulations of the drying chute equipment were performed using the correlation for K previously obtained in the GR-1. The CFD simulations of the drying chute involved a porous zone model to describe the sieve that composes the equipment. Physical coherence of the model was investigated and considered appropriate. The contours of velocity, temperature and humidity of both the fluid and solid phases were presented, as well as the regions in which the drying rate was higher. In addition, the impacts of closing some outlets of the equipment was evaluated using the simulator. Numerical results provided a better understanding of the operation in the drying chute and the simulator showed potential to evaluate possible improvements in its geometry and operation. |
id |
SCAR_ccddbe8c4c3efc87a78a681a0b171600 |
---|---|
oai_identifier_str |
oai:repositorio.ufscar.br:ufscar/17462 |
network_acronym_str |
SCAR |
network_name_str |
Repositório Institucional da UFSCAR |
repository_id_str |
4322 |
spelling |
Souza, Amarílis Severino eBéttega, Rodrigohttp://lattes.cnpq.br/1379682125857376http://lattes.cnpq.br/34335035735663790da9e934-c0af-43f2-b95e-b7e0449b70e02023-03-08T18:38:53Z2023-03-08T18:38:53Z2023-02-27SOUZA, Amarílis Severino e. Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/17462.https://repositorio.ufscar.br/handle/ufscar/17462Conventional transfer chutes are equipment used to change the solids flow direction in transporting systems that use conveyor belts. During operation, the solid transported by the upper conveyor belt enters the chute and falls, from where it is directed to the lower conveyor belt, changing its flow direction. A patent from Vale S.A company describes the adaptation of the transfer chute as an industrial drying unit, consisting of feeding hot air in the base of the equipment, which rises and exchanges heat and mass with the falling wet ore. One of the main advantages of the adapted equipment is the implementation of a moisture reduction process for iron ore concentrates in an equipment already installed on the production line. However, since it is a new technology, many aspects of its operation are unknown. The objective of this work was to simulate by computational fluid dynamics (CFD) the operation of the drying chute, referring to a unit installed in the pelletizing plant of São Luís/MA, analyzing and evaluating the momentum, heat, and mass transport phenomena involved. It was decided to experimentally obtain a correlation for the mass transfer coefficient (K), which is a key simulating parameter to be implemented in the CFD simulations for greater precision in describing the iron ore drying rate. The procedure for obtaining and validating the correlation for K was initially executed in a laboratory-scale dryer called FB-2. Thin layer drying experiments were carried out for various conditions of air temperature (50 °C ≤ Tf ≤ 90 °C) and air velocity (2.5 m/s ≤ uf ≤ 4.5 m/s). From these data, a correlation for K was obtained and implemented in CFD simulations of the FB-2 equipment. The validation procedure showed an excellent agreement between the experimental and simulated data for the variation of the dimensionless moisture with time. Afterwards, in order to obtain a correlation for a range of conditions closer to those of the drying chute, a new dryer (GR-1) was designed and constructed. In this dryer, for an air temperature of 140 °C and an air velocity of 15 m/s, a drying time of about 6 s was required to reduce the iron ore moisture by two percentage points (wet basis). From experimental data collected in the GR-1, a correlation for K was obtained for another range of air temperatures (100 °C ≤ Tf ≤ 140 °C) and air velocities (5 m/s ≤ uf ≤ 15 m/s), implemented in CFD simulations of the GR-1 equipment and validated against the experimental data. Finally, CFD simulations of the drying chute equipment were performed using the correlation for K previously obtained in the GR-1. The CFD simulations of the drying chute involved a porous zone model to describe the sieve that composes the equipment. Physical coherence of the model was investigated and considered appropriate. The contours of velocity, temperature and humidity of both the fluid and solid phases were presented, as well as the regions in which the drying rate was higher. In addition, the impacts of closing some outlets of the equipment was evaluated using the simulator. Numerical results provided a better understanding of the operation in the drying chute and the simulator showed potential to evaluate possible improvements in its geometry and operation.Os chutes de transferência convencionais são equipamentos utilizados para mudar a direção do escoamento de sólidos dos transportadores de correia. Durante a operação, o sólido transportado pela correia superior entra no chute e depois cai na parte de baixo, onde é direcionado para o transportador de correia inferior. Uma patente da empresa Vale S.A prevê a adaptação do chute de transferência como unidade de secagem industrial, cujo funcionamento consiste na alimentação de ar quente na base do equipamento, que ascende e troca calor e massa com o minério úmido que cai. Uma das principais vantagens do equipamento adaptado é a implementação de um processo de redução de umidade para concentrados de minério de ferro em um equipamento já instalado na linha de produção. No entanto, por ser uma nova tecnologia, muitos aspectos de sua operação são desconhecidos. O objetivo deste trabalho foi simular por fluidodinâmica computacional (CFD) a operação do equipamento de secagem em chute, referente a uma unidade instalada na planta de pelotização de São Luís/MA, abordando e avaliando os fenômenos de transporte de movimento, calor e massa envolvidos. Primeiro, optou-se por obter experimentalmente uma correlação para o coeficiente de transferência de massa (K), que é um parâmetro-chave a ser implementado em simulações por CFD, a fim de descrever a taxa de secagem do minério de ferro com maior precisão. O procedimento para obtenção e validação da correlação para K foi feito inicialmente em um secador em escala de laboratório, denominado FB-2. Experimentos de secagem em camada fina foram realizados para várias condições de temperatura (50 °C≤ Tf ≤ 90 °C) e velocidade (2,5 m/s ≤ uf ≤ 4,5 m/s) do ar de secagem. Com esses dados, uma correlação para K foi obtida e implementada em simulações por CFD do equipamento FB-2. O procedimento de validação apresentou uma ótima concordância entre os dados experimentais e simulados para a variação do adimensional de umidade com o tempo. Em seguida, de modo a obter uma correlação para K dentro de uma faixa de condições mais próxima às do chute industrial, um novo secador (GR-1) foi projetado e construído. Nesse secador, para uma temperatura do ar de 140 °C e uma velocidade do ar de 15 m/s, um tempo de secagem de cerca de 6 s era necessário para reduzir a umidade do minério de ferro em dois pontos percentuais (base úmida). A partir de dados experimentais coletados no GR-1, uma correlação para K foi obtida para uma nova faixa de temperaturas (100 °C≤ Tf ≤ 140 °C) e velocidades (5 m/s ≤ uf ≤ 15 m/s) do ar, implementada em simulações por CFD do equipamento GR-1 e validada frente aos dados experimentais. Finalmente, foram realizadas as simulações por CFD do equipamento de secagem em chute, utilizando a correlação para K anteriormente obtida a partir do equipamento GR-1. As simulações por CFD do chute industrial envolveram um modelo de zona porosa para descrever a peneira que existe em sua região central. A coerência física do modelo foi investigada e considerada apropriada. Foram apresentados os contornos de velocidade, temperatura e umidade das fases fluida e sólida, bem como identificadas as regiões nas quais a taxa de secagem era mais elevada. Além disso, foi avaliado por meio das simulações o impacto de fechar algumas saídas de ar do equipamento. Os resultados numéricos forneceram uma melhor compreensão da operação de secagem no chute e o simulador apresentou potencial para avaliar possíveis melhorias em sua geometria e operação.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brasil (CNPq) – Código de Financiamento [142102/2019-9]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Código de Financiamento 001porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Engenharia Química - PPGEQUFSCarAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/info:eu-repo/semantics/openAccessMineraçãoCFDMinério de ferroCinética de secagemTransferência de massaMiningIron oreDrying kineticsMass transferENGENHARIAS::ENGENHARIA QUIMICA::OPERACOES INDUSTRIAIS E EQUIPAMENTOS PARA ENGENHARIA QUIMICAENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICASecagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacionalConvective drying of iron ore concentrate: experimental approach and simulations using computational fluid dynamicsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis600600a8b181e8-2587-4ff2-986f-7c9d09fddee3reponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALTese_amarilis_versao final.pdfTese_amarilis_versao final.pdfTese_Amarílisapplication/pdf14853073https://repositorio.ufscar.br/bitstream/ufscar/17462/1/Tese_amarilis_versao%20final.pdf05808c5c1c91f6ac033d2142e4098701MD51CC-LICENSElicense_rdflicense_rdfapplication/rdf+xml; charset=utf-8810https://repositorio.ufscar.br/bitstream/ufscar/17462/2/license_rdff337d95da1fce0a22c77480e5e9a7aecMD52TEXTTese_amarilis_versao final.pdf.txtTese_amarilis_versao final.pdf.txtExtracted texttext/plain338535https://repositorio.ufscar.br/bitstream/ufscar/17462/3/Tese_amarilis_versao%20final.pdf.txt92637114d68440153e3c1eb6995bc187MD53THUMBNAILTese_amarilis_versao final.pdf.jpgTese_amarilis_versao final.pdf.jpgIM Thumbnailimage/jpeg6099https://repositorio.ufscar.br/bitstream/ufscar/17462/4/Tese_amarilis_versao%20final.pdf.jpg585f84b5a12e09faab5a4367bbe1c050MD54ufscar/174622023-09-18 18:32:25.171oai:repositorio.ufscar.br:ufscar/17462Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:32:25Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
dc.title.alternative.eng.fl_str_mv |
Convective drying of iron ore concentrate: experimental approach and simulations using computational fluid dynamics |
title |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
spellingShingle |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional Souza, Amarílis Severino e Mineração CFD Minério de ferro Cinética de secagem Transferência de massa Mining Iron ore Drying kinetics Mass transfer ENGENHARIAS::ENGENHARIA QUIMICA::OPERACOES INDUSTRIAIS E EQUIPAMENTOS PARA ENGENHARIA QUIMICA ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
title_short |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
title_full |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
title_fullStr |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
title_full_unstemmed |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
title_sort |
Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional |
author |
Souza, Amarílis Severino e |
author_facet |
Souza, Amarílis Severino e |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/3433503573566379 |
dc.contributor.author.fl_str_mv |
Souza, Amarílis Severino e |
dc.contributor.advisor1.fl_str_mv |
Béttega, Rodrigo |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/1379682125857376 |
dc.contributor.authorID.fl_str_mv |
0da9e934-c0af-43f2-b95e-b7e0449b70e0 |
contributor_str_mv |
Béttega, Rodrigo |
dc.subject.por.fl_str_mv |
Mineração CFD Minério de ferro Cinética de secagem Transferência de massa |
topic |
Mineração CFD Minério de ferro Cinética de secagem Transferência de massa Mining Iron ore Drying kinetics Mass transfer ENGENHARIAS::ENGENHARIA QUIMICA::OPERACOES INDUSTRIAIS E EQUIPAMENTOS PARA ENGENHARIA QUIMICA ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
dc.subject.eng.fl_str_mv |
Mining Iron ore Drying kinetics Mass transfer |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA QUIMICA::OPERACOES INDUSTRIAIS E EQUIPAMENTOS PARA ENGENHARIA QUIMICA ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA |
description |
Conventional transfer chutes are equipment used to change the solids flow direction in transporting systems that use conveyor belts. During operation, the solid transported by the upper conveyor belt enters the chute and falls, from where it is directed to the lower conveyor belt, changing its flow direction. A patent from Vale S.A company describes the adaptation of the transfer chute as an industrial drying unit, consisting of feeding hot air in the base of the equipment, which rises and exchanges heat and mass with the falling wet ore. One of the main advantages of the adapted equipment is the implementation of a moisture reduction process for iron ore concentrates in an equipment already installed on the production line. However, since it is a new technology, many aspects of its operation are unknown. The objective of this work was to simulate by computational fluid dynamics (CFD) the operation of the drying chute, referring to a unit installed in the pelletizing plant of São Luís/MA, analyzing and evaluating the momentum, heat, and mass transport phenomena involved. It was decided to experimentally obtain a correlation for the mass transfer coefficient (K), which is a key simulating parameter to be implemented in the CFD simulations for greater precision in describing the iron ore drying rate. The procedure for obtaining and validating the correlation for K was initially executed in a laboratory-scale dryer called FB-2. Thin layer drying experiments were carried out for various conditions of air temperature (50 °C ≤ Tf ≤ 90 °C) and air velocity (2.5 m/s ≤ uf ≤ 4.5 m/s). From these data, a correlation for K was obtained and implemented in CFD simulations of the FB-2 equipment. The validation procedure showed an excellent agreement between the experimental and simulated data for the variation of the dimensionless moisture with time. Afterwards, in order to obtain a correlation for a range of conditions closer to those of the drying chute, a new dryer (GR-1) was designed and constructed. In this dryer, for an air temperature of 140 °C and an air velocity of 15 m/s, a drying time of about 6 s was required to reduce the iron ore moisture by two percentage points (wet basis). From experimental data collected in the GR-1, a correlation for K was obtained for another range of air temperatures (100 °C ≤ Tf ≤ 140 °C) and air velocities (5 m/s ≤ uf ≤ 15 m/s), implemented in CFD simulations of the GR-1 equipment and validated against the experimental data. Finally, CFD simulations of the drying chute equipment were performed using the correlation for K previously obtained in the GR-1. The CFD simulations of the drying chute involved a porous zone model to describe the sieve that composes the equipment. Physical coherence of the model was investigated and considered appropriate. The contours of velocity, temperature and humidity of both the fluid and solid phases were presented, as well as the regions in which the drying rate was higher. In addition, the impacts of closing some outlets of the equipment was evaluated using the simulator. Numerical results provided a better understanding of the operation in the drying chute and the simulator showed potential to evaluate possible improvements in its geometry and operation. |
publishDate |
2023 |
dc.date.accessioned.fl_str_mv |
2023-03-08T18:38:53Z |
dc.date.available.fl_str_mv |
2023-03-08T18:38:53Z |
dc.date.issued.fl_str_mv |
2023-02-27 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
SOUZA, Amarílis Severino e. Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/17462. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/17462 |
identifier_str_mv |
SOUZA, Amarílis Severino e. Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional. 2023. Tese (Doutorado em Engenharia Química) – Universidade Federal de São Carlos, São Carlos, 2023. Disponível em: https://repositorio.ufscar.br/handle/ufscar/17462. |
url |
https://repositorio.ufscar.br/handle/ufscar/17462 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.confidence.fl_str_mv |
600 600 |
dc.relation.authority.fl_str_mv |
a8b181e8-2587-4ff2-986f-7c9d09fddee3 |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Engenharia Química - PPGEQ |
dc.publisher.initials.fl_str_mv |
UFSCar |
publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFSCAR instname:Universidade Federal de São Carlos (UFSCAR) instacron:UFSCAR |
instname_str |
Universidade Federal de São Carlos (UFSCAR) |
instacron_str |
UFSCAR |
institution |
UFSCAR |
reponame_str |
Repositório Institucional da UFSCAR |
collection |
Repositório Institucional da UFSCAR |
bitstream.url.fl_str_mv |
https://repositorio.ufscar.br/bitstream/ufscar/17462/1/Tese_amarilis_versao%20final.pdf https://repositorio.ufscar.br/bitstream/ufscar/17462/2/license_rdf https://repositorio.ufscar.br/bitstream/ufscar/17462/3/Tese_amarilis_versao%20final.pdf.txt https://repositorio.ufscar.br/bitstream/ufscar/17462/4/Tese_amarilis_versao%20final.pdf.jpg |
bitstream.checksum.fl_str_mv |
05808c5c1c91f6ac033d2142e4098701 f337d95da1fce0a22c77480e5e9a7aec 92637114d68440153e3c1eb6995bc187 585f84b5a12e09faab5a4367bbe1c050 |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 MD5 MD5 |
repository.name.fl_str_mv |
Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR) |
repository.mail.fl_str_mv |
|
_version_ |
1802136417990606848 |