Navegando por Assunto "FMEA"

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Acesso aberto (Open Access)
Aplicação da ferramenta de risco FMEA para análises dos modos de falha de uma barragem de terra: estudo de caso Projeto Formoso do Araguaia-TO
(Universidade Federal do Pará, 2023-05-15) SANTOS, Andreia Arruda; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The Formoso River Project, located in the state of Tocantins, is the largest irrigation project in Latin America and its structures, made up of three dams, have worried the supervisory body due to the compromised state of conservation of these structures, with evidence of pathologies and anomalies at various points. The state government, which is the developer of the dams, in 2012 even contracted revitalization projects for the enterprise, but to date the works have not been carried out, which makes the safety of the dams more vulnerable. The general objective of the research is to analyze the risk situation of the Calumbi II dam, which makes up the Rio Formoso irrigation project, through the application of the FMEA (Failure Mode and Effects Analysis) risk tool, identifying the most likely failure modes and with greater potential. Other objectives would be: the description of the interventions recommended by the consultancy hired by the entrepreneur and the critical analysis of the lack of dam safety management. The research methodology was based on four stages: a) characterization of the Rio Formoso Project and the case study dam; b) survey of anomalies and pathologies found in the dam; c) application of the FMEA risk tool and d) critical analysis of the dam's safety management case study. The results indicated that the Calumbi II dam presents several pathologies and anomalies (presence of large trees and shrub vegetation on the crest, retraction cracks, erosion and water surges on the slopes), and that despite the dam operating at minimum levels, failures may occur. The FMEA tool demonstrated that the highest priority failure mode would be upstream slope instability (NPR=336), secondly, failure due to piping (NPR=320) and thirdly, but more remote, failure due to dam overtopping ( NPR=144). From the aspect of the analysis of the safety management of the Calumbi II Dam, the vulnerability of the enterprise was concluded, since the dam does not have a PSB or PAE, it does not have installed instrumentation, there is no professional responsible for safety, it does not have studies of risk assessments, does not receive regular periodic inspections by the supervisory body.
Acesso aberto (Open Access)
Proposta de integração da metodologia FMEA na gestão de segurança de barragem hidréletrica
(Universidade Federal do Pará, 2022-03-18) CARVALHO, Regiana Barbosa; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The dam failure scenario in Brazil has been more frequent than expected around the world and, therefore, dam safety management has become a central focus of entrepreneurs who have sought to meet legal requirements and supervisory bodies. In this context, risk analysis methodologies applied in several sectors of the industry, started to be considered in the management of dam projects, adding benefits in the activities of control and monitoring of the structures, as well as in the prediction of failure modes and accidents. Therefore, the present research has as a general objective, to propose the integration of the risk analysis methodology, FMEA methodology (Failure Modes and Effects Analysis) to the safety management system practiced at UHE Tucuruí, seeking to expand the entrepreneur's management to the scope of the failure mode scenarios and their respective causes, including the monitoring of indicators related to the dam's safety status, occurrence and detection rates. The research methodology was based on five steps, namely: a) characterization of the dam, a case study; b) identification of anomalies present in the structure's history; ç); analysis of the entrepreneur's management process; d) application of the FMEA methodology resulting in scenarios with higher NPR and; e) proposal to integrate the FMEA into the safety management system practiced by the entrepreneur. The results of the FMEA application indicated that among the failure modes simulated for the dam case study, the scenario “internal erosion caused by clogging of filters and drains in the earthen dam on the right bank” presented the highest NPR, and therefore, this is the scenario that requires prioritization of actions. Also, for most of the simulated failure modes, the detection rate resulted in a 'low detection', due to weaknesses in the dam monitoring system, as recorded in the dam instrumentation reports. In the case of the UHE Tucuruí safety management process, it was possible to integrate the FMEA methodology into the plant's flowchart, taking advantage of the "Periodic Review" stage, using the same team hired for this demand, optimizing the flowchart. Finally, it is expected that the integration of the FMEA methodology in the dam management process will provide the following benefits: a) dam safety management oriented towards the management of failure mode scenarios; b) management of risk control mechanisms and continuous assessment of the project's monitoring system.
Acesso aberto (Open Access)
Verificação de desempenho dos sistemas de filtragem de resíduo bauxita por tambor e prensa como alternativa para barragens
(Universidade Federal do Pará, 2023-02-26) PANTOJA, Ronaldo Guimarães; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
Tailings dams generally function as a reservoir of tailings and water, due to existing disposal methods, this is due to the characteristics of the processing processes of mining companies and refineries, which use a very high concentration of water in this process, resulting in tailings with low solids contents and that offer risks in the disposal and that also directly impact the environment in which they are inserted. In view of the occurrence of accidents involving tailings dams in Brazil and worldwide and the need to reduce the impacts caused, mining companies and ore processing industries have invested in innovative technology that promote waste dewatering, making them drier and providing a safer form of disposal. However, in this direction, this study presents the methods of disposal of wet and dry tailings in the form of landfills, obtained from filtration systems, highlighting the advantages and disadvantages of the use of the filter press compared to the drum filter for the disposal of bauxite residue. Experimental landfills of bauxite residues from an alumina refinery, located in the state of Pará, were used, which allowed the knowledge of the material behavior after filtering by filter press, when submitted to compaction by track tractor and compactor roller. A qualitative risk analysis of the FMEA type was also analyzed to identify the risks involved in the method of disposal of the filtered residue by drum filter. The residue dewatered through the drum filter reaches an average solids content of 60% at the end of the process and per filter press up to 80%. The compaction tests allowed the knowledge of dry density, optimum humidity and degree of compaction of the material dewatered by filter press, when arranged in the form of a controlled landfill. The two waste filtration systems (Drum Filter and Press Filter) were compared considering the operational, safety and environmental aspects, allowing to know the advantages and disadvantages of each system and the safer disposal method, less impacting on the environment and less susceptible to structural problems. The FMEA analysis identified the main triggers and failure modes related to geotechnical risks in the operation of the waste system with drum filter, for disposal via construction of platforms. The aspects of "insecurity" and "dam galling" were analyzed and generated the risk matrices and their consequences / effects. The results "High Risks" helped to define the change in the filtering system and arrangement method.