Pelletizing furnace refractory lining life cycle extension by applying thermography analysis and direct refractory injection.

The induration furnace is one of the most important devices in the pellet production system. It is responsible for ensuring the quality of pellets produced, since a high level of thermal energy is necessary to reach the physical properties needed. Therefore, the refractory lining performance is important to guarantee the quality of pellets and to avoid thermal losses. Minor failures in the refractory lining may result in serious damage, if it not previously identified and repaired. This article was written to explain a preventive technique to identify and repair such minor issues with the refractory lining before escalation. The use of this technique in the proper frequency may result in furnace life cycle extension

Modelling and optimization of green pellets classification on roller screens using the discrete element method

The present work studies the classification of green pellets in roller screens using the Discrete Element Method. For this, the individual and bulk properties of the green pellets are determined in physical tests for calibration and validation by comparison with industrial data of contact models that reproduce with verisimilitude the movement of these solids. According to the results, the JKR model was the one that best fitted the interactions of low resistance moist pellets among themselves and rolls surface. Exploratory simulations evaluated the sensitivity of the model to different operating conditions. The application of the methodology of design and analysis of experiments made possible the understanding of the main process control variables amplitude of influence. Based on the results, optimization proposals were elaborated and simulated indicating positive perspectives. The double deck screen in operation and a new segregator double deck design were tested. The results for the new proposal have shown to be promising: better efficiency and higher voidage fraction of the bed of pellets in the grid car.O presente trabalho estuda, através de simulações por Métodos de Elementos Discretos, a classificação de pelotas verdes em peneiras de rolos. Para tal, as propriedades individuais e a granel das pelotas verdes são determinadas em ensaios físicos para calibração e validação por comparação com dados industriais de modelos de contato que reproduzam com verossimilhança o movimento destes sólidos. De acordo com os resultados, o modelo JKR foi o que melhor se adequa para as interações de pelotas úmidas de baixa resistência entre elas e a superfície dos rolos. Simulações exploratórias avaliaram a sensibilidade do modelo à diferentes condições operacionais. A aplicação de metodologia e análise de experimentos permitiram o entendimento e amplitude da influência das principais variáveis de controle de processo. Com base nos resultados, propostas de otimização foram elaboradas e simuladas indicando perspectivas positivas. A peneira duplo deck em operação e o um novo projeto de peneira segregadora foram testados. Os resultados para a nova proposta demonstraramse promissores: melhor eficiência e maior fração de vazios para o leito de pelotas no carro de grelha

Pelletizing furnace refractory lining life cycle extension by applying thermography analysis and direct refractory injection

Abstract The induration furnace is one of the most important devices in the pellet production system. It is responsible for ensuring the quality of pellets produced, since a high level of thermal energy is necessary to reach the physical properties needed. Therefore, the refractory lining performance is important to guarantee the quality of pellets and to avoid thermal losses. Minor failures in the refractory lining may result in serious damage, if it not previously identified and repaired. This article was written to explain a preventive technique to identify and repair such minor issues with the refractory lining before escalation. The use of this technique in the proper frequency may result in furnace life cycle extension