102 resultados para Jizhou kiln


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Bodies of Ding kiln white porcelains and their imitations from Guantai and Jiexiu kilns of the Chinese Song dynasty (960-1279 AD) were analysed for 40 trace elements by inductively coupled plasma mass spectrometry (ICP-MS). Numerous trace element compositions and ratios allow these visually similar products to be distinguished, and a Ding-style shard of uncertain origin is identified as a likely genuine Ding product. In Jiexiu kiln, Ding-style products have trace element features distinctive from blackwares of an inferior quality intended for the lower end market. Based on geochemical behaviour of these trace elements, we propose that geochemically distinctive raw materials were used for Ding-style products of a higher quality, which possibly also underwent purification by levigation prior to use. Capable of analysing over 40 elements with a typical long term precision of < 2%, this high precision ICP-MS method proves to be very powerful for grouping and characterising archaeological ceramics. Combined with geochemical interpretation, it can provide insights into the raw materials and techniques used by ancient potters. (C) 2004 Elsevier Ltd. All rights reserved.

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We compare the trace element and Sr isotopic compositions of stoneware bodies made in Yaozhou and Jizhou to characterise these Chinese archaeological ceramics and examine the potential of Sr isotopes in provenance studies. Element concentrations determined by ICP-MS achieve distinct characterisation for Jizhou samples due to their restricted variation, yet had limited success with Yaozhou wares because of their large variability. In contrast, Sr-87/Sr-86 ratios in Yaozhou samples have a very small variation and are all significantly lower than those of Jizhou samples, which show a large variation and cannot be well characterised with Sr isotopes. Geochemical interpretation reveals that Sr-87/Sr-86 ratios will have greater potential to characterise ceramics made of low Rb/Sr materials such as kaolin clay, yet will show larger variations in ceramics made of high Rb/Sr materials such as porcelain stone. (c) 2005 Elsevier B.V. All rights reserved.

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The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87-92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management. © 2013 Elsevier Ltd.

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The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87-92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management. © 2013 Elsevier Ltd.

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The Haloclean process, a rotary kiln process for pyrolysis, developed by researchers at the Forschungszentrum Karlsruhe, Germany makes it possible to recover copper and precious metals from the scrap, ready for recycling. Pyrolysis neatly turns brominated electronic scrap plastics into recyclable copper and methanol feedstock while removing the halogens. The process has demonstrated its ability to recycle brominated electronic scrap in extensive parametric studies. A method suitable for the selective production of HBr in the presence of chlorine is the treatment of the pyrolysis oils with molten polypropylene. This treatment is offers the possibility to use the gas and liquid fraction from pyrolysis of electronic scrap as fossil fuel substitute in copper smelter processes or as feedstock for methanol production via gasification.

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The main hypothesis of this thesis is that the deve lopment of industrial automation applications efficiently, you need a good structuri ng of data to be handled. Then, with the aim of structuring knowledge involved in the contex t of industrial processes, this thesis proposes an ontology called OntoAuto that conceptua lly models the elements involved in the description of industrial processes. To validat e the proposed ontology, several applica- tions are presented. In the first, two typical indu strial processes are modeled conceptually: treatment unit DEA (Diethanolamine) and kiln. In th e second application, the ontology is used to perform a semantic filtering alarms, which together with the analysis of correla- tions, provides temporal relationships between alar ms from an industrial process. In the third application, the ontology was used for modeli ng and analysis of construction cost and operation processes. In the fourth application, the ontology is adopted to analyze the reliability and availability of an industrial plant . Both for the application as it involves costs for the area of reliability, it was necessary to create new ontologies, and OntoE- con OntoConf, respectivamentem, importing the knowl edge represented in OntoAuto but adding specific information. The main conclusions of the thesis has been that on tology approaches are well suited for structuring the knowledge of industrial process es and based on them, you can develop various advanced applications in industrial automat ion.

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Use of higher proportions of fly ash as a cement replacement in concrete has obvious environmental and performance benefits but high volumes of fly ash are not commonly used due to perceived lower early age strengths. In this investigation, addition of cement kiln dust (CKD) and gypsum to activate the fly ash was studied and the proportions used in the paste mixes were designed to optimize the mixture ingredients to achieve the highest early age compressive strength. Change of mineral phase composition and micro structure of the composites was analyzed. It was found that CKD was much more effective in activating the fly ash than gypsum. Appreciable early age compressive strengths were achieved for fly ash contents up to 60% of the binder and these observations were supported by analysis of the mineral phases.

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O presente trabalho realizou-se no âmbito do Projeto Galp 20-2020 implementado na empresa Sanindusa, em parceira com a Universidade de Aveiro. Como principal objetivo pretendia-se estudar o consumo de energia durante o processo de cozedura das peças cerâmicas com o intuito de avaliar a viabilidade da substituição do refratário existente na empresa. Uma vez que esta medida implicaria um tempo de retorno do investimento demasiado elevado, optou-se por estudar o consumo de energia associado a uma placa horizontal, de massa unitária, de qualquer tipo de material refratário. Para tal, foi desenvolvido um Modelo Teórico capaz de calcular o calor absorvido por uma placa de refratário ao longo de todo o percurso dentro do Forno Túnel 2, existente na empresa e utilizado no processo de produção das peças cerâmicas. Através deste estudo foi possível concluir que o Modelo Teórico é bastante útil na medida em que permite a criação de vários cenários, através da alteração de diversas variáveis, permitindo conhecer qual o impacto de cada uma no consumo de energia neste equipamento. Como trabalho futuro propõe-se o desenvolvimento do Modelo Teórico apresentado para o estudo da transferência de calor bidimensional. Esta melhoria permitiria analisar o consumo de energia associado a diferentes formas de material refratário utilizado no processo de cozedura de peças cerâmicas (o que não é possível quando se aplica o conceito de transferência de calor unidimensional).

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O presente relatório resulta de um estágio realizado no âmbito da eficiência energética assente no programa Galp 20-20-20 que tem por génese uma parceria entre a Universidade de Aveiro e a empresa de coberturas cerâmicas, CS – Coelho da Silva S.A. A Fábrica alvo de estudo é uma consumidora intensiva de energia, despendeu no ano de 2013 cerca de 3.768 tep. Devido aos seus processos de cozedura e secagem, apresenta uma elevada dependência de Gás Natural, representando pouco mais de 78% do consumo global da fábrica. Deste consumo de energia térmica, 83% respeita ao forno e os restantes 17% encontram-se alocados ao secador, pelo que as medidas de eficiência energética presentes neste relatório centram-se da redução deste vetor energético. São então propostas três medidas para a redução da dependência deste vetor. A primeira, incide na recuperação de calor residual presente nos gases de exaustão através da instalação de um permutador de calor. Esta medida permite uma redução do consumo na ordem dos 10% e conta com um payback de 2,3 anos resultante de uma economia anual de 150.000 €. Para este estudo foi desenvolvido um modelo dinâmico em excel que permite a simulação de diversos cenários. São também propostas mais duas intervenções que incidem na alteração do circuito térmico. Estas medidas têm um impacte mais reduzido no que respeita ao percentual de redução energético, ambas com menos de 1% de redução do consumo global da fábrica. Contudo são medidas bastante interessantes dada a sua simplicidade e contam com poupanças anuais na ordem dos 6.000 € que resultam num payback inferior a 2 meses. Paralelamente executaram-se dois estudos para a iluminação, o primeiro sugere a instalação de um modelador de tensão que reduz a potência de iluminação em 36%, implicando uma redução da iluminância de cerca de 5%. A redução da potência resulta numa economia energética na ordem dos 0,4% da energia global da instalação. Este equipamento poderá ser adquirido por completo ou em renting. Ao optar pela compra integral, o investimento será apenas ressarcido em 2,8 anos resultante de uma poupança anula de perto de 6.500 €. Caso seja por renting este não tem qualquer custo adicional e as economias monetárias são partilhadas entre a empresa que fornece o equipamento e a CS-Coelho da Silva, S.A. Por fim é sugerida a substituição de parte da iluminação atual da fábrica por tecnologia LED, com esta medida reduz-se o consumo global em 0,76%. Esta medida gera uma economia monetária na ordem dos 11.500 € sendo ressarcida em 2,1 anos.

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Com este trabalho pretende-se analisar o consumo de energia na indústria de faiança e identificar medidas de poupança energética. Em 2014, o consumo específico foi de 191 kgep/t e a intensidade carbónica 2,15 tCO2e/t, tendo havido uma redução de, respectivamente, 50,2% e 1,3%, comparativamente a 2010. O consumo total correspondeu a 1108 tep, sendo 66% relativo ao consumo de gás natural. Foi utilizado um analisador de energia eléctrica nos principais equipamentos consumidores, e na desagregação de consumos térmicos, efectuaram-se leituras no contador geral de gás natural e foram utilizados dados das auditorias ambiental e energética. O processo de cozedura é responsável por 58% do consumo térmico da instalação, seguido da pintura com 24%. A conformação é o sector com maior consumo de energia eléctrica, correspondendo a 23% do consumo total. As perdas térmicas pelos gases de exaustão dos equipamentos de combustão e pela envolvente do forno, considerando os mecanismos de convecção natural e radiação, correspondem a cerca de 6% do consumo térmico total, sendo necessário tomar medidas a nível do isolamento térmico e da redução do excesso de ar. A instalação de variadores de velocidade nos ventiladores do ar de combustão do forno poderia resultar em poupanças significativas, em particular, no consumo de gás natural – redução de 4 tep/ano e cerca de 2500€/ano– tendo um tempo de retorno do investimento inferior a 1 ano. Deverá ser, no entanto, garantida a alimentação de ar combustão a todos os queimadores, bem como, a combustão completa do gás natural. O funcionamento contínuo do forno poderia resultar no aumento da sua eficiência energética, com redução de custos de operação e manutenção, sendo necessário avaliar os custos adicionais de stock e de mão de obra. Verificou-se que as medidas relacionadas com a monitorização de consumos, eliminação de fugas de ar comprimido e a instalação de variadores de velocidade nos ventiladores do ar de combustão do forno poderiam resultar em reduções de consumo de 26 tep e de emissões de 66tCO2e, num total de quase 14 000€.

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The micro-chemical/mineralogical composition of samples of grey-paste imitations of Italic Late Republican black gloss tableware displaying a particular kind of lozenge-shaped decoration (“Losanga pottery”) from Portuguese and Spanish archaeological sites in SW Iberia has been analysed by BSEM + EDS, μXRD, Powder XRD, Portable XRF and μRaman spectroscopy. “Losanga” decorated ceramics have been found throughout the Western Mediterranean. Most of the sherds display a green-brown to greyish-black engobe at the surface resembling the gloss found in Attic pottery from Classical Greece. The overall chemical, mineralogical and fossiliferous homogeneities of the ceramic paste show common features (low K-feldspar/plagioclase ratio, high Ca content, abundance of well-preserved fragments of foraminifera microfossils) that indicate low firing conditions in the kiln ranging from 650 to 900 °C. With respect to the ceramic body, analytical results confirm an enrichment in the surface gloss layer of iron, potassium and aluminium and a depletion in silicon and calcium; the very fine grain size of the surface coating suggests elutriation of iron oxide-rich clays as confirmed by the presence of magnetite, maghemite and goethite in μ-XRD scan. Chemical and mineralogical data also suggest that the firing process was performed in a 600–850 °C temperature range, adopting the well-known technique of alternating oxidizing and reducing firing conditions largely employed at the time. The analytical results, while compatible with the archaeological hypothesis of a common provenance of the raw materials for pottery production from the Guadalquivir valley workshops cannot be considered conclusive due to the similarity in the geological substrate in the two SW Iberian regions under study.