With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-03Bitstream added on 2014-06-13T19:29:28Z : No. of bitstreams: 1 faria_fa_me_sjrp.pdf: 429706 bytes, checksum: 7b61ae3ccd98c41f064983d50ad2329e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O abacate (Persea americana Mill.) é uma fruta muito popular que destaca-se pela sua qualidade nutricional e composição em substâncias bioativas capazes de prevenir e controlar diversas doenças. Na literatura há ainda pouca informação reportada sobre processamento da polpa de abacate, seja para viabilizá-la para a extração e o refino do óleo, seja para seu consumo direto em diferentes formas de apresentação. O presente trabalho tem como objetivo investigar a secagem da polpa dos frutos de abacate da variedade Fortuna, como um pré-processamento para processos de extração e refino do óleo, assim como a desidratação osmótica dessa mesma polpa, como um processo mínimo para obtenção da fruta para consumo direto. A influência da temperatura e do branqueamento térmico sobre propriedades de sorção da polpa de abacate foi avaliada por meio das isotermas às temperaturas de 30ºC, 50ºC e 70ºC. Ensaios de secagem determinaram o efeito do branqueamento térmico e da temperatura sobre a cinética de secagem convectiva com ar aquecido a 50, 60 e 70°C. Ensaios de desidratação osmótica de fatias de abacate em solução de sacarose com adição de ácido cítrico foram conduzidos para determinação da cinética do processo e caracterização físico-química do produto. Os modelos matemáticos de BET, GAB, Halsey, Henderson, Peleg e Oswin foram ajustados aos dados experimentais de sorção de água obtidos para abacate fresco e branqueado. Todos os modelos testados apresentam ajustes satisfatórios, porém o modelo de GAB, com três parâmetros, e o de Peleg, com quatro, foram os que melhor descreveram as isotermas. Segundo a classificação de Brunauer, a forma das isotermas de dessorção do abacate fresco e branqueado determinadas a 30ºC, 50ºC e 70ºC, são do tipo III ou estão entre o tipo... / The avocado (Persea americana Mill.) is a popular and it is very important fruit by its nutritional quality and composition in bioactive substances which are able to prevent and control several diseases. There is a lack of scientific researches on avocado pulp processing, both for pre-treatment to further extract and refine the oil and for minimum processing of ready-to-eat products. Therefore, the aim of this work was to investigate the air-drying of the Fortuna avocado fruit as a pre-treatment for oil extraction and refining, as well as the osmotic dehydration, aiming to obtain a minimum processed product. The water sorption data of fresh and blanched avocado pulp were determined at 30ºC, 50ºC and 70ºC. The BET, GAB, Halsey, Henderson, Peleg and Oswin mathematical models were fitted to the equilibrium moisture experimental data. All the tested models presented satisfactory fitting, but the GAB model, with three parameters, and the Peleg, with four, were the ones which best described the isotherms. According to the Brunauer classification, the isotherm desorption form of fresh and blanched avocado determined at 30ºC, 50ºC and 70ºC was of type III or are of the type II and III (slightly sigmoidal). The drying kinetics was determined for 50, 60 and 70ºC temperatures, according to the moisture content reduction in relation to the time. Fresh and blanched samples show similar results. The net isosteric heat and entropy of sorption were calculated for fresh and blanched avocado, based on sorption isotherm fit by GAB model. The net isosteric heat of sorption, estimated by applying Claussius-Clapeyron equation, increased with moisture content decrease. The effective diffusivity (Def) was obtained by the use of the Fick diffusion theory which describes drying in the decreasing rate period. The model was fitted... (Complete abstract click electronic access below)

Orientador: Maria Aparecida Mauro / Banca: Patricia de Carvalho Damy Benedetti / Banca: José Antônio Gomes Vieira / Resumo: O abacate (Persea americana Mill.) é uma fruta muito popular que destaca-se pela sua qualidade nutricional e composição em substâncias bioativas capazes de prevenir e controlar diversas doenças. Na literatura há ainda pouca informação reportada sobre processamento da polpa de abacate, seja para viabilizá-la para a extração e o refino do óleo, seja para seu consumo direto em diferentes formas de apresentação. O presente trabalho tem como objetivo investigar a secagem da polpa dos frutos de abacate da variedade Fortuna, como um pré-processamento para processos de extração e refino do óleo, assim como a desidratação osmótica dessa mesma polpa, como um processo mínimo para obtenção da fruta para consumo direto. A influência da temperatura e do branqueamento térmico sobre propriedades de sorção da polpa de abacate foi avaliada por meio das isotermas às temperaturas de 30ºC, 50ºC e 70ºC. Ensaios de secagem determinaram o efeito do branqueamento térmico e da temperatura sobre a cinética de secagem convectiva com ar aquecido a 50, 60 e 70°C. Ensaios de desidratação osmótica de fatias de abacate em solução de sacarose com adição de ácido cítrico foram conduzidos para determinação da cinética do processo e caracterização físico-química do produto. Os modelos matemáticos de BET, GAB, Halsey, Henderson, Peleg e Oswin foram ajustados aos dados experimentais de sorção de água obtidos para abacate fresco e branqueado. Todos os modelos testados apresentam ajustes satisfatórios, porém o modelo de GAB, com três parâmetros, e o de Peleg, com quatro, foram os que melhor descreveram as isotermas. Segundo a classificação de Brunauer, a forma das isotermas de dessorção do abacate fresco e branqueado determinadas a 30ºC, 50ºC e 70ºC, são do tipo III ou estão entre o tipo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The avocado (Persea americana Mill.) is a popular and it is very important fruit by its nutritional quality and composition in bioactive substances which are able to prevent and control several diseases. There is a lack of scientific researches on avocado pulp processing, both for pre-treatment to further extract and refine the oil and for minimum processing of ready-to-eat products. Therefore, the aim of this work was to investigate the air-drying of the Fortuna avocado fruit as a pre-treatment for oil extraction and refining, as well as the osmotic dehydration, aiming to obtain a minimum processed product. The water sorption data of fresh and blanched avocado pulp were determined at 30ºC, 50ºC and 70ºC. The BET, GAB, Halsey, Henderson, Peleg and Oswin mathematical models were fitted to the equilibrium moisture experimental data. All the tested models presented satisfactory fitting, but the GAB model, with three parameters, and the Peleg, with four, were the ones which best described the isotherms. According to the Brunauer classification, the isotherm desorption form of fresh and blanched avocado determined at 30ºC, 50ºC and 70ºC was of type III or are of the type II and III (slightly sigmoidal). The drying kinetics was determined for 50, 60 and 70ºC temperatures, according to the moisture content reduction in relation to the time. Fresh and blanched samples show similar results. The net isosteric heat and entropy of sorption were calculated for fresh and blanched avocado, based on sorption isotherm fit by GAB model. The net isosteric heat of sorption, estimated by applying Claussius-Clapeyron equation, increased with moisture content decrease. The effective diffusivity (Def) was obtained by the use of the Fick diffusion theory which describes drying in the decreasing rate period. The model was fitted... (Complete abstract click electronic access below) / Mestre