Atualmente as indústrias alimentícias brasileiras estão trabalhando para a conservação de energia, principalmente no setor industrial, com o uso de tecnologias mais eficientes voltadas para esta necessidade. Nesse sentido, a reestruturação tecnológica traz o desenvolvimento de novos produtos, reduzindo os gastos com energia e os impactos ambientais associados ao interesse dos consumidores na garantia e qualidade dos alimentos. No que se referem a alimentos assados, muitas indústrias usam forno tipo túnel. Sendo assim, entender o comportamento térmico de tais fornos é crucial para os programas que visam aperfeiçoar o controle dos gastos com energia, tanto quanto avaliar os impactos ambientais associados ao consumo dela e assim garantir a competitividade, cujo principal requisito é a produção de alimentos com qualidade de maneira sustentável. Dentro deste contexto, este trabalho teve como objetivo monitorar o perfil de temperatura em um forno tipo túnel de uma mini linha experimental de produção de biscoitos em tempo real, utilizando sensores de temperatura acoplados a um sistema de comunicação sem fio. A metodologia desenvolvida usa um sistema de aquisição de dados, no qual seis sensores termopar tipo K foram distribuídos em três zonas de aquecimento do forno. Estes termopares foram conectados a um dispositivo eletrônico denominado AD595 que fez o condicionamento do sinal e a saída do mesmo, a qual estava conectada a um sistema de transmissão que usa o protocolo Zigbee. Este protocolo Zigbee foi controlado por um software na linguagem Visual Basic versão 6.0. Os resultados obtidos mostraram que tal metodologia permitiu monitorar as temperaturas em tempo real das seis diferentes zonas de aquecimento do forno, permitindo assim obter o perfil ideal para cozimento. / Currently Brazilian food industries are working to conserve energy, especially in the industrial sector with the use of more efficient technologies for this need. In this sense, the technological restructuring brings the development of new products, reducing energy costs and environmental impacts associated with consumer interest in quality assurance and food. As they relate to baked goods, many industries use tunnel kiln type. Therefore, to understand the thermal behavior of such furnaces is crucial for programs aimed at improving the control of energy expenditure as much as evaluating the associated environmental impacts her consumption and thus ensure competitiveness whose main requirement is the production of quality food sustainably. Within this context, this study aimed to monitor the temperature profile in an oven of an experimental mini biscuit production line in real time, using temperature sensors coupled to a wireless communication system type tunnel. The methodology developed uses a data acquisition system, in which six K-type thermocouple sensors were divided into three heating zones of the furnace. These thermocouples were connected to an electronic device called AD595 which made the signal conditioning and output the same, which was connected to a transmission system that uses the Zigbee protocol. This Zigbee protocol was controlled by software in visual basic language version 6.0. The results obtained showed that this methodology allowed monitor the temperatures in real time the six different heating zones of the furnace, thus allowing optimal for cooking profile.

This master's thesis is aimed at development and realisation of a thermoregulation control unit with applications at school and in practice. The work briefly introduces the reader into the principles of electronic temperature measuring in practice and peripheral interconnection of Arduino platform using different types of serial communication. The main part of the thesis is the creation of the control unit itself and its subsequent application for school and laboratory purposes. The work contains several example laboratory tasks, which can fully utilise the potential of the constructed device.

L'évolution vers le monde des nanotechnologies croît actuellement très rapidement. Ces technologies sont présentes dans de nombreux secteurs d'activités allant de l'automobile à la recherche, mais sont encore bien méconnues dans leurs aspects fondamentaux du domaine industriel et scientifique. Nombreux sont les process industriels faisant appel à la température : chauffage, cuisson, traitement thermique, fusion, etc. Les procédés mis en œuvre pour la contrôler et la réguler forment un ensemble complet, la chaîne de mesure thermique. En première ligne, au cœur du process, le capteur constitue l'élément sensible de cette chaîne. Depuis un demi siècle, les techniques de microscopies évoluent pour caractériser la matière et comprendre les phénomènes locaux. Afin de mieux maîtriser cette compréhension les microscopies thermiques ont vu le jour pour déterminer également à l'échelle locale la température afin de connaître le niveau d'énergie. La sonde utilisée est également au cœur du problème. La conception jusqu'au développement de cette nouvelle sonde s'appuie sur des technologies hybrides basées sur des techniques de dépôts en salles blanches ainsi que sur des techniques classiques d'élaboration de thermocouples. La sonde réalisée, certes intrusive, permet d'allier la mesure de températures aux contacts de matériaux et d'offrir la possibilité d'être une sonde active. Elle pourra notamment compléter les sondes actuellement proposées en microscopie de champ proche.

<p>The demand for more accurate measurements is increasing in today’s industry. One reason for this is to optimize production and thus maximize profits. Another reason is that in some cases government regulations dictate that supervision of certain parameters must be followed. At Preemraff Lysekil there are basically four reasons for measuring skin temperatures inside fired process heaters, namely; because of government regulations, in order to estimate the load of the fired process heater, to estimate the lifetime of the tubes inside the fired process heater and finally, to determine the need of decoking. However, only the first three of these reasons are applied to H2301/2/3. The current skin thermocouple design has been in use for many years and now the question of how well it measures surface temperature has risen. Furthermore a new weld-free design is under consideration to replace the old skin thermocouple design. Another question is therefore how well the new design can measure the surface temperature under the same operating conditions as the old one. In order to evaluate this, three–dimensional computer simulations were made of the different designs. As this thesis will show, the differences in calculated skin thermocouple temperature and calculated surface temperature is about the same for the two designs. However, the current design will show a lower temperature than the surface temperature, while the new design will show a higher temperature. Regarding the core of the skin thermocouple designs, namely the thermocouple, no hard conclusions can be drawn, although the industry appears to favor type ’N’ over type ’K’.</p>

The demand for more accurate measurements is increasing in today’s industry. One reason for this is to optimize production and thus maximize profits. Another reason is that in some cases government regulations dictate that supervision of certain parameters must be followed. At Preemraff Lysekil there are basically four reasons for measuring skin temperatures inside fired process heaters, namely; because of government regulations, in order to estimate the load of the fired process heater, to estimate the lifetime of the tubes inside the fired process heater and finally, to determine the need of decoking. However, only the first three of these reasons are applied to H2301/2/3. The current skin thermocouple design has been in use for many years and now the question of how well it measures surface temperature has risen. Furthermore a new weld-free design is under consideration to replace the old skin thermocouple design. Another question is therefore how well the new design can measure the surface temperature under the same operating conditions as the old one. In order to evaluate this, three–dimensional computer simulations were made of the different designs. As this thesis will show, the differences in calculated skin thermocouple temperature and calculated surface temperature is about the same for the two designs. However, the current design will show a lower temperature than the surface temperature, while the new design will show a higher temperature. Regarding the core of the skin thermocouple designs, namely the thermocouple, no hard conclusions can be drawn, although the industry appears to favor type ’N’ over type ’K’.

The first study researched turbulent forced convective heat (mass) transfer down- stream of blockages with round and elongated holes in a rectangular channel. The blockages and the channel had the same cross section, and a distance equal to twice the channel height separated consecutive blockages. Naphthalene sublimation experiments were conducted with four hole aspect ratios (hole-width-to-height ratios) and two hole-to-blockage area ratios (ratios of total hole cross-sectional area to blockage area). The effects of the hole aspect ratio, for each hole-to-blockage area ratio, on the local heat (mass) transfer distribution on the exposed primary channel wall between consecutive blockages were examined. Results showed that the blockages with holes enhanced the average heat (mass) transfer by up to 8.5 and 7.0 times that for fully developed turbulent flow through a smooth channel at the same mass flow rate, respectively, in the smaller and larger hole-to-blockage area ratio (or smaller and larger hole diameter) cases. The elongated holes caused a higher average heat (mass) transfer and a larger spanwise variation of the local heat (mass) transfer on the channel wall than did the round holes. The second study explored the heat transfer enhancement for pool boiling on nano-structured surfaces. Experiments were conducted with three horizontal silicon surfaces, two of which were coated with vertically aligned multi-walled carbon nanotubes (MWCNT) with heights of 9 and 25 ¹m, respectively, and diameters between 8 and 15 nm. The MWCNT arrays were synthesized on the two silicon wafers using chemical vapor deposition. Experimental results were obtained over the nucleate boiling and film boiling regimes under saturated and sub-cooled (5±C and 10±C) boiling conditions. PF-5060 was the test fluid. Results showed that the MWCNT array with a height of 25 ¹m enhanced the nucleate and film boiling heat fluxes on the silicon surface by up to 380% and 60%, respectively, under saturated boiling conditions, and by up to 300% and 80%, respectively, under 10±C sub-cooled boiling conditions, over corresponding heat fluxes on a smooth silicon surface. The MWCNT array with a height of 9 ¹m enhanced the nucleate boiling heat flux as much as the taller array, but did not significantly enhance the wall heat flux in the film boiling regime.

Many environmental cues are thought to influence nest site selection by loggerhead sea turtles, Caretta caretta, and much debate exists over the possible influence of sand temperature. This study had two primary objectives: (1) to measure thermal differences across transects of a major nesting beach of Casey Key (28.7 N, 82.3 W), Florida and (2) to evaluate thermal pattern variation that influenced nesting patterns of adult female loggerhead sea turtles. A secondary objective of this study was to determine the efficacy of infrared thermometers to collect sand surface temperatures in the field. Temperature data were collected from 145 nest events and 8 false crawls in the 2008 and 2009 nesting seasons. Infrared thermometers and thermocouple probes were used to obtain surface temperatures from the water, waterline, beach sand, body pit attempts, nest chamber attempts, eggs, and the surface of the gular skin of the nesting female, within the crawl track created by the female and at one meter adjacent to the crawl track (from undisturbed sand). Weather influences at the time of nesting were recorded, including the presence or absence of rain, wind, or clouds. Beach slope was measured using an angle locator. Temperature data from the infrared thermometer and the thermocouple probe were highly correlated, indicating that an infrared thermometer is an effective measurement tool on a nesting beach. In 2008, there was a significant difference between temperatures collected within the crawl tracks of false crawl events and nest events, indicating a potential for females to use thermal cues in choosing whether to false crawl or nest. In both nesting seasons, the sand temperature in the body pit and the surface of the gular skin of the nesting female were nearly identical, suggesting females may locate a suitable nest site using their skin temperature. Data collected at other loggerhead rookeries in the United States and Australia yielded similar results, however, variability in the use of temperature may arise seasonally, and according to different nesting environments. Rain, wind and cloud cover significantly thermally altered several locations on Casey Key, but it remains unclear if these weather events significant affect turtle nesting behavior. Additionally, crawl distance and beach slope were significantly, positively correlated. Gravid females most likely use multiple environmental cues to select a nest site. Assimilating information from multiple sources allows for the highest degree of adaptability, and future studies should consider implications for climate change and beach renourishment projects.

[pt] Em 1990, com a adoção da Escala Internacional de Temperatura de 1990, o termopar de platina e platina/ródio deixou de ser o instrumento de interpolação entre 630 graus Celsius e 1064 graus Celsius, em virtude de sua pouca estabilidade, sendo a partir daí utilizados o termômetro de resistência de platina de alta temperatura (TRPAT) e o termômetro de radiação. Este estudo realiza uma investigação prática das características de um termopar de ouro e platina, ambos com pureza superior a 99,999 por cento, no que diz respeito à sua estabilidade termoelétrica e à homogeneidade de seus termoelementos, questionando a possibilidade de seu uso como alternativa ao emprego do TRPAT em processos de medição que exijam grande exatidão com custo mais baixo. Neste trabalho, o termopar estudado foi submetido a temperaturas próximas ao seu limite máximo de operação, que é de 1000 graus Celsius, por mais de 1500 horas, sendo avaliadas a sua estabilidade e a sua homogeneidade em função do tempo de uso, com o auxílio de uma célula de ponto fixo da prata do Inmetro, que é um padrão primário de temperatura. / [en] In 1990, with the adoption of the International Temperature Scale of 1990, the platinum/platinum-rhodium thermocouple was removed as the interpolation instrument between 630 graus Celsius and 1064 Celsius degrees, due its low stability, in favor of the high temperature standard platinum resistance thermometer (HTSPRT) and the radiation thermometer. In this work, it is performed a practical investigation of the characteristics of a 99,999 percent purity gold-platinum thermocouple, concerning its thermoelectric stability and homogeneity of its thermoelements, questioning the possibility of its use as an alternative to the HTSPRT in measurement processes requiring high accuracy with lower costs. In this work, the test thermocouple was exposed to temperatures close to its upper limit (1000 Celsius degrees) for more than 1500 hours, being its stability and homogeneity evaluated as function of time, with aid of a silver fixed point cell from Inmetro, that is a temperature primary standard.

Polymer extrusion is an energy intensive process whereby the simultaneous action of viscous shear and thermal conduction are used to convert solid polymer to a melt which can be formed into a shape. To optimise efficiency, a homogeneous melt is required with minimum consumption of process energy. In this work, in-process monitoring techniques have been used to characterise the thermal dynamics of the single screw extrusion process with real-time quantification of energy consumption. Thermocouple grid sensors were used to measure radial melt temperatures across the melt flow at the entrance to the extruder die. Moreover, an infrared sensor flush mounted at the end of the extruder barrel was used to measure non-invasive melt temperature profiles across the width of the screw channel in the metering section of the extruder screw. Both techniques were found to provide useful information concerning the thermal dynamics of the extrusion process; in particular this application of infrared thermometry could prove useful for industrial extrusion process monitoring applications. Extruder screw geometry and extrusion variables should ideally be tailored to suit the properties of individual polymers but in practise this is rarely achieved due the lack of understanding. Here, LDPE, LLDPE, three grades of HDPE, PS, PP and PET were extruded using three geometries of extruder screws at several set temperatures and screw rotation speeds. Extrusion data showed that polymer rheology had a significant effect on the thermal efficiency on the extrusion process. In particular, melt viscosity was found to have a significant effect on specific energy consumption and thermal homogeneity of the melt. Extruder screw geometry, set extrusion temperature and screw rotation speed were also found to have a direct effect on energy consumption and melt consistency. Single flighted extruder screws exhibited poorer temperature homogeneity and larger fluctuations than a barrier flighted screw with a spiral mixer. These results highlighted the importance of careful selection of processing conditions and extruder screw geometry on melt homogeneity and process efficiency. Extruder scale was found to have a significant influence on thermal characteristics due to changes in surface area of the screw, barrel and heaters which consequently affect the effectiveness of the melting process and extrusion process energy demand. In this thesis, the thermal and energy characteristics of two single screw extruders were compared to examine the effect of extruder scale and processing conditions on measured melt temperature and energy consumption. Extrusion thermal dynamics were shown to be highly dependent upon extruder scale whilst specific energy consumption compared more favourably, enabling prediction of a process window from lab to industrial scale within which energy efficiency can be optimised. Overall, this detailed experimental study has helped to improve understanding of the single screw extrusion process, in terms of thermal stability and energy consumption. It is hoped that the findings will allow those working in this field to make more informed decisions regarding set conditions, screw geometry and extruder scale, in order to improve the efficiency of the extrusion process.

Atualmente as indústrias alimentícias brasileiras estão trabalhando para a conservação de energia, principalmente no setor industrial, com o uso de tecnologias mais eficientes voltadas para esta necessidade. Nesse sentido, a reestruturação tecnológica traz o desenvolvimento de novos produtos, reduzindo os gastos com energia e os impactos ambientais associados ao interesse dos consumidores na garantia e qualidade dos alimentos. No que se referem a alimentos assados, muitas indústrias usam forno tipo túnel. Sendo assim, entender o comportamento térmico de tais fornos é crucial para os programas que visam aperfeiçoar o controle dos gastos com energia, tanto quanto avaliar os impactos ambientais associados ao consumo dela e assim garantir a competitividade, cujo principal requisito é a produção de alimentos com qualidade de maneira sustentável. Dentro deste contexto, este trabalho teve como objetivo monitorar o perfil de temperatura em um forno tipo túnel de uma mini linha experimental de produção de biscoitos em tempo real, utilizando sensores de temperatura acoplados a um sistema de comunicação sem fio. A metodologia desenvolvida usa um sistema de aquisição de dados, no qual seis sensores termopar tipo K foram distribuídos em três zonas de aquecimento do forno. Estes termopares foram conectados a um dispositivo eletrônico denominado AD595 que fez o condicionamento do sinal e a saída do mesmo, a qual estava conectada a um sistema de transmissão que usa o protocolo Zigbee. Este protocolo Zigbee foi controlado por um software na linguagem Visual Basic versão 6.0. Os resultados obtidos mostraram que tal metodologia permitiu monitorar as temperaturas em tempo real das seis diferentes zonas de aquecimento do forno, permitindo assim obter o perfil ideal para cozimento. / Currently Brazilian food industries are working to conserve energy, especially in the industrial sector with the use of more efficient technologies for this need. In this sense, the technological restructuring brings the development of new products, reducing energy costs and environmental impacts associated with consumer interest in quality assurance and food. As they relate to baked goods, many industries use tunnel kiln type. Therefore, to understand the thermal behavior of such furnaces is crucial for programs aimed at improving the control of energy expenditure as much as evaluating the associated environmental impacts her consumption and thus ensure competitiveness whose main requirement is the production of quality food sustainably. Within this context, this study aimed to monitor the temperature profile in an oven of an experimental mini biscuit production line in real time, using temperature sensors coupled to a wireless communication system type tunnel. The methodology developed uses a data acquisition system, in which six K-type thermocouple sensors were divided into three heating zones of the furnace. These thermocouples were connected to an electronic device called AD595 which made the signal conditioning and output the same, which was connected to a transmission system that uses the Zigbee protocol. This Zigbee protocol was controlled by software in visual basic language version 6.0. The results obtained showed that this methodology allowed monitor the temperatures in real time the six different heating zones of the furnace, thus allowing optimal for cooking profile.