Dusting is one of the major problems in the operation of lime kilns because dust particles interfere with kiln operation and reduce its efficiency. A numerical model is developed to predict the rate of dust formation in rotary lime kilns. The model consists of four major components: 1) a 3D model for the kiln gas, solving fluid flow, heat transfer, and combustion in the gas region; 2) a 1D model for the kiln bed, solving for variation of the solids composition, including moisture content, along the kiln; 3) a 3D model to predict the motion of the solids in the bed, and to estimate the reaction rates; 4) a mathematical model to predict the rate of particle pickup from the bed. Additionally, motion of dust particles was modeled, for the first time, using Stochastic Separated Flow model (a Lagrangian approach). The developed model of particle tracking enables the user to predict distribution of dust particles in the gas section of the kiln. Different components of the model were validated using experimental data published in the literature. The developed model was used to simulate operation of a full-scale lime kiln at typical operating conditions, i.e. at different fuel and air flow-rates. Dusting signatures were also estimated for each setting to determine the effect each operating condition has on dusting. The results presented in this thesis indicate that dust formation is mainly affected by the kiln gas velocity. Effect of other operating conditions was found to be negligible within the ranges studied. The results presented here suggest that dust formation can be controlled by minimizing the input gas flow rate.

Dusting is one of the major problems in the operation of lime kilns because dust particles interfere with kiln operation and reduce its efficiency. A numerical model is developed to predict the rate of dust formation in rotary lime kilns. The model consists of four major components: 1) a 3D model for the kiln gas, solving fluid flow, heat transfer, and combustion in the gas region; 2) a 1D model for the kiln bed, solving for variation of the solids composition, including moisture content, along the kiln; 3) a 3D model to predict the motion of the solids in the bed, and to estimate the reaction rates; 4) a mathematical model to predict the rate of particle pickup from the bed. Additionally, motion of dust particles was modeled, for the first time, using Stochastic Separated Flow model (a Lagrangian approach). The developed model of particle tracking enables the user to predict distribution of dust particles in the gas section of the kiln. Different components of the model were validated using experimental data published in the literature. The developed model was used to simulate operation of a full-scale lime kiln at typical operating conditions, i.e. at different fuel and air flow-rates. Dusting signatures were also estimated for each setting to determine the effect each operating condition has on dusting. The results presented in this thesis indicate that dust formation is mainly affected by the kiln gas velocity. Effect of other operating conditions was found to be negligible within the ranges studied. The results presented here suggest that dust formation can be controlled by minimizing the input gas flow rate.

Gotland has a very long tradition of lime burning. Traces of lime burning on Gotland stretch back to the 12th century. An inventory of all the lime kilns in Gotland was made in 1942. Since then the market, the use and the tradition of lime burning have changed significantly. By the start of WW2 a shortage of black coal occurred. This meant that the large, traditional lime kilns could no longer be operated with the same capacity. The small, wood-burning kilns were the only furnaces that survived. With the cement's entry the demand for lime mortar got heavily reduced, which in turn meant the end for the last lime kilns. The cement quickly proved inadequate in many situations, especially in the field of monument care​​, and the demand for traditional lime mortar increased again already in the 1960s. Since then, three lime kilns were taken into use on Gotland; two smaller, traditional lime kilns and one large, industrial kiln. This thesis intends to follow up on the inventory that was made in 1942 in order to create a basis for further discussion of the historical values the lime kilns possesses and how these values can be cared for. In order to ensure the being of cultural heritage of the traditional lime industry, it requires popular demand, care and knowledge of the furnace, its use and production and its product. / Gotland har en mycket lång tradition av kalkbränning. Spår av kalkbränning sträcker sig på ön tillbaks till 1100-talet. En inventering av samtliga kalkugnar och kalkmilor på Gotland gjordes år 1942. Sedan dess har marknaden, användningen och traditionen av kalkbränning förändrats kraftigt. Vid andra världskrigets början uppstod en bristsituation på stenkol. Detta medförde att de stora, traditionella kalkugnarna inte längre kunde drivas med samma kapacitet. De mindre, vedeldade ugnarna var de enda ugnarna som överlevde. Med cementens intåg minskade även efterfrågan på kalkbruk, vilket i sin tur betydde slutet för de sista kalkugnarna. Cementen visade sig snabbt vara bristfällig i flera situationer, särskilt inom kulturvårdens praktik, och efterfrågan på traditionellt kalkbruk ökade igen redan på 1960-talet. Sedan dess har tre kalkugnar tagits i bruk på Gotland; två mindre, traditionella kalkugnar och en stor, industriell ugn. Uppsatsen ämnar följa upp inventeringen som gjordes 1942 för att skapa ett underlag för att vidare resonera kring de kulturhistoriska värden kalkugnarna besitter och hur dessa tas till vara. För att kunna vårda kulturarvet från den traditionella kalkindustrins dagar fordras efterfrågan på kalk, vård och kunskap om ugnarna, dess användning och produktion och dess produkt.

The pulp and paper industry has been struggling to meet the new and stringent TRS (Total Reduced Sulphur) emission compliance standards established in recent years. However, a new approach by some regulatory bodies gives intricate operational parameters a new and important role in achieving environmental compliance. TRS compounds that cause the distinctive pulp mill odour, originate from sodium sulphide in white liquor used in the kraft pulping process. Up to 20% of TRS emissions could originate from the lime kiln and lime mud solids content is one of the operational parameters that could help reduce the TRS emissions from the lime kiln. Residual sodium sulphide in the lime mud that results in TRS gases, is dissolved in the moisture content of the mud. Although efficient lime mud washing can remove most of the residual sodium sulphide, the remaining moisture content of the mud still contains some sodium sulphide. Therefore, improved lime mud dewatering can be effective in reducing the TRS emissions from the lime kiln. Data presented in this study confirms that as the lime mud solids content increases, TRS emissions from the lime kiln decrease. Data analysis demonstrates a negative linear correlation at 5% significance level between TRS emissions and lime mud solids.

The pulp and paper industry has been struggling to meet the new and stringent TRS (Total Reduced Sulphur) emission compliance standards established in recent years. However, a new approach by some regulatory bodies gives intricate operational parameters a new and important role in achieving environmental compliance. TRS compounds that cause the distinctive pulp mill odour, originate from sodium sulphide in white liquor used in the kraft pulping process. Up to 20% of TRS emissions could originate from the lime kiln and lime mud solids content is one of the operational parameters that could help reduce the TRS emissions from the lime kiln. Residual sodium sulphide in the lime mud that results in TRS gases, is dissolved in the moisture content of the mud. Although efficient lime mud washing can remove most of the residual sodium sulphide, the remaining moisture content of the mud still contains some sodium sulphide. Therefore, improved lime mud dewatering can be effective in reducing the TRS emissions from the lime kiln. Data presented in this study confirms that as the lime mud solids content increases, TRS emissions from the lime kiln decrease. Data analysis demonstrates a negative linear correlation at 5% significance level between TRS emissions and lime mud solids.

This thesis investigates the application of latent variable methods to three combustion processes. Multivariate analysis of flame images and process data is performed to predict important quality parameters and monitor flame stability. The motivation behind this work is to decrease operational costs and greenhouse gases in these energy intensive processes. The three combustion processes studied are a lime kiln, a basic oxygen furnace and a coal-fired boiler. In lime kiln operation, the main goal is to stabilize final product temperature in order to reduce fouling and energy costs. Due to long process dynamics, prediction of product temperature is required at least one hour in advance for potential use in a control scheme. Several methods for extracting features from flame images were investigated for the prediction of the temperature. The best method is then combined with process data in a PLS model that also incorporates dynamic information. The analysis revealed that prediction one hour into the future is successful using latent variable methods. In the basic oxygen furnace analysis, the main goal is to predict end-point carbon of the batch process. Termination of the batch as soon as the desired carbon is attained reduces oxygen consumption and thus operational cost. Traditional image analysis is used to identify a constant field of view in the flame images. Multivariate image feature extraction methods were then used in combination with process data to successfully predict the final carbon content of the heat. The coal-fired boiler analysis focuses on monitoring of flame stability at different production and air to fuel levels of the boiler. Prediction of energy efficiency and off-gas chemistry from flame images is also investigated. An unexpected result was the ability to use the installed cameras for localized fouling monitoring. This thesis showed that the use of multivariate analysis of flame images and process data in combustion process is very promising. / Thesis / Master of Applied Science (MASc)

Waste generation is a constant activity of daily life, encompassing a wide variety including municipal, hazardous, industrial, agricultural, medical, radioactive, and mining waste, as well as sewage sludge. The purpose of this study is to concentrate on utilizing industrial waste, which adversely affects our environment, for use in engineering construction projects. This aims to evaluate the enhancement in both the soil’s index and engineering properties. In most civil engineering projects, the underlying soils are often unsuitable for construction purposes. Some of these soils experience significant volume changes due to moisture variations, leading to damage and instability of structures and infrastructure built on them. The complete removal and replacement of such high plastic clay and expansive soils is not always a cost-effective solution. Therefore, there's a pressing need to improve their utility by stabilizing them through eco-friendly and sustainable methods.The present research employs five industrial waste materials to enhance the clayey soil available in Carbondale, Illinois. These waste materials include Lime Sludge (LS), Lime Kiln Dust (LKD), Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBS), and Cement Kiln Dust (CKD). Lime Sludge and Lime Kiln Dust were mixed with the soil at proportions of 2%, 4%, 6%, and 8%. In contrast, Fly Ash and Cement Kiln Dust were used at higher ratios of 8%, 16%, 24%, and 32%. Lastly, Ground Granulated Blast Furnace Slag was added at levels of 5%, 10%, 15%, and 20%, all based on the soil's dry unit weight. The samples were prepared for Unconfined Compression Strength (UCS) and Resilient Modulus (RM) based on the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) data obtained from miniature Proctor test. These specimens underwent a 14-day curing period, sealed in plastic film and Ziploc bags, and were stored in a controlled water tub at room temperature. The UCS value for the untreated Carbondale soil was 320 kN/m2. The results indicated that with higher content of Lime Kiln Dust (LKD) and Cement Kiln Dust (CKD), the UCS strength tends to increase with CKD exhibiting the most desirable strength characteristics. The UCS value for 8% LKD was 1377.70 kN/m2 i.e., 330.52% increase. While the UCS improvements for 5% GGBS is 51.32% and 6% Lime Sludge (LS) is 51.65% with no significant enhancements, these waste materials can be more effective as modifiers. Furthermore, the study revealed that the optimal quantity of Class F fly ash for soil stabilization is 8% by dry unit weight with UCS value of 486.46 kN/m2 resulting in 52.01% increase in UCS strength, exceeding this percentage might cause reduction in strength. The highest UCS strength was obtained with 24% CKD at 3263.14 kN/m2 which corresponds to 919.70% increase when compared to the untreated soil. The results of the Resilient Modulus (RM or Mr) test indicate that the incorporation of additives to untreated Carbondale soil significantly improved its stiffness characteristics and resistance to different load cycles on the subgrade. However, the soil treated with GGBS showed a decrease in stiffness. The Resilient Modulus values ranged from 2% to 70% for LS, 47% to 128% for LKD, 4% to 35% for FA, 90% to 243% for CKD, and -16% to 0.3% for GGBS for different confining pressures. The regression analysis, using the Uzan (1985) model, showed R² values of 0.910, 0.838, 0.803, 0.871, 0.773, and 0.809 for Carbondale soil, Carbondale soil mixed with 6% LS, 8% LKD, 8% FA, 5% GGBS, and 24% CKD, respectively. These results confirm the reliability of the test, as all samples except the GGBS-treated one have R² values greater than 0.800. Additionally, consolidation tests were conducted to assess the compressibility characteristics of the additives in the soil. The selected samples were those with the mix proportions that yielded the highest UCS strength for each additive. These samples were meticulously prepared based on the moisture-density relationship obtained from the miniature Proctor test and were subjected to loading and unloading in a specific sequence. The results indicated an increase in the Compression Index (Cc) for mixtures with LS, LKD, FA, and CKD. Conversely, the mix containing GGBS displayed a reduction in the Compression Index (Cc). The Carbondale soil stabilized with 6% LS can be used for subbase stabilization as the UCS strength is greater than 345 kPa. Also, 2 to 8% LKD content can be used for subbase and base course stabilization. 8% FA without any activator can be used for subbase stabilizer. GGBS can be used for subbase soil stabilization and finally CKD can be used for both subbase and base course stabilization.

BillerudKorsnäs AB (BK) i Gävle är ett av de världsledande företagen inom tillverkning av vätskekartong. För att fortsatt vara ett ledande företag arbetar de dagligen med förbättringsförslag för att utveckla och öka fabrikens säkerhet och tillgänglighet. Detta examensarbete innehåller ett av många förbättringsförslag på avdelningen, Lut och Kraft. BillerudKorsnäs AB har en tydlig önskan om att åtgärda ett känt problem som kan leda till förödande ekonomiska konsekvenser.  Examensarbetet har bestått av att införa en automatisk nedkylningssekvens av mesaugnen, med fokusområde på säkerhet och programmering. Säkerhet är ett brett område och arbetsuppgifterna har avgränsats till automationsnära uppgifter för att hålla sig inom tidsramen på tio veckor. För att hålla samma kontinuitet och standard hos BK har programmeringen utgått från att använda nuvarande programmeringsspråk funktionsblocks diagram i styrsystemet AC450 från ABB.  Metoden som har använts i arbetet är aktionsforskning som innehöll planering, riskanalys och dokumentation för att minimera och eliminera tänkbara risker, relaterade till personsäkerhet och maskinutrustning.  Målsättningen med examensarbetet var att ha en fungerade, säker och pålitlig nedkylningssekvens. För att optimera processen, avlasta processoperatören och förbättra arbetsmiljön i kontrollrummet genom att automatisera ett arbetsmoment. Simuleringen har påvisat att nedkylningssekvensens funktion uppfyller BK önskan. På grund av fabriksstopp under examensarbetets tidsram har idrifttagning blivit försenat och provkörningen har flyttats fram. / BillerudKorsnäs AB (BK) in Gävle is one of the world-leading companies in the manufacture of liquid board. To continue to be a leading company, they work daily with improvement proposals to develop and increase the factory's safety and availability. This thesis contains one of many improvement proposals in the department, Lut och Kraft. BillerudKorsnäs AB has a clear desire to remedy a known problem that can lead to devastating financial consequences.  The degree project has consisted of introducing an automatic cooling sequence of the lime kiln, with a focus area on safety and programming. Security is a broad area and the tasks have been limited to automation-related tasks to stay within the time frame of ten weeks. To maintain the same continuity and standard at BK, the programming has been based on using the current programming script function block diagram in the control system AC450 from ABB.  The method that has been used in the work is action research that included planning, risk analysis and documentation to minimize and eliminate possible risks, related to personal safety and machine equipment.  The goal of the degree project was to have a functional, safe, and reliable cooling sequence. To optimize the process, relieve the process operator and improve the working environment in the control room by automating a work step. The simulation has shown that the function of the cooling sequence fulfills the BK desire. Due to a factory shutdown during the degree project's time frame, commissioning has been delayed and the test drive has been moved forward.

La chaufournerie constitue un secteur de production artisanale situé à l’interface entre le bâtiment et les arts du feu. Moyennant une approche pluridisciplinaire, un portrait de cet artisanat méconnu a été dressé. Au cours du second Moyen Âge, les techniques de fabrication de la chaux utilisées dans les régions de l’arc nord-occidental de la Méditerranée sont très diversifiées. Le milieu naturel influe beaucoup sur les techniques mises en œuvre, mais aussi sur les formes d’organisation de cet artisanat. En amont de la cuisson de la chaux, les chaufourniers mettent en œuvre des processus techniques complexes, destinés à récolter et à transformer les matériaux en vue de leur utilisation dans les fours. Ainsi, les pierres à chaux doivent être extraites, concassées puis chargées. En parallèle, le combustible est récolté puis préparé. Ce sont plusieurs chaînes opératoires qui sont mobilisées pour fabriquer la chaux. Cette multiplicité n’est pas seulement technique, et trouve une traduction sociale. En effet, si la conduite de la cuisson est nécessairement l’affaire d’artisans spécialistes, les autres étapes du processus technique peuvent être confiées à d’autres catégories d’ouvriers, qui, parfois, se chargent seulement d’une séquence de ce processus. Le savoir-faire des artisans apparaît comme le fruit de contraintes matérielles et techniques, mais aussi sociales. La chaufournerie occupe une place particulière dans la société et l’économie de la fin du Moyen Âge. Malgré le caractère essentiel de la production de chaux pour alimenter certains secteurs d’activité, les chaufourniers, très minoritaires, n’occupent qu’une place secondaire dans la société. / Lime burning is a section of handmade production interfacing with construction and uses of fire. With pluridisciplinary approach, a statement of this unwell known craft was exposed. During the second Middle Age, making lime technics used in the Mediterranean north-occidental areas are plural. Natural environment makes a great influence on the used technics and also on the ways to organize this craft. Before cooking the lime, lime burners are using intricated technic process in collecting and transforming materials for kilns use. The limestone must be extracted, crushed then charged up. Several “chaînes opératoires” are involved in making the lime. This multiplicity is not only a technic one but a social translation also. If the cooking section is indeed leaded by professionals handworkers, other technic sections can be consigned by other kind of workers even sometimes for just only one section. The handworkers expertise appears to be resulting material and technic restraints, but also social ones. Lime burning hold a special position in both society and economy in the end of the Middle Age. Despite the essential use of lime production in some particular industry, lime burners – not numerous - are only holding a secondary position in the medieval society

Made available in DSpace on 2015-03-26T14:01:16Z (GMT). No. of bitstreams: 1 texto completo.pdf: 793841 bytes, checksum: ee6c687009a5748f89407dde55951878 (MD5) Previous issue date: 2013-09-23 / The Six Sigma has been an important management tool used in several production and services sectors in order to increase processes efficiency and provide higher profit to the corporations. This work presents a successful case of the use of this methodology in a kraft pulp mill in order to reduce the fuel oil demand in a lime kiln. The project had a goal to reduce in 6% the oil consumption in the lime kiln, i.e., reduce from an average of 167 to 157 kg/t CaO. Implementing DMAIC tool (D-define, M-measure, A-analyzing, I-improve, C-control) was possible to achieve the project goal and this achievement represented an annual financial return equivalent to approximately U$ 1,4 million. / Na busca de um aumento de eficiência, do desempenho e uma maior lucratividade das empresas, a ferramenta Seis Sigma encontra-se bastante difundida e utilizada em diversos setores de produção e serviços. Baseado em resultados encontrados, e ciente dos inúmeros benefícios que a implantação dessa ferramenta oferece, este trabalho vem demonstrar uma experiência de aplicação da metodologia Seis Sigma para a redução do consumo de óleo combustível em um forno de cal de uma empresa de polpa celulósica kraft. O projeto teve como meta reduzir em 6% o consumo de óleo, passando de uma média de consumo de 167 para 157 kg/t de CaO. Com a implantação das etapas referentes à ferramenta (D-definir; M-medir; A- analisar; I-implementar; C-controlar) foi possível alcançar a meta do projeto. O alcance da meta gerou um retorno financeiro anual equivalente a R$ 3.24 milhões.