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This PhD thesis investigated solid and liquid waste treatment systems for Sureclean, a waste Management company based in the North of Scotland. Sureclean receives a diverse range of waste streams and the increasing need for sustainable development as well as stringent environmental legislation motivated this research to develop an integrated waste treatment system. Waste characterisation was conducted using a range of analytical instrumentation to identify the TPH, COD, heavy metals content, TOC, and particle size of Sureclean waste streams. From there, four treatment systems were investigated utilising Sureclean waste streams: mechanical separation, chemical treatment, electro-coagulation and the advanced oxidation process. Laboratory and field trials were conducted using these different treatment techniques and the analysis was performed to verify the treatment results. The result of these trials led to the development of four modular waste treatment units, that form the outcome of this research: the Sureclean Water Treatment System (SWTS), a filtration based mechanical separation system was shown to reduce the TSS, BOD and TOC content of an oily wastewater; the Sureclean Sludge Separation System (SSSTS), a chemical-enhanced filtration based system was demonstrated to reduce 52.6 % of the sewage sludge volume; the Sureclean Electro-coagulation Water Treatment System (SEWTS), a system that agglomerates colloid particles and demulsifies oil removed 99.9 % of TPH from Sureclean interceptor effluent; and the Sureclean Advanced Water Treatment System (SAWTS), an advanced oxidation process which was demonstrated to reduce the TPH of a contaminated groundwater collected from an ex-gas work. The treated effluent could be discharged to Sureclean interceptor. The four treatment units developed in this research expanded Sureclean waste treatment capabilities and an integrated system was developed to treat different waste streams and to improve the treatment efficiency thus increasing the revenue and future waste stream options for Sureclean.

Seismic events around the globe directly affect all ranges of structures, from complex and expensive ‘skyscrapers’ to simple frame structures, the latter making up a higher proportion of the number of structures affected as they are a much more common type of structure. The impact of a seismic event can be devastating, especially if adequate predictions of their impact and imposed structural response are not made during the design stage of the structure. Knowing what response to expect allows the engineer to design the structure to survive an event and protect the occupants. The structural response to a seismic event is very complex and can be affected by a wide range of structural, geotechnical and environ parameters. While larger, expensive structures make use of expensive, time consuming, finite element analytical procedures to determine their response the cheaper, simpler, frame structures have to make do with existing, simplified, spectral method predictions. This research firstly involves finite element analysis of simple frame structures, considering different structural and geotechnical parameters which may influence the seismic response, namely the stiffness of the structural joints, the geometry of the structure (influencing the individual structural element flexibility) and the foundation conditions (fixed base or shallow foundations with soil structure interaction). A range of frames, of varying geometry, are considered which mobilise different amounts of inter-storey drift, local rotation and global rotation response. The influence of soil structure interaction (SSI) and frame rigidity (i.e. the properties of the joints) on the response behaviour is investigated. The finite element database is then used to validate improved methods for predicting the spectral response parameters, specifically the natural period and damping of equivalent single degree of freedom (SDOF) systems, which include the effects of frame rigidity, geometry and SSI. Dynamic centrifuge testing is also carried out in order to further validate the improved spectral model for the case of real soil with shear dependant stiffness. The physical model testing is also extended to consider how environs, such as other structures in close proximity, influence the response of a structure.

Le compresseur d'air alimentant en oxygène la pile est un élément important dans les systèmes pile à combustible. Le compresseur peut consommer jusqu'à 20% de l'électricité produite dans les cas les plus défavorables. Le choix et le dimensionnement du compresseur, ainsi que son système de contrôle associé, sont directement liés à la performance du système global. La taille et le poids du système de compression d'air doivent être réduits pour le rendre plus adapté aux applications automobiles. En outre, le contrôle du système de compression d'air est également une problématique importante car il affecte l'efficacité et la sécurité de fonctionnement de la pile à combustible. Pour éviter une sous-alimentation en oxygène de la pile, le débit massique d’air fourni doit être géré de façon appropriée en fonction de la demande de la charge électrique. Pendant ce temps, la pression ne doit pas montrer de trop grandes variations ou ondulations qui peuvent endommager la membrane de la pile.Un contrôle à découplage proposé récemment dans la littérature, nommé contrôle à découplage de perturbation (DDC), est utilisé pour le système de compression centrifuge. Le DDC traite les interactions internes comme une perturbation, puis les éliminent dans le contrôle. Les performances du DDC sont comparées à un dispositif de commande en mode glissant décentralisé. Grâce à la comparaison de ces deux contrôleurs, les résultats montrent que le DDC proposé est performant tant pour des cas stables que dynamiques. Le compresseur centrifuge est donc utilisable pour les systèmes pile à combustible automobiles. Sur un banc d'essai hardware-in-the-loop (HIL), le contrôleur proposé est validé avec un modèle de pile à combustible de 10 kW avec des demandes de charge variables. En outre, une méthode d'évitement d’instabilité, à savoir un limiteur de référence, est proposé pour empêcher le dépassement de la ligne de pompage du compresseur. Les résultats expérimentaux montrent que, dans tous les cas, la zone d’utilisation du compresseur est bien cantonnée à droite de la ligne de pompage. / Air compressor supplying the oxygen to the stack is an important component in the fuel cell systems. The compressor can consumes up to 20 % of the generated power in the most severe cases. The selecting of the compressor and corresponding control are directly related to the performance of the fuel cell. The size and weight of the air compressor has to be reduced to make them more feasible for automotive applications. Moreover, the control of the air compression system is also an important issue, which affects the efficiency and the safety of the fuel cell. To avoid oxygen starvation of the stack, the mass flow of the supplied air has to be controlled appropriately according to the load demand. Meanwhile, the pressure should not have large deviations or ripples which may damage the stack membrane.A recently proposed disturbance decoupling control (DDC) is used for the centrifugal compression system. DDC treats the internal interactions as a disturbance and then eliminates them in the control. The performance of the DDC is compared with a decentralized sliding mode controller. Through the comparison of those two controllers, the results show that the proposed DDC performs better in both the steady state and dynamic conditions, making the centrifugal compressor is capable of applying to the fuel cell in automotive applications. On a hardware-in-the-loop (HIL) testbench, the proposed controller is validated with a 10 kW fuel cell model under varied load demands. Moreover, a surge avoidance method, namely reference limiter, is proposed to prevent the compressor from surging. The experimental results show that the operation is restricted to the right of the surge line.

In paper pulp production, many details can be optimized. For optimal separation of soap from black liquor, it is important to know the amount of soap in the black liquor. A project to produce a method for sampling black liquor and a method for measuring how much soap is present in black liquor by centrifugation was done at Södra Cell Mönsterås. Through centrifugation faster analysis can be done. It took a long time to develop a satisfactory sampling method, but with the help of careful checking of temperature and time, a method was achieved that worked at temperatures between 90 and 100°C, which were the temperatures that were most frequently found, but are higher than the optimum temperature for soap separation. The black liquor turned out to be inhomogeneous, so the project failed to obtain an optimal analysis method within the framework of this project. In the experiment, the centrifuge settings were optimized to 87°C, 2500 rpm and 10 minutes Further attempts could provide more optimal settings for the centrifuge and a substitute for black liquor could make a validation of the centrifuge possible. / Pappersmassaproduktion är komplex, och en rad faktorer kan optimeras. En viktig parameter vid såpavskiljning är innehållet såpa i svartlut eftersom en värdefull produkt, tallolja utvinns av såpa. Projektet syftar till att ta fram en metod för provtagning av svartlut och en metod för att mäta halten såpa i svartluten genom centrifugering. Genom centrifugering kan snabbare analyser göras.  Arbetet har utförts på Södra Cell Mönsterås. Arbetet att utveckla en tillfredsställande provtagningsmetod var komplicerad, men med hjälp av noggrann koll på temperatur och tid uppnåddes en metod som fungerade vid temperaturer mellan 90 och 100°C, vilket var de temperaturer som oftast fanns, men som är högre än optimal temperatur för såpavskiljning. Svartluten visade sig vara inhomogen, därför lyckades det inte att få fram en optimal analysmetod inom ramen av detta projekt. I försöket optimerades centrifugens inställningar till 87°C, 2500 rpm (varv per minut) och 10 minuter. Vidare försök skulle kunna ge mer optimala inställningar för centrifugen genom den utvecklade prov, och ett substitut för svartlut skulle kunne göra en validering av centrifugen möjlig.

Les ventilateurs centrifuges à action dits « à cage d'écureuil » sont largement utilisés dans diverses applications. Ces machines sont caractérisées par des écoulements complexes fortement décollés et présentent des rendements aérodynamiques assez médiocres. Cette thèse concerne la prédiction numérique, la mise en oeuvre et l'analyse expérimentale du comportement aérodynamique instationnaire et aéroacoustique des ventilateurs centrifuges à action. Les travaux réalisés ont consisté en la simulation numérique des écoulements internes fortement tridimensionnels observés dans ces ventilateurs. Ces simulations numériques de type URANS effectuées sur différents débits de fonctionnement ont été validées expérimentalement. La validation expérimentale a concerné les grandeurs globales de l'écoulement (performances aérodynamiques), les grandeurs locales (fluctuations de pression pariétale) et les grandeurs acoustiques obtenues en champ libre et lointain. D'autre part, les essais expérimentaux ont contribué à valider une récente modélisation de la turbulence basée sur l'approche SAS. Outre la validation des modèles numériques utilisés dans les simulations, l'étude expérimentale couplée à d'autres calculs numériques appliqués à plusieurs prototypes de ventilateurs a permis de contribuer à l'optimisation des performances aérodynamiques et aéroacoustiques de ce type de machine. Ainsi, d'une géométrie à une autre, l'influence d'un certain nombre de paramètres géométriques constructifs a été évaluée.

As global demand for nuclear energy and threats to nuclear security increase, the need for verification of the peaceful application of nuclear materials and technology also rises. In accordance with the Nuclear Nonproliferation Treaty, the International Atomic Energy Agency is tasked with verification of the declared enrichment activities of member states. Due to the increased cost of inspection and verification of a globally growing nuclear energy industry, remote process monitoring has been proposed as part of a next-generation, information-driven safeguards program. To further enhance this safeguards approach, it is proposed that process monitoring data may be used to not only verify the past but to anticipate the future via prognostic analysis. While prognostic methods exist for health monitoring of physical processes, the literature is absent of methods to predict the outcome of decision-based events, such as the production of undeclared enriched uranium. This dissertation introduces a method to predict the time at which a significant quantity of unaccounted material is expected to be diverted during an enrichment process. This method utilizes a particle filter to model the data and provide a Type III (degradation-based) prognostic estimate of time to diversion of a significant quantity. Measurement noise for the particle filter is estimated using historical data and may be updated with Bayesian estimates from the analyzed data. Dynamic noise estimates are updated based on observed changes in process data. The reliability of the prognostic model for a given range of data is validated via information complexity scores and goodness of fit statistics. The developed prognostic method is tested using data produced from the Oak Ridge Mock Feed and Withdrawal Facility, a 1:100 scale test platform for developing gas centrifuge remote monitoring techniques. Four case studies are considered: no diversion, slow diversion, fast diversion, and intermittent diversion. All intervals of diversion and non-diversion were correctly identified and significant quantity diversion time was accurately estimated. A diversion of 0.8 kg over 85 minutes was detected after 10 minutes and predicted to be 84 minutes and 10 seconds after 46 minutes and 40 seconds with an uncertainty of 2 minutes and 52 seconds.

When a water soluble granular fertilizer, such as potash, is wetted and then dried during storage and transportation processes, clumps or cakes often form in the material even when the maximum moisture content is less than 1% by mass. In order to avoid or decrease these occurred cakes, it is essential to characterize cake strength and to explore the process of cake formulation or caking through theoretical/numerical analysis. In this thesis, both experimental measurements of cake strength and theoretical/numerical simulations for recrystallization near a contact point are used to investigate the relationship between the caking process and the cake strength for important factors such as initial moisture content and drying time. <p>In this research, a centrifugal loading method has been developed to determine cake strength in a caked ring specimen of potash fertilizer where internal tensile stresses dominate. Research on fracture mechanics states that brittle materials, such as caked potash, fail at randomly positioned fracture surfaces in tension so the centrifuge test method is well suited to provide good data. A two-dimensional plane stress analysis was used to determine the area-averaged tensile stress at the speed of the centrifuge when each specimen fractures. Repeated tests and uncertainty calculations give data with a narrow range of uncertainty. <p>The centrifuge test facility was used for a series of tests in which the initial moisture content, drying time, particle size and chemical composition (i.e. magnesium content) of the samples were varied. For particle sizes in the range from 0.85 to 3.35 mm, experimental data show that the cake strength increased linearly with initial moisture content for each drying method and particle size, and decreased with increasing particle size for each initial moisture content and drying method. As well, it was also found that cake strength will increase essentially linearly with magnesium content from 0.02% to 0.1% for samples with the same initial moisture content, particle size and drying method. All data show that potash samples tend to form a stronger cake with a slower drying process. <p>A theoretical/numerical model is presented in this thesis to simulate ion diffusion and crystallization near one contact point between two potash (KCl) particles during a typical drying process. The effects of three independent factors are investigated: initial moisture content; evaporation rate; and degree of supersaturation on the surface surrounding the contact point. The numerical results show that the mass of crystal deposition near the contact point will increase with increased initial moisture content and decreased evaporation rate. These numerical predictions for recrystallization near the contact point are consistent with the experimental data for the cake strength of test samples of particle beds. With variations in the solid crystal surface degree of supersaturation near the contact point, simulations showed up to 5 times the increase in the crystal mass deposition near the contact point. This prediction of increased roughness is consistent with another experimental investigation which showed that the surface roughness of NaCl and KCl surfaces increased by a factor of five after one wetting and drying process.

When a water soluble granular fertilizer, such as potash, is wetted and then dried during storage and transportation processes, clumps or cakes often form in the material even when the maximum moisture content is less than 1% by mass. In order to avoid or decrease these occurred cakes, it is essential to characterize cake strength and to explore the process of cake formulation or caking through theoretical/numerical analysis. In this thesis, both experimental measurements of cake strength and theoretical/numerical simulations for recrystallization near a contact point are used to investigate the relationship between the caking process and the cake strength for important factors such as initial moisture content and drying time. <p>In this research, a centrifugal loading method has been developed to determine cake strength in a caked ring specimen of potash fertilizer where internal tensile stresses dominate. Research on fracture mechanics states that brittle materials, such as caked potash, fail at randomly positioned fracture surfaces in tension so the centrifuge test method is well suited to provide good data. A two-dimensional plane stress analysis was used to determine the area-averaged tensile stress at the speed of the centrifuge when each specimen fractures. Repeated tests and uncertainty calculations give data with a narrow range of uncertainty. <p>The centrifuge test facility was used for a series of tests in which the initial moisture content, drying time, particle size and chemical composition (i.e. magnesium content) of the samples were varied. For particle sizes in the range from 0.85 to 3.35 mm, experimental data show that the cake strength increased linearly with initial moisture content for each drying method and particle size, and decreased with increasing particle size for each initial moisture content and drying method. As well, it was also found that cake strength will increase essentially linearly with magnesium content from 0.02% to 0.1% for samples with the same initial moisture content, particle size and drying method. All data show that potash samples tend to form a stronger cake with a slower drying process. <p>A theoretical/numerical model is presented in this thesis to simulate ion diffusion and crystallization near one contact point between two potash (KCl) particles during a typical drying process. The effects of three independent factors are investigated: initial moisture content; evaporation rate; and degree of supersaturation on the surface surrounding the contact point. The numerical results show that the mass of crystal deposition near the contact point will increase with increased initial moisture content and decreased evaporation rate. These numerical predictions for recrystallization near the contact point are consistent with the experimental data for the cake strength of test samples of particle beds. With variations in the solid crystal surface degree of supersaturation near the contact point, simulations showed up to 5 times the increase in the crystal mass deposition near the contact point. This prediction of increased roughness is consistent with another experimental investigation which showed that the surface roughness of NaCl and KCl surfaces increased by a factor of five after one wetting and drying process.

A batch vacuum frying system, which processes fruits and vegetables, includes a frying pan, a surface-condenser, and a vacuum pump. With health and safety issues in mind, this research focused on developing a modified surface-condenser to prevent cavitation of the vacuum pump. The final oil-content was reduced by centrifugal de- oiling of the product under vacuum, which make the product healthier than what is currently available. The de-oiling mechanism consists of a centrifuge with a motor attached to the basket shaft, rotating up to 750 rpm (63 g units). The condenser consists of a (counter- flow) spiral-coil heat exchanger (SHE) connected to a refrigeration system that uses R404a refrigerant. De-oiling for 40 s at 300 and 750 RPM removed up to 67% and 72% of the chip’s surface oil, respectively. At 750 RPM for 10 s, 40 s, and 60 s the oil-content was reduced by 38%, 44%, and 51%, respectively. The convective heat transfer coefficient (h) of the frying oil was determined at 120°C and 140°C using the lumped capacitance method. The h-values were 217±13 W/m2K (120°C) and 258±37 W/m2K (140°C) using a copper-ball thermocouple. The h- values increased to 3.6 times during the boiling period. COMSOLTM Multiphysics was used to model the heat transfer in the vacuum fryer pan. Based on the simulation results, a 1.5 cm thick insulation material was installed in the fryer to reduce the energy losses. The refrigeration system operates at Tevap = -26°C and Tcond = 50°C with 26°C sub-cooling. Sensitivity analysis showed that the system Coefficient of Performance (COP) was about 3.87 at these conditions and compressor power requirement (CPR) was 74 W (85% efficiency) when frying 30 g of potatoes slices. The best results were obtained at Tevap = -10°C and Tcond = 40°C with 26°C sub-cooling and superheat of 5°C. The predicted COP was 4 and the CPR 70 W. The ice-formation on coils reduced the condensation rate. Reducing the refrigerant temperature to -10°C (from -26°C) reduced the condensation rate by 30%. These results show a more effective vacuum frying system for high-quality fruits and vegetables than the system previously used.