Diss. Linköping : Linköpings universitet, 2007. / 147/2007.

Fluid dispensing is a process used to deliver fluid materials to targets such as substrates, boards, or work-pieces in a controlled manner. This process has been widely used in electronic packaging industry for such processes as integrated circuit encapsulation (ICE) and surface mount technology (SMT). The most important parameters needed to be controlled in this process are the flow rate of fluid dispensed and the profile of fluid formed on a target. The modeling and control of such a process involves different engineering disciplines including mechanical, control, software/hardware, and material sciences. <p>The present research is aimed to carry out a comprehensive study on the modeling of the rotary-screw dispensing system, in which a motor-driven screw is used to deliver fluid materials. At first, characterization of the flow behavior of fluids used in the electronic packaging industry is addressed. Under the assumption that the pressure applied to feed the fluid material has reached its steady state value, a steady state model is then developed to represent the flow rate of fluid dispensed in the rotary-screw dispensing process. On this basis, by taking into account the fluid compressibility and the fluid inertia, a dynamic model is developed to represent the dynamics of the flow rate, which is critical if the amount of fluid required to dispense is very small. <p> Experiments conducted on a typical commercial dispensing system of DS-500 (provided by Assembly Automation Limited, Hong Kong) were used to characterize the flow behavior of the fluid dispensed based on the model developed. The method of identifying the flow behavior from dispensing experiments, rather than a rheometer, allowed us to eliminate the massive measurements needed in the use of rheometer. <p>To validate the steady state model, simulations were carried out in Matlab and the results were then compared with the experimental results obtained. It is shown that the simulation results are in close agreement with the experimental results. Based on the dynamic model developed in this study, simulations were carried out to investigate the effects of operational parameters, such as temperature and fluid properties, on the flow rate of the fluid dispensed. In addition, the inconsistency in the fluid amount dispensed was also investigated by using the dynamical model. It has been shown that for dispensing small amounts of fluid, the dynamics of the flow rate dominates the process and that in this situation, the amount dispensed can be predicted by using the dynamic model developed and, in contrast, the use of the steady state model, which is commonly adopted in industry, can result in a large error in the model prediction. <p>Based on the dynamic model, a new approach is developed to integrate the model into the design of fluid dispensing system. This approach could be used not only to evaluate the existing dispensing systems, but also to design new dispensing systems.

Fluid dispensing is a process used to deliver fluid materials to targets such as substrates, boards, or work-pieces in a controlled manner. This process has been widely used in electronic packaging industry for such processes as integrated circuit encapsulation (ICE) and surface mount technology (SMT). The most important parameters needed to be controlled in this process are the flow rate of fluid dispensed and the profile of fluid formed on a target. The modeling and control of such a process involves different engineering disciplines including mechanical, control, software/hardware, and material sciences. <p>The present research is aimed to carry out a comprehensive study on the modeling of the rotary-screw dispensing system, in which a motor-driven screw is used to deliver fluid materials. At first, characterization of the flow behavior of fluids used in the electronic packaging industry is addressed. Under the assumption that the pressure applied to feed the fluid material has reached its steady state value, a steady state model is then developed to represent the flow rate of fluid dispensed in the rotary-screw dispensing process. On this basis, by taking into account the fluid compressibility and the fluid inertia, a dynamic model is developed to represent the dynamics of the flow rate, which is critical if the amount of fluid required to dispense is very small. <p> Experiments conducted on a typical commercial dispensing system of DS-500 (provided by Assembly Automation Limited, Hong Kong) were used to characterize the flow behavior of the fluid dispensed based on the model developed. The method of identifying the flow behavior from dispensing experiments, rather than a rheometer, allowed us to eliminate the massive measurements needed in the use of rheometer. <p>To validate the steady state model, simulations were carried out in Matlab and the results were then compared with the experimental results obtained. It is shown that the simulation results are in close agreement with the experimental results. Based on the dynamic model developed in this study, simulations were carried out to investigate the effects of operational parameters, such as temperature and fluid properties, on the flow rate of the fluid dispensed. In addition, the inconsistency in the fluid amount dispensed was also investigated by using the dynamical model. It has been shown that for dispensing small amounts of fluid, the dynamics of the flow rate dominates the process and that in this situation, the amount dispensed can be predicted by using the dynamic model developed and, in contrast, the use of the steady state model, which is commonly adopted in industry, can result in a large error in the model prediction. <p>Based on the dynamic model, a new approach is developed to integrate the model into the design of fluid dispensing system. This approach could be used not only to evaluate the existing dispensing systems, but also to design new dispensing systems.

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 60).

The elutriation of fine materials from the solids bed in rotary kilns was studied in a laboratory scale steel cylinder of 0.2m in diameter and 2.4m in length. The cylinder was charged with a batch of fine alumina particles having a mean size of 64jum and the average elutriation rate measured at different air flow rates, rotational speeds and percentage of solids fill. All measurements were done at room temperature. To show the effect of fines concentration and segregation in the solids bed, a binary mixture of fine alumina and coarse Ottawa sand was used. Local dust concentration profiles were measured in the freeboard through a probe equipped with a filter. Design factors such as the geometry of the kiln exit dams, were found to influence dust carryover into the cleaning equipment by accelerating the flowing gas and or obstructing the flow of solids in the gas phase. Wall roughness and imperfections also affected elutriation especially at higher rotational speeds by exposing trapped fines directly into the flowing gas. Dust concentration measurements revealed that most of the solids in the gas phase travelled in saltation within about 2 cm above the bed surface. With the wall effect eliminated by an insert, increasing the rotational speed was found to exhibit a negative effect on the elutriation rate. Dust concentrations were higher in the gas phase above the lower edge of the rotating bed than at the upper edge or midpoint. However, while the concentration above the rest of the bed remained fairly constant with increased rotational speeds, at the lower edge of the bed it decreased. Banding segregation occurred in the beds composed of fine and coarse particles. Elutriation increased with the number of fine bands formed which was proportional to the concentration of fines. The location of the bands from the exit also influenced elutriation. Saltating particles returning to the bed close to the exit had a better chance of ejecting other particles if they landed on fine bands than they would if they landed on coarse bands. Gas velocity exhibited the strongest influence on elutriation rate. A correlation of experimental results showed a velocity dependence of U⁶ regardless of initial fines concentration in the bed. An entrainment mechanism has been formulated based on the collision of saltating particles on the solids bed. Subsequently, a simple mathematical model was developed to describe the influence of the operating variables on elutriation. The model predictions were verified with the experimental data and the scanty data in the literature. The model requires knowledge of the saltation height and the threshold shear stress for particle movement. Model predictions for typical industrial kilns are presented. The predictions are in fairly good agreement with values reported in a survey of industrial kiln operations made prior to the experimental program, given that the effect of kiln internals was not accounted for in the model. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Two modes of transverse solids motion, slumping and rolling, in rotary kiln operation have been experimentally characterized and mathematically modelled in this study. Other modes of bed behaviour encountered in rotary cylinders; slipping, cascading, cataracting and centrifuging have been formulated mathematically. The models have been verified using experimental observations reported in the literature. An experimental study of those conditions under which the bed changed from slumping to rolling was undertaken and the characteristics of these modes of motion quantified using different types of solids in three horizontal rotary cylinders and a small pilot kiln. A Bed-Behaviour Diagram which is a plot of bed depth versus rotational speed was developed to delineate the various areas of dominance of slumping and rolling and it was shown using this Diagram that bed behaviour observations made on batch cylinders were representative of solids motion in a continuous kiln operation, the effects of bed depth, particle size, particle shape and cylinder diameter on the position of the slumping-rolling boundary were also experimentally investigated. The quantitative characterization of slumping and rolling indicated that a new interpretation of the change in bed motion from slumping to rolling was required. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Biosolids Drying is the process of producing a fertilizer product for beneficial reuse from solids produced during municipal wastewater treatment. The drying of biosolids involves the evaporation of water to stabilize the material and produce a product for beneficial use. Thermal energy needs to be transferred to the biosolids to evaporate the water and heat the solids. Energy can be provided by combustion of fuels, re-use of waste heat or solar radiation (WEF, 2014). The most common technology for biosolids drying in the United States utilizes rotary drum dryers. In these systems, fines and crushed oversized pellets produced during the drying system are mixed with dewatered biosolids upstream of the dryer to create a 55% - 65% dry biosolid in the form of pellets. Reducing the percentage of fines generated during the drying process can potentially reduce the amount of energy required for drying. In earlier research completed by Zhang (2018) it was shown that energy modifying amendments, specifically cationic polyelectrolytes, can reduce the zeta potential of biosolids in solution and possibly promote aggregation of the fines. One of the tested amendments, polydiallyldimethylammonium chloride (PDADMAC), was also shown to increase the particle size of the biosolids in solution. In this work, a bench scale drying system was designed and developed to apply the polyelectrolyte amendments to biosolids during the mixing phase, and to gauge the impact on the pellet size distribution and the percentage of fines generated after drying. It was shown that PDADMAC, which is a high charge density cationic polyelectrolyte, had a measurable, though inconsistent, impact on pellet size when applied during the mixing phase. This work also highlights the varying characteristics of biosolids and the recycled biosolids produced during the drying process. Both PDADMAC, and polyallyamine, another cationic polyelectrolyte, when applied to biosolids during the mixing phase limited the increase in fines production as the mixing time was increased prior to drying.

The chapters subsequent to the design discussion describe the evolution of the project. During the progression of the project, four case studies were undertaken. Each of these case studies involved the design of an engine, using the principles expounded in the early chapters. The parts of three of these were manufactured. The project has culminated in case study four which consisted of the conception, design and component manufacture of a new type of engine: the Hudson 5 Cycle Rotary Engine. It does not reciprocate, nor is it orbital (Sarich) and is not peritrocoidal (Mazda). It operates with pure rotary motion. It also promises to have a favourable environmental aspect due to its excellent fuel efficiency and because of its exceptional power to weight and power to size ratios plus a low component count. The small size and low number of parts make it very economical to produce, both in materials and energy.

Emphasis on soil conservation in recent times has been brought about by the degradation of soils due to intensive tillage operations. A relatively new tillage philosophy, coined conservation tillage, has opened up a new realm of tillage equipment design. The Rotary Tine Aerator (RTA) is new tillage tool that is starting to see commercial applications within the agriculture industry.<p> Being a new tillage tool, very little information has been gathered about the RTA and especially the variables that affect tool loading. For the purpose of improving the design of the soil engaging components of the RTA, an experiment was carried out investigating the effect various settings have on tool loading. A factorial experiment was set up with three factors and two levels. The variables examined were depth, velocity of the tool carriage and tine, and the tine gang angle, with soil density and moisture content maintained constant.<p> Draft and vertical forces on the frame were seen to increase with depth. Side loading on the bearing mounts was seen to be primarily affected by the angle of the tine gang, increasing as the gang angle increased. Tool shape was seen to affect the side loading of the bearing mounts causing the force to change directions when the tool was working and 20 cm depth and the tine gang was set a 0º. Forward velocity was not seen to be a significant factor affecting forces on the frame.<p> The loading in the X, Y and Z direction on the tine increased as depth increased from 10cm to 20 cm. A decrease in force on the tine in the X, Y and Z direction was seen with increasing tine velocity. It is suggested that an overlap in soil failure zones could be the cause of this relationship. Opening the gang angle from 0º to 10º increased the force in the Z direction and decreased the force in the X direction. Tool shape was also seen to affect the direction of the load on the tine in the Z direction when the tine was tilling at a depth 20cm with a tine gang of 0º.<p> From the information gathered in this experiment, statistical models were developed for the loading on the tine and frame. The all possible regressors approach was used to formulate the statistical models. As each regressor was added, the new equations fit was assessed using the coefficient of determination (R2 ) and the sum of squared error (SSE). If there was a discrepancy as to whether an added regressor significantly contributed to the fit of the equation, a hypothesis test using the F-statistic was used to justify the regressors addition or removal. The models were then compared against the original data.<p> The models developed for the tine loading showed sufficient accuracy. The models for side loading of the bearing mounts and draft loading of the tool frame contained only one significant regressor. The lowest coefficient of correlation was R=0.63 for the model of side loading of the bearing mount. The statistical model for the vertical loading correlated well with the test data with a coefficient of correlation of R=0.95.

Emphasis on soil conservation in recent times has been brought about by the degradation of soils due to intensive tillage operations. A relatively new tillage philosophy, coined conservation tillage, has opened up a new realm of tillage equipment design. The Rotary Tine Aerator (RTA) is new tillage tool that is starting to see commercial applications within the agriculture industry.<p> Being a new tillage tool, very little information has been gathered about the RTA and especially the variables that affect tool loading. For the purpose of improving the design of the soil engaging components of the RTA, an experiment was carried out investigating the effect various settings have on tool loading. A factorial experiment was set up with three factors and two levels. The variables examined were depth, velocity of the tool carriage and tine, and the tine gang angle, with soil density and moisture content maintained constant.<p> Draft and vertical forces on the frame were seen to increase with depth. Side loading on the bearing mounts was seen to be primarily affected by the angle of the tine gang, increasing as the gang angle increased. Tool shape was seen to affect the side loading of the bearing mounts causing the force to change directions when the tool was working and 20 cm depth and the tine gang was set a 0º. Forward velocity was not seen to be a significant factor affecting forces on the frame.<p> The loading in the X, Y and Z direction on the tine increased as depth increased from 10cm to 20 cm. A decrease in force on the tine in the X, Y and Z direction was seen with increasing tine velocity. It is suggested that an overlap in soil failure zones could be the cause of this relationship. Opening the gang angle from 0º to 10º increased the force in the Z direction and decreased the force in the X direction. Tool shape was also seen to affect the direction of the load on the tine in the Z direction when the tine was tilling at a depth 20cm with a tine gang of 0º.<p> From the information gathered in this experiment, statistical models were developed for the loading on the tine and frame. The all possible regressors approach was used to formulate the statistical models. As each regressor was added, the new equations fit was assessed using the coefficient of determination (R2 ) and the sum of squared error (SSE). If there was a discrepancy as to whether an added regressor significantly contributed to the fit of the equation, a hypothesis test using the F-statistic was used to justify the regressors addition or removal. The models were then compared against the original data.<p> The models developed for the tine loading showed sufficient accuracy. The models for side loading of the bearing mounts and draft loading of the tool frame contained only one significant regressor. The lowest coefficient of correlation was R=0.63 for the model of side loading of the bearing mount. The statistical model for the vertical loading correlated well with the test data with a coefficient of correlation of R=0.95.