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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Measuring wall forces in a slurry pipeline

El-Sayed, Suheil. January 2010 (has links)
Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 15, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Engineering Management, Department of Mechanical Engineering, University of Alberta. Includes bibliographical references.
2

The effect of pipe roughness on non-Newtonian turbulent flow

Van Sittert, Fritz Peter January 1999 (has links)
Thesis (MTech (Civil Engineering))--Cape Technikon, Cape Town, 1999 / Pipe roughness is known to greatly increase the turbulent flow friction factor for Newtonian fluids. The well-known Moody diagram shows that an order of magnitude increase in the friction is possible due to the effect of pipe roughness. However, since the classical work of Nikuradse (1926 -1933), very little has been done in this area. In particular, the effects that pipe roughness might have on non-Newtonian turbulent flow head loss, has been all but totally ignored. This thesis is directed at helping to alleviate this problem. An experimental investigation has been implemented in order to quantify the effect that pipe roughness has on non-Newtonian turbulent flow head loss predictions. The Balanced Beam Tube Viscometer (BBTV), developed at the University of Cape Town, has been rebuilt and refined at the Cape Technikon and is being used for research in this field. The BBTV has been fitted with pipes of varying roughness. The roughness of smooth P\'C pipes was artificially altered using methods similar to those of Nikuradse. This has enabled the accumulation of flow data in laminar and turbulent flow in pipes that are both hydraulically smooth and rough Newtonian and non-Newtonian fluids have been used for the tests. The data have been subjected to analysis using various theories and scaling laws. The strengths and problems associated with each approach are discussed and It is concluded that roughness does have a significant effect on Newtonian as well as non-Newtonlan flow.
3

The effect of the particle size distribution on non-Newtonian turbulent slurry flow in pipes

Thorvaldsen, Gary Sven January 1996 (has links)
Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town,1996 / The handling of solid-liquid suspensions is an important concern within the chemical and processing industries and many theoretical models have been proposed to try and explain and predict turbulent flow behaviour. However, the prediction of turbulent flow from only the viscous properties of non-Newtonian suspensions has over the years been questioned by researchers. This thesis considers theoretical models well established in the literature and the Slatter model, which uses both the rheology of the suspension and the particle size distribution of the solids. These models are used to analyze the experimental data and the effect that particle size and the particle size distribution has on turbulent flow behaviour. The literature concerning the rheological fundamentals relevant to fluid flow in pipes has been examined. The Newtonian turbulent flow model as well as the non-Newtonian models of Dodge & Metzner, Torrance, Kemblowski & Kolodziejski, Wilson & Thomas and Slatter have been reviewed. Test work was conducted at the University of Cape Town's Hydrotransport Research Laboratory using a pumped recirculating pipe test rig. The test apparatus has been fully described and calibration and test procedures to enable collecting of accurate pipeline data have been presented. Three slurries were used in test work namely kaolin clay, mixture I (kaolin clay and rock flour) and mixture 2 (kaolin clay, rock flour and sand) with ad,s particle size ranging from 24/Lm to 170/Lm. The yield pseudoplastic model has been used to model and predict the laminar flow of the suspensions that were tested and the meth9J adopted by Neill (1988) has been used to determine the rheological constants. The pipeline test results have been presented as pseudoshear diagrams together with the theoretical model lines providing a visual appraisal of the performance of each model. The Slatter model predicts the test data best with the other theoretical models that were considered tending to under predict the head loss. The reason the Slatter model performs better than the other theoretical models is because this model can account for the wall roughness and particle roughness effect. Evidence to support this statement has been presented. This thesis highlights the fact that the particle size distribution is a vitally important property of the suspension and that it does influence turbulent flow behaviour. It shows that turbulence modelling using the particle roughness effect (eg Slatter, 1994) is valid and can be adopted for non-Newtonian slurries. It is concluded that the particle size distribution must be used to determine the particle roughness effect and this effect must be incorporated in the turbulent flow analysis of non-Newtonian slurries.
4

Bingham yield stress and Bingham plastic viscosity of homogeneous Non-Newtonian slurries

Zengeni, Brian Tonderai January 2016 (has links)
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016. / This dissertation presents how material properties (solids densities, particle size distributions, particle shapes and concentration) of gold tailings slurries are related to their rheological parameters, which are yield stress and viscosity. In this particular case Bingham yield stresses and Bingham plastic viscosities. Predictive models were developed from analysing data in a slurry database to predict the Bingham yield stresses and Bingham plastic viscosities from their material properties. The overall goal of this study was to develop a validated set of mathematical models to predict Bingham yield stresses and Bingham plastic viscosities from their material properties. The interaction of the non-Newtonian material properties is very complex at varying mass solids concentrations. The evaluation of these interactions in terms of constitutive equations is almost impossible and the relationship between material properties, mass solids concentration and rheology can only be modelled in a statistical manner. The validity of each model is checked to ensure that predictions and interpretations are unbiased and efficient. This is done by comparing the resulting models to experimental data generated from test work. An in-depth analysis was conducted to see the interrelationship between the material properties and how they affect the yield stress and viscosity values.
5

Optimum Design Of Slurry Pipelines

Yildiz, Burhan 01 December 2008 (has links) (PDF)
There exist various applications of transportation of slurries through pipelines all over the world. In the present study, the problem is formulated as a &quot / transportation problem&quot / to determine the pipe diameters and amounts of slurry to be transported from the demand (production) points to the processing (factory) points. The minimization of the cost consisting of the pipe and energy cost terms is considered as the objective function to determine the stated decision variables. Pipe cost is given as the function of pipe diameters and the energy cost is defined as function of pipe diameters and slurry amounts. Energy cost is obtained by using the relation that is previously determined after the experimental studies made for the magnetite ore. The optimization method used in the study is genetic algorithm method. A commercially available software written in C language is used and modified for the present study The proposed methodology to solve this nonlinear programming problem is applied to a transportation system and it is seen that the methodology made the complex, labor intensive equation solution process very convenient for the users.
6

The Simulation and Water Quality Characterization of a Coal Slurry Involving Eastern Coal

Todd, Michael R. 01 January 1983 (has links) (PDF)
The water quality characteristics of a coal slurry were found to vary widely, depending upon the coal used and the use of a corrosion inhibitor. The coal-water interactions were evaluated in a pilot-plant closed-loop coal slurry pipeline. Pulverized coal from eastern Kentucky and tap water were slurred and pumped through a 40 foot (12.2 m) pipe loop for ten days. Slurry samples were collected at 3 hours, 7 hours, 1 day, 2 days, 4 days, 7 days and 10 days from the start of a run. The samples were filtered and analyzed for 29 water quality parameters, including 15 metals. Two runs were performed without adding a corrosion inhibitor and two runs were performed with the addition of a corrosion inhibitor. The coal slurry filtrate contained high levels of sulfates, total dissolved solids, conductivity, acidity, iron, magnesium, manganese, lead and aluminum. The pH dropped initially, depending upon the percent sulfur in the dry coal and the alkalinity in the slurry, but returned to 6-7 after 10 days in the pipeline. Metal concentrations were a function of the pH, which affected solubility. Organics in the filtrate were at low levels. The addition of a corrosion inhibitor increased the concentrations of most parameters.
7

Wastewater Characterization and Treatability for anEastern Coal Slurry

Flint, Mark J. 01 January 1984 (has links) (PDF)
A complete wastewater characterization study was performed on an eastern Kentucky coal slurry after a 10-day circulation period in a 40 foot (12.2 m) pilot-scale pipeline. The resulting wastewater was settled and decanted for additional lime and alum treatability studies. Easter coal slurries were characterized by high TDS, conductivity, sulfates and iron. Significant concentrations of a number of trace metals were also found; however, organics were very low. Wastewater quality varied considerably among several experiments and was presumed to be influenced by different properties of the coal and the addition of a corrosion inhibitor. The major treatment concern was removal of high concentrations of iron, manganese, and trace metals if wastewaters were to be discharged. Lime treatment was found to effectively remove iron, magnesium, manganese and many other trace metals from coal slurry wastewaters. Alum treatment methods were considerably less effective for metals removal; however, alum was more effective in removing organics, color and turbidity. The addition of a corrosion inhibitor was found to reduce treatment removals for both lime and alum treatment. Several alternative uses were proposed for slurry wastewaters based on predicted water quality and volumes.
8

A coal-air flowmeter for measuring the air-fuel ratio in a pulverized coal carrying pipe line

Giddings, Stanley M., Speegle, Hobart January 1949 (has links)
M.S.
9

An assessment of the offstream storage requirements and low-flow frequencies characteristics to supply coal slurry piplines originating in southwestern Virginia

Santos, German R. (German Ricardo) January 1983 (has links)
M. S.
10

Centrifugal pump derating non-Newtonian slurries: analysis of the viscosity to be used in the hydraulic institute method

Kalombo, Jean-Jacques Ntambwe January 2013 (has links)
Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2013 / Centrifugal pumps are the most commonly used pumps in slurry transport systems. The design of pumping systems dealing with liquids more viscous than water requires a reliable method of pump performance prediction for the pump selection. For Newtonian fluids, the Hydraulic Institute method is well established, but there is no generally accepted method for non-Newtonian fluids. Many authors have fallen back on using the Hydraulic Institute method for non-Newtonian fluids. This requires a constant viscosity while non-Newtonian fluid viscosity varies with the shear rate. The question arises: What viscosity should be used in this method for non-Newtonian fluids? Two approaches have been developed: the use of a Bingham plastic viscosity made by Walker and Goulas (1984) and the use of the apparent viscosity calculated using an “equivalent hydraulic pipe” diameter, designed by Pullum et al. (2007). Previous results obtained from these two approaches are not in agreement. Therefore, the aim of this study is to explore a suitable procedure to determine a representative non-Newtonian viscosity to be used in the Hydraulic Institute method to predict the pump performance. To achieve this goal, a set of data was experimentally obtained and the existing data were reused. Test work was conducted using the pump test rig in the Flow Process Research Centre at the Cape Peninsula University of Technology. A Warman 4/3 pump was tested, using four concentrations of kaolin suspension and three concentrations of CMC solution. Five pump speeds were chosen to run these tests: 1200, 1400, 1600, 1800, and 2000 rpm. An additional data set obtained by testing two submersible centrifugal pumps with eight concentrations of sludge, in Stockholm, Sweden, was also analysed. These sets of data were analysed firstly according to the Walker and Goulas (1984) approach and secondly according to the Pullum et al. (2007) approach. The use of the apparent viscosity led to the better pump head prediction. The results of this prediction were close to those obtained in the Pullum et al. (2007) work, and even better in some cases. On the other hand, the use of the Bingham plastic viscosity showed better pump efficiency prediction, although the Walker and Goulas (1984) efficiency prediction range was achieved only for one pump out of five. The apparent viscosity reflected the non-Newtonian behaviour but it could not represent alone the non-Newtonian viscosity because of the poor efficiency predictions and the sensitivity of the Pullum et al. (2007) approach to a change in viscosity. From the results of this work, it is advisable that the pump performance prediction be done using both apparent and Bingham plastic viscosity, the apparent viscosity for the head prediction and the Bingham plastic viscosity for the efficiency prediction.

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