Osmotic distillation is a process of removing water from an aqueous solution, driven by water vapour pressure gradient across a hydrophobic membrane. The process occurs at or below ambient temperature and under atmospheric pressure. This research project investigates the osmotic distillation process in hollow fibre modules using hollow fibres PP375, PV375 and PV660 supplied by Memcor Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux. Models for heat and mass transfers were used to study the polarisation phenomena in osmotic distillation. Temperature and concentration profiles at the membrane surfaces due to polarisation were quantified. Scholfield and Ordinary Diffusion models for flux prediction based on the bulk conditions were developed and validated. Models for water activity and viscosity of aqueous glucose and calcium chloride solutions were also developed and validated in this work. / Master of Science (Hons)

<p> The separation of a mixture of carbon tetrachloride in water was studied in a 2 inch diameter glass hydrocyclone. First, the effect of a mixing valve and of oil/water ratio on the volume/surface diameter of the dispersion in the feed to the hydrocyclone was studied using a statistical experiment design. Secondly, the effect of feed drop size distribution, oil/water ratio, and overflow/underflow split on the separation in the hydrocyclone was determined, again using a statistical experiment design. In both designs, five levels of each variable were studied. Flow rate, design shape, and temperature were kept constant. The range of variables was: </p> <p> 1. Mixing Value Pressure Drop 17.95 to 88.25 mm. Hg </p> <p> 2. Oil/Water Ratio 0.132 to 0.211 </p> <p> 3. Overflow/Underflow Split 4/1 to 8/1 </p> <p> From the first part of the work it was found that oil/water ratio had no significant effect on the volume/surface diameter, and that there was a linear relationship between the volume/surface diameter and mixing valve pressure drop. </p> <p> From the second part of the work it was found that volume split had most significant effect on hydrocyclone separation for the range of variables studied. The oil/water ratio had the next most significant effect on separation, and finally, drop size distribution was also found to be significant, but was the least important of the three variables. The interactions of the variables were no significant. The hydrocyclone separation could be predicted. The prediction of the overflow drop-size distribution agreed very well with the distribution observed photographically. Both predictions required assumptions that short-circuit flow and drop-drop coalescence was negligible. </p> / Thesis / Master of Engineering (ME)

Both Part I and Part II are included. / The separation of a mixture of glass spheres in water using 2 inch hydrocyclones was studied. <p> Three operating parameters were investigated: feed concentration, volume split and feed flow rate. In addition, three design parameters were cone angle, inlet diameter, and vortex finder length. The performance criterion parameters were the efficiency with which the solids were separated from the liquid, and the energy required per unit mass flowing through the hydrocyclone. </p> <p> First the experimental data were analyzed by three different statistical methods and the results compared in an attempt to determine which statistical method was most suitable for this two criteria system. The three methods were principal component analysis, canonical correlation analysis and multiple regression analysis. The theory behind these methods is briefly outlined. Our conclusion is that using all three methods give much more insight than could be obtained from any individual method. </p> <p> Second, an analysis of the above eight hydrocyclonc parameters of hydrocyclones with cylindrical sections indicated that for the range of parameters covered in this work, feed flow rate and inlet diameter influenced the energy loss most; volume split influenced the separation efficiency the most. Energy loss and separation efficiency are quite independent; this means that it is possible to design and run a hydrocyclone with high separation efficiency and low energy loss. The dilute concentrations used in this work indicate that a hydrocyclone of conventional design can be used in waste water treatment. When the parameters were correlated, a power model gave more consistent interpretation than a linear model. </p> <p> Third, the effect of the three operating parameters on hydrocyclones with three different body shapes suggested that the most efficient cyclone was one with a straight cone and no cylindrical section. The body shape dictated which parameters would significantly affect performance. </p> / Thesis / Master of Engineering (ME)