| dc.contributor.author | Seidshazileh, Kazem. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:09Z | |
| dc.date.available | 1999 | |
| dc.date.issued | 1999 | en_US |
| dc.identifier.other | AAINQ63484 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55752 | |
| dc.description | This thesis is mainly concerned with phase inversion and coalescence processes in immiscible liquid systems and how they are affected by their interfacial characteristics. The phase inversion was investigated using several oil-in-aqueous (O/A) and aqueous-in-oil (A/O) systems in which the interfacial characteristics were changed by the controlled addition of different concentrations of the Triton X family of non-ionic surfactants. The coalescence characteristics of O/A dispersions were determined at low dispersed-phase holdups. | en_US |
| dc.description | This investigation was triggered by the difficulties encountered in the "Inverse Doctor Treatment" used to remove impurities from gasoline that has been transported by pipelines carrying multiple products in sequence. The phase inversion behavior of several industrial samples obtained from this process was therefore investigated. | en_US |
| dc.description | All experiments were carried out in a mechanically-agitated, baffled tank equipped with a single Rushton impeller. | en_US |
| dc.description | The dynamic interfacial characteristics of the systems investigated were determined using several drop-based techniques. | en_US |
| dc.description | Following a step decrease in agitation intensity, the Sauter mean diameter was found to increase rapidly and keep on increasing until a new steady state was reached. The presence of surfactants was found to result in slowing the rate of change in Sauter mean diameter as well as reducing its equilibrium value. This effect is more pronounced in higher surfactant concentrations. Our results show that the static (equilibrium) interfacial properties cannot suitably explain this behavior. On the other hand, the diffusivity of the surfactant, was found, to correlate with all coalescence rate data (covering a wide range of surfactants concentration and type) as well as quasi-steady Sauter mean diameter reasonably well. | en_US |
| dc.description | Phase inversion was successfully interpreted as a dynamic process, in which inclusion and escape of the continuous phase droplets compete constantly. It was found that the system's tendency to invert increases as the dispersed phase holdup and agitation intensity increase, and as the surfactant concentration decreases. Significant delay times were observed in conjunction with A/O dispersions, with the magnitude being a function of the deviation from the critical phase-inversion holdup. | en_US |
| dc.description | Our results show that the static (equilibrium) interfacial properties can not adequately be correlated with phase-inversion holdup. On the other hand, reasonably good correlation was obtained using the elasticity due to the presence of surface-active agent. Better correlation was obtained when the diffusivity was used instead of the maximum elasticity. This was found to apply to simple systems dominated by a single surfactant as well as in the case of complex industrial streams. (Abstract shortened by UMI.) | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1999. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Engineering, Chemical. | en_US |
| dc.title | Effect of interfacial characteristics on phase inversion. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
