Atomization of High Viscosity and Suspension Fluids

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In Canada's oil sands, bitumen is mixed with steam and the mixture is sprayed into a coker to upgrade bitumen to synthetic crude oil. The spray characteristics is one of the determining factors in the efficiently of this process. However, due to the complexity of this fluid (bitumen-steam mixture), there is very limited information on the spray characteristics of these sprays. The available studies on this type of systems, have replaced this complex mixtures with water and air mixtures or some oil and air mixtures. Bitumen-steam mixture is a highly viscous fluid with large percentage of suspended solid particles, and it is too simplistic to model it with mixture of water-air. The objective of the present proposed research is to characterize sprays of high viscosity fluids with suspended particles, in general, and actual bitumen-steam mixtures, as well as coal slurries, in particular. In order to achieve this objective the following tasks will be pursued. (1) Develop an atomization and spray model to predict the spray formation of heavy oils and liquids with suspensions from typical nozzles used in Canadian oil sands. (2) Conduct experimental spray testing on nozzles used in Canadian oil sands using actual fluids, such as bitumen and heavy oils with suspensions. (3) Use the atomization model developed here to predict spray characters from the Canadian oil sands with actual fluids. Use the experimental data to fine tune the spray model. (4) Use the validated spray code to predict the spray characteristics of large scale nozzles. (5) Perform parametric studies to improve nozzle performance both in terms of spray droplet sizes and also reducing wear and tear of the nozzle. The present research is also aimed at addressing the following questions: (i) In a highly turbulent jet, what triggers the gas-liquid interface instability and how does this instability grow resulting in the formation of ligaments and droplets. (ii) How does the liquid viscosity affect the breakup of liquid masses from an interface? (iii) How the existences of suspended particles effect the atomization process?