(524b) A Novel Design for in-Flow Deposition Property Measurement

While wax deposition is a fairly well-known phenomena due to chemical potential gradients and solid-liquid equilibrium, effectively visualizing and measuring the thickness and strength of the deposition formed during flow without disturbing the crystalline structure is very difficult. Members of the department of Chemical Engineering at the University of Utah have constructed a flow loop that allows for non-invasive exploration of many facets of wax deposition. This loop includes an all-steel experimental heat exchanger where controlled deposition takes place under specified heat fluxes including ?cold flow? ? slurry conditions (below WPT), and zero heat-flux through the walls (isothermal) ? and a clear acrylic plexiglass exchanger for controlled deposition and PIV visualization. Both sections are interchangeable, use pure ethylene glycol coolant, and also use high-resolution pressure transducers to measure pressure drop across the exchanger, allowing for accurate thickness measurements to be calculated using a modified Hagen-Poiseuille equation. In addition, the novel flow loop design incorporates a large, temperature-controlled reservoir to maintain fluid properties, as well as a particle size analyzer for use in determining particle size effect on deposition rate, strength, etc, and a conditioning loop to control these sizes. A method for determining in-line yield stress is also being developed so as to not break the crystals by transport out of the temperature controlled loop. The method currently considered is a pneumatic piston that fits flush inside the test section and will apply shearing stress until the deposition yields. Rheology of oils is extensively explored. Overall the flow loop design is unique, robust, and provides some of the most extensive information regarding the study of deposition available. Data generated shows measurement techniques within high accuracy of visual measurements. Novel design is also useful for any oil type, and is designed to handle water. Water effects to be explored after complete diagnostics and plain-oil exploration complete.