Browsing by Author "Calabrese, Richard V."
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Item Analysis of Drop Size Distributions Produced in Dilute, Agitated Liquid-Liquid Systems.(1987) Calabrese, Richard V.; Gentry, James W.; Bryner, Nelson P.; ISRItem Applications of Condition Numbers A-Priori Analysis of Moment Method for Describing Size Distributions.(1987) Gentry, James W.; Calabrese, Richard V.; ISRA procedure for estimating the effectiveness of algorithms which retrieve size distribution parameters from cumulative fractions or moments is described. The principle of the algorithm is to select moments, or cumulative fractions, which minimize the condition number. Extensive tests of the algorithm for a distribution consisting of the sum of two log normal distributions were carried out. This procedure can be easily extended to use different numbers and types of constituent functions. The simulations indicated that moment methods which include positive and negative moments give the best result. When the means of the constituent distribution are close, the large condition numbers indicate that no algorithm will give unambiguous values for the parameters.Item The Dispersion of Viscous Liquids by Turbulent Flow in a Static Mixer.(1987) Berkman, Paul D.; Calabrese, Richard V.; ISRDrops are stabilized in agitated liquid-liquid systems by both surface and internal viscous forces. The dispersion of an inviscid liquid into a turbulent continuous phase in static mixers has been studied but the effect of dispersed phase viscosity is not well understood. Systematic experiments have been conducted in a Kenics mixer by photographically examining dilute suspensions of viscous oils in water to determine how viscosity and conditions of agitation affect equilibrium mean drop size and size distribution. A semi-empirical theory is developed which correlates the mean size data and collapses to the well-known Weber No. result in the inviscid limit. A correlation for drop size distribution in terms of cumulative volume frequency is developed by normalization with D_32. Measurements at the mixer entrance indicate that the method of introduction of the dispersed phase should be considered when evaluating mixer performance.Item Drop Breakup in Stirred-Tank Contactors. Part III: Correlations for Mean Size and Drop Size Distribution.(1987) Calabrese, Richard V.; Wang, C.Y.; Bryner, Nelson P.; ISRIn Part II, the extent to which dispersed-phase viscosity and interfacial tension influence equilibrium mean drop size and drop size distribution was determined for dilute suspensions produced in baffled cylindrical tanks of standard geometry equipped with six-blade Rushton turbines. Low to moderate viscosity dispersed- phase systems behaved similarly in that Sauter mean diameter could be correlated using the mechanistic arguments of Part I, and drop sizes, normalized with respect to D_32, could be correlated by a normal distribution in volume. Limited moderate viscosity data were reported in Part I but were not used to develop the correlations of Part II. The objective of this study is to combine the low to moderate viscosity data of Parts I and II with those obtained by other investigators to obtain correlations of broader utility, and to extend these via mechanistic arguments so that they apply to nondilute systems.Item Drop Breakup in Turbulent Stirred Tank Contactors. Part I: Effect of Dispersed-Phase Viscosity.(1987) Calabrese, Richard V.; Chang, T.P.K.; Dang, P.T.; ISRThe extent to which dispersed-phase viscosity influences equilibrium mean drop size and drop size distribution at constant interfacial tension is determined for dilute suspensions by dispersing silicone oils of various viscosity grades in water. A mechanistic model for mean drop size is developed which predicts the moderate-viscosity data and whose parameters correlate the high-viscosity results. Tends in the mean size data coincide with those for the drop size distribution, which broadens considerably as viscosity increases and suggests a dependency on breakage mechanism.Item Drop Breakup in Turbulent Stirred-Tank Contactors. Part II: Relative Influence of Viscosity and Interfacial Tension.(1987) Wang, C.Y.; Calabrese, Richard V.; ISRThe relative influence of dispersed-phase viscosity and interfacial tension on equilibrium drop size and drop size distribution is studied for dilute suspensions by dispersing various silicone oils in water, methanol, and their solutions. Correlations for Sauter mean diameter, D_32, are developed in terms of syatem variables using the mechanistic models of Part I. Drop sizes for low to moderate viscosity dispersed phases are normally distributed in volume and can be correlated by normalization with D_32. Trends in the distributions are explained in terms of a parameter representing the relative resistance to breakage.Item Evaporation of a Volatile Chemical from a Multicomponent Liquid Spill.(1987) Cologer, Peter C.; Calabrese, Richard V.; ISRThe evaporation of volatile species from an otherwise non- volatile liquid spill is considered to assess the effects of initial composition and liquid phase resistance to mass transfer on evaporation rate. An idealized but resaonable general model is developed for the liquid phase. At the surface, vapor-liquid equilibria and mass transfer by wind convection are incorporated into a non-linear, third type, jump boundary condition. The resulting moving boundary value problem is solved numerically and the dimensionless surface flux and cumulative fraction evaporated are found to depend upon a modified Biot No., molecular weight ratio and initial mass fraction of volatile. Limiting case models are developed for the extremes of infinitely dilute versus pure fluid, and surface convection limited versus liquid phase diffusion limited behavior. Their range of applicability is determined by comparing their predictions with those of the general model. By estimating the range of Biot No. that might be encountered, it is shown that liquid phase resistance is important even for shallow spills and that detailed knowledge of vapor-liquid equilibria is often not required. Application of the models to real spills is discussed.Item A Goal Oriented Edunctional Tree Structure for Nuclear Power Plant Emergency Preparedness.(1987) Calabrese, Richard V.; Roush, M.L.; ISRGuidelines for development and implementation of emergency response plans do not provide the planner/implementer with an adequate overview of the functions to be achieved or a measure of their relative importance. To provide a framework in which this importance can be recognized, understood and quantified, a logical goal oriented tree structure has been developed which integrates and gives a clear visual representation of the functions required to meet the emergency preparedness objective. The tree considers a spectrum of both high and low probability events which may require mitigation both onsite and offsite.