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This study compared experimental and Computational Fluid Dynamics (CFD) results for heating and cooling in a packed bed (N=5.33). The experimental data was compared between heating and cooling, and was also used to validate the CFD model. The validated models were used to compare theoretical heat transfer parameters. For the experiments, it was found that the effective thermal conductivity was comparable for heating and cooling, and the wall Nusselt number for heating was higher. For the CFD results, it was found that both the wall Nusselt number and effective thermal conductivity were comparable for heating and cooling. The wall Nusselt number was slightly higher for cooling, however this difference decreased as the Reynolds number increased.

This study compared experimental and Computational Fluid Dynamics (CFD) results for heating and cooling in a packed bed (N=5.33). The experimental data was compared between heating and cooling, and was also used to validate the CFD model. The validated models were used to compare theoretical heat transfer parameters. For the experiments, it was found that the effective thermal conductivity was comparable for heating and cooling, and the wall Nusselt number for heating was higher. For the CFD results, it was found that both the wall Nusselt number and effective thermal conductivity were comparable for heating and cooling. The wall Nusselt number was slightly higher for cooling, however this difference decreased as the Reynolds number increased.

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Thesis (Ph. D.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 75-77). Also available via the World Wide Web.

Thesis (Ph.D.)--University of Tulsa, 1981. / Bibliography: leaves 160-171.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

A packed condenser and the auxiliary equipment were designed, built and tested for the condensation of steam in direct contact with Aroclor 1242 and 1248, which are commercial heat transfer agents and are immiscible with water. The co-current flow of steam and liquid, through a four inch inside diameter column packed with three-eighth inch ceramic Raschig rings, was studied. The packing heights used in the condensation of steam were estimated from the liquid temperature profile in the column. The heights of the transfer units for condensation and the average volumetric overall heat transfer coefficients were calculated. The height of the transfer unit for condensation was found to be affected largely by the mean viscosity and the flow rate of the liquid. Two empirical equations have been developed to describe the results of this study. HCU = F ( μ ) (n) where n = 1. 10 for Aroclor 1242 and n = 1. 16 for Aroclor 1248 is mean viscosity of the Aroclor in centipoise. For Aroclor 1242, F= 0.0535 + 8.90 x l0⁻⁶ L when L ≤ 2290 and F =-0. 0737 + 6. 44 x 10⁻⁵ L when L > 2290. For Aroclor 1248, F = 0. 02765 + 1. 244 x 10⁻⁵ L. L is superficial mass velocity of the Aroclor in lb /hr. ft² / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Gas absorption with chemical reaction is an important unit operation in the chemical and petroleum industries for the selective removal of components from industrial gas streams. Apart from choosing absorption media, the most difficult problems facing the design engineer are the sizing and performance prediction of the absorption tower due to the scarcity of fundamental design data, especially when novel absorption media and/or packings are used. The solubility of carbon dioxide in 2 and 3 M solutions of 2-amino-2-methyl-1-propanol (AMP), which is a newly introduced absorbent, was determined at 20, 40, 60 and 80 °C and for CO₂ partial pressures ranging from approximately 1 to 100 kPa. The results were interpreted with a modified Kent-Eisenberg model which predicted the present and previous experimental results well. The absorption capacities of AMP and monoethanolamine (MEA) solutions were also compared. Detailed concentration and temperature measurements were reported for the absorption of carbon dioxide from air into NaOH, MEA and AMP solutions. A full-length absorber (0.1 m ID, packed with 12.7 mm Berl Saddles up to heights of 6.55 m) was used. It was operated in countercurrent mode and at 30 to 75 % flooding velocities which are typical for gas absorber operations. The following ranges of operating conditions were employed: superficial gas flow rate 11.1 to 14.8 mol/m² s; superficial liquid flow rate 9.5 to 13.5 m³/m² h; feed CO₂ concentration 11.5 to 19.8 %; total absorbent concentration 1.2 to 3.8 kmol/m³; liquid feed temperature 14 to 20 °C; total pressure 103 kPa. The measurements for the CO₂-NaOH and CO₂-MEA systems were compared with predictions from a previously developed mathematical model. Generally good agreement was obtained except at high CO₂ loadings of MEA solutions. Compared with MEA, AMP was found to have superior CO₂ absorption capacities and inferior mass transfer rates. A new procedure, called the Pilot Plant Technique (PPT), for designing gas absorbers with chemical reactions has been developed. The PPT is primarily intended for designing absorbers for which fundamental design information is lacking. It is based on the premise that full-length absorption columns can be sized by making a minimum number of tests using a small-scale pilot plant. Two special features of the PPT are (i) the details of hydrodynamic parameters (i.e. mass transfer coefficients, effective interfacial area and liquid hold-up) and the physico-chemical information of the system (e.g. reaction mechanism, reaction rate constants) need not be known and (ii) complex calculations are avoided. Using the PPT to size the height or to predict the performance of a given full-length absorber, the specific absorption rate, which is the essential information, can be measured directly using the pilot plant model (PPM) column if both columns have the same hydrodynamic conditions. This can be achieved by using the same type and size of packing in the PPM and the full-length columns and ensuring that the end and wall effects are negligible. The PPM column must also be operated at the same superficial fluid velocities as those of the full-length column. The specific absorption rate was then obtained from the gradient of the fluid composition profile along the PPM column. The validity of the PPT was demonstrated by determining the height and predicting the performance of the full-length column in which carbon dioxide was absorbed from air by aqueous solutions of NaOH and AMP at various operating conditions; good agreement was obtained. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate