The diffusion coefficient of ¹⁴C-labelIed ethylene in normal ethylene was measured at temperatures of 25, 50, and 75°C in the range up to 10 × 10^-3 mol/cm-sp³ density and 197 atm pressure. The measurements were made through a plug of porous bronze in a diffusion cell of two-chamber type by using the radioactive tracer technique. The diffusion coefficient-density products decreased slightly with increasing density, and could be predicted by a modified Enskog-Thorne theory. The values obtained in this study agreed fairly well with those calculated from a generalized chart which was prepared from correlation of experimental data.

View full abstract

The thermodynamic equations have been derived for determining infinite dilution binary activity coefficients in liquid phase for the system containing one vapor associating substance by means of isobaric bubble point-concentration data (T-x) or isothermal total pressure-concentration data (P-x).
Bubble points for the acetic acid-water system at 760, 600, 400, 200 mm of Hg were measured by means of ebulliometers, and using the bubble points so measured, infinite dilution activity coefficients in the liquid phase for acetic acid-water system were determined.
Calculation of vapor-liquid equilibria for the acetic acid-water system by modified Tao equation, applying infinite dilution activity coefficient and T-x data, showed good agreement with literature values.

View full abstract

To discuss prediction of vapor-liquid equilibria with esterification on the basis of the ASOG model, infinite-dilution binary activity coefficients were measured for five systems in the 40°-100°C range by an ebulliometric method. The systems measured are methyl acetate-n-heptane, ethyl acetate-ethanol, ethyl acetate-water, acetic acid-n-heptane, and acetic acid-ethyl acetate. The group Wilson parameters for any system made up of CH₂, OH, COO, COOH groups were determined in the 40°-100°C range by infinite-dilution activity coefficients. Vapor-liquid equilibria predicted for three quaternary esterification systems and for 26 binary and ternary systems involving alcohols, water, paraffins, esters, and carboxylic acids agreed fairly well with observed values.

View full abstract

The velocity of glass beads entrained with air flow in a horizontal square duct was measured in a range of pressures: 760-1 mmHg, u_a: 10, 18 m/sec, d_p: 81.5-184 microns, D: 2.45 cm. It is pointed out that with respect to the flow regions in duct and around particle the present experimental conditions are considerably different from those in previous works at atmospheric pressure. Data obtained under reduced pressure are correlated within ±30% by the following equation, which includes the Cunningham correction coefficient Cm.
(u_a-U_p)/u_a=1.22Cmd_pu^0.4_a
u_a=air velocity [cm/sec], u_p=particle velocity [cm/sec], d_p=particle diameter [cm].

View full abstract

The flow of rarefied gases through sphere packed beds under free molecular region was analyzed statistically by the Monte Carlo method. In analysis, the random packed beds were considered as a collective of regular packed units, and the permeability of this unit was calculated by the Monte Carlo method.
For extension to the packed bed, Oatley''s method was used for the direction of flow and proportional allotment with the ratio of unit area to beds was adopted for the direction of cross section. The calculated results were in good agreement with observed values, suggesting that this analytical method affords easy calculation of conductance of packed beds.

View full abstract

An analytical method is proposed for the problem of rarefied gas channel flow, on the basis of the concept of locally-uniform velocity distribution, and the flow in a circular tube is analyzed. The solution is in good agreement with the experimental results over the whole range of Knudsen number. From the derived results, a new expression of the slip coefficient is also proposed.

View full abstract

Effects of viscoelasticity on the drag coefficient for creeping flow past a single air bubble or carbon tetrachloride droplet were investigated. Experimental data were presented for seven dilute aqueous polymer solutions: a 3.5% sodium carboxymethylcellulose solution, a 1.0% polyethylene oxide solution, 0.52%, 0.86%, 2.07% and 2.95% sodium polyacrylate solutions, and a 2.01% methylcellulose solution. A relationship has been obtained by the variational method applied to a Sutterby model fluid, considering the changeability of the shape of fluid spheres. The data for elastic fluids were not fitted by this correlation based on a purely viscous model such as the Sutterby model. This deviation was expressed by the Weissenberg number based on the maximum relaxation time of Spriggs model fluids, and the drag coefficient was correlated with a modified Reynolds number.

View full abstract

The flow behavior of the laminar liquid film and the turbulent gas stream flowing cocurrently or countercurrently in a wetted-wall column was studied theoretically and experimentally. Analytical solutions were obtained for the velocity profiles of gas and liquid and the frictional pressure drop for the gas stream. Frictional pressure drops for the gas stream were measured for the air-water system and the air-glycerol solution system. Experimental results were in good agreement with the theoretical predictions.

View full abstract

A general algorithm for solving multicomponent distillation problems is presented. This algorithm is constructed from the tridiagonal matrix method with the quasi-linearization technique and the solution procedure similar to the second-order Runge-Kutta method.
Satisfactory convergence for strongly non-ideal systems with hard operational conditions has been shown by solving some numerical examples.

View full abstract

Theoretical breakthrough curves for an ion exchange column are presented for the case where equilibrium constant based on mass action law is infinite and particle diffusion is the rate-controlling step. An effect of the electric field caused by the difference in diffusivity of counter ions on the breakthrough curves is evaluated by applying the Nernst-PIanck equation. Approximate equations are proposed for breakthrough curves whose maximum error from the exact solution is 4%. The theoretical values agree fairly well with experimental results in the R-H-NaOH system (equilibrium constant is infinite) and the R-Na-Ce(NO₃)₃ system (equilibrium constant is finite), respectively.

View full abstract

The catalyst fouling process in the consecutive hydrogenation of chlorobenzene on a peripherally supported rhodium-alumina catalyst was studied. The activity factor, defined as the relative reaction rate, was correlated with process time by a combined curve of an exponential and a linear form. It was also found experimentally that the activity factor was correlated with the total coke amount, which was obtained from continuous measurement of the catalyst weight under reacting conditions, rather than from the involatile coke amount.
A mathematical analysis considering the rate equations for coke formation gave an equation of the activity factor identical to the empirical one.

View full abstract