Equations were developed for evaluating the laminar flow behavior of high-solids suspensions from the physical properties of the liquid and solid components. A technique was developed for calculating suspension flow rates as a function of pressure drop. The technique is applicable to the design of pipe lines. Flow measurements were made in pipe-line viscometers of a unique design that minimized entrance and exit effects. Experimental flow data were obtained for suspensions consisting of nickel, alumina, copper, or glass solids in sodium, xylene, or glycerine vehicles with solids concentrations of 28 to 55 vol. %. The basis for the correlation of the data was an analytical investigation of the flow behavior that considered the particle-particle interaction that tokes place in a settled suspension. The correlation equations fit all systems investigated. They take into account the effects of liquid viscosity, liquid and solid densities, particle size, size distribution, particle surface area, volume fraction of solids i n the suspension, and volume fraction of solids at maximum settled conditions.The design of pipe flow systems for suspensions of highsolids content requires a detailed knowledge of the nonNewtonian laminar flow properties (1 to 3) of the suspension. Normally, the flow properties of suspensions of interest have to be determined experimentally over a wide range of flow rates. Mathematical models, such as the well-known Bingham plastic model, that relate shear stress to shear rate are helpful in describing the flow properties of non-Newtonian fluids. However, for most suspensions (particularly where particle size, shape, and degree of dispersion differ) the parameters in the mathematical models have to be measured for each suspension.The objective of the present investigation was to provide a means of predicting flow behavior by making a general rheological study of solid-liquid suspensions and relating suspension viscosity to physical properties of the solids and liquids. Suspensions of high-solids content were of particular interest in this study, since little work has been done on such systems.Other investigators have proposed equations for relating suspension viscosity to properties of the constituents, but none of the investigations have been concerned simultaneously with the non-Newtonian flow region and suspensions of high-solids content.Robinson ( In 777 = - -k+where k = 0.60937. The parameter a is a shape factor, and must be 2.5 for spheres. Vand derived this equation by taking into account the interaction of the solid particles and applying the Arrhenius formula. Mooney ( 6 ) described the interaction between particles at higher concentration as essentially a crowding effect. Mooney suggests a = 2.5, and 1.35 < k < 1.91.Landel (7) proposed an equation for suspension viscosity that is applicable to very high solids concentrations, but the equation was limited to the flow region of constant viscosity observed at low shear rates. Non-Newtonian flow was observed by Landel, but no attempt was made...

PROCESS DEVELOPMENT tion, through the agency of hypochlorous acid, of the aldehydes to the corresponding acetic acid, dichloroacetic acid, and trichloroacetic acid. Both types of side reaction can be controlled through proper arrangement of temperature and conditions pertaining to the introduction of chlorine. The chlorination can be carried batchwise, but is most efficiently managed on a semicontinuous or completely continuous basis.

A method for measuring flow porosity with values from 35 to 100% of the open porosity measured is described. The accuracy of electrical conductivity measurement to obtain net diffusibilities was verified for media containing at least 75% of pore volume with radii greater than five mean free paths. It is pointed out that long dead‐end pores feeding into larger diameter flow pores can contribute to the effective diffusion coefficient inside porous media, and methods of estimating their length and maximum possible contribution to diffusion are described.

Sorption of water vapor from air at 1 atm. under dynamic adiabatic conditions was studied to improve understanding of industrial gas dryer operation. A new type of behavior was caused by a temperature wave which preceded the sorption wave under certain conditions. A multiple correlation yielded a high correlation coefficient and a regression equation which expressed operating time below 0" F. effluent dew point as a function of four independent variables: temperature, moisture content and flow rate of inlet air, and desiccant bed depth. The adiabatic operating capacity of a desiccant bed is much less than that calculated from isothermal equilibrium data.The regression equation for adiabatic capacity here presented can be used for design of large industrial gas dryers which operate without internal cooling.

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