ISSN:0001-1541    

DOI:10.1002/aic.690120102

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690120103

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractA method is reviewed which allows data points to be chosen in such a fashion that precise estimates of the parameters in nonlinear reaction rate models can be obtained. This method allows each future data point to be selected such that the confidence region of the estimated parameters is smaller with it than with any other possible data point within the region of experimentation. This procedure is applied for Hougen‐Watson models with hypothetical experimental data which were generated with the guidance of an example from the current chemical engineering literature. It is found that, for the same number of data points, the parameters in the model can be estimated eighteen times more precisely by using this suggested experimental design than by another commonly used design. Confidence regions are presented for the parameters of the Hougen‐Watson models with two types of designs.It is found that the positions of the data points in the well‐designed experiments are more sensitive to the functional form of the model than to the current estimates of the magnitudes of the parameter v

ISSN:0001-1541    

DOI:10.1002/aic.690120104

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractThe theory of solute extraction in viscous single‐drop systems is extended to show (1) the dependence of the asymptotic Nusselt number on the Peclet number fromNPe= 0, the molecular diffusion limit, toNPe= ∞, the Kronig and Brink limit, and (2) the dependence of the diffusion entry region Nusselt number on the Peclet number and the initial concentration profile.A numerical solution of the diffusion equation, limited to dilute solute concentrations and solute transport by viscous convection and molecular diffusion, is presented from which the nature of the Nusselt number is deduced. The observed oscillatory behavior of the Nusselt number in the diffusion entry region, asNPe→ ∞, is given a simple physical interpretation in terms of the circulation period of the drop liquid.The model is based upon the Hadamard stream function which theoretically is limited to creeping flow; however some experimental evidence indicates that flow fields similar to the Hadamard stream function exist at continuous phase Reynolds numbers of the order

ISSN:0001-1541    

DOI:10.1002/aic.690120105

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractThis paper describes a preliminary study of the linear flow of a non‐Newtonian fluid, a water solution of Dextra (a polysaccharide), in porous media. A modification of Darcy's law, which uses capillary rheology data, is developed to describe non‐Newtonian flow in underground reservoirs. The generalization, in effect, replaces the porous media with a capillary of equivalent radius proportional to the square root of the ratio of permeability to porosity. The constant of proportionality αoshould be independent of permeability and porosity for a given type of rock. This has been partially confirmed experimentally. In principle, a capillary rheogram and a single core test permit evaluation of αo. Then non‐Newtonian flow can be predicted in this type of rock regardless of porosity, permeability, or fl

ISSN:0001-1541    

DOI:10.1002/aic.690120106

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractBoth nonisothermal and isothermal catalytic effectiveness factors are computed for kinetic rate laws of the Langmuir‐Hinshelwood, Hougen‐Watson type, involving surface coverage by reactant and products. Selectivity taxation is also treated and the significant influence of interphas heat and mass gradients surrounding the catalyst is displayed. The complexities of these real kinetic systems suggest caution in the use of prior generalizations based upon simpler rate l

ISSN:0001-1541    

DOI:10.1002/aic.690120107

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractSolids dispersion due to the simultaneous diffusion (random particle motion) and classification (segregation) of fluidized spheres has been investigated. The model developed permits calculation of the mean concentration of spheres of both sizes in a mixture of two sizes of fluidized spheres as a function of bed length. Fick's law has been applied to the diffusional phenomenon. A hypothesis has been advanced and confirmed which permits calculation [Equation (5)] of the classification velocity for each size of sphere in a fluidized mixture. Calculation of the classification velocities in a mixture of spheres is based on the relation of void fraction to superficial velocity for the individual sizes of spheres. To facilitate carrying out these calculations, a generalized equation has been developed for the relation of void fraction to superficial velocity in terms of the Galileo number (d3gΔρρƒ/μ2) and sphere‐to‐column diameter ratio. Measurement of the bead size gradients (change in bead size with bed length) at steady state fluidization was used to investigate dispersion. Closely sized glass beads of 0.1 and 0.2 cm. diameters were fluidized with liquids of 1 and 15 cps. at void fractions of 0.5 to 0.8 in 2.5 and 5.0 cm. columns. Lead beads of 0.12 cm. diameter were also used. Further, several experiments were conducted by a method which is analogous to that used in molecular diffusi

ISSN:0001-1541    

DOI:10.1002/aic.690120108

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractHeat transfer data are presented for condensing steam at 2 in. Hg absolute pressure on the outside of nine copper and nine titanium horizontal tubes in a vertical row. The condensing coefficient correction factor was maximum for the top titanium tube and was 46% higher than the correction factor for the top copper tube. The difference between the correction factors for titanium and copper tubes diminished with the number of tubes in a vertical row to 8% higher than the correction factor for copper tubes with six to nine tubes in a vertical row.

ISSN:0001-1541    

DOI:10.1002/aic.690120109

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractPhotographic measurements have been made of the mean and fluctuating components of velocity of water in a fully baffled stirred tank. Confirmation of much of the photographic data was obtained with a Kiel impact tube. Eulerian correlation coefficients and also Eulerian scales of turbulence were calculated from the photographic data. The Eulerian scale was of the same order as the blade dimensions, a result consistent with earlier measurements on the turbulence behind grids.Equations have been developed to describe the flow of energy and the conservation of angular momentum in the impeller stream of a stirred tank with a radial flow impeller and vertical baffles. These are simplifications of the Navier‐Stokes equations and the energy equation. They relate energy, angular momentum, and pressure to the mean and fluctuating components of velocity in the impeller stream.The equations derived are used with the photographic data on mean and fluctuating velocities to estimate the angular momentum at different radial sections of the tank and to calculate the flow of energy through these sections. The estimates are compared with more accurate values of the total torque and energy determined with a torque tabl

ISSN:0001-1541    

DOI:10.1002/aic.690120110

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY

摘要:

AbstractA two‐way capillary viscometer for measuring shear rates from1,000,000 sec.−1at pressure drops up to 1,000 lb./sq.in. has been designed. It consists of a capillary tube mounted vertically between two sample reservoirs, of which the lower one is connected to a mercury manometer. The driving force, gas under pressure in a large tank, is connected to the upper reservoir and the manometer, thus allowing the sample to be moved in either direction through the capillary. The special feature of this viscometer is the indirect automatic measurement of bulk velocity of the fluid sample (3 to 20 cc.) in the capillary tube by means of a mercury manometer.The precision of measurement of the velocity is one part in four hundred and can be maintained over the whole range of shear rates by the appropriate choice of the ratio of the diameter of the capillary and manometer tube.Energy losses due to capillary heating and kinetic energy are given in terms of ΔPacross the capillary. Couette end effect was found to be 0.3 diam.A study of the rheology of polyacrylonitrile (PAN) in concentration range of ½ to 10½% PAN shows that the non‐Newtonian behavior and elasticity of PAN solution increases rapidly with conce

ISSN:0001-1541    

DOI:10.1002/aic.690120111

出版商:American Institute of Chemical Engineers    

年代:1966

数据来源: WILEY