ISSN:0001-1541    

DOI:10.1002/aic.690020102

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractData on liquid entrainment are reported for rectangular‐cap bubble trays on 24‐in. tray spacing for an air‐water system. Several tray variations were studied, and entrainment is given for trays containing eight, twelve, and sixteen caps a tray. Some hydraulic characteristics (pressure drop, liquid backup, minimum vapor velocity, and downflow froth height) are also reported. It was found in this study that decreasing liquid path lenght increased the entrainment from a bubble‐cap tray and increasing tray bubbling area decreased entrainment. It was also found that decreasing slot area generally had no effect on liquid entrainment over the range inves

ISSN:0001-1541    

DOI:10.1002/aic.690020103

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractGraphical correlations of binary gas diffusion coefficients are developed based on the Hirschfelder‐Bird‐Spotz diffusion equation and the theorem of corresponding states. A critical diffusion coefficient is defined and is used in turn for a definition of a “reduced” coefficient. The reduced diffusion coefficient is correlated graphically in generalized form in terms of the reduced properties of the diffusing gas. Using air as a reference “barrier” gas, the authors compared critical diffusion coefficients for various gases diffusing through a single barrier gas with the critical coefficients for these gases through air. This ratio, termed thebarrier gas ratio, was found to be independent of the properties of the diffusing gas. A graphical correlation of the barrier gas ratio enables rapid estimation of a binary diffusion coefficient with a minimum of

ISSN:0001-1541    

DOI:10.1002/aic.690020104

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractA method of estimating the true conditions of operation of a bubble‐cap tray is presented. Intermediate between the Murphree and the Lewis methods, which represent the extremes of actual operation, this method involves the use of a correlation to determine the degree of liquid mixing on the tray and the use of new relations between the Murphree vapor efficiency, the Lewis case I efficiency, and the true local efficiency. For the last, partial liquid mixing is taken into account.Data were obtained on an 18‐in. O.D. three‐tray bubble‐cap tower containing ten 3‐in. bubble caps a tray. Partial liquid mixing was correlated for changes in vapor and liquid rates, pressure, temperature, and weir height for the system ethylene dichloride‐toluene.Efficiency data on acetone‐water, ethanol‐water, and ethylene dichloride‐toluene showed the following effects: (1) low concentration of lwo boiler usually, but not always, resulted in low true local efficiencies, always with high Murphree efficiencies; (2) vapor velocity effects are more intimately connected with slot velocity than superficial velocity (and hence entrainment); (3) raising the pressure gives higher efficiencies; (4) an increase in liquid depth increases the true local efficiency but may have no effect on the Mu

ISSN:0001-1541    

DOI:10.1002/aic.690020105

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractThe rates of nitration of benzene by nitric acid in mixed acid to produce mononitrobenzene have been measured in well‐emulsified reaction mixtures in the temperature range from 34° to 54°C. The acid‐phase compositions ranged from 1.6 mole % nitric acid and 27 mole % sulfuric acid to 35 mole % nitric acid and zero % sulfuric acid; the organicphase composition ranged from 4 to 95 mole % benzene, and the relative extent of the acid and organic phases was varied from 25 to 80 volume % acid phase.The reaction rate based on the total volume of the reacting mixture is shown to be a function of the phase compositions, temperature, and volume % of acid

ISSN:0001-1541    

DOI:10.1002/aic.690020106

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractIn the usual method of calculating the solvent extraction of complex mixtures it is assumed that the complex mixture behaves like a binary mixture. However, the hypothetical binary composition of the mixture is never explicitly used; rather, an additive property of the mixture is used as an indication of its composition. The calculation must be done graphically on a triangular diagram or its equivalent.On the assumption that the complex mixture consists of only two hypothetical components, empirical equations have been arrived at relating the distribution coefficients of these two components and of the solvent to the phase compositions. These equations contain three arbitrary constants. By use of the data from a minimum of three simple laboratory batch extractions of a given complex mixture, the three constants, plus the hypothetical binary composition of the original complex mixture, can be determined.With the equations for the distribution coefficients, the equilibrium curve and tie lines for the system can be calculated. Properties of the raffinates and extracts can be measured and related to the hypothetical binary compositions of these mixtures.The use of the method is demonstrated by comparing calculated results with laboratory yields and properties. The calculated results show good agreement with the experimental results. Calculations can be carried out not only on the triangular diagram, but by any of the other graphical methods that have been developed for the solvent extraction of binary mixtures. Equally important, calculations can be done analytically, and therefore the use of automatic computers is feasible.

ISSN:0001-1541    

DOI:10.1002/aic.690020107

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractA procedure for obtaining equilibrium data and predicting ideal‐stage requirements in a complex liquid‐liquid extraction system is presented. Preliminary equilibrium data are obtained from a simulated column run involving a series of batch contacts operated in such a manner as to approach steady state countercurrent conditions. The flow ratios and stage requirements for continuous operation are then estimated by trial‐and‐error by use of a modified McCabe‐Thiele method.The procedure lends itself particularly well to those systems with interdependent distribution of the two components. Data for the separation of hafnium from zirconium are presented to show the utility of t

ISSN:0001-1541    

DOI:10.1002/aic.690020108

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractBecause of the large scale of the motion responsible for mixing in turbulent fields, turbulent transport processes differ from molecular transport processes in that the mixing depends on the previous history of the diffusing material and turbulent fields are generally nonhomogeneous.The effect of the time dependency of the diffusion process is examined for the case of heat transfer from a hot wall to a cold wall through a turbulently flowing fluid. The fluid is assumed to have a uniform velocity and the turbulence is assumed to be homogeneous and isotropic. The calculations are carried out by assuming a distribution of heat sources along the hot wall and of heat sinks along the cold wall. G. I. Taylor's theory of turbulent diffusion for a homogeneous isotropic field is used to describe the properties of these sources and sinks. These calculations are compared with temperature profiles obtained as a solution to Fick's Law using a constant diffusion coefficient. A marked difference between the two sets of curves is obtained in the vicinity of the wall and in the beginning of the heat exchange section.A calculated profile on the basis of an idealized model of heat transfer in channel flow is compared with actual measurements made by Page, Corcoran, Schlinger, and Sage (7) at a distance far enough downstream so that the temperature profile had reached a steady condition.

ISSN:0001-1541    

DOI:10.1002/aic.690020109

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractThe hydrogenation of carbon monoxide and carbon dioxide on various steel catalysts was studied in the temperature range of 800° to 1,300°F. and at pressures from 5 to 30 atm. The feed gases (3.75 to 20 SCFH) were passed over a catalyst bed of 1/8‐in. steel balls supported in a brass‐lined reactor 0.81 in. in diam. The percentage of carbon oxides in the feed was 30% in the runs using a H2CO2feed and varied from 15 to 38% in the runs with a H2CO feed. The effects of temperature, pressure, feed composition, space velocity, and mass velocity were studied. Carbon deposition did not affect the activity of the catalyst and could be remove

ISSN:0001-1541    

DOI:10.1002/aic.690020110

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY

摘要:

AbstractThe physical processes are discussed by which a fluid is displaced from a porous medium during steady state viscous flow by another fluid of the same density and viscosity under conditions of complete miscibility of the two fluids. The displacement occurs on a microscopic scale as a result of combined convective and diffusional mixing. The length of the zone of mixing which comprises the displacement front is predicted to be dependent upon the rate of flow, the diffusion coefficient for the two‐fluid system, the characteristics of the pore geometry, and the distance the front has traversed at the time of its observation.Experimental data are presented for the displacement of benzene by ethyln‐butyrate at several rates of flow from packed sand columns. These data show that the length of the frontal mixing zone after a prescribed distance of flow is greater at the higher rates of flow. The postulated dependence of the length of the front upon the diffusion coefficient and the pore geometry has not yet been investiga

ISSN:0001-1541    

DOI:10.1002/aic.690020111

出版商:American Institute of Chemical Engineers    

年代:1956

数据来源: WILEY