ISSN:0001-1541    

DOI:10.1002/aic.690010301

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractValues of thermal conductivity and temperature coefficients for fifty‐three pure organic liquids, obtained with newly designed, extensively tested apparatus, are presented. For thirty‐one of these liquids values of thermal conductivity or temperature coefficients have not been previously reported. The statisically determined maximum error in the presented values of thermal conductivity of liquids is ±1.50%.A method of correlating the thermal conductivity of liquids based on a modified statement of the theory of corresponding states is presented. Group contributions to the thermal conductivity were calculated. The thermal conductivity of liquids was predicted by this method and the average deviation of the calculated from the observed values for forty‐seven liquids is ±1.50%. The proposed method of correlation permits the calculation of the thermal conductivity of a series of liquids at any temperature from a single know

ISSN:0001-1541    

DOI:10.1002/aic.690010302

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractThe splitting of globules is an important phenomenon during the final stages of disintegration processes. Three basic types of deformation of globules and six types of flow patterns causing them are distinguished.The forces controlling deformation and breakup comprise two dimensionless groups: a Weber groupNWeand a viscosity groupNVi. Breakup occurs whenNWeexceeds a critical value (NWe)crit. Three cases are studied in greater detail: (a) Taylor's experiments on the breakup of a drop in simple types of viscous flow, (b) breakup of a drop in an air stream, (c) emulsification in a turbulent flow.It is shown that (NWe)critdepends on the type of deformation and on the flow pattern around the globule. For case (a) (NWe)critshows a minimum value ∼ 0.5 at a certain value of (NVi) and seems to increase indefinitely with either decreasing or increasing ratio between the viscosites of the two phases. For case (b) (NWe)critvaries between 13 and ∞, depending onNViand on the way in which the relative air velocity varies with time, the lowest value refers to the true shock case andNvi→0. For case (c) (NWe)crit, which determines the maximum drop size in the emulsion, amounts to ∼1, and the corresponding values ofNViappear to be small. A formula is derived for the maximum dr

ISSN:0001-1541    

DOI:10.1002/aic.690010303

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690010304

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690010305

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractApplication of a dynamic or unsteady‐state technique to the problem of radial mixing in a tube is described. Measurement of the amplitude attenuation suffered by a sinusoidally modulated gas composition wave as it flows within an open (unpacked) tube makes possible the direct determination of an “equivalent gas film thickness” from which a mass transfer film coefficient may be readily calculated.A brief summary of the method employed for obtaining the necessary mathematical relationships is presented, along with descriptions of the techniques developed for measurement of small amplitude differences at wave frequencies as high as 10 cycles /sec.Experimentally, conditions were varied to include a range of Schmidt number from 0.18 to 1.24 and of Reynolds number from 4,000 to 50,000. The results of this work appear to fall nearly in line with the semitheoretical equation of Martinelli as written for mass transfer. Generally speaking, a was found to be an increasing function ofNSc, varying from about 0.5 to a maximum of 0.77; β, in turn, was found to increase withNRefrom 0.3 to 0.5.A suggestion for extending the method to measurement of eddy diffusivities in the axial direction is in

ISSN:0001-1541    

DOI:10.1002/aic.690010306

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractBinary vapor‐liquid equilibrium data for use in the successful design and operation of mass transfer equipment at pressures down to approximately 5 mm. Hg may be advantageously obtained by the method of total pressures. In this method the desired equilibrium data are derived from pressure vs. temperature measurements on a convnient number of made‐up solutions covering the entire composition range.With a modified Smith and Menzies isoteniscope, it is possible to measure accurately the data required for making the equilibrium calculations down to 2 mm. abs. pressure without the “bumping,” supercooling, and superheating encountered with equilibrium stills. The isoteniscope is simple to construct and operate from 1 atm. to 2 mm. abs.The use of the total pressure method and the isoteniscope is illustrated by the determination of the vapor‐liquid equilibrium in the aniline‐nitrobenzene system at 5 and 10 mm. abs. In nineteen out of twenty instances the vapor compositions for a given liquid composition are precise to within ± 0.9% and the relative volatility, which varied between 2.54 and 1.85 over the composition and temperature ranges, is precise w

ISSN:0001-1541    

DOI:10.1002/aic.690010307

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractThe oxidation of ammonia in the presence of manganous oxide‐bismuth oxide catalyst supported on small alumina spheres was studied in both fixed and fluidized beds in the temperature range from 205° to 250°C. The column used was 4½ in. in diameter and 43 in. high. The experiments were made so that the transport effects in the fluidized bed might be separated from the chemical kinetic effects.In accordance with the theory of two‐phase fluidization proposed in a previous paper, comparison is made between the reaction rate associated with the discontinuous phase and that associated with the continuous phase as estimated from the results in the fixed bed. The over‐all reaction‐rate constants in the fluidized bed can be related to those in the fixed bed by an exponential term in the superficial gas velocity,Vn;nis a constant which depends on the reaction system and the size and type of t

ISSN:0001-1541    

DOI:10.1002/aic.690010308

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractExtraction studies were made with the systems toluene water benzoic acid and kerosene water benzoic acid in two dimensionally similar cylindrical extractors, one 6 in. in diameter by 6 in. high, the other 12 in. in diameter by 12 in. high. Each extractor contained four radial baffles, of width equal to 16.7% of the extractor diameter. The extractors were agitated by six‐bladed dimensionally similar turbine impellers, the diameters of which were in each case one third the diameter of the extractor.When the extractors were full of liquid, i.e., in the absence of an air‐liquid interface, the power required for a given impeller speed was independent of the rate of flow of liquid. However, such operation required more power than the equivalent open‐tank agitator, and more baffling was required to produce fully turbulent flow.Flow rates were varied from 0 to 4,000 lb./hr. and solvent‐to‐water mass ratios from 3:1 to 1:6. Extraction stage efficiencies were found to be appreciable even at zero agitator speed.The additional stage efficiency produced by agitation was found to be a function of the power input per unit volume of liquid flowing. This relationship permitted the correlation of all extraction efficiency data for a given system at a constant solvent‐to‐water ratio over eight‐fold range of power input. It was found possible to predict the performance of an extractor in continuous flow from batch‐extraction measurements through the methods of Ma

ISSN:0001-1541    

DOI:10.1002/aic.690010309

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractRate data are presented for both the constant ‐ and the falling‐rate drying of closely sized spheres of silica‐alumina hydrogel. This hydrogel, which contains a fine powder, is the starting material from which petroleum cracking catalysts may be prepared. During the constant‐rate period the drying rate is directly proportional to the difference between the dry‐ and wet‐bulb temperatures of the air. In the falling‐rate period the rate is proportional to the free water content, the proportionality factor being an undetermined function of the dry‐bulb‐wet‐bulb differential.Drying severity during the falling‐rate period is shown to be the major determinant of the final pellet density. At constant wet‐bulb temperature, density is inversely related to the dry‐bulb‐wet‐bulb differential. If this differential is held constant, density is directly related to the wet‐bulb temperature.The variation in drying rate with position in the bed for through‐circulation constant‐rate drying of deep beds of particles is analyzed for the case where the direction of air flow is periodically reversed for equal time intervals. It is indicated that uniformity of drying should increase with an increase in air velocity, but decrease as bed depth is increased. At constant conditions and bed depth, large particles should dry more uniformly than small. Within normal operating ranges, air temperature and humidity should have

ISSN:0001-1541    

DOI:10.1002/aic.690010310

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY