摘要:

AbstractA model which describes the operation of a fibrous bed coalescer is presented. From this model, a theoretical equation can be derived for the filter coefficient, λ, at small velocities where the effect of turbulence is negligible. This expression which considers the void fraction of the bed, ϵ, the drop diameter, dp, the average saturation, Sm, the fiber diameter, dP, and the effective fiber diameter dfe, is:where β is the fraction of collisions which lead to coalescence. At larger velocities, a suitable empirical equation is obtained by multiplying the above expression by the square root of the velocity at which the filter coefficient begins to decrease divided by the superficial velocity. These equations describe the data of various workers.A method of obtaining the average saturation in a fibrous bed is presented. A possible correlating equation is found to be:where U is the superficial veloci

ISSN:0008-4034    

DOI:10.1002/cjce.5450520102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractThe phenomenon of turbulent diffusion was studied by using computed models. Free pseudo‐turbulent fluid flow was simulated on a digital computer by ensembles of randomly positioned moving and interacting vortices to represent the eddy structure of the turbulence. A vortex model, which had statistical values corresponding to a measured real flow in an Eulerian frame of reference, was then obtained. By considering the motion of a particular vortex or a fluid particle in the computed pseudo‐turbulent flow it was possible to determine measurements in a Lagrangian frame of reference. Estimates of the mean square lateral excursions of a marked particle were obtained and finally the Lagrangian auto correlation was compared with the auto correlation in a moving frame of refere

ISSN:0008-4034    

DOI:10.1002/cjce.5450520103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractA rapid finite‐difference procedure for computing stagnation point flows at a given Reynolds number in terms of stream function and vorticity distributions is described. The method is illustrated for spherical and cylindrical curvature for Reynolds number ranges of 1 ≤ Re ≤ 400 and 4 ≤ Re ≤ 100 respectively. Predicted radial and angular velocity distributions in the frontal region are compared with results from numerical solutions of the full elliptic equations of motion. The use of a modified potential flow outer boundary condition reduces the region of numerical co

ISSN:0008-4034    

DOI:10.1002/cjce.5450520104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractTwo‐phase gas‐liquid flow has been investigated in a 1‐inch internal diameter vertical tube coil containing two risers and a downcomer all connected by “U” bends. Flow pattern data were obtained in the three vertical tubes, each 17.30 ft. long, for five different air‐liquid systems at about 25 psia over flow ranges of 0–700 lbmair/min‐ft2and 140–25300 lbmliquid/min‐ft2. Liquid phase viscosities ranged from 1 to 12 cp.A flow pattern classification with six regimes including coring‐bubble, bubbly‐slug, falling film, falling bubbly‐film, froth and annular flow regimes was established for downflow. Flow patterns in the bends were also classified.Data from the present investigation were used to formulate an empirical flow pattern graphical correlation for both upflow and downflow which is based upon the coordinates (Rv)1/2and FrTP/A, where Rvis the delivered gas‐to‐liquid volume ratio, FrTPis the mixture Froude number, and A = μs/(SLσs3)1/4in which μs, SL, σsare specific viscosity, specific density and specific surface tension respectively of the liquid with reference to water. The correlation was satisfactorily tested with independent literature data for upflow systems, including air‐water, steam‐water at various pressures, nitrogen‐mercury and air‐heptane, and data from flowing gas‐oil wells. No independent literature data appear to be available for testing the correlation for downflow systems, but it is anticipated that the correlation will prove to be generally applicable.The coring phenomenon in downward bubble flow was examined by means of high speed motion photography and is explained by

ISSN:0008-4034    

DOI:10.1002/cjce.5450520105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractStudies carried out on the absorption of hexane from inert carrier gases into paraffin oil have shown that mass transfer can affect flow characteristics in unstable vertical two‐phase flow. In the absence of mass transfer chain‐flow patterns prevailed. These patterns were broken when mass transfer took place from the gas to the liquid phase. Bullet shaped slugs were then formed, the slugs pairing and coalescing as they rose up the column. The direction of mass transfer was critical no effect on flow pattern being observed when mass transfer took place from the liquid to the gas phase.Slug frequencies and slug sizes were found to be influenced by mass transfer and an effect of overall absorber length was observed. Individual slug sizes and separation distances were measured and varied widely even under constant flow conditions. Rise velocities were correlated using an equation of the form:where C2was a function of the fluid flow‐rates and system physical‐pro

ISSN:0008-4034    

DOI:10.1002/cjce.5450520106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractA mathematical model has been developed for prediction of the performance of a continuous ion‐exchange column, comprising a series of fluidized beds of resin, operated with periodic flows of both phases. Simple small‐scale tests provide the data required in calculations. Experimental work was carried out on uranium extraction from unfiltered ore leach pulps and clarified liqu

ISSN:0008-4034    

DOI:10.1002/cjce.5450520107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractA new algorithm was developed for the solution of the equations that describe multicomponent, multistage separation processes operating at steady state. The algorithm is based on the use of newly defined energy and volatility parameters as the primary successive approximation variables. A third parameter was defined for each stage as a unique combination of the liquid and vapor phase rates and the temperature, and the quasi‐Newton method of Broyden was employed to iterate on these parameters. The exceptional stability of the new algorithm in very difficult cases, as well as its efficiency in easy cases, are demonstrated using a variety of example problem

ISSN:0008-4034    

DOI:10.1002/cjce.5450520108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractA six inch diameter sieve plate absorption column was used to assess the effect of perforation size on the performance of sieve trays under otherwise identical conditions. Four separate test trays with equal gas flow areas but perforations of 1/8‐inch, 1/4‐inch, 1/2‐inch and 1‐inch respectively, were used with the liquid phase absorption‐controlled system of carbon dioxide — water at 77°F and approximately 830 mm. mercury.Comparisons of overall efficiencies indicated that the trays with 1‐inch diameter perforations had efficiencies similar to, or slightly lower than those of 1/8‐inch diameter. Concentration profiles within the froth were measured, with distinct profiles being observable in both the horizontal and vertical directions.This indicated that neither the plug flow nor the completely mixed models accurately described the actual transfer process. Accordingly, comparisons of volumetric mass transfer coefficients computed from both models were made. Comparison of volumetric mass transfer coefficients showed that for most gas and liquid flowrates the plates with 1‐inch perforations performed as well as plates with smaller holes. For this system it was concluded that trays with large holes would be much better suited to fouling services and, indeed, they would be only marginally less attractive than trays with smaller hole

ISSN:0008-4034    

DOI:10.1002/cjce.5450520109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractThe gravity‐viscous spreading of crude oil on artificially prepared ice surfaces was investigated. Five different types of crudes were studied with three surface roughnesses at ‐14°C. Crude oil No. 1 was also studied at ‐8 and ‐3°C. All spreading experiments were made with an oil volume of 45 and 20 ml. Regardless of temperature, surface roughness, oil type and oil volume, all data may be correlated by: where ρ, V and μ are the density, volume and viscosity of the oil, respectively, R is the radius of the oil slick, t is time, C is a constant and g is the acceleration

ISSN:0008-4034    

DOI:10.1002/cjce.5450520110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY

摘要:

AbstractIn an effort to obtain a macroscopic model predicting the effect of ultrasonics on chemical reactions, irreversible thermodynamic coupling between the chemical reaction rate and the trace of the viscous pressure tensor is investigated. The analytical predictions of the proposed model will be verified by the presentation of experimental data showing the effect of ultrasonics on the reaction rates near equilibrium conditions for the hydrolysis of methyl acetate.

ISSN:0008-4034    

DOI:10.1002/cjce.5450520111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1974

数据来源: WILEY