摘要:

AbstractEmpirical and theoretical correlations, published since 1940 are reported which predict liquid film mass transfer coefficients in packed columns. Brief comments on the usefulness of the equations are given together with the range of operating variables, where available. Dimensional constants in the empirical correlations have been recalculated for the cases where the original values were not in SI units.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610401

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

年代:1983

数据来源: WILEY

摘要:

AbstractA system of differential equations to obtain concentration and velocity distributions for quasi‐uniform particle slurry flows is presented. Numerical solutions for various flow conditions have been obtained using an explicit algorithm. A “supported load” concept is proposed to explain the type of interaction through contact between solid particles in neighboring layers or between particles and the pipe wall. In the analysis, the relative contributions of terms describing turbulent shear stresses, particle interactions, and mixing effects vary with the dimensions of solid particles.The approach is tested for four kinds of sand of narrow size distributions (d= .65 mm, .48 mm, .52 mm and 13 mm), flowing with water in pipelines of various diameters (between 50 and 500 mm), at concentrations below 40% by volume. The coefficients used to estimate local parametes of the two‐phase model are related to particle diameter. A comparison of numerical predictions and measurements of concentrations, velocities and headlosses shows the applicability of the model and the possibility of extrapolating available experimental

ISSN:0008-4034    

DOI:10.1002/cjce.5450610402

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe maximum centreline penetrations, l**, of cross‐current liquid jets in a Venturi scrubber were measured for orifice diameters,d, of 1.397, 2.108, 2.565 and 3.860 mm. The data are correlated by\documentclass[article]\pagestyle[empty]\begin[document]$$\[\frac{{l^{**}}} {d} = 0.1145\frac{{\rho _j V_j}} {{\rho _j V_j }}\]$$\end[document]for the range of conditions, 36 ≤ gas throat velocity Vg≤ 125 m/s; 1.2 ≤ liquid injection velocity Vj≤ 18 m/s;0.06 ≤ liquid to gas ratio\documentclass[article]\pagestyle[empty]\begin[document]$ 0.06 \le {\rm liquid}\,{\rm to}\,{\rm gas}\,{\rm ratio}\,{\rm L/G} \le 2\frac{{{\rm m}^3 \,{\rm of}\,{\rm liquid}}}{{1000\,{\rm m}^3 \,{\rm of}\,{\rm gas}}} $\e

ISSN:0008-4034    

DOI:10.1002/cjce.5450610403

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

年代:1983

数据来源: WILEY

摘要:

AbstractHydrodynamics and effective interfacial area in a 25 mm i.d. packed tube column were studied over a wide range of operating conditions for demister pad packings (DPP). Flow maps have been prepared. Values of effective interfacial area as high as 1880 m−1in the spray flow regime were obtained. Data on pressure drop and effective interfacial area have been correlated for different flow regimes. Values of liquid side volumetric mass transfer coefficient,kLa, were measured by absorption and desorption of oxygen in different packed tube columns containing Pall rings (standard and low height to dia. ratio), multifilament wire gauge packings (MFWGP) and DPP.kLawas found to vary from 0.017 to 0.34 s−1for DPP.Values of wall side solid‐liquid mass transfer coefficient,kSL, were obtained in a 25 mm i.d. copper tube column packed with MFWGP by the dissolution of copper in acidic dichromate solutions. Values of wall side heat transfer coefficient could be obtained by an

ISSN:0008-4034    

DOI:10.1002/cjce.5450610404

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe mass transfer characteristics of 0.2, 0.6 and 1.0 m diameter bubble columns having a low height to diameter ratio (0.6

ISSN:0008-4034    

DOI:10.1002/cjce.5450610405

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

年代:1983

数据来源: WILEY

摘要:

AbstractLiquid/liquid dispersion in static mixers has been investigated using Lightnin “In‐liner” mixing elements. The average drop size was found to decrease with increasing residence time, gradually approaching an equilibrium size whose magnitude agrees reasonably well with Kolmogoroff's theory for drop rupture in turbulent flows.The efficiency at which mechanical energy is utilized in the generation of new interfacial area was evaluated as a function of design and operating conditions and was found to be highest when the final drop size is much larger than the achievable equilibrium

ISSN:0008-4034    

DOI:10.1002/cjce.5450610406

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

年代:1983

数据来源: WILEY

摘要:

AbstractAn accelerated method for evaluating the compaction behavior of dense suspensions is presented, in which centrifugal force is used to enhance settling rates and a highly‐compensated compound pendulum is used to detect the resultant small shifts in centre of gravity.The results obtained by following the temporal variation in suspension characteristics indicate that a Richardson and Zaki type of equation can describe the subsidence of very concentrated suspensions. The exponentn, and the ultimate sediment compaction density were found to be strongly influenced by small changes in the physicochemical characteristics of the suspended solid

ISSN:0008-4034    

DOI:10.1002/cjce.5450610407

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe induced air flotation (IAF) of a highly stabilized oil in water (o/w) emulsion has been studied experimentally in a batch column 10 cm in diameter and 150 cm in height. Column performance was strongly affected by the method of air distribution. The main variables investigated were the type of air distributor (either porous plate, single hole plate, or multi‐hole plate), initial oil concentraton (30‐600 mg/L), oil drop size distribution of feed (1.0‐30 μm), surfactant type, and gas superficial velocity. Results were successfully analyzed in terms of a first order kinetic rate model which yielded a removal rate constant (K1) that varied from 2.0 to 60.0 h−1. Corresponding total organic carbon (TOC) removal efficiencies went from 20 to 99.9 percent, illustrating the wide performance range for the flotat

ISSN:0008-4034    

DOI:10.1002/cjce.5450610408

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

年代:1983

数据来源: WILEY

摘要:

AbstractA laboratory experiment has been made on the adsorption of the Cr3+ion on freshly‐precipitated titanium dioxide, in order to determine the effect of the concentrations of the Cr3+and H+ions in solution on the amount of the adsorbed chromium. The adsorption isotherms have been determined at 5 pH's (3.25 to 4.25). The adsorption at each pH is well shown by the Langmuir isotherm; it could be generalized by expressing the two parameters of the equation in function of the H+proton activity: the maximum adsorption capacity may be represented by a second‐degree polynomial (1/verbar;Hverbar;) and the adsorption constant by a power law.The general model proposed is the following:\documentclass[article]\pagestyle[empty]\begin[document]$$ X = \frac{{\left[ {92.0 + \frac{{9.1 \times 10^{ - 3} }}{{|{\rm H}^ + |}} - \frac{{1.5 \times 10^{ - 7} }}{{|{\rm H}^ + |^2 }}} \right]\left[ {\frac{{1.8 \times 10^{ - 7} }}{{|{\rm H}^ + |^{1.63} }}} \right]{\rm C}}}{{1 + \left[ {\frac{{1.8 \times 10^{ - 7} }}{{|{\rm H}^ + |^{1.63} }}} \right]{\rm C}}}$$\end[document]where X and C represent the adsorbed chromium concentration and the chromium concentration in solution, respectively.The aforesaid study has permitted to explain the coprecipitation of chromium (III) and titanium (IV) during the continuous neutralization of an industrial effluent containing both met

ISSN:0008-4034    

DOI:10.1002/cjce.5450610409

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

年代:1983

数据来源: WILEY

摘要:

AbstractProcessibility curves have shown that strong inorganic bases or anionic surfactants are effective as process aids in the hot water extraction of bitumen from oil sand, but maximum bitumen recovery for each oil sand type is the same for both types of aid. Nonionic surfactants were not useful and there was no general relationship between recovery and surface tension or pH. Bitumen recovery could be correlated with the fine solids component of oil sand. The amount of NaOH required to reach maximum recovery and the rate of aging of oil sand were also functions of the fine solids content. Shear during slurrying was also found to be important, and it was shown that, without a certain amount of mechanical energy, good bitumen recovery could not be achieved, regardless of how much process aid was used. A theory of processibility is proposed to explain the interactions among process aids, mechanical energy, oil sand fines, and age of oil sand after mining.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610410

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

年代:1983

数据来源: WILEY