摘要:

AbstractThe performance of a horizontal liquid‐air ejector system was greatly enhanced by creating mixing shock. Principles of macroscopic momentum and energy balances were employed to define an overall loss factor which was found to be a useful correlating parameter in the case of homogeneous bubble flow. Empirical correlations are proposed to predict mass ratio as a function of different parameter

ISSN:0008-4034    

DOI:10.1002/cjce.5450500301

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

年代:1972

数据来源: WILEY

摘要:

AbstractFinite difference numerical solutions have been obtained to the Navier‐Stokes equations for entry‐region flow in a falling liquid film issuing from a slot. The iterative method developed does not neglect surface tension forces, however the effect of surface tension on the film acceleration is shown to be small. The results show a smooth transition between the initial velocity profile and the final fully‐developed profile. The starting length, defined as the distance required for the surface velocity to reach 95% of its final value, is on the order of 20 times the initial film thickness and increases with Reynolds number. A comparison of the calculations with available experimental data shows fair agre

ISSN:0008-4034    

DOI:10.1002/cjce.5450500302

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

年代:1972

数据来源: WILEY

摘要:

AbstractA general one‐dimensional theory for predicting the average holdup or column concentration in three phase flow is formulated. The analysis takes into account the local relative velocity between the phases, the non‐uniform flow and holdup distribution across the column, and the effect of the concentration of the dispersed phase on the relative velocity. The present theory is compared with the previous analyses for two phase flow reported in the literature and it is shown that all of them are special cases of the general theory proposed h

ISSN:0008-4034    

DOI:10.1002/cjce.5450500303

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

年代:1972

数据来源: WILEY

摘要:

AbstractExperimental data on air‐water‐glass beads system flowing cocurrently and countercurrently in a vertical column 1.5‐in. ID and 5‐ft. long at 1 atm. and room temperature are presented. The ranges of variables studied were: superficial gas velocity 0 to 2.55 cm/sec upward, superficial liquid velocity 7.6 cm/sec downward to 32.2 cm/sec upward, input solid concentration in the the slurry 0 to 6% by volume and the mean diameter of solid particles 0.0118 and 0.0059‐in. All flows involving gas were in the bubbly regime. The experimental data were in good agreement with the theory presented

ISSN:0008-4034    

DOI:10.1002/cjce.5450500304

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

年代:1972

数据来源: WILEY

摘要:

AbstractA nondisturbing photochromic dye trace technique has been employed to study the flow profiles of water‐alcohol solutions containing the drag reducing polymer Polyox at concentrations of 0.55 to 5.5 ppm. Drag reductions of from 33 to 75% were observed in a smooth glass pipe. The dye traces show a thicker wall layer for the drag reducing solutions than that for the solvent alone. The core region is relatively unaffected by the polymer at 0.55 ppm and at 5.5 ppm the relative thickness of the turbulent core region has been greatly reduced. Earlier, unpublished work of Corinthios shows effectively no core at 33 ppm. Mean velocity and apparent axial turbulence intensity profiles obtained are in general agreement with previous data in the literature obtained with other methods and in the wall region the low frequency intensity is greater than that of the pure solvent. This is consistent with the results of Spangler but not those of Seyer. Higher low frequency intensities measured in the wall region suggest that higher frequency fluctuations are suppressed and/or that the time stability of eddies is increased as indicated by the reduced frequency of wall ejections in drag reducing solution

ISSN:0008-4034    

DOI:10.1002/cjce.5450500305

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

年代:1972

数据来源: WILEY

摘要:

AbstractIt has been found that the supported metal catalyst, chromia on alumina, prepared in the presence of ultrasonics (90 kHZ) is a more active catalyst for the decomposition of hydrogen peroxide (8N aqueous solution) than the catalyst prepared in the absence of ultrasonics. The catalyst preparation consisted of insonation for one hour during the impregnation stage and subsequent drying and calcination. The activity measurements were carried out at 25, 30, 40, 50 and 60°C in a batch reactor. The higher activity of the insonated catalyst has been explained on the basis that chromia is better dispersed on alumina in case of the insonated catalyst. The conclusion for the better dispersion of metal in the insonated case is based on BET surface areas and pore volumes and on electron microprobe analyser measurements of chromium metal distribution

ISSN:0008-4034    

DOI:10.1002/cjce.5450500306

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

年代:1972

数据来源: WILEY

摘要:

AbstractLes auteurs montrent l'influence de plusieurs paramètres sur l'intensité du court‐circuit, dans un réservoir imparfaitement agité en régime continu. On a utilisé plusieurs formes d'agitateurs, plus particulièrement l'hélice de type marin.De façon génerale, le court‐circuit diminue quand la vitesse de l'agitateur augmente. Aux faibles vitesses, toutefois, le court‐circuit est souvent supérieur à celui qui existe quand l'agitateur est au repos. On explique la nature du court‐circuit maximum qui se manifeste à une certaine vitesse de l'agitateur.L'intensité du court‐circuit diminue en général lorsque le diamètre de l'agitateur augmente et quand la distance entre l'entrée et la sortie augmente. Par contre, le court‐circuit augmente avec le débit.En présence de chicanes, le court‐circuit est peu ou pas influencé par la largeur, la posi

ISSN:0008-4034    

DOI:10.1002/cjce.5450500307

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe solubility of hydrogen in ammonia, monomethylamine, monoethylamine andn‐propylamine was determined at temperatures from −70°C to 25°C and in 1,2‐propanediamine and 1,2‐ethanediamine over the temperature ranges −25°C to 11°C and 25°C to 34°C respectively. Measurements were made at total pressures up to 300 psig. The solubility data were correlated in terms of Henry's law and the solubilities are in the range 1 × 10−5to 3 × 10−4mole fraction at a hydrogen partial pressure of 1 atmosphere. The measured solubility data were used to extend a correlation proposed by Yen and McKetta. This revised correlation may be used to estimate the solubility of hydrogen in pol

ISSN:0008-4034    

DOI:10.1002/cjce.5450500308

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

年代:1972

数据来源: WILEY

摘要:

AbstractA simplified form of perturbation theory for mixtures is applied to the prediction of gas solubility in mixed solvent systems. A method for the determination of Henry's Law constants for gases as a function of solvent composition for any general multicomponent solvent mixture is presented. The theory requires molecular parameters and solvent density to predict the gas solubility. For the accurate prediction of solubility of complex molecules if is necessary to use gas solubility data for the pure solvent; however, solvent mixture activity coefficient data are not required. Comparisons with experimental results indicate that the theory works well for both polar and nonpolar solvent mixtures, provided that the dissolved gas does not chemically combine or associate with the solvents.

ISSN:0008-4034    

DOI:10.1002/cjce.5450500309

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe design of sampled‐data controllers for a binary distillation column was studied for several types of controllers and for various control tray locations, sampling rates and disturbances. Minimal prototype control was superior to continuous PI control under some conditions but, as expected, was only satisfactory for a specified disturbance.dual “A” control scheme that compensates for both setpoint and load disturbances was developed. Two separate algorithms are implemented simultaneously, one receiving its input signal from the setpoint and the other from the measured variable. Dual control is superior to continuous control, particularly when both disturbances are encountered at the same time, and is superior to the “switching” method proposed by Mos

ISSN:0008-4034    

DOI:10.1002/cjce.5450500310

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

年代:1972

数据来源: WILEY