摘要:

AbstractPipeline transportation of heavy oils as oil‐in‐water emulsions has been proposed as an alternative to blending the crude oil with natural gas condensate or other diluent. An 18 m long, 0.02 m I.D. closed loop was constructed to investigate the behaviour of an emulsified Cold Lake crude oil under pipeline flow. Pressure drop was measured as a function of flow rate for freshly produced emulsions to establish correlations of friction factor versus Reynolds number. Stability was observed for long term pipeline flow. The time at which the emulsion breakdown occurred was found to be a function of oil concentration and shear rate. The breakdown of the emulsion was clearly indicated by a simultaneous change in the system variables of pressure drop, temperature and power required to turn the pump at constant sp

ISSN:0008-4034    

DOI:10.1002/cjce.5450650301

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe effect of particles on entrainment into free jets has been reexamined. As previously reported, particles can increase, decrease or have no effect on jet entrainment. This study suggests that the effect correlates with the ratio of particle stopping distance to nozzle diameter. For values of this ratio less than 3 entrainment increases due to the presence of particles. For values of the ratio between 3 and 65, entrainment is decreased. For values greater than 65, the presence of particles in the jet has no effect on entrainment. If the suggested correlation proves to be correct, it will assist the design engineer who wishes to rapidly mix particles with surrounding gas in a free jet. In particular, the region where a decrease in entrainment is observed should be avoided as there will be a corresponding decrease in mass and heat transfer.

ISSN:0008-4034    

DOI:10.1002/cjce.5450650302

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

年代:1987

数据来源: WILEY

摘要:

AbstractHydrodynamic measurements were obtained in a flat‐based half‐cylindrical column of diameter 0.91 m and inlet orifice diameters of 76 to 114 mm. Beds of 3.5 to 6.7 mm diameter particles with static depths of 0.53 to 1.83 m were spouted with air. In agreement with measurements by earlier workers in smaller columns, it was found necessary to operate with inlet orifice diameters less than about 30 times the mean particle diameter in order to be able to achieve stable spouting. Correlations for minimum spouting velocity developed on small vessels generally gave poor predictions for the large diameter vessel employed in this work and failed to predict the observed dependence ofUmson the static bed height. Substantial dead regions where particles were stagnant were observed in the lower outer portion of the vessel. Other aspects of behaviour studied, including spout diameters and shapes, fountain heights, pressure profiles and gas velocities in the annulus, were qualitatively similar to those in smaller columns, although equations developed for the smaller vessels did not always provide accurate predicti

ISSN:0008-4034    

DOI:10.1002/cjce.5450650303

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

年代:1987

数据来源: WILEY

摘要:

AbstractAxial mixing measurements in single phase (water) flow have been taken in open‐type reciprocating plate columns of diameters 25.4 and 508 mm. In the case of the smaller column, two‐phase axial mixing was measured, both in the dispersed phase (water dispersed in n‐heptane) and the continuous phase (with n‐heptane dispersed in water). Pulse injection of a tracer solution of ammonium chloride and methanol in water was used.Under single phase conditions, the axial dispersion coefficients were found to go through a minimum as the agitation level was increased from zero. The coefficients were nearly an order of magnitude higher in the 508 mm column than in the 25,4 mm column. In two phase flow in the 25,4 mm column, the continuous phase axial dispersion coefficients also went through a minimum as agitation was increased. The dispersed phase axial dispersion coefficients decreased monotonically as agitation was increased from zero. The results of this work and previous data are used in modelling the scale‐up of reciprocating plate columns by means of Pratt's simplified technique. The existing empirical scale‐up equation is consistent with an assumption that continuous phase mixing increased with column diameter but dispersed phase mixing remain

ISSN:0008-4034    

DOI:10.1002/cjce.5450650304

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

年代:1987

数据来源: WILEY

摘要:

AbstractEquations for the radial and linear drainage of non‐Newtonian fluids in horizontal and inclined films are presented. For a power law fluid with index m, the variation in dimensionless film thickness Δ with dimensionless time T is given by:\documentclass{article}\pagestyle{empty}\begin{document}$$ T = \frac{{\left( {2m + 1} \right)}}{{\left( {m + 1} \right)}} \cdot \frac{1}{{\Delta ^{\left( {m + 1} \right)/m} }} $$\end{document}where Δ and T are appropriately defined for drainage in radial horizontal and linear inclined films. The corresponding approximate expression for a Bingham plastic fluid is:\documentclass{article}\pagestyle{empty}\begin{document}$$ T = \frac{2}{{A^2 }}\left\{ { - \ell n\left( {1 - \frac{A}{\Delta }} \right) - \frac{A}{\Delta }} \right\} $$\end{document}in which A is the minimum film thickness defined appropriately at the asymptotic limits when Δ » A and

ISSN:0008-4034    

DOI:10.1002/cjce.5450650305

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

年代:1987

数据来源: WILEY

摘要:

AbstractDarcy's law for the laminar flow of Newtonian fluids through porous media has been modified to a more general form which will describe the flow through porous media of fluids whose flow behavior can be characterized by the Herschel‐Bulkley model. The model covers the flow of homogeneous fluids with a yield value and a power law flow behavior.Experiments in packed beds of sand were carried out with solutions of paraffin wax in two oils and with a crude oil from the Peace River area of Canada. The model fitted the data well.A sensitivity analysis of the fitting parameters showed that the model fit was very sensitive to errors in the flow behavior index,n, of the Herschel‐Bulkley model. A comparison of the“n”values calculated from viscometer measurements and from flow measurements agreed well.A more general Reynolds number for flow through porous media, which includes a fluid yield value, was developed. The data were fitted to a Kozeny‐Carman type equation using this Reynolds number. The constant in the Kozeny‐Carman equation was determined for the two packed beds studied using Newtonian oils.The data could all be represented, within the experimental error, by the relationshipf*= 150/Re*. Since the mean volume to surface diameter of the packing was determined by the measurement of its permeability to a Newtonian oil, assuming C' = 150, the new definition of the Reynolds number allows the direct use of the Kozeny‐Carman equation with Herschel‐Bulk

ISSN:0008-4034    

DOI:10.1002/cjce.5450650306

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

年代:1987

数据来源: WILEY

摘要:

AbstractGas hold‐up structure was studied in a three phase sparged reactor of 200 mm diameter. Air and aqueous solutions of carboxymethyl cellulose were used as gas and liquid phases. Spherical glass beads formed the solid phase. The superficial gas velocity, rheological properties, particle size and solid loading were varied over a wide range and their effects on gas hold‐up structure were studied. A correlation for the estimation of the gas hold‐up as a function of superficial gas velocity, apparent liquid viscosity, particle settling velocity and solid loading was establ

ISSN:0008-4034    

DOI:10.1002/cjce.5450650307

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe fluid dynamics of stirred aerated slurry reactors with A‐310® propeller, 4‐blade 45° pitch turbine and 6‐blade Rushton disc turbine were studied over a wide range of gas flow rates. With respect to power consumption, gas hold‐up, and fluid dynamically limiting cases, viz., suspension and flooding, the Rushton disc turbine was found to be the best in stirred aerated slurry reactors. The influence of particle density, shape and mass fraction and of liquid properties on gassed critical stirrer speed,Njsg, and of gassed power input per unit volume,Pjsg, on particle suspension and gas dispersion, were investigated. Empircal correlations in combination with that of Zwietering were established for scale‐up design in three‐phase sl

ISSN:0008-4034    

DOI:10.1002/cjce.5450650308

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe ablation rate of frozen mixtures of water or wax with finely divided solids subjected to a turbulent axisymmetric water jet was investigated both experimentally and theoretically. The range of the water jet Reynolds number was 8700–29300 and the jet temperature varied between 22 and 60°C. The solids used were very fine kaolinite clay, titanium oxide and aluminium powder.The type of solids and their concentration were found to affect the ablation rate of ice‐solids and wax‐solids mixtures. This is mainly due to changes in the physical properties of the melt layer of the water‐solids or wax‐solids mixtures which forms between the impinging jet and the froze

ISSN:0008-4034    

DOI:10.1002/cjce.5450650309

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

年代:1987

数据来源: WILEY

摘要:

AbstractHydrodynamic studies of the two‐phase flow of air‐water mixtures were carried out in an innovative air‐lift system called the “Atara Piston Bubble Cannon Mixer”. Slug and churn flows were observed in the discharge tube. The bubble velocity in the slug flow regime and the pressure drop were measured. Bubble entrance effects, found to affect the pressure drop particular to this configuration, are explained The air‐lift pump performance is analysed and a hydrodynamic model is developed to predict the pumping capacity as a function of the ga

ISSN:0008-4034    

DOI:10.1002/cjce.5450650310

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

年代:1987

数据来源: WILEY