摘要:

A theoretical expression based on the cell model has been developed to predict the dependence of the flow properties of a suspension in a wide range of solids concentration when the dispersing medium is a non-Newtonian liquid. Theoretical predictions show that the increase of the relative consistency coefficient of a suspension with increasing particle concentration is less dramatic when the flow index of the suspending medium is lower. Comparison with published data shows that the predictions of the present model for the relative consistency coefficient of a suspension in a non-Newtonian fluid are fairly accurate.

ISSN:0098-6445    

DOI:10.1080/00986448308940585

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This investigation focuses on slow, isothermal, two-phase flow of gas bubble suspensions in Separan solutions, prepared with the help of a sodium borohydride blowing agent at room temperature. The total residence time in these experiments is much smaller than characteristic times for growth or rise of bubbles. The variation of bubble volume fraction across a narrow gap between two planes, is recorded at two locations along the flow direction. This is done with a Cesium gamma-radiation source focused on a region of area.012 cm2in the flow plane, and a Sodium iodide detector across the channel yielding a resolution of.01 over the range of void fractions investigated from.02 to.08. This measurement allows us to identify conditions under which the two-phase flow may be described by a two fluid model with a uniform bubbly core and a bubble free wall layer. With this two phase flow structure, a relative viscosity equation for the suspension is used to compute an apparent viscosity. Such calculations indicate that the observed reduction in apparent viscosity for the two phase flow may be attributed to a bubbly core which is more shear thinning than the medium. The additional shear thinning factor for the suspension is related to the elasticity of the medium.

ISSN:0098-6445    

DOI:10.1080/00986448308940586

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Direct-contact heat transfer between two immiscible liquids in turbulent pipe flow is studied under non-boiling conditions. The salt water and BP-Transcal 65 heat transfer oil are used as immiscible liquids. The diameter and the length of the pipe are 1.33 cm. and 304 cm., respectively. The effects of oil volume fraction, inlet salt water concentration, average liquid velocity, inlet oil temperature and pipe length on the over-all volumetric heat transfer coefficient are investigated.

ISSN:0098-6445    

DOI:10.1080/00986448308940587

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448308940588

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448308940589

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The equations describing the retardation by surfactant of an essentially spherical droplet in creeping flow through an unbounded Newtonian liquid are developed in a general way. The concentration distribution is determined by convection and the coupled mass transfer processes of liquid-phase diffusion, adsorption kinetics, and surface diffusion. Assuming that mass transfer occurs rapidly, an asymptotic solution is obtained showing uniform retardation, treating both phases and all mass transfer mechanisms simultaneously. For slow mass transfer, an asymptotic solution is obtained for stagnant cap behavior.

ISSN:0098-6445    

DOI:10.1080/00986448308940590

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Various chemical, physical and mechanical methods to prevent unwanted deposition of mineral scale are briefly described. The suitability of the different methods, which largely depends on the specific features and requirements of the system involved, is discussed. Special emphasis is placed upon the threshold treatment, where the growth process is retarded by the addition of trace amounts of growth inhibitors. Growth experiments have been performed on barium sulfate and calcium sulfate dihydrate seed crystals. suspended in a supersaturated solution with and without organic bisphosphonates as inhibitors. Two methods are selected for the analysis of the growth data, A degree of inhibition is defined to obtain a quantitative description of the influence of a growth inhibitor on the growth rate of the crystals. In addition the influence of the molecular structure of various bisphosphonates with different substituents is shown. The effect of a bisphosphonate on the geometry of calcium sulfate dihydrate crystals is illustrated.

ISSN:0098-6445    

DOI:10.1080/00986448308940591

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A mathematical model for adsorption in a batch fluidized bed is developed considering fluidized bed behaviour. A criterion is also developed to determine the validity of the proposed model. The unsteady state equation of the model is solved by assuming a non-linear equilibrium relationship. A simple procedure is also evolved to estimate back the parameters of the equilibrium relationship from simple batch experiments. Experiments are reported on the adsorption of moisture in air on silica gel for various air flow rates and bed mass. The best values for the parameters of the assumed equilibrium relationship are estimated. It is found that a unique set of values for these parameters predict the experimental results satisfactorily for the whole range of variables studied, thus proving the applicability of the proposed method of obtaining the equilibrium relationship and the proposed model.

ISSN:0098-6445    

DOI:10.1080/00986448308940592

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor