摘要:

A study of the dynamic interfacial tension behavior of reacting acidic oil/alkaline solutions has been conducted for both an artificially acidified synthetic oil and a real crude oil for four different alkalis at various concentrations. The IFT values between a 10 mM acidified synthetic oil and various 25 mM alkaline solutions, before the minimum IFT value was reached, were found to be in the descending order: KOH, NaOH, Na2SiO3and LiOH. The corresponding IFT values between diluted Lloydminster heavy crude oil and the same alkaline solutions, again before the minimum was reached, were found to be in the descending order: LiOH, NaOH, Na2SiO3and KOH. The crude oil exhibited lower minimum IFT values against alkaline solutions than the synthetic acidified oil. The general trend of decreasing IFT towards a minimum value followed by an increase in IFT thereafter was noted for all solutions tested.

ISSN:0098-6445    

DOI:10.1080/00986449608936501

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The separation of the constituent minerals of an ore is never achieved in one stage. It is carried out in multiple stages incorporating recycling of streams to increase the recovery of the required mineral. This paper outlines a methodology for designing a separation process system consisting of nonsharp separation stages and involving recycles and mixtures instead of pure component as products.

ISSN:0098-6445    

DOI:10.1080/00986449608936502

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Mass transfer from assemblage of irregularly shaped particles to fluid was analysed using a combination of “cell” and “channel” concepts. The theoretical analysis predicts that blending active grains with inert spheres will result in an enhancement of the mass transfer due to a decrease of the overlapping of the neighbour particles and to a change of the bed geometry. The comparison between the derived relationship and available literature and our own experimental data shows a reasonably good agreement.

ISSN:0098-6445    

DOI:10.1080/00986449608936503

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The creeping transverse flow of incompressible Carreau model fluids past an array of infinitely long cylinders has been analysed theoretically. The hydrodynamic interactions between cylinders have been simulated using a simple cylinder-in-cylinder free surface cell model. In this formalism, the overall mean porosity characterises an array of cylinders without any assumption regarding the actual geometrical arrangement of the individual cylinders. The resulting non-linear field equations have been solved approximately by employing the well known velocity and stress variational principles. The resulting upper and lower bounds are non-coincident and diverge increasingly with the rising extent of non-Newtonian behaviour of the liquid medium. However, the mean value of the drag coefficient deviates from the individual bounds by no more than 22% and therefore, the use of the arithmetic mean of the upper and lower bounds is suggested. The theoretical predictions reported herein encompass wide ranges of physical and kinematic conditions as follows: 1 ≥n≥ 0.2; 0.9 ≥ ϵ ≥ 0.3 and ∧ ≤ 500. The paper is concluded by presenting comparisons between the present predictions and the scant experimental results for two limiting cases, namely, for the flow of Newtonian fluids (n= 1) through assemblages of solid rods and random fibrous beds, and for the flow of power law liquids (i.e., for large values of ∧) through banks of rods. The correspondence is found to be satisfactory.

ISSN:0098-6445    

DOI:10.1080/00986449608936504

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor