A. Bascoul

Measurements of local interfacial area: application of bi-optical fibre technique

Local mean interfacial area in gas-liquid bubbly flow is experimentally investigated; data is obtained from the experiments carried out with a double optical sensor intrusive probe and analysed by statistical methods. Local variables are measured in the riser of an external loop airlift reactor in air/water medium. The results are presented in the form of the radial profiles of void fraction, bubble diameter and local average interfacial area at superficial gas velocities ranging from 0.003 to 0.1 m/s. The axial variations of the same parameters are also investigated. The values of local interfacial area obtained from the classical equation (ā i t =6e g /đ 32 ) and from bubble velocity statistical treatment methods agree reasonably well. This shows that the double optical probe is a reliable method for local measurements of interfacial area. Eventually, the maximum angle α 0 between the probe vertical direction and bubble velocity vector at the piercing point is evaluated and the influence of gas superficial velocity on α 0 is demonstrated.

Mouvement des particules solides en fluidisation liquide solide

Abstract Solid motion in liquid fluidized beds has been analysed using a radioactive particle and two detection devices partly superimposed, dividing the be Particle velocity was determined by two different estimations, using the net flux across a zone frontier and the residence time between two successive Particle dispersion coefficients, determined from residence time distribution, were also strongly increasing with increasing liquid velocity. It was co

Glucose oxidation in a three-phase stirred airlift reactor: experiments and model

The three-phase catalytic oxidation of glucose into gluconic acid is studied in a new type of reactor: a stirred internal-loop airlift reactor. The influence of oxygen flow rate and of agitation on reaction rate are experimentally checked. By means of a model, a better knowledge of the reaction kinetic order for oxygen is reached.