A stochastic dispersion model in gas-liquid flow systems

✍ Scribed by R. Nassar; J. Schmidt; A. Luebbert

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 666 KB
• Volume: 47
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(92)85082-m

✦ Synopsis

A stochastic model is developed that gives the probability density of the axial displacement and of the flow-time of a particle with variable velocity in a gas-liquid flow system, such as a bubble column or an airlift loop reactor, where dispersion is dominated by rising bubbles. A property of the model is the fact that its variance is proportional to tc (1 < c < 2) which is in accord with results from heat-pulse experiments. As t approaches infinity, the variance of the model becomes proportional to t in accord with a diffusion-like model. On the other hand, as t approaches zero, the variance becomes proportional to 9 in agreement with the convective model. Thus, the present model gives a realistic description of the dispersion of particles in turbulent multiphase flows which cannot be adequately described by diffusion-like or convective models. Excellent fits of the model to flow-time data from airlift loop reactors have been obtained.