MODELING OF GAS DISPERSION AT TUYERES IN REFINING BY A 2-DIMENSIONAL SYSTEM

Gas injection and globe-growth processes in refining can be investigat ed by three-dimensional modelling studies, but the opacity and distort ion of the 3-D gas-liquid interface prevents direct observation of the internal dynamic gas-liquid interactions which lead to bubble instabi lity and break-up. This paper examines the use of a thin pseudo 2-D sy stem to reveal interface and impingement behaviour, the role of the tu rbulent gas jet in the jet cavity and insights into gas globe stabilit y. The bubble formation sequence for horizontal injection is studied t heoretically and by experiment in a water model, and bubble shape, gas jet penetration and the wave behaviour of the gas-liquid interface ar e investigated by use of high speed cinematography. Wave instabilities produced by glancing contact of the gas jet on the lower gas-liquid i nterface are shown to generate droplets that contribute to globe disru ption. Jet cavity penetration and wave behaviour are weakly related to the nozzle modified Froude number. For a modified Froude number range of 5.0-2917, wavelengths were of the order of 7.0-16.0 mm. Copyright (C) 1996 Canadian Institute of Mining and Metallurgy. Published by Els evier Science Ltd