DETERMINATION OF PRESSURE-DROP COEFFICIEN TS IN GAS-SOLID DIPHASIC FLOWS IN BENDS

The aim of the study is to determine the singular pressure drop coeffi cients zeta(bm)' used in gas-solid diphasic dilute and dense dilute fl ow in sharp bends. Visualization of this flow at singularities permits us to understand the aerodynamic comportment of particles and to form ulate accurate hypotheses on flow comportment in bends. Many measures of pressure on the wall in different parts of the pipe on each side of the singularity with ten different materials, characterizing a large range of Geldart classification types, enable us to determine the sing ular pressure drop coefficients of these different materials. Finally, a simplified model estimating the pressure drop coefficients is propo sed with a critical comparison between the numerical and experimental results. It permits us to define the limits of the validity of the mod el.