Fluid to Particle Mass Transfer Studies in Downers

Gases to particle mass transfer coefficients are measured in a downer. The effects of gas velocity, solid flux and particle size on Mass transfer coefficients are studied. The effect of downer diameter on Mass transfer coefficients was studied by plotting Mass transfer coefficients in terms of dimensionless parameters. Downers are down flow fluidized beds. They offer several advantages compared to risers. 1. Reduced gas and solid back mixing. 2. Reduced contact time between different phases 3.Better control over the reactions. These advantages become significant in several fields where down flow fluidized beds (downers) are used e.g. petroleum industry (FCC), glass industry, fertilizer industry, etc. Some studies have already been done on other parameters of downers like Heat transfer, Particle velocity profiles, etc. The present work reports experimental observation on fluid to particle mass transfer in downers.