Fluid Beds: At Last, Challenging Two Entrenched Practices

摘要: Originating in the 1920' s and 1930's, two distinct fluidization arts have emerged, one for treating coarse solids other fine powders. Fluidization research has tended to focus on bubbling beds of solids, but designers such burning coal learned appreciate importance combustion char particles freeboard. Designers successful processes powders focused bubble suppression. Since about 1980, fluid both types are challenging conventional pulverized-coal boiler; they provide better means controlling emissions from high-sulfur fuels. Progress "bubbleless" is increasing bed's competitiveness with fixed-bed catalytic reactor. Efforts advance bed catalysis, besides gas velocities beyond levels that most researchers used past, must include systematic study level smaller than 40 micrometers.