Solids mixing in a spouted, fluidized bed, cold flow model
Solids mixing and jet penetration were studied in a half-cylindrical, 8-inch diameter, cold-flow model of a spouted fluidized bed. Experimental data were collected for various gas flows through a multi-annular jet with continuous solids feed at two pressures, 14.5 and 22.7 psia. The internal circulation rates of solids flowing into the centrally located jet were measured analyzing video taped recordings and high-speed pressure fluctuations. Particle beds which surrounded the jet can be considered in three regions: fixed bed, moving bed, and minimum fluidized bed zones. The inlet jet or spout exhibited a well defined, high velocity, dilute jet which penetrated at the conical-shaped base of the fluid bed through the fixed bed and downward flowing moving bed zones without significant radial spreading. The dilute spout continued its upward penetration until radial leaking gas imparted sufficient flow to the outer, downward-flowing annulus of solids causing the relative velocity between the gas and solids to exceed the solids' minimum fluidization velocity. In this fluid bed region, the local solids transfer rate into the jet was much greater than that in the lower, moving-bed and fixed bed regions. Above this point the jet reached its maximum penetration dependent on process conditions. At this location the bed was fluidized or bubbling, but further up, the fluid bed gas bubbles gathered to form a slugging bed. These bed attributes were quantified and, where possible, correlated with process variables. Process indications for relative mass flow rates are suggested.
- Research Organization:
- Dept. of Energy, Morgantown, WV (US)
- Sponsoring Organization:
- US Department of Energy
- OSTI ID:
- 20006779
- Report Number(s):
- CONF-990534--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Minimum spouting velocity of flat-base spouted fluid bed
Fluidization and fluid particle systems: Recent advances