Experiments were conducted in a 76 mm diameter jacketed riser of a dual-loop high-density circulating fluidized bed facility with FCC particles of 65 lm Sauter mean diameter as bed material. The suspension temperature and the average and local suspension-to-wall heat transfer coefficients were measured. After superimposing the heat transfer results when the suspension near the wall is allowed t...

Oxyfuel-firing of a steam boiler is a low risk high-efficiency technique for CO2 capture in a power plant. Oxyfuel-firing can be readily adapted to a new power plant or to retrofit applications. Development and design of pulverized coal and circulating fluidized bed oxyfuel boilers and balance of plant equipment have been conducted to identify the required specific features, which will maximize...

The history of fluidized bed technology dates back 60 years. Gasification of pulverized coal in the Winkler process during the 1920's marked the beginning of fluidized bed application. Consider­ ,able work done during World War II by U.S. oil companies to improve the catalytic cracking of kerosene led to the development of the Fluid Catalytic Cracking process. Fluidized bed technology later exp...

Two-interconnected fluidized bed systems are widely used in various processes such as Fisher-Tropsch, hot gas desulfurization, CO2 capture-regeneration with dry sorbent, chemical-looping combustion, sorption enhanced steam methane reforming, chemical-looping hydrogen generation system, and so on. However, most of two-interconnected fluidized beds systems require riser and/or pneumatic transport...

Complex hydrodynamic behavior of circulating fluidized beds makes their scale-up very complicated. In particular, large-scale lateral solids segregation causes a complex two-phase flow pattern which influences significantly their pe$ormance. Lateral solids segregation has been attributed to direct collisional interactions between particles as well as to interaction between gas-phase eddies and ...

the objective of this study was to examine the effects of the fluidized-bed drying me-thod on the final quality of two varieties of iranian rice, medium- and long grain. the re-sults were compared to that of paddy drying using a traditional method. rough rice was treated in the fluidized bed drier at 140ºc for 2 minutes. similar samples were dried for 8-10 hrs by the traditional method. dried s...

The objective of this work is to show a procedure for mesh generation in a fluidized bed using large eddy simulations (LES) of a filtered two-fluid model. The experimental data were obtained by [1] in a laboratory fluidized bed. Results show that it is possible to use mesh with less cells as compared to RANS turbulence model with granular kinetic theory flow (KTGF). Also, the numerical results ...

the presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. the aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coefficie...

CFB reactors are increasingly used for both gas catalytic and gas/solid reactions. Gas flow patterns in the riser are important in their design and subject of the present research. A literature review on the gas mixing in the riser highlights the contradictory results of previous investigations for CFB risers: some investigators neglected back-mixing of gas, whereas others report a considerable...

This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential chara...