The fluidization in the furnace of circulating fluidized bed (CFB) boilers is described. Data have been obtained from a 12 MWth CFB boiler and literature. bottom bubbling rather than fast or turbulently as often assumed. There an extended splash zone above this bed, which particles are thrown up by bubbles fall back onto bed. Other carried further into transport zone, initially saturated gas fl...

This paper presents the development of a reduced-order model (ROM) for dynamics of fluidized beds, based on the proper orthogonal decomposition (POD) method. Several implementations of this ROM were developed for a two-dimensional bubbling fluidized bed using numerical results from a full computational fluid dynamics (CFD) simulation of the bed. The solutions of the ROM were used to investigate...

Particle shape can significantly affect the bubble dynamics of bubbling fluidized beds (BFB). In this paper, findings obtained from simulations using CFD-DEM are summarized to discuss effect particle on and properties such as size, velocity at a single orifice uniform bed. Particles with aspect ratios 0.5 (oblate), 1 (spherical) 2 (prolate) employed represent disc-like, spherical rod-like parti...

Nanoparticles (NPs) are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process NPs. NPs cannot be fluidized individually; they fluidize as very porous agglomerates. The objective of this article is to review the developments in nanopowder fluidization. Often, it is needed to apply an assistance meth...

The fluidization characteristics of binary mixtures containing tobacco stem (TS) and cation exchange resin (a substitute for coal) were studied in a rectangular bed with the cross-section area of 0.3 × 0.025 m(2). The presence of herbaceous biomass particles and their unique properties such as low density and high aspect ratio resulted in different fluidization behaviors. Three fluidization vel...

Bed particle layer and crack characteristics at different ages were studied for quartz K-feldspar bed particles from a 30 MWth bubbling fluidized 90 circulating bed, both using woody biomass as fuel. X-ray microtomography (XMT) was utilized to determine the distribution on particles' surface. For each type, average thickness well volume fractions of layers entire determined three by utilizing X...