Spouted fluidized bed

Downer 6 Cross-current Fluid Bed 7 Counter-current Fluid Bed 8 Spouted Fluidized Bed 9 Floating Fluidized Bed 10 Twin Fluidized Bed E Large particles/low gas load... 

Ciro-Velasquez, H.J., Cunha, R.L., and Menegalli, F.C., Drying of Xanthan Gum using a two-dimensional spouted fluidized bed (2DSFB) with inert particles Performance and rheological considerations, Drying TechnoL, 28, 389-401, 2010. 

CLC reactor configuration with spouting fluidized bed for biomass combustion. 

Patterson Emily E, Halow Jack, Daw Stuart Innovative method using magnetic particle tracking to measure sohds circrflation in a spouted fluidized bed, Ind Eng Chem Res 49 5037-5043, 2010. 

Ye B, Lim CJ, Grace JR. Hydrodynamics of spouted and spout-fluidized beds at high temperature. Can J Chem Eng 70 840-847, 1992. 

Fig. 10.7 Types of fluidized bed reactors [43], Reprinted with permission from the authors. The primary fluidized bed reactor types 1 bubbling fluidized bed, 2 turbulent fluidized bed, 3 circulating fluidized bed, 4 riser, 5 drowner, 6 cross-current fluid bed, 7 counter-current fluid, 8 spouted fluidized bed, 9 floating fluidized bed, 10 twin fluidized bed. The key issues leading to re-design of the conventional bubbling fluid bed A higher gas velocity, B counter-current contacting is beneficial, C incompatible differences in desired environment, D dusty environment, E large paiticles/low gas load...

LinkJM, Godlieb W, Deen NG, Kuipers JAM Discrete element study of granulation in a spout-fluidized bed, Chem Eng Sci 62 195-207, 2007. 

Sutkar VS, Deen NG, Mohan M, et al Numerical investigations of a pseudo-2D spout fluidized bed with draft plates using a scaled discrete particle model, Chem Eng Sci 104 790-807, 2013. 

Figure 7 CFD-DEM time series for spout fluidized bed simulations with droplet injections. Due to collisions between solid particles and droplets, the particles grow in size.

As an example of the novel applications of CFD-DEM, we present results of a spout fluidized bed with liquid injection. In this simulation, both solid particles and liquid drops are modeled as particles. The droplets are injected at a low Weber number such that droplet breakage can be neglected. When a droplet and solid particle collide, the hquid is assumed to form a uniform liquid layer around the particle. When wetted particles collide, the restitution coefficient is as given in the previous subsection. 

Group D particles are large, on the order of 1 or more millimeters (1000 fim) in average particle size. In a fluidized bed, they behave similarly to Group B particles. Because of the high gas velocities required to fluidize Group D particles, it is often more economical to process these particles in spouted or in moving beds, where lower gas rates suffice. 

Suspended Particle Techniques. In these methods of size enlargement, granular soHds are produced direcdy from a Hquid or semiliquid phase by dispersion in a gas to allow solidification through heat and/or mass transfer. The feed Hquid, which may be a solution, gel, paste, emulsion, slurry, or melt, must be pumpable and dispersible. Equipment used includes spray dryers, prilling towers, spouted and fluidized beds, and pneumatic conveying dryers, all of which are amenable to continuous, automated, large-scale operation. Because attrition and fines carryover are common problems with this technique, provision must be made for recovery and recycling. 

Spouted Beds The spoutedT)ed technique was developed primarily for sohds which are too coarse to be handled in fluidized beds. Although their applications overlap, the methods of gas-sohds mixing... 

This concept was first called a recirculating fluidized bed by Yang and Kearins (1974). Several other names have also been used to describe the same concept the fluid-lift solids recirculator (Buchanan and Wilson, 1965), the spouted fluid bed with a draft tube (Y ang and Keaims, 1983 Hadzismajlovic et al., 1992), the internally circulating fluidized bed (Milne et al., 1992 Lee and Kim, 1992) or simply a circulating fluidized... 

Another type of fluidized bed, where the jetting phenomena is an important consideration, is the spouted fluid bed, where a large portion of... 

Silva, E. M. V., Ferreira, M. C., and Freire, J. T., Mean Voidage Measurements and Fluid Dynamics Analysis in a Circulating Fluidized Bed with a Spouted Bed Type Solids F eeding System, Proc. of2nd European Thermal-Sciences and 14th UIT National Heat Transfer Conference, Rome (1996)... 

Figure 2. Spouted and fluidized beds used in coating operations.

However, for small scale equipment, Cheng (1993) and Xu (1993) measured the circulation times of a single tagged particle in a 150 mm diameter fluidized bed coater with a draft tube and found that typical circulation times were between 2-10 seconds. Robinson and Waldie (1978) made similar measurements in a 6" diameter conventional spouted bed and found mean circulation times in the range of 3-6 seconds. 

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