Spray fluidized beds

Bottom-fermenting yeasts, 26 465 Bottom-pressure casting method, 23 269 Bottom-spray fluidized-bed units, 16 448-449... 

Dewettinck, K. and Huyghebaert, A., Top-spray fluidized bed coating effect of process variables on coating efficiency, Lebensmittel Wissenschaft Technologie, 31 (1998) 568-575. 

Dewettinck, K., De Visscher, A., Deroo, L. and Huyghebaert, A., Modeling the steady-state thermodynamic operation point of top-spray fluidized bed processing, /. Food Eng., 39 (1999b) 131-143. 

Jones DM. Effect of process air dew point on a top-spray fluidized bed-coating process. Presented in Session 265 Coating in the pharmaceutical industry. Proceedings of AIChE Annual Meeting, 1998. 

Coating procedure, top spray (Fluidized bed Aeromatic Strea-1)... 

Many reports have been made on experimental and theoretical investigations in the area of liquid sprayed-fluidized beds by Heinrich [30], who dealt comprehensively with the modeling of heat and mass transfers, as well as with particle populations in the fluidized beds. 

It is clear from Fig. 16.57 that the conversions can be realized up to 90 % for small NTU of 3 in a liquid-sprayed fluidized bed. It also shows that the assumption of ideal plug flow of gas (PFTR) is more appropriate than the assumption of ideal mixing of the gas (CSTR). 

In the present studies, the possibility of realizing absorption processes with reactive conversion of the absorbed gas component in liquid-sprayed fluidized beds is investigated. The goal of this new technology is the production of a free-floating product and a simultaneous high conversion of the absorbed gas component. The main subject of these studies is the experimental investigation of reactive absorption and... 

If sufficient calcium hydroxide is present in the spraying drop, then the diffusion of sulfur dioxide is small. In liquid-sprayed fluidized beds the drops or films on the particles are under permanent stresses, and particle-particle impacts lead to constant destruction of the film surface. Thus, no converted calcium hydroxide reaches the film surface to perform the reaction for disposal, and consequently a strongly over-stoichiometric process is not necessary. 

The average particle diameter which is growing during granulation and agglomeration has no effect on the conversion of sulfur dioxide. An increase in particle diameter leads to higher Re-numbers, and thus to an enhanced mass transfer of sulfur dioxide. However, the opposite phenomenon is that the increased mass transfer of the evaporation reduces the mass transfer surface. In addition, these experimental studies illustrate that the liquid-sprayed fluidized bed can be used as a reactive absorber. 

M. Henneberg, et ah, Study of dynamic multi-dimensional temperature and concentration distributions in liquid sprayed fluidized beds, Chem. Eng. Sci.,... 

FIGURE 2 A representative example of a conventional top. spray fluidized bed processor. Source Courtesy of Glatt Air Techniques, Inc. 

Granulate substance I in a top spray fluidized bed with dispersion II (Inlet air temperature 50 °C, outlet air temperature about 26 °C, nozzle 1.2 mm), mix with III and press to tablets with low compression force (9 kN) on a rotary press. ... 

Fig. 5.13 Sketch of the material processing section of a bottom spray fluidized bed coater (Wurster coating system) [B.71]...

D. M. Lipps and A. M. Sakr, Characterization of wet granulation process parameters using response surface methodology. 1. Top-spray fluidized bed, J. Pharm. Sci., 83, 937-947 (1994). 

The choice of dryer is more difficult when the drying step is also used to shape the product. Typical designs here are the spray dryer and the sprayed fluidized bed. If necessary, drying can be followed by a classification step in which undesired particles, for example, fines, are reyded to the feed stream for the dryer. When the desired product properties, for example, freedom from dust, pourabUity, rate of dissolution, and bulk density, are not attainable in the drying step, additional steps such as compaction and granulation must be used. 

The coating powders are applied by cold electrostatic spraying EP resins can also be applied by hot electrostatic spraying, fluidized bed, and blowing. For deflnition of abbreviations, see Table 3.6. Smooth flow and low gloss are not obtained at low stoving temperatures. Hot and cold... 

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