Fluid-bed granulator

Figure 20-87 shows a typical production-size batch fluid-bed granulator. The air-handling unit dehumidifies and heats the inlet air. Heated fluidization air enters the processing zone through a distribu-... 

Continuous fluid-bed granulators are used in the fertilizer and detergent industries. For fertilizer apphcations, near-size grannies are recycled to control the granule size distribution. Dust is not recycled directly, but first remelted or slurried in the liquid feed. 

TABLE 20-48 Specifications of Glatt Rotary Fluid-Bed Granulators ... 

Figure 9. Coating in fa) a conventional fluid bed granulator and (b) a rotor granulator.

Several excellent reviews of fluid bed granulation were published by Nienow and coworkers (Nienow, 1983, Nienow and Rowe, 1985 and Nie-now, 1994) in which the operation is described in detail. Heat and mass balances on the system are presented and a granule growth model is proposed. The advantages and disadvantages of the operation are discussed. The present approach differs from the above work by looking at the microscale... 

Figure 18. The influence of contact angle on fluid-bed granulation nuclei size.

Figure 9.5 Layering on perforated bottom plate in semi-industrial scale fluid bed granulator after several days of production. The thickness of the layer is approximately 5 mm.

Within the pharmaceutical industry, granulation is a widely used process to prepare drug substance and excipient particles for compression. " There are wet and dry granulation procedures herein high shear wet grannlation, fluid bed granulation and roller compaction will be discussed. 

Applications in the pharmaceutical industry included determining the end points of high-shear and fluid bed granulation [128-130], fluid bed drying, powder mixing [131], crystallisation [132] and obtaining information from other processes involving particulates [133]. 

Nienow, A.W. and Rowe, RN., Fluid bed granulation. Separation Process Services, Harwell, 1975. 

Gas atomizing nozzle (two-fluid nozzle) the two-fluid (binary) nozzle where the binder solution (first fluid) is atomized by compressed air (second fluid) is the most commonly used nozzle for the fluid-bed granulation (Fig. 9A and B). 

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