Granulation operations

The main goal of this chapter is to provide a technical basis or framework for analyzing fluidized bed coating and granulation operations. 

Corning Mill Dust. This is also called meal powder, or by the Fr pulverin. Corning mill dust is the finest and the most intimately incorporated BkPdr dust remaining in the mill after the "corning" or granulating operations. Various types of machines are used to manuf granulate BlkPdr, such as "Wheel Mill "Stamp Mill" illustrated by Davis (Ref 2), and "Corning Machines" illustrated by Marshall (Ref 1)... 

A major disadvantage of granulation on completion of th e manufacturing process is th e need to transfer a solid material to a plastic or liquid state, whereas in production of thermosetting plastics such a state is passed in homogenization, that is, the granulating operation substantially complicates the entire production process. Such a situation may be justified only if a portion of the material to be supplied to the user is to be granulated (but not the entire lot). 

Granulation binder spray guns are placed above the product bed. They usually consist of several spray nozzles. Dual flow nozzles are widely used to atomize granulation binder before it reaches the solids bed. A good atomization is very important for granulation operation. The nozzles should also provide uniform spray across the bed surface. 

Similarly, the degree of grinding of oversize product and its recycle back to the bed together with fines strongly influences the creation of new granule centres. Control of the fineness and amount of recycled solids is the most satisfactory way to control particle size and stabilize granulator operation [12,22]. 

Figure 111. Schematic representation of a pan granulator operating at equipped...

R. Fogel, Physical variables affecting granulation of superphosphate in rotary granulators operating batchwise , J. Appl. Chem., 10, Part 3B, 139-144 (1960). 

For some products the USP/EP/JP rotating basket apparatus (Figure 2) may be more appropriate for example, in the case of floating capsules and granules. Operation of the basket apparatus is similar to that of the paddle apparatus, except that the basket containing the dosage form is immersed in the dissolution medium prior to starting the rotation. 

The granulation operation consists of increasing the diameter of the particles of a powder in order to confer on it the properties required for flow and mold filling. Several granulation processes are used in the ceramic industry [BAK 96] they can be classified briefly in the following way ... 

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