Granulation scale

Chowhan, Z.T. Aspets of granulation scale-up in high shear mRbEBrm. Technol12 (1998), 26-44. 

Watano, S. Sato, Y. Miyanami, K. Apphcation of a neural network to granulation scale-up. Powder Technol. 1997, 90, 153-159. 

FIG. 21-170 Niro Precision Granulation process. Agglomeration in bottom-spray draft tube fluid-bed granulation. Scale-up is accomplished by replicating draft tube geometry. Courtesy Niro Fharma Systems.)... 

White powder, granules, scales. Freely sol in water, in isotonic sodium chloride soln, in glucose solns. Also sol in alcohol, glycerol, acetone, ethyl acetate, chloroform. Insol in fixed oils, liquid petrolatum. pH of an aq soln contg 20,000 units per ml is 5.0 to 6.5. 

Suitably, an article by Ennis et al. (26) highlights the fact that understanding granulation scale-up is a needed growth area for further research. 

Figure 6.22 Hierarchical structure of starch, (a) Whole granule (scale pm), (b) Growth rings ( 100s nm), (c) crystalline and amorphous lamellae ( 9 nm) and (d) molecular structure of amylopectin ( A). [Reproduced with permission from T. A. Waigh, Applied Biophysics, John Wiley Sons. Copyri t (2007) John Wiley Sons Limited]...

Figure 15.2 Optical images in transmission of starch granule (scale bar 50 pm) [a] potato and (b) wheat. Reprinted from Salerno et al., 2014, with permission from Elsevier.

Place 2 1 ml. (measured from a micro-burette) of nitro-benzene and 5 g. of granulated tin in a 150 ml. round-bottomed flask fitted with a small reflux water-condenser. (A large flask is employed because the mixture when subsequently boiled may bump violently.) Pour 10 ml. of cone. HCl down the condenser on this scale the reaction is not sufficiently vigorous to get out of control. Heat over a gauze for 15 minutes. Cool the flask and add a solution of 7 5 8- of NaOH in 10 ml. of water to redissolve the initial precipitate. Add about... 

Fluidized-bed filters. Fluidized beds of granules have received considerable study on theoretical and experimental levels but have not been applied on a prac tical commercial scale. 

These mixers are particularly suited for rapid mixing of powders and granules with liquids, for dissolving resins or solids in liquids, or for removal of volatiles from pastes under vacuum. Scale-up is usually on the basis of maintaining constant peripheral velocity of the impeller. 

Method Product size (mm) Granule density Scale of operation Additional comments Tyj)ical applications... 

Drum and disc granulators generally operate in continuous feed mode. A key advantage to these systems is the abihty to run at large scale. Drums with diameters up to four meters and throughputs up to 100 ton/hr are widely used in the mineral industiy. 

TABLE 20-43 Characteristics of Large-Scale Granulation Drums ... 

Scale-Up and Operation Scale-up of pharmaceutical mixer granulators is difficult because geometric similarity is often not preserved. Kristensen recommends constant relative swept volume ratio... 

Power dissipation can lead to temperature increases of up to 40°C in the mass. Note that evaporation of liquid as a result of this increase needs to be accounted for in determining liquid requirements for granulation. Liquid should be added through an atomizing nozzle to aid uniform hquid distribution in many cases. In addition, power intensity (kW/kg) has been used with some success to judge granulation end point and for scale-up, primarily due to its relationship to granule deformation [Holm loc. cit.]. Swept volume ratio is a preliminary estimate of expected power intensity. 

Particle Motion and Scale-Up Veiy little fundamental information is published on centrifugal granulators. Qualitatively, good operation rehes on maintaining a smoothly rotating stable rope of tumbling... 

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