APPLICATION OF FUZZY-LOGIC TO BED HEIGHT CONTROL IN AGITATION-FLUIDIZED BED GRANULATION

Development of a new technique for producing spherical and well-compac ted granules, and the application of fuzzy control to a fluidized bed granulation process are described. An agitation-fluidized bed, a type of fluidized bed equipped with an agitator blade, was used for granula tion; bed height was controlled by fuzzy logic based on a linguistic a lgorithm employing IF-THEN rules, to maintain a constant bed height an d impart effective agitation to the granules. It was shown that bed he ight control was effective in preventing defluidization and channeling , and was necessary for automatic operation. The effects of bed height and agitator rotational speed on granule properties, such as apparent density, and on granule shape were investigated. A new technique is p roposed for utilizing bed height control to produce spherical and well -compacted granules, which cannot be done using conventional fluidized bed techniques.