AUTOMATION OF THE MANUFACTURING PROCESS OF COLD REMEDY GRANULES BY A TUMBLING FLUIDIZED-BED APPLYING THE FUZZY CONTROL METHOD

The automated manufacturing process of cold remedy granules using a tu mbling fluidized bed will be described. Powdered materials, containing salicylamide and acetaminophen as the main components and having been used for the extrusion process previously, were granulated by a tumbl ing fluidized bed. Effects of the operational variables on the propert ies of granules were investigated,,which led to the conclusion that th e exact control of bed height and moisture content was indispensable f or continuously producing desired granules. The fuzzy control method b ased on a linguistic algorithm of if-then rules was applied to the bed height control, and programmed control of the moisture content was us ed for the continuous operation from mixing, granulation to drying. By means of the system developed, a series of operations could be conduc ted automatically. Properties of the granules thus obtained were evalu ated, and a comparison of the granules by this process to those by the extrusion process used previously was conducted. It was concluded tha t by means of the control system developed, desired granules which had sharp particle size distribution, high yield, i.e., almost 100% of gr anules, large apparent density and remarkably good flowability were ea sily produced.