Scale-Up of Mixing Equipment

By means of scale-up rules, operating and design data of known machines – so called models – can be applied to larger and smaller machines, the so called pilot plants. Scale-up rules are based on the principle of similarity. According to this principle, all physical and technical facts are similar which are described by the same dimensionless characteristic values (dimensionless products), also called π-values, if they are allocated to the same state of the dimensionless space of characteristic numbers. First of all we want to note the dimensionless groups, which are relevant for mixing processes. These are the basis for scale-up and scale-down rules of the continuous, steady-state and discontinuous processes. We also cover the relevant mixing equipment. Among these are melting extruder and plasticizing extruder, rubber extruder, co-rotating and counterrotating intermeshing and non intermeshing twin screw extruder, kneaders, mixing rolls, mixing elements, internal mixes and mechanically agitated vessels.