IMPROVED PRODUCT QUALITY AT A COOLING CRYSTALLIZATION PROCESS BY MEASUREMENT AND CONTROL OF SUPERSATURATION

A new supersaturation measurement technique is presented, based on for ced encrustation of a cooled sensor surface. After a short discussion of aspects of the control of supersaturation, the measurement principl e is introduced. The relationship between encrustation mass and crysta llization heat on the one hand and supersaturation on the other hand i s explained. As a main Feint of this presentation the technical realiz ation of the supersaturation sensor are shown. The explanation of the innovative sensor technique is split into two parts. First, the techni cal construction is shown and second the detection and analysis of the measuring signal is presented. The integration of the sensor into a c ontrol strategy is possible or laboratory experiments. As the experime ntal results show, supersaturation measurement for systems with a smal l metastable zone width, such as KNO3, can be carried out in a reliabl e and accurate way. Furthermore, the universal applicability for vario us readily soluble solutes poses no problem.