Hygroscopic bulk solids are substances that absorb atmospheric humidity during storage and form hydrates. „Hygroscopic“ means the property of solids, to absorb, retain or emit water and to dissolve in water. On account of moisture migration, hygroscopic solids form clumps, crusts and layers in open or closed containers (silos) and also in conveying and dosing systems. The loading of subsequent processes is disturbed or in the worst case even stopped entirely. Common measures to control the behaviour of hygroscopic bulk solids are the addition of dry air and the insulation of containers and conveying systems. In some cases, the problems can be minimized this way. In the case of highly hygroscopic substances these measures are not suffi cient. Hygroscopic materials are very sensitive to the three parameters: 1. ambient humidity, 2. temperature and 3. moisture content of the material. If one of the three factors changes, the fl ow behavior of your bulk material will also change, which may affect negatively downstream processes. On the following pages you will learn more about cause and effect in relation to these three parameters, measures to control the bulk solids and, of course the latest state-of-the-art solutions. The two main components for the effi cient handling of your hygroscopic materials - Oszillomat and Multigon - will be introduced. The patented Multigon silo system is the preferred choice for hygroscopic materials. The most evident difference to conventional round silos is the octagonal cross section. Very special benefits of the Multigon silo are: • the outstanding insulation value, which prevents/minimises condensation • smooth internal silo walls, which prevent layers from forming • the use of premium stainless steel is considerably cheaper than when used for round silos The Oszillomat system is able to discharge the bulk solids equally over the whole outlet cross-section. The oszillating beams enforce mass fl ow, all zones inside the silo are in movement. In addition, an accretion or bridge building are avoided. At the same time layers and clumps are crushed, without breaking the individual bulk solids particles. The downstream processes are prevented from damage and subsequent processes are fed reliably and precisely! Fully automated! Download the article about this topic.

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