Maschinenfabrik Gustav Eirich, Hardheim, Germany, points out that in ceramic and chemical industries it is often necessary to manufacture granulates from powders or powder mixtures. The properties of these are tailored to the requirements of subsequent processing, with regard for example to the size of the granulate, strength, density, pourability, freedom from dust and porosity. Fundamentally different mechanical and thermal granulation techniques are available. Among the mechanical techniques, there are many adherents of build-up granulation provided by the EIRICH mixer, which is now also available for granulates down to 100 microns.

 

Whereas in the past granulates were primarily demanded in sizes ranging from 500 microns to several millimetres, nowadays customer requirements tend towards much finer ranges, down to 100 microns or even finer. For this reason the company has developed rotor tools with a special geometry (patent pending) that can be used to manufacture granulates with even finer grain sizes. Even within this fineness range the width of the grain spectrum or the grain size distribution can be modified with the aid of parameters like the tool speed, granulating time and granulation moisture, and adapted to the particular requirements of the specific application. In the size recommended for granulating, the EIRICH mixer used for this application has just one rotor tool which can run at speeds up to 30m/s. This makes it possible to generate high shear forces and distribute liquids quickly. www.eirich.com