Process
In the continuous mixing and agglomeration unit, agglomerates are formed by incorporating liquids into powders that are either already mixed or fed as unmixed individual components. This agglomeration, also known as wet granulation, offers great opportunities to improve physical properties such as wettability and dispersibility, bulk density and product appearance. The granules produced have a porous, raspberry-like structure, excellent solubility and outstanding flowability. Typical particle sizes that can be achieved with this system are in the range of 10 – 2000µm with a common D50 value of 300 – 800µm.
The material to be mixed is fed into the mixing chamber from above via metering devices. The mechanical energy is provided by mixing blades (knives) mounted on a vertically arranged, rapidly rotating shaft. The mixing blades can be adjusted in their inclination, which allows the angle at which the particles impinge and are accelerated to be changed. At the same time, a turbulent air flow is created, through which powder and liquid particles are intensively mixed. To ensure that there is always a uniform ratio of powders and liquids in the process, the flow is controlled by a gravimetric metering system and metered liquid nozzles. Additions of several liquids, binder solutions and colorants, from heated and/or agitated containers are also possible without any problems.
The resulting agglomerates fall into a fluidized-bed dryer, with hot air flowing through the bottom of the dryer.
Further processing of the wet agglomerates via fluidized bed / drying chute
Over a distance of several meters, the product is slowly conveyed here to the discharge and dries in the process. The desired particle size distribution is then ensured by a tumbler screen. The coarse material is crushed in a mill and returned to the mixing process together with the fine material.
Advantages
excellent solubility, outstanding flowability, homogeneous processing of solids and pasty materials in a single step, porous structure of the particles.
