Fluidized bed drying

The efficient solution for controlled particle drying

Fluidized bed drying is the optimal method for controlled, gentle and even drying of wet solids. The intensive heat/mass exchange of the fluidized bed product makes this method particularly effective and time-saving. The technology is also suitable for post-drying of spray granulated or extruded products with very low residual moisture.

Fluidized bed drying can be used in the entire powder processing industry. In the pharmaceutical industry, this innovative method has replaced the time-consuming tray drying long ago: The drying process with fluidized bed drying reduces the drying time in the drying oven by approximately twenty times. In addition, fluidized bed drying provides controlled and uniform drying conditions compared to the uneven drying in trays.

No matter whether the product was produced in the fluidized bed or a high-shear mixer, whether in batch or continuously: With fluidized bed drying, it must be ensured that drying always takes place in a thermodynamic equilibrium. The inlet air temperature must be selected such that only so much moisture evaporates from the surface of the granulate as is transported through the capillaries from the interior of the granulate to the surface. If the inlet air temperature is too high, a surface crust will most likely form which will hamper or even prevent the moisture being transported from deeper layers to the outside. This will delay the entire drying process rather than accelerate it.

For the process variants spray granulation, spray agglomeration or spray coating, it should be noted that not only the moisture needs to evaporate until it has reached a defined residual value, but also that drying takes place during the entire spray process. Too high inlet air temperatures can lead to insufficient liquid bridges, instable granulate structures or inhomogeneous looking films.

Properly used, fluidized bed drying provides an efficient solution for the gentle and even drying of your product.