Redrying

As the basis powder used for agglomeration is remoistened to obtain the desired surface characteristic for an optimal stickiness, this additional moisture has to be evaporated again in order to reach the specified moisture content.

The agglomerates may break down again, if they are exposed to extensive mechanical handling, such as pneumatic conveying system. It is therefore necessary to perform the drying in a Vibro-Fluidizer®. However, as the rewetted powder is to be compared to a layer of wet snow when entering the Vibro-Fluidizer®, a relatively high air velocity is required to fluidize the powder. Otherwise, lumps will be formed, and the drying efficiency of the Vibro-Fluidizer® will decrease.