Many pharmaceutical powders are cohesive and do not flow consistently out of the supply hopper during feeding. Examples of such poor flowing materials can include excipients such as micronized lactose, magnesium stearate and various active pharmaceutical ingredients or API’s. Such poor flow properties can lead to the formation of rat holes or even material bridges, making it difficult to accurately deliver these materials to the process. This is especially of importance when feeding to continuous processes such as continuous direct compression, granulation, extrusion or coating. The Coperion K-Tron ActiFlow™ Bulk Solid Activator is the perfect solution to avoid this problem. This technology ensures maximum possible optimization of material flow, is easy to clean and has no effect on the material properties.
Poorly flowing bulk material can impact feeding
A rat hole is a narrow, vertically oriented tunnel from the top of the material bed in the hopper to the discharge device of the feeder. Although material can continue to flow through these holes, the discharge rate of the feeder is considerably lower and material deposits may remain in the hopper for an indefinite amount of time. Material bridges similarly restrict the flow of material through the feeder. These material bridges can lack even the vertical tunnel of a rat hole, causing the material flow to be completely blocked.
A traditional method of coping with these problems is to install a vertical agitator in the feeder hopper. On the one hand, this solution is very reliable but on the other, it also has several disadvantages such as significant cleaning effort and additional headroom. In addition, due to the pulsations caused by the vertical agitator, fluctuations during feeding cannot be ruled out.
Controlled vibration keeps the material moving
Coperion K-Tron’s unique ActiFlow Bulk Solid Activator reliably prevents the formation of bridges with even the most poorly flowing materials. It essentially consists of the ActiFlow device attached to the outside of the stainless steel hopper and the ActiFlow control module which closely interacts with the KCM feeder control module. The ActiFlow device gently activates the material in the hopper with an optimized amplitude and frequency, while the KCM in combination with the ActiFlow control module ensures that there is always an optimal material flow in the hopper. This in turn provides for consistent and highly accurate feeding.