In bulk solids handling, impactors are deployed to support material flow, dislodge build-ups, break arching, and eliminate product blockages.
Under certain unfavourable conditions in the processing of challenging bulk materials, technicians and maintenance personnel face a familiar issue: restricted material flow. This may be caused by inadequate surface properties of the vessel, material moisture, or a tendency for the product to cake, adhere, or interlock. In such cases, high-frequency electric or pneumatic vibrators, with their sinusoidal oscillations, are often no longer sufficient to resolve the problem. For removing stubborn deposits from silo walls, pipes, and containers, breaking bridges, and ensuring complete discharge, an impact with sufficient energy is required. In practice, this is frequently carried out manually using a rubber mallet at known critical points—however, this leaves visible dents and deformation on the plant walls and requires manual intervention by personnel.
Pneumatic impactors of the PKL series from NetterVibration provide a reliable, effective, and material-friendly cleaning solution, preventing deformation-related narrowing of outlets that can gradually impede material flow. The operating principle is comparable to the traditional “silo hammer”: strongly adhering materials are released by the impact of the PKL on its impact plate. The pneumatic knocker generates an optimised, elastic impulse.
An Electric Twin
The long-established PKL 740 now has a new counterpart: an electrically actuated version that delivers impact on demand, enabling deployment in virtually any environment. It can even be operated portably via battery power—for example, in outdoor silo installations without a fixed power supply. When powered by renewable energy sources, the ePKL also contributes to improved sustainability. Its compact control unit enables both single and cyclic impact operation. Furthermore, it is designed for seamless integration into modern control systems, offering expandable, process-dependent functionalities—such as linking operation to silo level measurement to avoid unnecessary actuation.
Proven in Practice
One of Germany’s largest and most advanced lime plants produces a wide range of lime products, specialised blends for construction protection, and mineral materials for road building. For more than 40 years, maintenance teams and plant managers have relied on pneumatic impactors of the PKL type from NetterVibration. In this demanding environment, PKL units deliver excellent performance in removing stubborn deposits from pipes and vessels, preventing hose and bridge formation, and ensuring reliable residual emptying of silos. In areas with existing compressed air infrastructure and integration into the plant control system, conventional PKL models are used successfully. Where flexible solutions are required, however, the fully electric ePKL demonstrates its strengths: for instance, on a filter that requires only occasional, sporadic cleaning, the ePKL was easily installed, connected to a standard power outlet, and activated as needed.
