Dust Protection for Sensitive Bulk‑Material Processes

Dust formation is a major factor in vibration‑supported bulk‑material processes such as conveying, compacting and loosening: penetrating dust can damage piston vibrators. Enhanced dust protection can minimise this risk. 

• Piston vibrators fitted with a specialised protective cap are more resistant to damage from dust accumulation and can be used in a wide variety of bulk‑material processes. 
• The vibrators presented, featuring a housing made of coated aluminium, are robust whilst space‑saving in design. 
• Special versions made from stainless steel, with ATEX certification and lubrication‑free operation, enable use even in hygiene‑sensitive or explosion‑hazard areas. 

At the processing of bulk materials dust formation is a common problem. Dust can lead to material losses, contaminate machines, products and production areas—and last but not least pose a threat to employee health. For improved dust protection of pneumatic piston vibrators, supplier NetterVibration has extended its NTK AL series with the NTK AL MG versions, which have a protective cap with a matched thread. 

Precise Vibration for Sensitive Processes

All vibrators of this series generate a linear vibration to support the flow of bulk materials of all kinds. Unlike vibrators using circular oscillation, the vibration is produced by a freely oscillating, self‑adjusting piston. Piston vibrators start and stop in any installation orientation without delay. This makes them particularly suited for applications in which a linear and precisely controlled direction of the applied forces is required or desired. 

Additional oscillating masses fitted to these vibrators increase their amplitude and efficiency. However, this also raises the risk of malfunctions and defects, because dust can accumulate between the screwed‑on weights and the vibrator housing. A common solution to this issue—especially to protect the piston rod from contamination—is bellows, for example the NFB series. 

Alternative to a Bellows

As an alternative to a bellows, the vibration specialist has now introduced the MTK AL MG upgrade to its piston vibrators. With a screwed thread, the protective cap can be firmly attached on the appropriately equipped versions NTK 8 AL, NTK 18 AL, NTK 25 AL, NTK 40 AL and NTK 55 AL. With this precisely fitting cover the component including any protruding edges and corners is sealed dust‑tight. The cap may also be used without restriction together with oscillating masses that were especially developed for these models. In addition, the vibrators are distinguished by a compact design and comparatively low weight.

The series of vibrators is available in various versions including ATEX or stainless steel. The vibration frequency is controlled via supply pressure, while the amplitude (oscillation width) is adjustable via exhaust throttling. The aluminium‑housing devices of type NTK AL are made from an aluminium alloy, are protected against corrosion by an anodised layer and can be operated with oil‑free compressed air up to a pressure of 6 bar at temperatures from –20 °C to +130 °C. The noise level is also below 80 dB. 

The pneumatic piston vibrators are suitable, due to their directed oscillations, especially for conveying, compacting and loosening of bulk materials. They are ideally used on hoppers and containers, as vibration drives for small discharge and conveying troughs, and as drives for small vibration tables and chutes. A particular application case is the resonance conveying system of the FlexiLink series. 

Flexible under Challenging Conditions

Production processes can also be mechanically stimulated, for example to maintain material flow and resolve blockages. Here a further special feature of the piston vibrators comes into play: both the housing and the piston can be mounted on the device to be vibrated.

For bulk‑material processes in the food, pharmaceutical and chemical industries high legal requirements apply to hygiene and explosion‑protection standards. For such sensitive applications Netter has expanded its portfolio with the NTK S stainless‑steel variants for contact with foodstuffs and the NTK AL EL version with Ex‑protection and protective cap in oil‑free operation. These versions are particularly suitable as drives for conveying and screening troughs. 

Read the full article here (in German, published in CHEMIETECHNIK 9/2025).

More on NTK