The bulk material remaining after gravimetric emptying in flat bottom silos can be effectively discharged using a 360° rotating screw. Almost all currently available silo diameters [Ø20 m to Ø60 m] can be equipped with such a screw. During filling and gravimetric emptying, the screw remains in the parked position. The screw, which is released after gravimetric emptying, then conveys the remaining bulk material in the area of the flat bottom to the central discharge funnel. From there, the bulk material is then transported away.

 The up to 28 m long special screw has no intermediate mounting or other support structures. The screw is only mounted once on the outer radius and once in the central dome. All mountings, drives and sensors are situated outside the silo interior, so no lubricant contamination can occur in the silo interior at any time. This is an essential part of product quality assurance in the food industry. This design also avoids the presence of mechanical and electrical sources of ignition in the silo interior. Use of the residue screw is thus permitted in explosive areas.

The residue emptying screw is generally supplied with the corresponding control mechanism and software, so that optimum operation can be guaranteed from the outset.

The components which are in contact with the product can be made from food-safe or corrosion-resistant materials. The entrance to the central dome, via the silo base, provides safe access to the silo interior. The residue emptying process can be observed and monitored from there.

Key features

  • large silo diameter without interim mountings possible
  • Emptying over 360° possible
  • complete mechanical emptying of the storage silo possible
  • Food-safe and/or corrosion-resistant materials possible
  • Explosion-proof design [ATEX directive 2014/34/EU]

Economic advantages

  • compact and robust design
  • for powdery, fine-grained, free-flowing or slightly agglomerated products
  • semi-automatic operation using proven controls possible
  • Dosing operation possible
  • food-safe design possible
  • Explosion-proof design [ATEX directive 2014/34/EU]
  • low operating costs due to low number of operators and low maintenance requirements
  • safe and emission-free operation possible
  • Economic efficiency as a result of standardized components
  • environmentally friendly