Reliable and easy feeding

of biogenic raw material and solid waste

Feeding the digester is crucial for the economical and efficient operation of a biogas plant. The safe and reliable dosing of solid material that is best suited for the respective biogas plant can increase the gas yield and reduce the energy consumed by other operations such as stirring, agitating or pumping.

It may sound simple, but the failure-free digester feeding presents a challenge for the technology used. Renewable raw materials, for instance, contain stones and sand which can increase wear and malfunctions. As the variety of substrates grows every year, it becomes increasingly more important to choose a feeding technology that is also capable of processing substrates that are difficult to convey.

The basic principle of Vielfraß®

The Vielfrass® solid material in feed unit is based on these requirements and was developed to process renewable raw materials, grass silage, solid dung or similar biomass. The basic principle includes two counter-rotating screws that evenly distribute and mix the substrate. The so-called feeder screw subsequently introduces the substrates into the upper part of the digester. This enables high output while exerting less force. An interval controller assures a uniform and automated feeding process.

The Vielfrass® system includes extremely robust, safe and low-maintenance stainless steel components. All parts prone to corrosion are made of V2A stainless steel for ultra-long durability.

Flexible feeding technology thanks to type variants

The selective feeding of the fermentation process is based on the principle of flexible dosing. By installing expansion modules, the Vielfrass® standard version, developed to suit the needs of small plants in particular, can be used for larger plants and additional feeding options.

Vielfraß® FA
– optimum substrate separation

The heart of Vielfrass® FA consists of a stationary dosing unit with cutting attachment including three additional rotary grinders.  By maintaining a consistent cutting operation, this technology supports the proper separation of the transported substrate and reduces the proneness to winding. After consistent cutting, the feeder screw introduces the processed substrate into the digester.

Vielfraß® Top
– feeding from above

According to the different biogas plants, Vielfrass® Top is also capable of feeding the substrates into the digester from the top. This design enables a special construction through expansion modules, ascending screw and tamping auger.


For both variants, the feeder volume can be increased to 40m3.


Your benefits at a glance:

  • Excellent to ferment solid dung, grass silage and renewable raw material
  • Energy-saving and save dosing of the substrate
  • Optional expansion of the feeder volume
  • Selective feeding via automatic interval control (optionally with weighing facility)
  • Low maintenance effort due to high-quality stainless steel components
  • Robust feeder screw for reliable feeding

Minimum wear thanks to resistance against foreign bodies.


Call us, we will be pleased to advise you!
Tel.: +49 9826-65959-181
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icon pdf Vielfrass® - The Biogas component: Solid material feeder unit