Mobile stone separator

The mobile stone separator Stonefex removes reliably and very effectively stones and inert items from biomass fuels. A patented system of pressure and suction blowers generates exactly the right air flow in the expansion chamber to remove stones and heavy objects from wood.

The outcome is a fuel nearly free of stones which can be sold at a higher price. Furthermore fractions that were previously unusable due to their high amount of stones can now be processed into fuel.

mechanical drive diesel electric

Advantages at a glance


Compatible with most commercially available mobile screening units


Dependable removal of more than 90 percent of stones and inert items from the input material

Komptech plus
Komptech plus

Throughput up to 100 m³/h designed for a input particle size of 10…20–150 mm

More business
More business

Low energy costs due to electrical drive of all components

  • Highlights

    The Stonefex pays off

    The Stonefex improves fuel quality by removing more than 90 percent of stones and insert materials. Biomass processors profit from better customer acceptance of their fuels, higher sale prices, and the ability to make a saleable product from material contaminated with stones.

  • Highlights

    A patented separating system

    The input material is loaded onto the intake conveyor. In the expansion chamber, a patented system of pressure and suction blowers separates the material into a stone fraction and a cleaned usable fraction, which conveyors take out to opposite sides. Fines and any light materials are collected in the container downstream of the suction fan.

  • Highlights

    Everywhere applicable

    The input material to the Stonefex is usually a usable biofuel fraction with a particle size from 10…20–150 mm for example:

    • Shredded rootstocks

    • Green cuttings (pre-shredded with or without composting phase)

    • Screen residue from compost

    • Forestry residues

  • Highlights

    Mobile and economically

    The single-axle trailer configuration makes the machine easy to manoeuvre, and it is approved for 80 km/h road speeds, so transportation to the site is no problem. The standard version of the stone separator uses grid electrical power. As an option, a diesel generator is available. This hybrid drive system guarantees low energy and maintenance costs.


Diesel generator (kV/A) 50
Material feeding
Filling width (mm) 1200
Filling height (mm) 3150
Material discharge
Max. discharge height conveyor belt (mm) 2500
Transport length (mm) 8300
Transport height (mm) 4000
Transport width (mm) 2550
Dependent on equipment (~t) 10
Max. Throughput
Dependent on material (m³/h) 100

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