Stone separator icon Diesel icon Electric icon Mechanical

The stone separator Stonefex removes stones and inert items reliably and very effectively 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. 


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Key facts
100 Throughput (m³/h)
50 Engine Power (kW)
10 Weight (t)
It 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 

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. 



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
Mobile and

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.  


Technical data

Open all plus symbol
Enginer plus symbol
Power (kW/PS)35/55
Diesel generator (kVA)30
Loading heights plus symbol
Filling width (mm)1200
Filling height (mm)3150
Weight* plus symbol
Trailer (t)9
*dependent on equipment
Throughput plus symbol
Throughput (m³/h)up to 100
Material discharge plus symbol
Max. discharge height (mm)2500
Fan plus symbol
Pressure blower (kW)7.5
Suction fan (kW)11

The Komptech plus

Great advice

We’ll show you how to optimize your processes, based on our experience and extensive data analyses. 

Service near you

Expert technicians are on-site quickly to make sure your machines keep running. 

Spare parts always available

Intelligent stocking for the fast, economical provision of highquality spare parts. 

All-in solutions

From individual mobile machine to complex stationary system, from us you get the right process solution. 

Productivity in view

App and integrated monitoring let you keep an eye on operating data and economy. 

Need-based service

Our maintenance and service agreements, as well as extended warranties, are aligned with your needs.