New mobile version of A TEC’s Rocket Mill

Handling and preparing alternative fuel materials has always presented challenges, mainly on account of their physical characteristics. Those materials tend to have high moisture content, with a wide range of particle sizes that must be homogenised before they can be used for firing.

Austria’s A TEC Production & Service GmbH provides an effective answer: A new grinding technology that works with no knives! The so called Rocket Mill® produces feed that is fragmented by impact with the rapidly rotating chains as well as through inter-particle collisions. The screens surrounding the crushing chamber allow only particles of the required size to pass through. Any uncrushable and heavy material is automatically removed via slide gates from the chamber.

In September 2017 A TEC launched a new version of its grinding mill: Rocket Mill® 2.00 single. This new and innovative mill is a compact version installed in a container. The mill consists of one grinding chamber with approx. 2 m diameter and has 315 kW power at the main drive. This will give roughly the half capacity of the double chamber Rocket Mill 2.50. The throughput when producing RDF for the main burner (90% < 50 mm) is about 10-12 tph.

Due to the compact equipment the required installation space is very small. This new development gives clients also the possibility to test their own product on side. Depending on existing situation only small connecting works to the existing equipment are necessary. In general the output material from the Rocket Mill® has big advantages in terms of its fuel properties. The process creates particles with a higher specific surface that improves ignition and combustion characteristics. The heat generated within the mill helps to reduce the inherent moisture content of the feed from typically 25% to 15% in the fine material. A separation of inorganics from the AF during the shredding process is given. The inorganics can be discharged during operation via slide gates.

The motivation to install A TEC’s Rocket Mill® is on the one hand a significant cost reduction due to the high substitution rate of fossil fuels. Positive effects on the pyroprocess could be seen immediately: a higher clinker quality due to the reduction of the FE-content and less sulphur circulation was only one of the advantages. On the other hand this innovative technology is also very successful in terms of CO₂ savings and the reduction of environmental impacts. Sustainability is given a high priority at A TEC.

A TEC alternative fuel preparation technology offers the following primary benefits compared to conventional technologies:

• Size reduction from 250 mm to 15 mm in one grinding step.
• Saving of one shredding step.
• Easy to operate.
• Easy maintenance.
• No knifes.
• Different output fuel particle sizes for main burner and calciner possible.
• Drying effect during operation.
• Significant reduction of fuel costs.
• Reduction of CO₂ emissions.
• Requires only two fuel preparation steps.
• Separated FE and non-FE materials can be fed back to the recycling process.
• Reduction of coal consumption.