In very many biogas plants only fast running submersible mixers have been installed. A large part of the energy input is thereby expunged, to some extent unnecessarily, by the creation of local turbulences, especially in fermenters and post-digesters. In extreme cases several fast runners then operate only in the restricted caverns that surround them. 

The Phantom 2500 is a sensible alternative here. Thanks to its 2.5 m diameter propeller this large mixer can produce extraordinarily large thrust despite low energy consumption, thereby creating a global underflow in the fermentation tank which is gentle on bacteria. Our Repowering-Pipe System can be easily retrofitted in the filled tank. Although the Phantom 2500 generates far larger thrust forces than a fast runner, it only requires a fraction of the energy, enabling both the mixing to be improved and the energy costs to be reduced by up to 70% as part of a retrofitting measure.