The HyperClassic Mixer was developed in 1985 in the Fluid Mechanics Department at the Friedrich-Alexander University, Erlangen-Nuremburg, to support a thesis on the most energy-efficient mixing system design.
Rather than just upgrading traditional mixer designs, the team started from scratch – drawing on a wealth of new technology and advances in Computational Fluid Dynamics (CFD Modelling). With no bias towards old designs holding them back, they added a whole new dimension to the world of mixing.
Results were so spectacular that they knew it would have immediate appeal to the wastewater market, and so in 1989 they released it to the industry.
The iconic HyperClassic Mixer has a vertical shaft with a patented, hyperboloid-shaped impeller. Minimal maintenance is required: all submerged parts are not subject to wear and the drive unit is easily accessible, being installed above water level.
Extremely rag resistant
The impeller is suspended just above the tank floor, and due to its unique shape and the large diameter shaft, ragging is virtually eliminated. This is unheard of in other designs.
Mixing where you need it most
The impeller fins create a very strong flow across the bottom of the tank, preventing sedimentation where it is most likely to occur.
No air entrainment
Upon reaching the walls, the flow rises upwards towards the water surface. By the time it reaches the surface, the flow velocity has reduced sufficiently to minimise turbulence and prevent air entrainment.
The secret of torroidal flow
The water flow is then directed towards the centre of the tank, where it is directed downwards again to the shaft and impeller. A torroidal flow pattern is created throughout the whole tank, ensuring complete homogenisation, i.e. all particles are distributed evenly throughout the tank. Torroidal flow patterns are common in nature: hurricanes, whirlpools and magnetic fields.
When used in wastewater treatment (especially in anoxic or anaerobic tanks), the unique water flow pattern generated by the HyperClassic Mixer can be used to create ‘virtual separating walls’, creating multiple zones to ensure complete mixing, and providing significant process benefits.
Independent mixing and aeration
When combined with aeration diffusers, the HyperClassic Mixer can be used for swing zones and SBR s, where intermittent aeration and mixing is required, as well as to maintain mixing in aeration zones with low BOD load where the energy from aeration is insufficient to maintain solids suspension.
The truth about other designs
Compared with other mixers, it is easy to see why the HyperClassic Mixer is the most efficient: most other vertical shaft mixers have only an axial flow, meaning that the water flow is directed either upwards or downwards. With either of these, much of the energy is absorbed on either the tank floor or lost at the surface. The latter also causes surface turbulence and results in little velocity at the sides and bottom. With horizontal mixers, a huge amount of energy input is needed at the start of the flow cycle to ensure that there is sufficient residual energy at the end of the flow cycle and in the tank extremities.
The HyperClassic Mixer however, has both an axial (vertical) and radial (radiating horizontal) flow, meaning that the entire contents of the tank are kept in motion with minimal energy input. For example, complete mixing with adequate bottom flow velocities to maintain activated sludge in suspension can be achieved at a power density of down to 1.5 W/m³. This means that a single 1.5kW HyperClassic Mixer can mix a tank of up to 1000m³.
A common trap
Mixer effectiveness should never be assessed on power density alone. Unfortunately, this is still a common, if flawed, practice. One of the best measures is bottom flow velocity along with traditional measures in dynamic systems using tracer dyes.
With installations around the globe, the HyperClassic Mixer is a proven success.
Look out for the revolutionary Evolution 7 design, which was launched at the IFAT Exhibition! Contact Corgin for more details.