ConCor (or “Contra- Co-Rotating”) milling is a new, patent-pending technology developed by Maelstrom as a scalable, clean and efficient alternative to conventional media milling, especially in nanomaterial applications where primary particles need to be effectively dispersed.
Instead of randomly grinding particles using hard beads of foreign materials, ConCor uses a controlled inline form of internal two-roll milling in which materials pass between co-rotating or contra-rotating rolls under extreme conditions. Roll gaps are adjustable in the typical range of 10 to 50 microns and rotational speeds range up to 20,000 rpm to allow very high shear forces to be applied to fluids passing through the roll gap. A critical aspect of the ConCor design is thermal management. High surface-area active cooling components occupy the otherwise empty space in the outer roll chamber. These cool the fluid and also define the ideal flowpath through the roll gap.
With both mill rolls turning in the same direction at similar surface speeds, the shear field between the rolls is relatively small and the primary effect is one of crushing or grinding. This is ideal for reducing the size of larger particles prior to finishing at the nano-scale using the contra-rotating mode.
If the mill rolls are rotated in opposite directions, enormous shear forces can be generated in the gap between them. These forces act on agglomerates and soft particles for very high dispersive performance. This mode is also highly effective for the generation of nano-emulsions.
The simple form of ConCor and its inherent scalability make it a very useful choice for customers who need very high de-agglomeration and dispersion performance. Maelstrom can provide complete processing packages based on ConCor, with storage and feed tanks, dosing pumps, automated control systems and SCADA integration. Please contact us for more information.