The Helix reactor is highly suited for precise reaction control based on good hydrodynamics. The hydrodynamics are controlled by the Dean vortices, which create excellent heat transfer properties, approach plug flow and avoid turbulence. The flexibility of this reactor has been demonstrated using a very exothermic, temperature sensitive alkylation reaction, a mechanically delicate emulsion polymerisation reaction and a precipitation reaction. It was demonstrated that the highly exothermic alkylation reaction could be controlled such that no side reactions occured. In the case of the emulsion polymerisation reaction the gentle mixing conditions of the Helix reactor were used to control the particle size and size distribution. Also for the precipitation reaction it was possible to obtain a narrow particle size distribution and to control the particle size. It can be concluded that the helix reactor is a versatile tool to perform reactions that are typically batch wise operated in a continuous way, and thereby reducing costs and improving safety and quality.@en