There is described a novel fluid treatment device that can induce Dean Vortices in the flowing fluid, and then induce a new set of Dean Vortices at an angle to those in the first set. Each subsequent curved section can induce vortices at an angle to those in the last curved section. This reactor has the effect of repeatedly twisting and splitting the fluid flow, resulting in targeted mixing similar to that of static mixers without the necessity of utilizing physical mixers. This is also an improvement over helical tubing configurations that generate only a single set of vortices and do not split and mix the flow.