We describe vortical thin layer film flow along a spiral channel designed to improve mass and heat transfer efficiency for a multitude of physicochemical reactions and processes. Spiral channels, commonly augmented by centrifugal rotation, support rapid reaction between one or more fluids in a given channel. Dean vortices generate screw-shaped patterns processing axially in the channel, repeatedly refreshing radial interfaces. Fluids self-align, self-assemble, stable, controllable, exhibit thin film geometry. Multiple discrete lamellae can flow with independent velocity separated by density and may be soluble or insoluble in one another. Membranes separating spirals allow other interactions. Energy can be provided and extracted from each flow. Flows can enter or exit independently along the channel length. The pressure within each channel is controlled even when operated at the liquid's vapor pressure. The device is scalable to include a multiplicity of flows in a multiplicity of centrifugally rotating chambers.