Abstract: An apparatus for processing high viscosity materials consisting of a heatable, horizontal vessel with a product inlet on the one end and a product outlet on the other end and, parallel to the axis of the vessel, a heatable rotating hollow shaft, supporting a plurality of heatable stirrer elements, and between these stirrer elements, fixed to the wall of the vessel, stationary baffle and scraping elements of different configurations.Each stirrer element comprises one to four stirrer wings, each with two hollow spokes and a peripheral, hollow ring-segment connecting the spokes, and fixed to the peripheral end of these ring-segment connections trailing product dragging blades.