Abstract: Mixing apparatus has a mixing container and a mixing device mounted in it, comprising a driven shaft connected to a driving motor and extending through the container along its longitudinal axis and mounted rotatably, and radially extending arms mounted on this shaft and having at their outer ends respective mixing tools moving around close to the wall of the container. Each tool is provided both on its leading and also on its rear end with at least one working flank extending at an angle to the plane of rotation of the tool. The working flank at the one end of each tool extends at a different angle of inclination to the plane of rotation of the tool from that at the other end. The shaft of the tool is driven with a reversible direction of rotation.

Abstract: A device for the heat treatment of bulk material comprising a horizontal trough-shaped container having a driven shaft extending longitudinally therethrough on which shaft are mounted radially extending arms on which are provided mixing tools and heat exchange plates removably suspended in the container between the mixing tools. A heating or cooling medium can be passed through the plates to heat or cool the bulk material.