The homogenizer installed vertically underneath the mixing vessel operates in accordance with the rotor-stator principle. The homogenizer allows the product to be dispersed or pumped either internally (short loop) or via the external circulation pipeline. In the rotor/stator, the product is accelerated to a tangential speed of 35 m/sec by the rotation of the rotor and then braked within a distance of 1 mm back down to 0 m/sec. The shear and transverse forces thus generated in the shear gap effect a droplet size reduction right down to 1 µm in the case of emulsions. Liquids and powders are drawn in under vacuum to the homogenizer, where they are wetted and dispersed. The product is returned to the mixing vessel for macromixing via the internal or external circulation pipeline. Compared with other designs, the special design of the spiral mixer has the advantage that dependent on the rotational direction of the stirrer, the product is transported along the inside walls of the mixing vessel either upwards or downwards. An optimum temperature exchange takes place on the surface of the walls. The contour scrapers fitted in the spiral mixer are laid out for both left-hand and right-hand rotation, and scrape product away from the vessel walls and accelerate the product in the centre of the mixing vessel.