Vertical Blender/Dryers feature a slow-turning auger screw orbiting a vacuum-rated conical vessel. As it turns, the screw gently lifts material upward and towards the center of the batch. At the same time, product from the top cascades back to the bottom while mixing with materials being moved upward by the orbiting screw. During the drying cycle, hot water, oil or steam is recirculated through the vessel jacket and vacuum is typically applied. Requiring relatively low temperatures to drive off moisture or solvents, vacuum drying is an excellent method for processing heat-sensitive formulations without fear of thermal degradation. Energy consumption is also minimized.

As opposed to conventional ovens and tray dryers where product is stationary, the layer of material contacting the Vertical Blender's heated sidewalls is constantly being renewed which, coupled with vacuum conditions, leads to significantly shorter drying rates. Another drying technology available to manufacturers is spray drying where an atomizer breaks up the feed into fine droplets and hot air forces the liquid components to evaporate, leaving behind solids with a uniform particle size. While this process is fast and can be operated continuously, high energy and pressure requirements, as well as maintenance issues, make it impractical for some applications.