The Nauta conical screw mixer is a convective mixer with high mixing efficiency. It is gentle and guarantees the highest level of mixing accuracy without product distortion. The screw has an average speed of 70 rpm, whilst the arm rotates at 1 to 2 rpm. The tip speed of the screw can fluctuate between 0.5 and 2 m/s, making it suitable for all ATEX zones. The rotating, cantilevered (free-hanging) mixing screw conveys the product from the bottom of the vessel to the product surface. The mixing screw is suspended from an orbital arm, which rotates the mixing screw along the conical inner vessel wall, causing convective mixing of particles and shear. The speed of particles in the downward massflow, when recirculated by gravity in a conical vessel, increases as the vessel diameter decreases. The result of these simultaneous actions is a fast and intensive mixing with low consumption of power together with high standards of mixing accuracy. Convective mixing effect The convective mixing effect is created by 3 factors: Axial mixing by the screw Radial mixing by shape of the cone Tangential mixing by the arm