The EMCO PSI – 12 works independently with the process at a constant temperature. The powder is fed at below sonic speeds into the flat cylindrical milling chamber tangentially through a venturi. The system uses compressed air. Once the particles are inside the milling chamber they are accelerated by a series of jets around the perimeter to supersonic speed, in a spiral movement. The micronising effect occurs when the slower incoming particles and the faster particles in the spiral path collide.