A homogenous mix of coarse and fine particles is constantly fed to the crusher so that a head of material is developed and maintained within the crusher. Incoming feed, at the center of the crushing cavity, is spread radially outward to the perimeter of the surge chamber by a motorized rotating feed distributor.
The descending velocity of the incoming material is reduced by the feed distributor and the feed is lightly deposited, in a circular path, layer upon layer. The particles within the feed mass are separated by a countless number of voids created by the loose layering of feed particles.
Each time the lower liner moves away from the upper liner a portion of the feed mix enters the attrition chamber from the surge load above. The flat angle of the lower liner is less than the angle of repose of the material undergoing reduction. If the lower liner where at rest the material delivered to the attrition chamber would not of itself slide downward through the chamber. The shallow liner angle offers enough resistance to the flow of material, by gravity, that it is only the motion of the head which advances the material outwardly a slight amount at each gyration.
The movement of material through the attrition chamber is positive to response to the carrying movement of the head. In other words the motion of the gyrating head and the pressure due to the height of the surge capacity in the cavity causes the material undergoing reduction, to move progressively outward through the attrition chamber in a series of short steps.
The passage of material through the attrition chamber is not continuous but intermittent. Somewhat like the introduction of fuel is an internal combustion engine, the Gyradisc crusher advances the feed material only prior to the power stroke. Because of the number of gyrations and cavity design, the percentage of oversize product is greatly reduced and highly efficient crushing takes place.