Stedman is promoting its “Expect More” HSI crusher line by re-educating process engineers about the unique design aspects of impactors. HSIs are capable of high ratio size reduction with no decrease in quality of the product even after long periods of operation. High size reduction ratios offer cost savings in handling, maintenance and wear parts.
Reduction ratios of up to 30 to 1 are achievable in a single stage. Product size is varied by changing rotor speed and the clearances between rotor breaker bars and apron breaker plates. The size reduction takes place along short fracture lines producing a more cubical product to meet aggregate specifications. This fast impact fracture is different from the slow compression breaking in cone or jaw crushers that produce more slabby or flat material (5 to 1 length to height ratio). Unlike hammermills, the open discharge impactor has no screens or grates holding material inside the crusher, so material is efficiently processed at high rates for low costs. Design simplicity offers safe and easy access for rotor breaker bar replacement and access to all areas of the crushing chamber. Horizontal Shaft Impactors have proven they are capable of size reduction of all types of material sizes and hardnesses with minimal maintenance and excellent cubical particle size distribution control.