International Dredging Review

International Dredging Review

Stedman is promoting its HIS crusher line re-educating process engineers about the design aspects of impactors.

The company said impact crushers are used in dredging applications on floating clamshell dredges which crush large river gravel for conveyance away from the dredge. The dredged material goes through a screening process then the over-sized solid material goes through the impact crusher.

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.

Stedman Machine Company offers a full line of HSI crushers for almost any material or application from wet and sticky to dry and friable. A GrandSlam™ HSI crusher is available for testing at Stedman’s Testing and Toll Processing Facility and more than 10000 other size reduction equipment tests are on file.