CONSTRUCTION FEATURES AND EFFICIENCY OF VERTICAL IMPACT CRUSHERS

Abstract

In the technical stone market, the most demanded grain size classes are 4/8, 2/4, -4, -2 mm, which weight portion being predominant in aggregates for production of concrete and asphalt. However, the production of these classes is not always simple. In adition to quantity requirements, the specific grain size distribution and grain shape of stone aggregate, as well as a minimal portion of the particles -0,09 mm are regurarly demanded. Until about ten years ago, impact and hammer crushers were most often used for the production of the above mentioned classes, while nowdays vertical impact crushers are being used with increasing frequency for this purpose. Compared to the first-mentioned crushers, vertical impact crushers represent a certain technological progress manifested primarily in a greater content of cubic shaped graines in output material and reduced wear of crusher lining and impact elements. The paper descibes the basic construction features and the operating principle of vertical impact crusher and analyzes their efficiency (grain size distribution of the crushed product, content of favourably shaped grains, filler content) as a function of the particular technological parameters (the paper is published in Croatian).

Keywords

• comminution
• vertical impact crushers
• high grade chippings