CONIC HELICAL MILL Russian patent published in 2009 - IPC B02C17/04 

FIELD: technological processes.

SUBSTANCE: invention is related to procedure of hard materials grinding. In order to expand technological resources, drum is arranged in the form of multi-section, multi-turn helical conic column assembled of sections that are made of alternately joined equilateral and isosceles triangles, lateral sides of which are equal to each other, and bases of isosceles triangles are more than length of their lateral sides, at that sections are joined to each other by free sides, number of equilateral and isosceles triangles in section is equal to at least six and has no limitation to the side of increase with creation of three, four, five, etc. broken helical lines of main direction along drum perimetre, with pitch that varies from loading to unloading, and accordingly three, four, five, etc, broken helical grooves of the main direction inside drum with alternating, increasing pitch from loading to unloading, and also three, four, five, etc. broken helical lines of opposite direction with pitch that varies from loading to unloading and accordingly three, four, five, etc. broken helical grooves of opposite direction inside drum with alternating pitch that increases from loading to unloading.

EFFECT: expansion of technological resources of drum.