| 摘要 |
The invention relates to a ground element for mills, mixers and worms used preferably for the grinding/processing of paper stock and plastics materials comprising ceramic fillings, other fibrous substances such as crude brown coal, beet chip and the like. The ground elements have at least two fastening elements, which can have undercuts (44), beads and/or corners, on the fastening side (36) opposing the working surface (38) for fastening the ground element (41) in corresponding holes in a support body. Ground elements of this type can be arranged on the rotors of high-speed refiners. Rotors of this type have annular sectors which can be composed of a large number of individual ground elements. Differing tasks can, in this case, be assigned to the individual annular sectors. A central sector is formed from securely embedded metal carbides which have high thermal stability and which have emergency running properties if the ground discs are scraped. As a result of the provision of a slightly smaller working gap in the region of this sector, the adjacent sectors are protected from scraping and can be formed by modularly constructed, cost-effective ground elements (lamellar bodies) made of ceramics or pressed carbon fibres. As a result of precise large-scale production by powder injection moulding (PIM) and pressing into a screen-like carrier plate, these lamellar bodies can be produced for any user as desired, with optimum geometry. Exchange is simple and rapid.
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