| 摘要 |
<p>The inventive multi-level furnace comprises a furnace wall (10) delimiting a cylindrical space having a vertical axis (11), a plurality of beds (12, 22) defining the levels inside said cylindrical space and at least one scraping arm (16, 16'; 26, 26') which is provided with a wall scraper (20, 20',32) and associated with the bed (12, 22) in such a way that it is rotatable about the vertical axis (11) of the furnace. During scraping arm (16, 16'; 26, 26') rotation, said wall scraper (20, 20'; 32) defines a scraped area (52; 52') on the internal surface of the furnace wall (10) which comprises a plurality of wall cavities (54; 54') forming a row of access openings (56; 56') in the scraped area (52; 52'), thereby making it possible to avoid the formation of a hardened crust adhered to the internal surface (42) of the furnace wall (10) and to develop braking shocks in the scraping arm (16, 16'; 26, 26').</p> |
