摘要 |
The inventive multi-level furnace comprises a furnace wall delimiting a cylindrical space having a vertical axis, a plurality of beds defining the levels inside said cylindrical space and at least one scraping arm which is provided with a wall scraper and associated with the bed in such a way that it is rotatable about the vertical axis of the furnace. During scraping arm rotation, said wall scraper defines a scraped area on the internal surface of the furnace wall which comprises a plurality of wall cavities forming a row of access openings in the scraped area, thereby making it possible to avoid the formation of a hardened crust adhered to the internal surface of the furnace wall and to develop braking shocks in the scraping arm.
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