| 摘要 |
FIELD: production of building materials. SUBSTANCE: method for producing expanded clay aggregate (trade name "ceramzite") comprises steps of preparing feedstock, producing granular material, heat pre-treatment of granules using heat of off-gases leaving firing zone, firing in fluidized bed, cooling of granules, followed by pneumatically transporting them to bin. Cooling step is carried out while simultaneously recovering heat as follows: first, as ceramzite is withdrawn from firing zone, convective heat transfer is effected between ceramzite together with off-gases leaving firing zone, and feedstock granules to be heat-pre-treated through heat-conductive wall, next ceramzite is held in crystallization vat and further cooling is combined with pneumatic transportation step so that still warm ceramzite is charged into bin, while heated air of pneumatic transport facilities is directed to fluidized bed in firing zone. Method uses following inventive features: ceramzite and off-gases are discharged from simultaneously to warm up through heat-conductive wall air directed to fluidized bed, and to heat-pre-treatment of granules. To separate this flow, gases are additionally used for blowing- through of granules transported to firing zone. Ceramzite firing method is carried out in unit comprising vertical body made of plurality of concentrically arranged casings to form firing chamber. Concentric casings form central channel for withdrawal of ceramzite from firing zone, circular shaft for feeding granules, circular shaft intended to withdrawal ceramzite and communicated via torus-shaped member to central channel, and circular shaft for directing air to fluidized bed zone. Each circular shaft accommodates helical blade, while lower part of casing, separating granules feeding shaft from ceramzite withdrawal shaft, is made perforated. EFFECT: ceramzite production by firing in fluidized bed with maximum heat recovery. 10 cl |
