循环率对循环流化床分解炉性能的影响

流化床反应器在水泥工业用于生料的预分解．为了提高物料分解率，开发出一种新型的循环流化床反应器并已用于水泥生产．这种循环流化床反应器中的固气比要高于传统的预分解反应器．在建立物料氧化钙平衡的基础上，建立了关于物料循环率和碳酸盐分解率之间相互关系的数学模型．模型的计算结果与现场测试结果吻合很好．此外还提出了分解炉热稳定性的概念，并给出了相应热稳定系数的表达式．结果证明：使用循环流化床分解炉可有效改进固体物料的最终分解率．当操作温度一定(850℃)时，循环率每增加100％，入窑物料的终分解率可提高8％～9％．外循环方案有助于改善分解炉的热稳定性并降低分解炉的操作温度；在终分解率不变的情况下，物料循环率每增加100％，分解炉的操作温度可降低30-500℃．

Effect of recirculation ratio on the operation of CFB calciners

Fluidized bed reactors have been used as calciners in cement industry for calcination of cement raw meal.Aiming at enhancing calcining rate, a new kind of circulating fluidized bed(CFB) reactor was developed and applied in cement plants. Inside this kind of CFB reactor, the mass ratio of solid to gas (S/G) was much higher than traditional one. Based on the balance of calcium oxide material, a mathematical model concerning the relationship between recirculation ratio of material and calcining rate of carbonate was developed. The computing results by using such relationship showed reasonable agreement with experiments. The concept of thermal stability of calciner was put forwarded, and the corresponding mathematical expression of thermal stability coefficient was determined. It was proved that application of CFB calciner improved the final calcination degree of solid material. At fixed operating temperature (850 ℃), the calcining rate of the carbonate into rotary kiln may be enhanced by 8%～9% with 100%increase of recirculation ratio. Meanwhile application of external re-circulation to calcining enhanced the thermal stability of calciner system. The required operating temperature inside a calciner may drop 30～ 50 ℃ by increasing recirculation ratio of 100%.