催化裂化待生剂分配器性能的冷模实验评价

高效待生剂分配器对改善催化裂化再生效果具有显著的影响。设计并建造了一套能够评价待生剂分配器性能的冷模实验装置，检验了依据现有工业设计方法制造的船型和管式分配器模型以及无分配器时的颗粒横向分配性能，对比了3种再生器待生剂入口结构性能的优劣，并找出了它们存在的缺陷。结果表明，在大型工业装置中，管式分配器是唯一能够显著改善颗粒横向分配均匀性的待生剂分配器，但它必须消耗大量的输送风，会因此增加装置能耗，并对待生管路的颗粒输送能力产生不利影响；船型分配器对颗粒横向分配均匀性的改善作用十分有限，尤其是在大型工业装置中。对于所有待生剂入口结构，增加输送风量能够显著改善颗粒横向分配的均匀性，增加松动风量也能改善船型和管式分配器的性能，但总体上效果不如增加输送风显著，而增大催化剂循环量后，3种待生剂入口结构的颗粒横向分配均匀性均有一定程度的恶化。由于受管内气 固相流型转变的影响，管式分配器存在一个临界输送气速，在此临界气速以上，颗粒横向分配均匀性可以显著改善。上述研究结果可为工业待生剂分配器的优化设计以及新型高效待生剂分配器的开发提供借鉴。

Performance Evaluation of FCC Spent Catalyst Distributors by a Large Cold Model

High-efficiency spent catalyst distributor could significantly improve FCC regeneration performance. A large cold experimental installation was designed and built to evaluate the performances of various spent catalyst distributors. Referring to existing industrial designs, a boat-type and a pipe-type spent catalyst distributor models were designed and tested under different operating conditions. Their capacities to improve lateral particle distribution uniformity were compared and their shortcomings were found. The experimental results indicated that, pipe-type distributor was the only spent catalyst distributor that could significantly improve lateral particle distribution uniformity in industrial units. However, it consumed large volume of transport air, resulting in higher energy consumption and affecting negatively the particle transportation capacity of the spent catalyst standpipe. The improvement to lateral particle distribution uniformity by utilizing boat-type distributor was very limited, especially in large industrial units. For all the three studied spent catalyst inlet structures, increasing transport gas velocity could improve lateral particle distribution uniformity remarkably. Increasing fluidizing gas velocity could also improve the performance of the two distributors, but not so effectively as increasing transport gas velocity. However, lateral particle distribution uniformity deteriorated slightly under higher particle circulation rates for all the three catalyst inlet structures. Due to inner gas-solid flow regime transition, there existed a critical transport gas velocity in a pipe-type distributor, beyond which an abrupt improvement of its lateral particle distribution uniformity could be observed. The above results were useful for optimizing design of industrial spent catalyst distributors and developing other novel high-efficiency spent catalyst distributors.