旋风分离器的入口烟道布置对性能的影响

大型循环流化床锅炉都采用多个旋风分离器并联布置在炉膛出口，这些旋风分离器的入口烟道受锅炉空间的限制都是短入口烟道，不同的入口烟道布置方式会直接影响旋风分离器的性能。在筒体直径为1 m的旋风分离器实验台上设计了内侧式与外侧式2种短入口烟道，对比研究入口烟道布置方式对旋风分离器性能的影响。实验结果表明，入口烟道布置方式显著影响旋风分离器的性能；在相同条件下，内侧式入口烟道的旋风分离器的分离效率比外侧式的高，压降也比外侧式略高。数值模拟结果显示，入口烟道布置方式对颗粒在短入口烟道中的分布有直接的影响；采用外侧式入口烟道时，颗粒流股在短入口烟道内无法贴向外壁，部分颗粒直接冲击排气管，导致分离效率降低。

Influence of Inlet Duct Layouts on Cyclone Performance

It is common in a large capacity circulating fluidized bed (CFB) boiler to adopt several cyclones in parallel to the furnace. The lengths of the inlet ducts of the cyclones are very short due to CFB boilers design. Different inlet ducts layouts affect the cyclones performance. Based on cold experiments and numerical simulation, the effects of inlet duct layouts (inner-side and outer-side) on the pressure drop and the separation efficiency of a cyclone with one meter in diameter were investigated. The separation efficiency of the cyclone with an outer-side inlet duct is lower than the one with an inner-side inlet duct, and the pressure drop is also lower. Some particles from the riser rush to the vortex finder of the cyclone directly resulting in the reduction of separation efficiency.