摘要
双循环旋风分离器通过将主进口设置在筒体中部,将顶部进气口设置为回流口,消除了进气口附近的二次流,避免了短路流,将大于3μm颗粒的分离效率提高至接近100%,并避免了少量11—15μm颗粒的短路逃逸。为了探索该设备的除尘机理,借助CFD软件,通过数值模拟研究的方式,辅助分析了2种进气口在分离性能上不同,传统旋风分离器不能完全分离3—8μm和11—15μm颗粒的机理,以及消除二次流的方法。计算结果表明:当回流气速低于主进气速时,会产生类似于顶端进气口的现象,即二次流、灰环和短路流,降低了小于6μm颗粒的分离效率。当回流气速略大于主进气速时,可以完全消除主进气口附近的二次流,使得所有粒径颗粒的分离效率都较高。模拟结果与实验结果从定性的角度符合较好。
By setting the main gas inlet on the middle part of the cylinder wall of double circulation cyclone separator, and the top inlet as a reflux inlet, the secondary flow at the first swirl of main inlet gas flow can be eliminated by the double circulation cyclone separator, thus improving the collection efficiency of particles larger than 3 μm to nearly 100%, and avoiding the shortcut of a few particles of 11-15 μm. For the purpose of researching the dust separation mechanism, based on CFD software and numerical simulation, the effect of two kinds of inlets on the performance of cyclone separator and the mechanism that conventional cyclone separators can not completely collect particles of 3-8 μm and particles between 11-15 μm were studied. The results show that when the gas velocity of reflux inlet is less than that of main inlet, the secondary flow occurs at the top of swirling field of main inlet gas flow, resulting in the decrease of collection efficiency of particles less than 6 μm; when the gas velocity of reflux inlet is slightly larger than that of main inlet, the secondary flow can be eliminated completely, and the collection efficiency of all particles are higher. From the qualitative viewpoint, the simulative results are in good agreement with the experimental results.
出处
《化学工程》
CAS
CSCD
北大核心
2012年第1期64-67,72,共5页
Chemical Engineering(China)
关键词
旋风分离器
二次流
数值模拟
颗粒轨迹
cyclone separator
secondary flow
numerical simulation
particle trajectory
