防返混锥对双循环旋风器性能的影响研究

Study on Effect of Anti-reentrainment Cone in Double Circulation Cyclone Separator

前面的研究表明,双循环旋风分离器的设计使得大于3μm颗粒的分离效率接近100%。本文通过CFD模拟软件Fluent 6.2对带有防返混锥的双循环旋风分离器内的压力场和颗粒轨迹进行了数值模拟,并与实验结果进行了比较,模拟结果和实验结果基本一致。模拟得出防返混锥可使分离器的阻力系数增加12%,并减小灰仓内3μm以下颗粒的返混量。实验结果表明,进口气速在8～21m/s时,防返混锥可使主进口和回流口的阻力系数分别增加14.6%和11.8%;当进口平均气速在15～19m/s时,若采用主进口进料,防返混锥可使总分离效率提高0.15%～0.2%;若采用回流口进料,可提高1.5%～2%。

The preceding study showed that the collection efficiency of particles larger than 3μm was nearly 100% in double circulation cyclone separator. A numerical simulation of the pressure field and particle trajectory was made in double circulation cyclone separator with anti - reentrainment using Fluent 6.2, and compared with an experimental results, the simulative results were in good agreement with the experimental results. It showed that anti -reentrainment cone could increase the drag coefficients by 12% in cyclone, and could decrease backmixing of particles less than 3μm in dust hopper. Experimental results showed that anti ＂ reentrainment cone could increase the drag coefficients of main inlet and reflux inlet by 14.6% and 11.8% respectively, while the inlet gas velocity was 8 -21m/s. If feeding by main inlet, anti - reentrainment cone could increase total collection efficiency by 0.15% - 0. 2%, and if feeding by reflux inlet, the total collection efficiency could be increased by 1.5% -2%, while inlet gas velocity was 15 - 19m/s.