关键词: 环流反应器, 强制循环液流, 流动区域, 局部传质行为

Abstract: A novel three-phase airlift loop reactor with forced slurry phase circulation was proposed. The reactor was divided into six regions. Experiment was conducted in a cold model apparatus with 300 mm ID plexiglas column and 1700 mm in height over a wide range of operation conditions with the superficial velocity in draft tube, UGr, from 0.006 to 0.19 m/s, the liquid velocity pumped into the reactor, Ucir, from 0.0307 to 0.0511 m/s, and the volumetric solid concentration, es, from 5% to 15%, respectively. The mass transfer coefficient, kLa, was measured in each flow region of the reactor by employing a new O2/air steady-state method. It was found that with kLa as high as 0.754 s-1, the downcomer affected region has a biggest mass transfer coefficient than other regions, while the annulus region, with kLa no more than 0.043 s-1, has a smallest one. Interestingly, the mass transfer coefficient of gas-liquid separation region approximately equals to that of whole reactor. In addition, the mass transfer coefficient of whole reactor increases with the increase of superficial gas velocity and superficial liquid velocity pumped into the reactor, but decreases with increasing solid loading.

Key words: airlift loop reactor, forced circulation slurry phase, flow region, local mass transfer behaviour