短接触旋流反应器导叶位置对气相流动的影响

采用雷诺应力模型对不同导叶位置下的短接触旋流反应器内气相流动进行数值模拟,并且用组分输运方程研究了气体在旋流反应器内停留时间的分布规律,分析了导叶位置对反应器内气相停留时间分布、气相流场以及排气管入口短路流的影响。结果表明:不同导叶位置的旋流反应器排剂口处气相停留时间分布曲线相似,而混合反应区内气相停留时间分布曲线仅在时间轴上发生微小偏移;叶片离反应器入口越远,混合反应区内切向速度越小,而排气管下方分离反应区内外旋流切向速度显著增大及准自由涡范围减小;叶片与排气管入口距离减小可以降低附近短路流率,减小催化剂的“跑损”,但也增大了排气管内气流旋转强度,造成不必要的能量损耗增大。

Effect of vane-guide location on gas flow behavior in short-contact cyclone reactor

The gas flow behavior of short-contact cyclone reactor with different vane-guide locations was numerically simulated with the Reynolds stress model(RSM).The gas RTD(residence time distribution)in the reactor was studied by using the species transport equation.The effect of vane-guide location on residence time distribution,gas flow field and short-cut flow was investigated.The gas RTD curves at the catalyst outlet of different vane-guide locations were similar,while those of the mixed reaction zone had some deviation.A larger distance from vane-guide location to the inlet of reactor would cause a smaller gas tangential velocity in the mixed reaction zone and induce a larger tangential velocity and smaller quasi-free vortex in the separated reaction zone.Though a smaller distance from vane-guide location to the exhaust pipe inlet would cause weaker short-cut flow near the exhaust pipe inlet,which made it difficult for catalyst to be carried out from the exhaust pipe,it would amplify gas flow rotation intensity in the exhaust pipe which contributed to energy loss.