带搅拌管式反应器中的流动特性

Study on flow characteristics in a stirred tubular reactor

以NaC l溶液为示踪剂,采用脉冲示踪法考察了搅拌转速、流量及液位对带机械搅拌装置的管式反应器内停留时间分布(RTD)曲线的影响.用Pec let操作准数表征轴向扩散特性.结果表明:增加搅拌装置后,反应器内的流动型态仍接近活塞流;随流量的减小和液位的升高,流体流动愈向活塞流靠近,即减小流量或者升高水位有利于减小返混;当搅拌转速超过100 r/m in时,搅拌转速对停留时间分布的影响不大.

A new type tubular reactor with a stirrer is designed for solid - liquid reaction. NaCl solution is used as tracer and the RTD curves are investigated at different stirring intensities, different flow rates and different water levels. Peclet number （Pe） is used to represent the axial dispersion. The results show that the flow pattern in the reactor is close to plug flow. With lower flow rate or higher water level, the flow pattern is closer to plug flow. Decreasing the flow rate and increasing the water level are both beneficial to reduce back mixing. When stirring intensity exceeds 100 r/min, it has no obvious effect on RTD.