连续进出料鼓泡流化床颗粒停留时间分布

Residence Time Distribution of Particles in a Bubbling Fluidized Bed with Their Continuous Input and Output

针对双流化床气化或双床热解气化工艺中鼓泡床反应器的设计,采用脉冲法研究了GeldartB类固体颗粒在连续颗粒进料和出料的矩形流化床内的停留时间分布(RTD),考察了气速、床料高度、粒径、物料流率等操作参数对RTD的影响.结果表明,物料流率、床料高度、粒径是影响颗粒RTD的主要因素,而气速则是次要因素.随物料流率和粒径增加,鼓泡床内颗粒流动向平推流靠近;随床料高度增加,物料在床内的混合更加充分,颗粒流动向全混流靠近.根据实验结果,推荐采用比理想平推流时间低9%～18%计算平均颗粒停留时间.

The characteristics of residence time distribution （RTD） of solid particles （Geldart B） with the pulse particle tracer approach in two cold rectangular bubbling fluidized beds （BFB） with continuous particle flow were experimentally investigated. The parameters tested were superficial gas velocity （U）, feeding rate of particles （Gs）, particle bed height （/4） and particle size （dp）, and the used tracer was coal particles. The results showed that Gs, H and dp were the major influential factors, while U affected little. The particle flow pattern in BFB reactor lied between those of the ideal plug flow reactor and completely stirred reactor （CSTR）, it was close to the plug flow when the particle bed height was lower and Gs larger, whereas the flow was much closer to the full mixing flow of the CSTR at the higher particle bed height and smaller Gs. The averaged residence time of particles was calculated as the value of 9%-18% below of the plug flow for the design of BFB based on the present experimental data.