双级料腿循环流化床中颗粒停留时间分布的研究

双级料腿循环流化床垃圾焚烧炉采用分级转化技术，燃烧前脱氯，有效解决了高温腐蚀和二噁英造成的二次污染。该文采用不同的大颗粒物料来模拟垃圾中的不同组分，在双料腿循环流化床试验台中研究了颗粒的停留时间分布。结果表明，影响大颗粒停留时间的主要因素是循环流率、表现流化气速、颗粒的密度和尺寸。循环流率增大，停留时间急剧降低。表观气速对停留时间影响较小。颗粒密度对停留时间的影响比尺寸要大。颗粒越轻，停留时间越短。根据实验结果，建立了两并联全混釜停留时间分布模型，模型计算结果与实验结果吻合较好。

A STUDY ON RESIDENCE TIME DISTRIBUTION OF PARTICLES IN DOUBLE DIPLEG CIRCULATING FLUIDIZED BED

The incineration technology of double-dipleg circulating fluidized bed, by stage-by-stage conversion and removal of HCl in pre-combustion stage, effectively solves the problem of coupling high temperature corrosion and the emission of dioxins. In this paper, the residence time distribution (RTD) of large particles simulating different components in wastes is investigated in second dipleg of double-dipleg circulating fluidized bed. Experiment results show that circulating flowrate, superficial velocity and density , size of particles all affect the RTD. The mean residence time of particles decreases sharply with an increase of the recirculating rate and slightly decreases as the superficial velocity increases. It appears that the density of particle has a stronger influence on the residence time than the particle size. The lighter the particles are the shorter residence time is. A model consisting of two parallel-mixed flow reactor was presented to simulate the RTD of large particles. The model is supported by the experimental results.