石油焦燃烧器烧焦管内固体颗粒的停留时间分布实验研究

采用脉冲磷光颗粒示踪法，对一套新型内混式石油焦燃烧器烧焦管内固体颗粒的停留时间进行了实验测试，分析了烧焦管内固体颗粒的扩散特性。实验结果表明，在烧焦管轴向上距示踪剂注入位置为1．0m的截面上，不同径向位置测得的颗粒停留时间分布呈较对称的单峰分布，从烧焦管轴心向边壁靠近。其峰高差别较大。而在示踪剂注入位置以上的4．0m及9．4m截面上，不同径向位置测得的颗粒停留时间分布曲线由一个尖而高的前峰和长拖尾所组成，曲线的峰高基本一致，表明颗粒沿轴向以弥散颗粒和颗粒团的形式扩散，颗粒沿径向的混合较均匀。分别对1．0m和4．0m及以上检测距离内的颗粒扩散行为建立了径向扩散模型和轴向两组分叠加模型，模型预测的颗粒浓度值与实验值吻合较好。

Experimental study of particle residence time distribution in coke-burning riser of combustor used for petroleum coke

The particle diffusion behaviors in the coke-burning riser of a novel internal mixing type of combustor used for petroleum coke were studied through measuring the residence time distributions(RTD) of particles by impulse phosphor tracer technique.The diffusion characteristics were analyzed.The experimental results show that the RTD curves of solids in 1.0 meter detecting distance of the riser are unimodal and the peak height decreases gradually from the axis to the wall.Moreover,the RTD curves of solids in 4.0 and 9.4 meter detecting distance of the riser are composed of a sharp-high leading peak and a long tail,and their peak heights are nearly same.The solids diffusion mechanism in the riser can be explained by the diffusion of dispersed particle and cluster.A lateral diffusion model and an axial superposition model were established to predict the particle diffusion behaviors in 1.0 meter and 4.0 meter detecting distance of the riser,respectively.The predicted results obtained by the model are in good agreement with the experimental data.