湍动流化床内密相的总体循环与气体混合

在内径２００ｍｍ，高５５００ｍｍ的流化床内，采用点源反向示踪的方法，利用气相色谱分析仪连续取样分好了湍动流化床内密相的浓度分布。实验表明，湍动流化床的密相除进行总体循环运动外，还存在着激烈的返混。密相内的气体混合行为可用二维扩散模型描述，表征混合程度的扩散系数可通过非线性估值求得，其值与流化气速呈线性关系。

Mixing and Cycling of the Dense Phase in a Turbulent Fluidized Bed

The concentration distribution of the dense phase in a turbulent fluidized bed, whose heightis 5 500 mm and inside diameter is 200 mm,was measured continually with gas chromatography.Thought a spot,the hydrogen tracer was injected continually in an opposite direction with thefluidized gas;The experiment results indicate that besides the cycling movement,there is a seriousbackmixing in the dense phase.The behaviour of mixing in thc dense phase can be described with thetwo-dimensional pseudo-dispersion model.The gas dispersion coefficient,which is used tocharacterize the extent of mixture,can be caiculated by no-linear estimation. This coefflcient is foundto have linear relation with the fluidized velocity.