Estimation of Permeability Distribution in a Packed Bed Similar to Blast Furnace Using X-Ray Radiography 

In counter-current metallurgical processes like blast furnace, high pack density has undesirable effect on process dynamics.  The pack density or porosity of a pack-bed is a function of packing media and the packing procedure followed.  However, as the internal structure of evolving pack-bed has never been estimated under hot condition, the understanding of the same is rather speculative. An improvement of this situation could be achieved through a non-destructive inspection of the prototype/simulated pack-bed, using real-time x-ray radioscopy.  The recent developments in X-ray radiography and digital image processing techniques have made it possible to qualitative/quantitative estimation and mapping of distribution of porosity in a packed bed.  At NML, a unique effort, using x-ray radioscopy and computed tomography has been initiated to study the internal void fraction of pack-beds.  In this report, the development of the experimental facility as well as the necessary software for computed tomography have been described along with few results (fig 1) obtained with the developed system for packed beds at room temperature.    

Schematic view of X-ray computed tomography system	Vertical CT slices of the cylindrical test objective indicating a single spherical void in the center