Blast Furnace Burden Topography

We have performed a series of experimental tests of the technology. These have been more substantially described in a Licentiate thesis [2]. The point-spread function (beam) of the system was determined by first simulating a point source at 1.5 m distance and then observing a differential image with a hole made in a coke surface at a distance of 1.7 m. The simulation indicates a clear round beam, while the observed beam showed some side-lobe structures. Some of these erroneous structures are caused by that the experiment target is not a perfect point source. Some of the side-lobe structures are caused by that our primary assumption is not quite correct. The positions of the reference point are translated for each element pair, resulting in a slight ellipsoid aberration of the interferometer optics. The data also need to be calibrated for cross-talk between antennae and Speckle formed at the burden surface. Work is presently going on to make a new data reduction algorithm, where the data are treated in true three dimensional format. A model of the surface is constructed from known a priori data, and then fitted to the observed complex data with a maximum entropy method. The three dimensional beam is shown in the figure above. We have demonstrated that an object can be detected and measured in three dimensions [2] with sufficient accuracy for a Blast Furnace surface. Sketch of a Blast Furnace. Material is added on top via a chute as layers of coke and ore. The interferometer array designed by us for the Blast Furnace application (upper panel) is mounted inside the Blast Furnace. The corresponding aperture plane coverage is shown in the lower panel.