Recording of a rotary kiln with a terrestrial laser scanner (TLS) from the outside and inside to determine the residual wall thickness, deformation and geometric shape at relevant/indicated points.
Due to the continuous use of the furnaces, this measurement can only be carried out during maintenance. The prerequisites for our work and for an optimal result are
Within four days, the rotary kiln surface was recorded from the inside and outside by using the TLS from several points of view.
In addition, the linkage points were also determined in a network measurement with a laser tracker in order to conclusively evaluate the network quality or to use it as a local stationing method. Based on this, the laser scanner is also able to orientate itself via the reference points determined by the laser tracker.
In order to link the reference points, linkage marks and linkage balls are used.
It was preferred to take the measurements ideally at night and during the early morning hours, as otherwise the geometry would have been influenced by material and temperature expansion.
In the first step a target contour was derived from the measured data of the outer contour for the current as well as all following measurements. Based on the shell thickness of the kiln and the nominal stone thickness of the inner lining, a target inner contour model was created.
The individual scans were then combined to form a complete point cloud and processed in Polyworks.
In the second step, the measured data of the inner measurement were compared with the nominal inner edge model and a 3D wall thickness model was generated for the outer contour. The wall thickness could be mapped by placing a cut at the desired and relevant points.
The remaining wall thickness was also visualized in the pipe frame with a colour scale so as to be better visually distinguishable.
Thanks to the data we provided, maintenance was now possible very precisely according to the gained insights and the corresponding fireclay bricks were replaced.
If you have any questions concerning these kind of measurements, please feel free to get in touch!