Measurements of geometry of a boiler drum by time-of-flight laser scanning

Abstract In the paper the application of ToF laser scanner in measurements of geometrical parameters of a boiler drum used in a power plant is presented. These parameters are required during renovation works, for verification of correctness of annealing process and optimization of the process of mounting a mechanical steam–water separation. The currently used separations are tightly placed in a boiler drum, so a welding process is not required anymore. This approach saves the time of renovation works, but the geometry of a separation has to be precisely matched against the geometry of the drum to ensure the tightness of connection and, in consequence, to ensure stability of steam parameters (pressure and temperature). Renovation works may include heating processes, after which geometry should also be carefully verified as improperly performed can lead to buckling of a boiler drum. In the presented approach ToF scanner provides cloud of points, which has been subjected to a set of post-processing operations including stitching, cylinder fitting, projection 3D data onto 2D map, 2D data interpolation and filtering. As the result, the required dimensions and tolerances are obtained and are ready for further implementation.