Outotec custom-designed the demolition robot lifting frame, a proprietary equipment. While not an entirely new concept to Outotec, the challenge was the wide diameter of 12.5m and the unique shape of the roaster vessel in which the machine needed to operate. In addition to safety, speed and efficiency were crucial to minimize the overall shutdown time, to enable customer to return to production and profitability as soon as possible.
The frame had to be installed on the roaster nozzle grate/floor, which was 12m in diameter, and then lifted to the upper wall where the roaster vessel widened to a diameter of 16m, all without human entry into this confined space. This was accomplished by incorporating telescoping hydraulic stabilizers to brace the frame against the vertical walls creating the required support for the robot to perform its task. A second machine was mounted on the opposite side of the frame, acting as a counterweight to balance the entire setup.
Despite weather delays during the critical shutdown period, Outotec completed the remote demolition work, the removal of the wall accretion on the sloping wall and low vertical wall and the cleaning of the bed, within the planned 10-day period without safety incidents. Such execution work enabled customer to accelerate the rest of the shutdown schedule and made Outotec the first company to accomplish a remote shutdown work on such a large vessel.
The customer was impressed with the ingenuity and execution meeting their needs in a fast and safe manner.