Silos have a higher frequency of failure than any other industrial asset. Examples of failure include complete collapse of the structure that accompany loss of use, worker injuries, and plant downtime. These failures are typically the result of refilling coal silos as they drain. With bottoms falling out and chambers collapsing, plants are looking for a better way to inspect assets, quickly and safely, without giving up coverage.
Gecko Robotics specializes in faster, safer, and preventative NDT inspections.
For a 1080MW plant in Belews Creek, NC, getting an inspection done on ten bituminous coal silos to help identify risks of failure was critical for maintenance. Because of coverage, traditional inspections could not fulfill their needs. Therefore, Gecko Robotics was selected to perform a robotic inspection during the plants downtime.
Inspection scope was limited to 30% of each silo; 15’ (4.5m) of each cone and 20’ (6m) of each silo wall. After performing initial runs with Gecko’s TOKA robot, operators discovered low thickness readings above the original scope line, at the 25’-35’ (7.6m - 10.7m) band. Plant managers recognized this area as the fill-line for when the silo would drain.
Gecko’s TOKA robot is a wall-climbing robot with eight transducers, speeds of 60’ (18m) per minute, and HD visual camera.
Gecko’s portal organizes and displays data in a visual thickness map as well as a downloadable excel document with thickness readings.
Two days later, the scope changed to inspecting all 60’ (18m) of the silo walls, giving Gecko the ability to inspect the entire surface area and providing the plant with a more comprehensive deliverable.
Coverage obtained during the inspection was able to show wear areas (degradation) at fill levels on all ten-coal silos. The plant was able to better understand how the cycle of corrosion and erosion, from filling activities, was detrimental to the integrity of silo walls. Gecko Vision, Gecko’s online portal, allowed the plant to have insight to these areas, discovering root causes, and provided a map to help guide where repairs would need to occur immediately and in the future. The portal allowed the plan to exceed expectations in preventative maintenance by having a 360-view of the assets; providing a longer asset life cycle and preventing forced outages, safety issues, and loss of revenue dollars.