Robotic surface treatment of large steel structures
Clemco Denmark has developed a new system for automated surface treatment of large wind turbine tower sections. Our automated system for surface preparation and treatment of larger steel structures is performed by a manipulator arm that can reach and maintain a defined distance from spray tool to the steel surface being coated.
The manipulator arm developed by Clemco Denmark for surface treatment is basically a 4-axis robot delivering an efficient spray pattern on large surfaces between 30 to 50 meters in length. The ideal steel structures we coat with this manipulator arm is wind tower sections measuring up to 8 meters in dimeter and 35 meters in length. These huge tower sections for off shore wind parks weight up to 250 tons each and has a surface area of up to 870 square meters.
The manipulator arm is constructed in high strength steel and can be mounted with a tool weight of up to 120 kg. The arm can be programmed to keep a constant distance from the tool center point (TCP) to the surface area. The arm and the peripheral spraying equipment such as metallizing wire drums can be mounted on the cart moving together with the manipulator arm. We have built and installed automated systems conveying a workload of up to 2,400 kg including 8 wire drums of 200 kg each. The spraying accuracy of such a metallizing system is +/- 1 cm at the tool center point.
The arm and the cart for peripheral equipment travels on a rail system that is floor mounted. That means we do not require built-in steel structures in booth walls to support the system. The rail system is simply mounted on floor level and the 1-axis is horizontally set up to position the tool heads in parallel with the wind turbine tower section.
The system can be used for Zn/Al coating, or in an explosion proof version for spray painting. The system can also be installed with a 6-axis industrial paint robot that will provide a much better optimization of the overlaps when spraying. Even though the initial costs for a paint robot has a higher installation cost, our calculations and practical experience show us, that installation costs are earned back, after coating only 120 tower sections. The cost savings are the increased reduction in paint and higher throughput per spraying session.