Underwater laser cutting
Underwater construction on offshore wind farms, bridges or locks must presently be done by scuba divers.
For maintenance and repair of metal constructions, a number of processes are available, but these are time consuming and difficult on the divers.
Underwater laser cutting is a fast and thus economical alternative to conventional processes.
For this reason, engineers at the Laser Zentrum Hannover e.V. (LZH) and the Leibniz Universität Hannover (LUH) are developing a process for automated, underwater laser cutting.
At the moment, mainly light arc oxygen cutting is being used for underwater cutting. The electrodes are hand-guided. Depending on the material thickness, divers need a workday to cut 20 meters in material. For a diving period of five hours this means a cutting speed of only 7 centimeter per minute.
Cutting seven times faster
With a laser-based automated process, the cutting speed should be increased by a factor of seven. “During pilot tests, we have already achieved a cutting speed of 0.5 meters per minute for 10 millimeter thick steel” says Dr.-Ing. Jörg Hermsdorf, head of the Machines and Controls Group at the LZH.
“With this process, underwater metal working could be considerably faster and thus less expensive. Our goal is to make the work of the divers safer and more efficient.”
Efficient dismantling of sheet piling
The process is being developed for dismantling sheet pilings in two to six meters deep water. For this, it is crucial that the pilings including the interlocks are reliably cut, as post processing is time-consuming and expensive. Since metal part corrode under water and are subject to overgrowth, the process is supposed to function reliably, even for varying material thicknesses and pollution levels.
The finished process could also be used for the maintenance and repair of offshore structures and other hydraulic structures. Also, dismantling of nuclear power plants is a further field of application.
The project “Laser cutting under water for higher productivity – LuWaPro” is supported by the German Federation of Industrial Research Associations "Otto von Guericke" e.V. (AiF).
http://www.lzh.de/de/publikationen/pressemitteilungen/2014/laserschneiden-unter-... - website with press realease and additional video
Lena Bennefeld | Laser Zentrum Hannover e.V.
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
Oceans formed before Tharsis and evolved together, shaping climate history of Mars
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...