World’s largest membrane tube wall bending machine

Power plant construction in Asia is booming. New power plants in India or China need to meet the growing energy demands of the aspiring economic nations. Power plant constructors are consequently also making provisions: new production sites are emerging, which guarantee efficient production of the components. One impressive example of the required plant technology is the world’s largest membrane tube wall bending machine, which has been developed by Schwarze-Robitec specifically for an Indian customer. It makes a vital improvement to the efficiency of the entire power plant construction.

Modern power plant construction is inconceivable without the use of membrane tube walls: before installation, individual tubes are welded to form larger tube walls, membrane tube walls or even finned tube walls. After welding the membrane tube walls, they need to be bent according to the boiler design. Inside the power plant block, fitters connect the tube walls to the actual combustion chamber of the power plant. As a huge conduit system, the tube walls are perfectly adapted to the shape of the block and ensure effective heat exchange. However, the membrane tube walls must be bent in advance, with millimetre precision, as Schwarze-Robitec Managing Director Bert Zorn highlights: “Even a minimal deviation in a bend will result in a tube wall no longer fitting the subsequent segment.”

The world’s largest membrane tube wall bending machine was developed for an Indian customer. The plant is equipped with the latest CNC control. It is able to bend membrane tube walls with widths of up to 3.6 metres – the previous maximum passage width in plant construction was three metres. Over 25 metres of tube walls are accurately fed into the machine and bending takes place with a bending angle of up to 135 degrees using a modified compression bending procedure. Unlike in a bending press, this allows the production of high quality bends. One outstanding feature is the mobility of the huge plant. It can be swivelled by 25 degrees in both directions. This allows diagonal bending of the membrane tube walls without the need to move the long “wall” sideways in the production hall. At the same time, a perfectly balanced bending mechanism, which only Schwarze-Robitec constructs in this form, guarantees high-precision results. “All components such as CNC control, hydraulics, bending tools, tensioning device and laser alignment are perfectly aligned to each other,” explains bending specialist Bert Zorn.

The system secures a huge leap in productivity for power plant construction, as larger membrane tube walls can be pre-finished in future. This significantly reduces installation effort and therefore costs. The system currently supplied is part of a large order for a total of eight bending machines for boiler construction. In the case of the Indian customer, a complete production plant for tube boilers is being created. Bert Zorn adds: “We are convinced that the combination of bending technology, CNC control and new passage width is of great interest to many power plant constructors.”