FEA - manufacture of parts weighing up to 80 t
ANDRITZ HYDRO AG is a leading supplier of equipment for hydropower plants in Switzerland. It is a member company of the ANDRITZ GROUP, an Austrian equipment manufacturer which operates globally.
The ANDRITZ HYDRO AG in Kriens (near Lucerne), Switzerland does not simply manufacture products for its own use, it also handles external orders. The Kriens mechanical workshop of ANDRITZ HYDRO AG has more than 150 years of experience in manufacture, assembly, testing, and commissioning. A wide range of machinery is installed here to produce parts ranging from 1 kg to 80 t in weight.
The production of equipment for hydropower plants is a key area of activity. ANDRITZ HYDRO Kriens is therefore the competence center for Pelton turbines (including “Compact” Pelton turbines for smaller power plants up to 15 MW) within the ANDRITZ GROUP, and the only site at which Pelton runners are manufactured with the patented MicroGuss build-up welding procedure. Instead of integral casting of the runners, a forged disk is used on which welding material is built up in layers by robots until the Pelton buckets have been formed. The final bucket shape is achieved by NC machining and grinding. The outcome is Pelton runners which are superior to cast runners in terms of material fatigue.
Overhaul, maintenance, and conversion of hydropower plants
Overhauls and conversion work require innovative solutions to meet impeccable quality standards with minimum passage times or the shortest possible interruption of service. Careful and well-prepared overhauls not only enable existing damage to be repaired, but at the same time enhance the functional quality and value of the equipment through the use of new materials and technologies, and bring a substantial reduction of maintenance costs.
Manufacturing and assembly orders
Alongside service work on all types of runners, third party orders are also important at the Kriens site (contract production and assembly through to the functional test).
ANDRITZ HYDRO Kriens offers
- Welding and grinding
- Materials testing
Full range of machinery
The following principal machine tools are available for mechanical processing:
- Center lathes with widths between centers in the 750–8,000 mm range and permitted workpiece weights of 25–15,000 kg, some with CNC control
- Vertical lathes (carousel) with plane disk diameters in the 1,250–4,500 mm range and permitted workpiece weights of 5–80 t, some with CNC control
- Various drilling and milling units with travel ranges of 860–12,000 mm (x-axis), some with CNC control
- Horizontal and vertical CNC machining centers with 3 to 5 axes and travel ranges of 300–6,400 mm (x-axis)
- Circular and flat grinding machines
Manufacture of machines where turning, drilling, and milling are possible without resetting the workpiece is particularly efficient. Smooth running is essential to ensure a long life cycle for bearings and shafts. The Kriens workshop therefore has suitable machinery for dynamic as well as static and hydrostatic balancing.
Heat treatment even for large parts
To permit stress relief annealing of workpieces and thus obtain a uniform metal structure, ANDRITZ HYDRO AG in Kriens uses a gas-fired annealing furnace. This is suitable for parts with dimensions of up to 7,800 x 7,800 x 3,900 mm and heated to a maximum temperature of 620° C. This procedure, including the controlled cooling phase, requires around three days.
Fault tracing and quality control tests
To detect cracks and other defects in structural components, the following non-destructive material tests can be performed in Kriens:
- Color penetration testing
- Magnetic powder testing
- Ultrasonic testing
- X-ray testing
- Hydraulic pressure tests for pressure samples with water or oil are possible up to 300 bar.
Coatings increase service life
Coating allows substantial extensions to the service life or the intervals between servicing of structural components which are exposed to heavy wear, such as Pelton buckets or Pelton nozzles. The high-velocity flame spray method (HVOF, high velocity oxy-fuel) enables tungsten carbide layers to be built up in the Kriens works for protection against abrasion. If recoating becomes necessary, the residue of the old coating can be removed by corundum blasting.
Preparation for transport is also important
In order to make sure that the machined parts reach their destination without damage, they must be suitably packaged. This work is handled in the dispatch department with its adjacent shop where packing cases are made.
Expertise and continuity
Thanks to the expertise and experience of its staff and the extensive range of machine tools installed, ANDRITZ HYDRO ensures the timely processing of internal and external orders to highest possible quality standards. Throughout its varied history under different names and owners (Bell, Escher Wyss, Sulzer, VA Tech Hydro, ANDRITZ HYDRO AG), it has always retained its role as a dependable partner.