LOI Thermprocess, a Tenova LOI Italimpianti company, will supply a large pit-type furnace for the stress relieving of turbine shafts for installation at Alstom’s plant in Birr, Switzerland. Another pit-type furnace will be supplied to Alstom’s plant in Chattanooga, Tenn. The new furnace in Switzerland is due to be commissioned in mid-2010. The bottom section of the furnace will have a maximum outside diameter of 256 inches (6,500 mm), and the overall height of the unit will be 630 inches (16,500 mm). The furnace will be used for treating rotors with weights up to 200 tons and lengths up to 472 inches (12,000 mm) in a protective, controlled atmosphere.
The pit-type furnace consists of a fixed base with recirculation fans, four heated rings and a cover. A Siemens S-7 400 PLC will control the furnace, which is charged from above and heated by low-maintenance electric heating elements.