Brush Ljungstrom radial-flow steam turbine, made by Brush Electrical Engineering Ltd, Loughborough, 1956.
This is a sectioned part of a 30 Megawatt Ljungstrom radial flow steam turbine manufactured by the Brush Electrical Engineering Company in Loughborough in 1956. It consists of the central arrangement of blade ring discs with spindles, shafts and steam chests and the bottom section of its central casing. The machine’s condenser, pipe and valve work, governing system, exciter and other casing do not remain.
The turbine gets its name from its designer, Birger Ljungstrom of Sweden, who alongside his brother Fredrik, patented it in 1910. In most steam turbines, known as ‘axial flow’, steam flows in and out parallel to the machine’s shaft, passing through rows of fixed and moving blades. In the Ljungstrom turbine, steam enters through holes near the middle of the turbine’s two discs and flows radially outwards through the blades, causing the discs to rotate in opposite directions on their independent shafts in a ‘double rotational’ arrangement. Steam then exits parallel to the shafts. Although radial flow turbines had already been considered, Ljungstrom’s was the first to be successfully built and marketed. The principal benefits of the Ljungstrom design were its high efficiency, ability to start and load quickly and its small footprint.
The Brush Electrical Engineering Company was established in 1880 and in 1912 acquired the English rights to manufacture the Ljungstrom turbine. Brush supplied Ljungstrom turbines to power stations throughout Britain, the first being installed at St Pancras power station in 1914. The Museum of Science and Industry’s 1956 example was used at Doncaster power station until 1980. It represents a later Ljungstrom design that appeared due to demand for larger outputs in that as well as its two radial blade rings, it also has two axial-flow sets of blades, so that after the steam has flowed radially outwards, it divides to flow axially through more blades, to generate more power.
Brush stopped manufacturing the Ljungstrom turbine in 1963, but STAL, the Swedish manufacturers of the turbine, continued to supply Ljungstrom. Over 2000 machines were produced by the various manufacturers in Britain, Sweden, Germany and Japan. STAL still manufacture a radial flow steam turbine based on the original Ljungstrom design, however axial flow is now the characteristic feature of the vast majority of modern steam turbines. The Ljungstrom ultimately fell out of use in British power stations because the size of sets required came to exceed the capabilities of the Ljungstrom’s design. The Brush Electrical Engineering Company now operates as the Brush Group, part of Melrose plc.