Classification and Types of Turbines
The specific choices of turbines types shown here are not meant to be complete, but only a partial introduction to classification and historically important turbines in the late 19th century. These notes are by a rank amateur - turbine engineers and technology historians no doubt will read and shudder like an unbalanced runner.
Refers to a type of mixed-flow turbine built by American manufacturers from about the 1870s into the 20th century. Companies and turbines of this type include Francis, Leffel, Hercules, Risdon, Swain and others.
American-type turbines receive water which flows inward from the periphery, downwards, and then flows outwards or radially.
The figure (from Tyler, W.W., 1898.) shows why the later American turbines are “mixed-flow”: The direction of water changes as it moves through the runner.
Direction of flow
Turbines can be classified by the general direction(s) of water flow through the runner buckets.
Axial flow turbine. Or parallel flow turbine. A turbine in which the direction of water flow through the buckets is generally along the direction of the runner shaft axis. A key early type of axial flow turbine was developed by French engineer Feu Jonval in the 1840s. Jonval turbine adaptations were developed and sold by U.S. manufacturers throughout the second half of the 19th century.
Mixed flow turbine. Water flow through the runner buckets changes direction.
Radial flow turbine. Flow of water in the runner buckets is perpendicular to the axis of the runner shaft
Inward flow turbine. The flow of water in the runner buckets is outside inwards. The early Francis turbines were inward flow, but later were developed into mixed-flow turbines as the shapes of the runner vanes became more complex. outward flow turbine. The flow of water in the runner buckets is from the inside outwards. Fourneyman-type turbines are the classic example.
An important type of American mixed-flow turbine invented and developed by British-born James Francis who emigrated as a young man to America (and worked briefly on the new railroad to Stonington Connecticut in 1833). Francis moved to Lowell Massachusetts and shortly thereafter became the Manager of Locks and Canals. He used a careful experimental approach to increase the efficiency of Uriah Boyden’s improved Fourneyman turbine. Francis-type turbine designs were hugely influential, widely used in the last half of the 19th century, and are still made and used today. Figure from Safford and Hamilton, 1922, p. 1253.
An outward flow turbine developed by French engineer Benoit Fourneyron beginning in the 1820s. An important turbine technology development since it was the first small turbine that could develop sufficient power for industrial use. The Fourneyron turbine greatly influenced the further development of modern turbines. This turbine technology was brought to the U.S. in the early 1840s and used throughout the nineteenth century. Figure from Safford and Hamilton, 1922, p. 1249.
James Leffel of Springfield, Ohio invented, developed, and manufactured turbines which were widely used through the last half of the 19th century. Leffel turbines are characterized by a series of 12 gates around the periphery of the case. The company was founded by Leffel in 1862 is still in business in Springfield, Ohio and producing turbines. Leffel turbines were also manufactured in New Haven Connecticut. Figure from 1885 Leffel catalog.
Pelton wheels are the most widely distributed and most commonly encountered type of impulse turbine. Their cast iron buckets have a characteristic tandem cup form that is credited with achieving their high efficiency. They were developed by Lester Pelton in the Mother Lode region of California in the 1870s to provide mechanical power for hard rock mining; Pelton's design achieved significant improvements in efficiency compared to other impulse wheels. In later decades Pelton wheels proved adaptable for hydroelectric power, particularly at locations with high head and low flow volume, for which purpose they have been scaled up massively to units of 100,000 HP and more. In the second half of the 20th century, improved forms of Francis turbines have displaced Pelton wheels except for installations with very high (>2,000 ft.) head. The wooden or cast iron shroud typically found on Pelton wheels helped direct water discharge (rather than direct the inflowing water jet as on reaction wheels).
Thank you to Mike Dalbey, volunteer at Wilder Ranch State Park in Santa Cruz, CA for Pelton wheel information.
Many turbine types are classified as reaction: power generation depends upon changes in water pressure acting on the turbine vanes within an enclosed case. Reaction turbines can be contrasted with impulse turbines in which a jet of water is directed onto the runner vanes. Impulse turbines do not require an enclosed case.
Very likely named for the inventor Timothy Rose, but believed by some to be named for the appearance of the water spraying out of the wheels when operating.
“…the cast iron scroll wheel (or rather one of them, for there were two, both set on a large wooden shaft, on the inner end of which was the saw crank-wheel. These wheels were sometimes called "Rose wheels" as the water would fly out at each side like the blossom of a rose, when running under a "full head" of water. The tail race of the mill runs just in front of the mill, and is the whole brook.”
From archival material at the Henry Ford Museum in Dearborn MI describing the Georgetown Massachusetts Spofford –Morse sawmill which was subsequently moved to and rebuilt at the Ford museum. Quote is from Peterson, Charles E.. Sawdust Trail, Annals of Sawmilling and the Lumber Trade from Virginia to Hawaii via Maine, Barbados, Sault Ste. Marie, Manchac and Seattle to the Year 1860. Bulletin of the Association for Preservation Technology. Vol. 5, No. 2, 1973. 84-153.
Also called scroll-type turbine. The figure shows a top-view cross-section of a Tyler turbine from J. Tyler US patent 20456 (1858) showing the scroll shape of the turbine case. There is typically a single gate controlling the entry of water into a scroll turbine. Blue arrows show direction of water flow in the case when the turbine control gate is open
Civil Engineering, Waterwheels parts 1 and 2. International Textbook Co., Scranton, 1907. International Correspondence School editorial staffJames Leffel & Co. Illustrated Handbook, 1885.Tyler, W.W. Evolution of the American type of water wheel. Journal of the Western Society of Engineers., vol 3 (2), 1898, 879-901. Tyler, J. Improvement in Water-Wheels, US patent 20456, 1858.Tylers turbine. Scientific American, v. 11, no. 19, Nov. 5, 1864, p 289.Safford & Hamilton The American Mixed Flow Turbine and its setting,", Trans. American Society Civil Engineers, 1922, volume 85, pp 1237- 1356.
More turbine references on Water turbine references page of this website.