Handbook of Turbomachinery Second Edition Revised - Ventech!

Figure 3 Reciprocating steam engine (1750).
steam turbines of two different designs: an impulse type and a reaction type,
respectively.
In 1883 de Laval built his first practical steam turbine, using highvelocity
steam jets to push blades of a turbine wheel. That single-stage,
single-wheel turbine operated at speeds up to 26,000 rpm with tip speeds of
the larger rotors over 365 m/sec (1,200 fps). de Laval had to solve several
problems that are still central to turbine design including (1) how to lower
the high centrifugal forces, (2) how to eliminate vibration, and (3) how to
ensure steady operation. He recognized the phenomenon of critical speed. In
the mid-1880s Charles Curtis patented a turbine design based on this
concept of expanding steam through a nozzle, then impacting the highvelocity,
low-pressure steam jet on the blades of a rotating wheel. It included
velocity compounding for the first time. This design was acquired by
General Electric in 1897 and has been the subject of constant improvement
since, including, for example, the issue of patents for reheating steam in 1905
and 1906, although the use of regenerative feedwater heating and reheat
were not actually incorporated until the 1920s.
In 1884 Parsons took a different approach and built a turbine that in
concept is very similar to today’s machines [3]. The steam entered a single
Copyright © 2003 Marcel Dekker, Inc.