See Also: Boiler - Fire Tube Type, Boiler - Water Tube Type
Early History
The first evidence of the idea of using steam energy to produce Power appeared in the Pneumatica of the Greek inventor and mathematician Hero of Alexandria in the first
century AD. In it he described an aeolipile, a steam Turbine consisting of a boiler connected by two hollow tubes to the poles of a freely
spinning hollow sphere. The sphere was equipped with two canted nozzles that
issued steam, causing the sphere to rotate. Other references are found in works
from the Middle Ages and Renaissance, but no practical devices seem to have
been built until the Italian architect and inventor Giovanni Branca designed a
boiler that emitted steam that struck blades projecting from a wheel, causing it
to rotate.
The first practical Steam Engine, built by the English engineer (see Engineer - You Might Be One If ... ) Thomas Savery in 1698, used two Co
pper vessels alternately filled with steam from a boiler. Savery's engine was used
for pumping water out of mines, as was the one developed in 1705 by the
British inventor Thomas Newcomen.
The Scottish inventor Watt, James improved upon Newcomen's steam engine design and introduced the first
significant boiler advance, the spherical or cylindrical vessels Heated from below by an open fire. Watt's boiler, built in 1785, consisted of a
horizontal shell encased in brick, with flues to circulate the hot combustion Gases over the boiler. Watt was one of the first engineers to apply new knowledge
about the thermodynamic (see Thermodynamics) properties of steam in his design. He used the lever safety valve, pressure
gauges, and water cocks to control the flow of water and steam in his boilers.
A device for Heating Water or generating steam above atmospheric Pressure. All boilers consist of a separate
compartment where the fuel is burned and a
compartment where water can be evaporated into steam. The picture at right
shows a typical Water Tube Boiler used in modern generating (see Generator) stations.