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The
first United States patent granted on an electric motor was issued on February
5, 1837. It was patent #132, granted to Thomas
Davenport, a Vermont blacksmith. |
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A steam engine is a device that
converts the potential energy that exists as pressure in steam, and converts
that to mechanical force. Early examples were the steam locomotive trains,
and steamships that relied on these steam
engines for movement. The Industrial
Revolution came about primarily because of the steam engine. The thirty
seconds or so required to develop pressure made steam less favored for
automobiles, which are generally powered by internal combustion engines.
The first steam
device was invented by Hero of Alexandria, a Greek, before 300BC, but never
utilized as anything other than a toy. While designs had been created by
varous people in the meanwhile, the first practical steam
engine was patented by James Watt,
a Scottish inventor, in 1769. Steam engines are of various types but most
are reciprocal piston or turbine devices.
The strength
of the steam engine for modern purposes is in its ability to convert raw
heat into mechanical work. Unlike the internal combustion engine, the steam
engine is not particular about the source of heat. Since the oxygen for
combustion is unmetered, steam engines burn fuel cleanly and efficiently,
with relatively little pollution.
One source
of inefficiency is that the condenser causes losses by being somewhat hotter
than the outside world. Thus any closed-cycle engine will always be somewhat
less efficient than any open-cycle engine, because of condenser losses.
Most notably,
without the use of a steam engine nuclear energy could not be harnessed
for useful work, as a nuclear reactor does not directly generate either
mechanical work or electrical energy - the reactor itself does nothing
but sit there and get hot. It is the steam engine which converts that heat
into useful work.*
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page > A
Short History of Gas Turbine Engines
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