...........................................
Water Wheels
The History of the
Water Wheel
by
Mary Bellis
The water wheel is an ancient
device that uses flowing or falling water to create power by means of paddles
mounted around a wheel.
The force of the water moves
the paddles, and the consequent rotation of the wheel is transmitted to
machinery via the shaft of the wheel.
The first reference to a
water wheel dates back to around 4000 B.C.
Vitruvius, an engineer who
died in 14 AD, is later credited with creating and using a vertical water wheel
during Roman times.
They were used for crop
irrigation, for grinding grains, and to supply drinking water to villages.
In later years, they drove
sawmills, pumps, forge bellows, tilt-hammers, trip hammers and to power textile
mills.
They were probably the first
method of creating mechanical energy to replace that of humans and animals.
Types of Water Wheels
There
are three main kinds of water wheels.
One is the horizontal water
wheel. Water flows from an aqueduct and the forward action of the water turns
the wheel.
Another is the overshot
vertical water wheel in which water flows from an aqueduct and the gravity of
the water turns the wheel.
Finally, the undershot
vertical water wheel is placed in a stream and is turned by the river's motion.
The First Water Wheels
The
simplest and probably the earliest water wheel was a vertical wheel with
paddles against which the force of a stream acted.
The horizontal wheel came
next. It was used for driving a millstone through a vertical shaft attached
directly to the wheel.
The geared mill driven by a
vertical water wheel with a horizontal shaft was the last in use.
The first water wheels can be
described as grindstones mounted atop vertical shafts whose vaned or paddled
lower ends dipped into a swift stream. The wheel was horizontal.
As early as the first
century, the horizontal water wheel – which was terribly inefficient in
transferring the power of the current to the milling mechanism – was replaced
by water wheels of the vertical design.
Water wheels were most often
used to power different types of mills. A water wheel and mill combination is
called a watermill.
An early horizontal-wheeled
watermill used for grinding grain in Greece was the called Norse Mill.
In Syria, watermills were
called "noriahs.” They were used for running mills to process cotton into
cloth.
Lorenzo Dow Adkins of Perry
Township, Ohio received a patent for his spiral bucket water wheel in 1939.
The Hydraulic Turbine
The
hydraulic turbine is a modern invention based on the same principles as the
water wheel.
It’s a rotary engine that
uses the flow of fluid, either gas or liquid, to turn a shaft that drives
machinery.
Hydraulic turbines are used
in hydroelectric power stations.
Flowing or falling water
strikes a series of blades or buckets attached around a shaft. The shaft then
rotates and the motion drives the rotor of an electric generator.
Mary Bellis
No comments:
Post a Comment