History of Water Wheels
How Water Wheels work
Different types of Water Wheels
What is a Turbine?
Modern Usage of Water Power
How do Water Wheels produce electricity?
How much power can a Water Wheel produce?
What is the future of Water Wheels?
The End Credits
Since ancient times, waterwheels have been used as tools to power factories in many different counties. The alternatives were windmills and human and animal power. The most common use of the water wheel was to mill flour in gristmills, but other uses included foundry work and machining, and pounding linen for use in the manufacture of paper.
The earliest known water turbines date to the Roman Empire.
Two helix-turbine mill sites of almost identical design were found at Chemtau and Testour, modern-day Tunisia, dating to the late
3rd or early 4th century AD. The horizontal water wheel with angled blades was installed at the bottom of a water-filled, circular shaft. The water from the mill-race entered tangentially the pit, creating a swirling water column which made the fully submerged wheel act like a true turbine.
Jan Andrej Segner developed a reactive water turbine in the mid
1700s. It had a horizontal axis and was a precursor to modern water turbines. It is a very simple machine that is still produced today for use in small hydro sites. Segner worked with Eula on some of the early mathematical theories of turbine design.
In 1820, Jean-Victor Pencelet developed an inward-flow turbine.
In 1826 Benoit Fournevron developed an outward-flow turbine. This was an efficient machine (~80%) that sent water through a runner with blades curved in one dimension. The stationary outlet also had curved guides.
In 1844 Uriah A. Boyden developed an outward flow turbine that improved on the performance of the Fourneyron turbine. Its runner shape was similar to that of Francis Turbine.
In 1849, James B. Francis improved the inward flow reaction turbine to over 90% efficiency. He also conducted sophisticated tests and developed engineering methods for water turbine design. The
Francis turbine, named for him, is the first modern water turbine. It is still the most widely used water turbine in the world today.
Around 1890, the modern fluid bearing was invented, now universally used to support heavy water turbine spindles.
Around 1913, Viktor Kaplan created the Kaplan turbine, a propeller-type machine. It was an evolution of the
Francis turbine but revolutionized the ability to develop low-head hydro sites.
A water wheel is a machine for converting the energy of flowing or falling wa ter into useful forms of power, the development of hydropower. In the Middle Ages , waterwheels were used as tools to power factories throughout different counties. The alternatives were the windmill and human and animal power. The most common use of the water wheel was to mill flour in gristmills, but other uses included foundry work and machining, and pounding linen for use in the manufacture of paper.
A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical shaft. Vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears; horizontal wheels usually directly drive their load.
Overshot water wheel
•A vertically-mounted water wheel that is rotated by falling water striking paddles, blades or buckets near the top of the wheel is said to be overshot .
•A typical overshot wheel has the water channeled to the wheel at the top and slightly to one side in the direction of rotation. The water collects in the buckets on that side of the wheel, making it heavier than the other "empty" side. The weight of the wheel, and the water flows out into the tail-water when the wheel rotates enough to invert the buckets. The overshot design can use all of the water flow for power (unless there is a leak) and does not require rapid flow.
The wheel is usually mounted inside the mill building below the working floor. A jet of water is directed on to the paddles of the water wheel, causing them to turn. This is a simple system, usually used without gearing so that the axle of the waterwheel become the spindle of the mill. This system is sometimes called the Norse mill. In a sense it is the ancestor of the modern turbine .
An undershot wheel (also called a stream wheel ) is a vertically-mounted water wheel that is rotated by water striking paddles or blades at the bottom of the wheel. The name undershot comes from this striking at the bottom of the wheel. This type of waterwheel is the oldest type of wheel. It is also regarded as the least efficient type, although subtypes of this waterwheel.
The advantages of undershot wheels are that they are somewhat cheaper and simpler to build, and have less of an environmental impact, as they do not constitute a major change of the river.
A vertically-mounted water wheel that is rotated by falling water striking buckets near the centre of the wheel's edge, or just above it, is said to be breastshot . Breastshot wheels are the most common type in the United States of America and are said to have powered the American industrial revolution. Breastshot wheels are less efficient than overshot wheels more efficient than undershot wheels, and are not backshot. The individual blades of a breastshot wheel are actually buckets, as are those of most overshot wheels, and not simple paddles. A breastshot wheel requires a good trash rake and typically has a masonry "apron" closely conforming to the wheel face, which helps contain the water in the buckets as they progress downwards.
Breastshot wheels are preferred for steady, high-volume flows such as are found on the fall line of the North American East Coast.
A backshot wheel (also called pitch back ) is a variety of overshot wheel where the water is introduced just behind the summit of the wheel. It combines the advantages from breastshot and overshot systems, since the full amount of the potential energy released by the falling water is harnessed as the water descends the back of the wheel.
A backshot wheel continues to function until the water in the wheel pit rises well above the height of the axle, when any other overshot wheel will be stopped or even destroyed. This makes the technique particularly suitable for streams that experience extreme seasonal variations in flow, and reduces the need for complex sluice and tail race configurations. A backshot wheel may also gain power from the water's current past the bottom of the wheel, and not just the weight of the water falling in the wheel's buckets.
A water turbine is a rotary engine that takes energy from moving water. Water turbines were developed in the nineteenth century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy source. Water turbine -
History. Water turbine - Swirl. Water wheels have been used for thousands of years for industrial power. Their main shortcoming is size, which limits the flow .
A noria is a machine for lifting water into a small aqueduct, either for the purpose of irrigation or, in at least one known instance, to feed seawater into a saltern.
There are three types of noria. The most common examples consist of a vertical wheel which is slung with a chain of buckets. The buckets hang down into a well which may be up to 8m deep.
The most primitive norias of this type are driven by donkeys, mules, or oxen. The animal turns another wheel, which is engaged with the noria and so causes it to turn. This causes the buckets to circulate.
A second type of noria uses the same system, of a necklace of clay or wooden buckets, but it is driven by the wind. The wind driven norias in the vicinity of Cartagena, Spain, are virtually identical in appearance with the local grinding mills.
The third type of noria uses the energy derived from the flow of a river. It consists of a large, very narrow undershot waterwheel whose rim is made up of a series of containers which lift water from the river to a very small aqueduct at the top of the wheel. Unlike the water wheels found in mills, a noria does not provide mechanical power to any other process. Its concept is similar to the modern hydraulic ram, which also uses the power of flowing water to pump some of the water out of the river.
There are several forms of water power currently in use or development. Some are purely mechanical but many primarily generate electricity. Broad categories include:
•Waterwheels, used for hundreds of years to power mills and machinery
•Hydroelectricity, usually referring to hydroelectric dams, or run-of-the-river setups
(e.g. hydroelectric-powered watermills)
•Dam less hydro, which captures the kinetic energy in rivers, streams and oceans
•Vortex power, which creates vortices which can then be tapped for energy
•Tidal power, which captures energy from the tides in horizontal direction
•Tidal stream power, which does the same vertically
•Wave power, which uses the energy in waves
•Osmotic power, which channels river water into a container separated from sea water by a semi permeable membrane.
•Marine current power which captures the kinetic energy from marine currents.
•Ocean thermal energy conversion which exploits the temperature difference between deep and shallow waters.
Water that is elevated has more gravitational potential energy than water at a lower level. As water flows from a higher level to a lower level, its potential energy changes to kinetic energy.
The kinetic energy of the moving water can be made to turn a bladed wheel to produce mechanical energy.
The shaft of the bladed wheel is usually attached through gears to other mechanical devices such as electric generators. In the past, mechanical energy from water wheels was used to grind grain and saw timber. Today, moving water is used primarily to generate electricity. Power plants are built at the foot of high dams. Powerful jets of falling water shoot through pipes from the reservoir behind the dam. The water hits the blades of dozens of specialized water wheels called turbines, making them turn hundreds of times per minute. These turbines then turn electric generators.
The key equation to remember is the following:
Power = Head x Flow x Gravity where power is measured in Watts, head in metres, flow in litres per second, and acceleration due to gravity in metres per second per second.
The acceleration due to gravity is approximately 9.81 metres per second per second - i.e. each second an object is falling, its speed increases by 9.81 metres per second (until it hits its terminal
Traditional water wheels could play a part in increasing the use of sustainable energy, according to a University of
Dr Gerald Müller from the University's School of Civil
Engineering and the Environment is convinced that oldfashioned hydropower can be relevant to the 21st century.
He believes water wheel designs can be refined to significantly increase their efficiency to that of modern turbines used in big hydro-electric projects.
'Turbines are commonly used where there is a considerable flow of water but research has shown they can kill or injure fish. They are also very expensive,' said Dr Müller. 'On the other hand, water wheels can generate sufficient power from smaller rivers to provide the electricity needs of individuals or small communities. Their contribution could be very valuable in future years.'
Our hope is to create and provide a course of action that will use a hydro powered electrical system and a water recycling system.
In a neighbourhood of about one hundred people or twenty families, these systems would hopefully subsidise the power bill of an average family and the water used because of the recycling water system.
The water from bathrooms(minus the toilet), spouting, gutters, and hose water will be on course to two pipes heading into a large lake. The lake leads to two large water wheels over the edge of a
20metre waterfall. The water wheels will be about 15metres tall.
The water which falls over the edge of the waterfall turns the waterwheel which are connected to two generators which sends the energy collected from the movement of the wheels to houses in the neighbourhood.
What It Is
Water recycling is taking used, dirty water and turning it back into something useful. The first thought may be that is just disgusting, but hold on a minute. Recycled water has many uses that are safe and sanitary, such as:
- water for wetlands
- water for crops
- water for industrial use
Additionally, recycled water can be safely used as drinking water.
How It Is Done
Obviously, in order to use waste water for drinking or anything else that needs to be safe and clean, the water must go through extensive cleaning. Treatment methods include using chemicals and methods that kill any bacteria or unsavoury thing in the water and purify the water back to a state of safe use.
Why Do It
Water recycling has the main benefit of preserving water supplies. It helps to keep water form being used from natural areas that need it. Water recycling is a widespread beneficial thing for the environment. Plants, animals and everything else in the environment need water and wasting water is something that just can not happen if all the ecosystems of the world are to survive. Water recycling is all about preservation.
Water recycling is something that has always been done in nature by the earth. The earth reuses water often in the forms of precipitation that falls to the earth, gathers here as bodies of water that evaporate back into the atmosphere and refall as precipitation, starting the cycle over.
Recycling water is also something regularly done commercially. It is quickly becoming something on a more popular level as water supplies are becoming limited and fear of shortages are more widespread. The future looks very good for water recycling to become a common occurrence because it can be done with no threat to public safety.
Date retrieved: 01/12/09 http://en.wikipedia.org/wiki/Noria
Date retrieved: 01/12/09 http://www.soton.ac.uk/mediacentre/ news/2006/feb/06_19.shtml
Date retrieved: 02/12/09 http://en.wikipedia.org/wiki/Water_turbine
Date retrieved: 01/12/09 http://en.wikipedia.org/wiki/Water_wheel
01/12/09 www.energyeducation.tx.gov/pdf/52ai nv.pdf -
Date retrieved: 02/12/09 http://www.recyclinggarbage.net/How
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Date retrieved: 03/12/09