Archimedes' screw facts for kids
Archimedes' screw is a machine used to lift water or other materials from a lower level to a higher level. It's named after Archimedes, a famous Greek mathematician and inventor who lived a long, long time ago (around 287-212 BC). However, some people think that this device was already being used in Egypt even earlier.
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History
The Archimedes' screw has a long and interesting history.
Some experts believe that the device was first used in ancient Egypt and Mesopotamia for irrigation. Archimedes is credited with describing the screw pump around 234 BC, during his visit to Egypt. He studied the device and explained how it worked, which is why it's named after him. The screw was used to lift water from rivers and lakes to irrigate fields, drain mines, and even remove water from ships.
How does it work?
Imagine a long tube with a spiral-shaped blade or screw inside it. This tube is placed at an angle, with its bottom end dipped into the water. When you turn the screw, it scoops up water at the bottom and moves it up along the spiral path inside the tube until it pours out at the top.
It's kind of like walking up a spiral staircase. Instead of lifting the water straight up, the screw moves it along a gentle, winding path, making it easier to raise it to a higher level.
Design
An Archimedes' screw typically consists of these parts:
- Outer Cylinder or Trough: This is the outer part that contains the screw. It can be a closed pipe or an open trough.
- Helical Screw or Blade: This is the spiral-shaped part inside the cylinder that does the work of lifting the water. It's like a winding staircase for the water to climb.
- Shaft: The central rod that the screw is attached to. When you turn the shaft, the screw rotates.
- Handle or Motor: This is what you use to turn the screw. It can be a handle that you turn by hand, a windmill, or an electric motor.
How it is made
The Archimedes screw is made by wrapping an inclined plane around a cylinder. The screw is made of a helical surface that surrounds a central cylindrical shaft inside a hollow pipe. The screw is turned using a windmill, manual labor, cattle, or a motor. As the shaft turns, the bottom end scoops up water.
Uses
The Archimedes' screw has been used for many different purposes throughout history, and it's still used today:
- Irrigation: In ancient times, it was used to water crops by lifting water from rivers and canals to higher ground.
- Drainage: It was used to drain water from mines and low-lying areas, like in the Netherlands where they used it to create polders (land reclaimed from the sea).
- Wastewater Treatment: Today, it's used in sewage treatment plants to move wastewater and solids.
- Hydroelectric Power: Sometimes, water is fed into the top of the screw, which makes it rotate and generate electricity. This is a clean and efficient way to produce power.
- Moving Materials: Similar screws, called screw conveyors, are used to move grains, powders, and other materials in factories and farms. You can even find them in snow blowers and combine harvesters!
- Fish Ladders: They can be used to lift fish safely from one place to another, like in fish farms.
- Stabilizing Structures: Believe it or not, an Archimedes' screw was even used to help stabilize the Leaning Tower of Pisa!
Modern Day Uses
Today, the Archimedes Screw is still used in limited applications and can range in size. Large screws are used to pump rainstorm runoff or to lift water or wastewater. They are also used to propel dry bulk materials.
Advantages
- It's a simple machine with few moving parts, making it easy to build and maintain.
- It can pump water that contains mud, sand, and other debris without getting clogged.
- It's very efficient at lifting water, especially at low heights.
- When used in reverse to generate power, it's safe for fish and other aquatic life.
Examples
- Some water parks use Archimedes' screws to lift water to the top of slides and attractions.
- Chocolate Fountains use a screw to pump melted chocolate to the top, where it flows down the tiers.
- Edinburgh Airport uses Archimedes' screws to collect excess water from the airfield and surrounding area.
Archimedes Screw Turbine
The Archimedes Screw can also be used as a turbine. The Archimedes screw turbine (AST) is considered an independent power plant in rural or remote areas. The advantages of the AST are that it is friendly to aquatic biota and has high and stable efficiency.
Interesting facts about the Archimedes screw
- The Archimedes' screw is also known as the water screw, Egyptian screw, or hydrodynamic screw.
- Archimedes never claimed credit for its invention, but it was attributed to him 200 years later.
- It's considered one of the earliest documented hydraulic machines (machines that use fluids to do work).
- The world's first seagoing steamship with a screw propeller was named the SS Archimedes, in honor of Archimedes and his invention.
- Some researchers think this device was used to irrigate the Hanging Gardens of Babylon, one of the Seven Wonders of the Ancient World
Images for kids
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An Archimedes' screw seen on a combine harvester
See also
In Spanish: Tornillo de Arquímedes para niños
