Archimedes’ Screw Design:
Archimedes’ screw consists of a screw, which is nothing but a helical surface wound around a cylindrical shaft, fitted inside a hollow pipe. On setting it up at an angle with the water level and turning the shaft manually or by a windmill, the water raises up the helical structure of the screw to the top end. Finally, the water pours out of the tube from its upper opening. The contact surface or the contact points between the screw and the hollow pipe need not be airtight if the amount of water to be drawn out is much larger than the amount of water leaking out from the contact points.
Archimedes’ Screw in History
Archimedes’ Screw Uses
Archimedes’ Screw Turbine
When used as a hydroelectric screw turbine, the tool works in the reverse order. In this case, water is allowed to enter into the screw from its topmost end at high speed. The energy stored in this flow of water is used to rotate the screw, which, in turn, revolves a generator attached to the base of the screw. The generator then converts the rotating mechanical energy of the screw to electrical energy.
Archimedes’ Screw Conveyor
An Archimedes’ screw not only allows water to flow through its turns. Loose granular materials can flow through it as well. It can be used as a conveyor when turned by a motor to move granular materials like food grains, plastic granules and liquids from one place to another.
Other Uses of Archimedes’ Screw
It is not necessary for all Archimedes’ Screws to have the same number of turns per unit length. Some might have gradually increasing number of turns along their lengths. Such screws are used for compacting waste materials. Their ability to melt materials find applications in die casting machines, injection molding machines and the extrusion of plastics. This simple device having a pumping action is a useful invention in Physics, which has stood the test of time. In today’s world of diminishing natural sources of energy, scientists are desperately researching alternative energy sources. This energy efficient machine is nothing short of a plausible option in this regard.
