Invented by : Otto Von Guericke
Invented in year : 1650
Air Pump is a device that removes gas molecules from a sealed volume or a chamber in order to leave behind a partial vacuum. By removing gas from a chamber, a vacuum pump reduces the pressure inside the chamber. This is because fewer and fewer gas molecules hit the chamber walls, creating less and less pressure. It is also known as Vacuum Pump. Usually two or more different types of vacuum pumps are used either in parallel or in series to create a high level of vacuum. It is not easy to achieve a high level of vacuum because the materials used must be capable of withstanding the high amount of heat and pressure generated during the process of vacuum generation. Therefore, materials such as greases, oils, plastic and rubber gaskets which are used to seal the chambers where vacuum is to be created must be able to withstand high heath and pressure so that they will not boil away or produce any gases while the process occurs. To do this, many a times the surfaces of the chamber which are to be exposed to vacuum creation are heated at high temperatures so that all the absorbed gases are removed. Vacuum pumps have various applications in various variety of works and as such have become an integral part of our modern lives
There are broadly 3 types of vacuum pumps
Positive Displacement Pumps – The pumps which expand a cavity and allow the gases to flow out of the sealed environment or chamber are known as Positive Displacement Pumps. Then they seal the cavity and cause it to exhaust it to the atmosphere. These pumps are most useful for creating low vacuums. Examples are: Diaphragm Pump, Piston Pump, and Scroll Pump.
Momentum Transfer Pumps or Molecular Pumps – The pumps which use high speed dense fluids or high speed rotating blades to remove gas molecules from the sealed environment or chamber are known as Molecular Pumps. These pumps are often used along with Positive Displacement Pumps to create high vacuum chambers. Examples are: Turbomolecular Pump and Diffusion Pump.
Entrapment Pumps – The pumps which catch gases in either a solid or in an absorbed state are known as Entrapment Pumps. These pumps are used along with Positive Displacement Pumps and Molecular Pumps to create ultra high vacuum chambers. Examples are: Ion Pumps and Cyropumps.
History of the Invention
Otto von Guericke, German physicist, engineer and a natural philosopher was the inventor of the Air Pump. In 1650, Otto von Guericke invented the air pump, used to create a partial vacuum. Using hollow copper spheres and an air pump of his own construction, Guericke demonstrated that a partial vacuum could be created by pumping the air out of the sphere. He also proved that the air remaining in the sphere (at a pressure below that of the atmosphere) was distributed evenly throughout the vessel. In 1663, Guericke demonstrated the power of a vacuum with his Magdeburg Hemispheres to Emperor Ferdinand III. During public demonstrations, teams of horses would attempt to pull the hemispheres apart which were held together by the force of atmospheric pressure created using his vacuum pump. By doing so, he proved the power of Vacuum. This also became the basic principle of the Newcomen steam engine. In 1671, Otto von Guericke published his treatise "Experimenta nova Magdeburgia de vacuo spatio" or "New Magdeburg Experiments About the Vacuum". And during the 17th century, Otto von Guericke experimented with and improved air compressors.
Development in the Invention of Air Pump
In 1662 British scientist Robert Boyle improved the vacuum pump design and discovered that the pressure of a gas is inversely proportional to its volume. The study of vacuum then lapsed until 1855, when Heinrich Geissler invented the mercury displacement pump and achieved a record vacuum of about 10 Pa (0.1 Torr). A number of electrical properties become observable at this vacuum level, and this renewed interest in vacuum.
During the latter half of the 19th century, scientists used vacuum pumps to create low gas pressures, which allowed them to investigate electrical discharges in gases. German inventor and glass blower Johann Heinrich Wilhelm Geissler invented a hand-operated pump with moving columns of liquid mercury that removed air from glass tubes in 1858. The tubes he created became known as Geissler tubes. They eventually led to the invention of the cathode-ray tube, which British scientist Sir Joseph Thomson used to discover the electron in 1897. In 1916 American chemist Irving Langmuir designed the condensation pump, which was the forerunner of modern diffusion pumps.
Role of Air Pump in the Improvement of Human Life
- The Invention of Vacuum Pump led to development of the vacuum tube which created a revolution and facilitated work in various areas.
- Creating a vacuum became essential for all kinds of further research into electronics and other innovations.
- Due to their specific functions, different types of vacuum pumps found their uses and applications in a variety of industrial environments.
- Vacuum pumps became widely used in the manufacture light bulbs, electronic components, metal production, atomic energy industry, freeze-drying in the medical, biological and food industries.
