James Dewar (1842-1923) was a Scottish physicist and chemist who lived in London.During his life, he had received numerous awards and medals, do an incredible amount of discovery, many of which have played an important role in the development of the exact sciences.Among his notable achievements in physics is considered to contribute to the study of the preservation temperature with the help of his device, which is called "Dewar."This unit is designed for the storage of substances at elevated or reduced temperatures.
History
Dewar is a modernized version of the device, which was developed by German scientist Veynholdom.He also has significant differences.Veynholda invention has the form of a glass box with double walls, and Dewar significantly changed such construction.By analogy with the compartment, its structure was also double-walled, between the walls of the apparatus was evacuated, and they were silver-plated, and in order to reduce evaporation of the liquid, the device has been narrowed throat.
Application
Today Dewars production reached an industrial scale because they are used widely not only in the various industries, but also in everyday life.Few people know that the thermos is also Dewar.As for industry, there is often used Dewar vessels for liquid nitrogen and other kriozhidkostey.Also this device is often used in veterinary medicine and for storage of various biological materials.
Since various different types of vessel target, and they are used in different ways, though in all cases, before placing the contents into the vessel, it is necessary to bring it to a suitable temperature, t. E. Heat or cool.The temperature of the substance, which is inside the device is saved due to two factors: thermal insulation and processes happening to him.
Thermos
most famous and popular form of Dewar flask is.In the early XX century, Reinhold Burger slightly modified the device to make it suitable for domestic use.The glass flask was placed in a metal case, thereby making it safer and more durable, and the cap, which is set in the Dewar, replace the stopper and cap.
inventor originally hoped that such a device is used to store food, but as a result of a thermos become popular precisely because of what he could for a long time to maintain the temperature of the beverage.Happy Birthday thermos can be considered September 30, 1903, since on that day Burger received a patent for his invention and began production.
Although the story does not end there.Dewar, who learned that an upgraded version of his device had a commercial success and helped earn decent Burger, filed a lawsuit.But because his device was not patented, the court did not satisfy its requirements.
Dewar invented by a Scottish scientist, gained widespread popularity almost immediately after his birth, and does not lose it to this day.It is widely used both in industry and in everyday life, making it one of the most important inventions of the XIX century.
