James Dewar (1842-1923) was a Scottish physicistand a chemist who lived in London. During his life he managed to get many awards and medals, to make an incredible amount of discoveries, many of which played an important role in the development of exact sciences. Among his achievements in physics, a contribution to the study of the conservation of temperature by means of the device created by him, which is called the "Dewar vessel", is considered remarkable. This unit is designed to store various substances at elevated or lower temperatures.
The Dewar vessel is an upgraded versiondevice, which was developed by the German scientist Weinhold. However, it has significant differences. The invention of Weinhold was a glass box with double walls, and Dewar significantly changed this design. By analogy with the box, its device was also double-walled, a vacuum was created between the walls of this device and they were silvered, and in order to reduce the evaporation of the liquid, the throat of the device was narrowed.
To date, the production of Dewar vesselshas reached industrial scales, since they are used everywhere not only in various industries, but also in everyday life. Few people know that the thermos is also a Dewar vessel. As for industry, Dewar vessels for liquid nitrogen and other cryogenic liquids are most often used here. Also this device is often used in veterinary medicine and medicine for storage of various biological materials.
Since different types of vessels have different purposes,then they are used differently, although in all cases before placing the contents in a vessel, it is necessary to bring it to the appropriate temperature, i.e., to heat or cool. The temperature of the substance that is inside the device is preserved due to two factors: thermal insulation and the processes occurring with it.
The most famous and popular kind of Dewar vesselis a thermos bottle. At the beginning of the 20th century, Reynold Burger slightly modified this device to make it suitable for domestic use. The glass flask was placed in a metal casing, making it safe and more durable, and the plug, which was mounted on the Dewar vessel, was replaced with a cork and a lid.
Initially, the inventor expected that suchthe device will be used to store food, but as a result, the thermos became popular precisely because it could keep the temperature of the drinks for a long time. The birthday of the thermos can be considered September 30, 1903, because it was on this day that Burger received a patent for his invention and started production.
Although this story does not end there.Dewar, who learned that the upgraded version of his device was commercialized and helped Burger decently earn, sued the court. But since his device was not patented, the court did not satisfy his demands.
The Dewar vessel, invented by a Scottish scientist,He gained wide popularity almost immediately after his birth and does not lose it to this day. It is widely used both in industry and at home, which makes it one of the most important inventions of the XIX century.
