In 19th century England, James Dewar invented the Dewar tank for storage of dissolved gases.
After some time his pupil Reinhold Burger found to commercialize his invention.
Very quickly, his company became known worldwide.
The company began producing nothing but a thermos.
And today thermos no different from his invention. Ultimately, a thermos is a glass or metal flask & housing.
If you need a thermos to visit the country, it is better to choose a metal flask as it is more durable. If it is intended for use in the city, you should choose a thermos with a glass bulb, as it is more hygienic. At the same time, they retain the same temperature.
Experts believe that in plastic termosisashto maintaining the temperature as metal. & Nbsp- good thermos maintain the temperature around 50 degrees even after 24 hours. These criteria are met Flasks Companies, Hangzhou ExCo, Penguin, Mimi & quot-Mimi & quot- & nbsp- etc.
When buying a water bottle such as Nova (see http://www.novowaterbottles.com/) make sure the plug is screwed in tightly. Basically maintaining the desired temperature dependent.
Also, the storage temperature depends on the volume. The larger volume, more heat is retained.
When buying a thermos is required to open it. If you feel an unpleasant odor, so the thermos made of substandard materials. If you decide to choose a thermos, this quality because of the price or design – do not do it because it distributes the liquid poisonous substances.
If you buy a glass flask, the bulb should not go out, otherwise just will sooner or later will surely be broken. Metal flask certainly stronger, but it is under heavy strain can get microcracks, resulting vacuum will disappear and lose their insulation and tightness.
According to experts – various welding and infusions should be prepared in a glass thermos.
You can check the quality thermos. It is necessary to pour it into boiling water and left for 10 minutes. If the body is warm, then the thermos defective.
Modern thermos not only for liquids but also for food.