A thermos is referred to as a small appliance designed for keeping hot things hot and cold things cold for quite a reasonable period of time. Thermos vacuum flask is useful for those who travel a lot as they can use it to keep some coffee or other food items. A Vacuum Thermos Flask has very good capacity to hold very cold liquids such as liquid nitrogen for a substantial length of time. Except vacuum flask, there are other types of thermos, such as Stainless Steel Vacuum Bottle, Stainless Steel Cola Bottle, Stainless Steel Vacuum Flask, Stainless Steel Vacuum Space Pot, Vacuum Pot, Stainless Steel Mug, Stainless Steel Vacuum Mug, etc.
How Thermos Work
A thermos doesn't give heat room for heat transfer by any of the three ways including convection, conduction, and radiation, which heat can travel. It is the silver coating located on the internal surface of the thermos that puts a stop to heat transfer by radiation, while the vacuum connecting its double wall avoids heat moving by convection. The thinness of the glass walls prevents heat from leaving or entering the thermos by conduction. Furthermore, the casing surrounding the thermos flask offers added insulation. What about radiation?
As soon as infrared radiation makes an effort to disappear from the hot liquid, the reflective lining of the inner chamber returns it back in again instantly. As a matter of fact, there is practically no way heat can break out from a thermos and a hot drink stored inside will remain steaming hot for several hours.