Introduction to thermos flask

Thermos flask, in short, is a cup that can keep warm. It is generally made of stainless steel and a water container with vacuum layer ，The top is covered and tightly sealed. The vacuum insulation layer can delay the temperature loss of internal water and other liquids, so as to achieve the purpose of thermal insulation. There are three ways of heat transmission: radiation, convection, and transmission. The stainless steel liner of the thermos cup can reflect the temperature radiation of hot water, and the vacuum layer blocks the heat conduction. Generally speaking, the larger the capacity of the cup body, the better the heat preservation effect. A good thermos cup can generally keep the water temperature above 70 ℃ for 6 hours.