What is the insulation principle of the thermos cup?

In the cold winter, a vacuum flask is essential in people's daily life. Many people like to drink hot water, and the thermos can keep the water temperature, so everyone basically uses it in winter. Why can the thermos be kept warm? Do you know the principle behind it?

The thermos cup is developed from the thermos. The principle of insulation is the same as that of the thermos. The bottle is made into a cup for the convenience of carrying. Earlier, people used thermos flasks to store hot water. Thermos flasks are also called thermos or boiling water bottles. The outer shell is made of plastic, iron sheet or bamboo strips, and the inner is double-glazed. The glass in the sandwich is silver-plated. The mouth is closed with a cork.

There are three ways of heat transfer: heat conduction, heat convection and heat radiation. The thermos flask has a double-layer glass structure, with a vacuum in the middle, which can reduce heat conduction; the glass liner is blocked with a cork that is not easy to transfer heat, and hot water can be poured into it to reduce heat convection; the double-layer glass of the flask is plated silver can reflect back the heat radiation in the bottle. Don't underestimate a small vacuum flask, it perfectly uses the three heat transfer methods to achieve the best insulation effect.

The earliest thermos cup liner was the inner liner of a small thermos bottle, but for drinking convenience, the mouth of the inner liner became open. With the development of society, this kind of fragile glass-lined thermos cup has been rarely seen, and more are thermos cups made of stainless steel, but the principle of insulation is the same.

The stainless steel vacuum flask is a double-layer structure, and the inner tank and the two layers of stainless steel are welded together to form a vacuum. The vacuum does not transfer heat; the cock of the qualified vacuum flask has good sealing performance, and it loses little heat through convection. Copper or silver is plated between the two layers of stainless steel in the inner tank and the cup body, which can effectively reduce the heat lost by radiation. Stainless steel vacuum flask is easy to carry, durable and easy to clean, and has gradually become the new favorite in the market.

Generally speaking, the worst part of the thermos bottle is the bottleneck. Therefore, the thermos bottle with a large capacity small bottle mouth will have a better insulation effect. When self-driving travel and outdoor sports, a large-capacity vacuum flask becomes a must for equipment.

The best thermos flask is to keep the temperature, not to keep it warm, so it not only keeps the hot water at a certain temperature, but also keeps things like sorbet at a certain temperature. The structure of the vacuum flask makes the heat inside not easy to lose, and the heat from the outside does not easily enter the inside, so the vacuum flask can keep "warm" and "cold". Traveling in summer, the sun is scorching, put iced mung bean soup in the thermos and tighten the lid, it will definitely make your summer travel cool and comfortable.