Thermos bottle, also known as electric kettle, is a daily necessities. The outer shell is made of bamboo stick, iron sheet or plastic, and the inner bottle is bottled. The bottle liner is made of double glass. The interlayer is plated with silver and other metals on both sides, and the middle is vacuumized. The bottle mouth has a plug, which can keep the temperature in the bottle for a long time. Hot water is usually called thermos; Cold food is often called an ice bottle.
Inventor of thermos bottle: British chemist and physicist james dewar (1892), so it is also called Dewar bottle.
The concept of thermos bottle is simple: the bottle has an inner wall and an outer wall; There is a vacuum between the two walls. Heat conduction and convection cannot be carried out in vacuum, but the metal-plated reflective layer can reflect thermal radiation. Therefore, any liquid poured into the bottle can keep its original temperature for a long time. This is why the thermos keeps warm in winter and cold in summer. Many people who have traveled many times find it hard to imagine what it would be like without a thermos.
Dewar bottles are made into liquid oxygen at a low temperature of -240℃. In order to preserve this liquid oxygen, he designed a bottle in which heat can't go in or out. The thermos bottle we use evolved from this Dewar bottle. Dewar's thermos bottle is designed according to heat transfer: ① it consists of two layers of glass bottles, and the middle of the bottle is vacuumized to isolate the heat conduction and convection of air; (2) Silver plating on the bottle wall is like a mirror reflecting light, which can reflect thermal radiation back into the bottle; (3) The cork of the bottle cap prevents heat from slipping out of the bottle. If it is used to hold boiling water, it becomes a thermos bottle.
However, it was the German glass manufacturer Reinhold Berg who realized that thermos bottles were useful in all kinds of situations. He obtained the patent of thermos bottle in 1903 and made a plan to put it on the market. Berg even held a contest to name his thermos. The award-winning name he chose was Thermos, which means hot in Greek. Berg's products were very successful, and soon thermos bottles were shipped all over the world.
Hot water bottles are usually used for scientific purposes, such as when the liquid needs to be kept at a constant temperature. Vaccinia, serum and other liquids are often transported in thermos bottles. Hot water bottles are no longer coated with mercury. Before the 1960s, it was coated with silver and magnesium oxide.
Classification and use
Thermos can be divided into three categories: ① Fine-mouthed type. Also known as thermos. Small mouth diameter and good thermal insulation performance. Mainly used for holding boiled hot water, fried Chinese medicine juice, hot drinks and cold drinks. ② Big mouth type. Usually called an ice bottle, it has a large diameter and is convenient to take and put things. It mainly includes ice cubes, sorbets, cold drinks with containers, ice, liquefied gas, anti-fermentation substances and so on. You can also use containers for hot food and hot drinks. 3 cups. Usually called a thermos cup, it has a large caliber and a small capacity. Tableware mainly used to reduce the influence of ambient temperature on contents in a short time.