The biggest purpose of thermos is to prevent the loss of heat energy, even if it is placed in the refrigerator, it can't disperse the temperature of water in thermos. The principle of thermos cup is the same as that of open water bottle, which uses vacuum principle to prevent cold air from entering hot water. Keeping the thermos cup in the refrigerator for a long time will affect the heat preservation effect of the cup, so it is not recommended to put the thermos cup in the refrigerator.
There can't be liquid water in the thermos. When liquid water freezes, its volume will expand, which may damage the thermos. The temperature of glass thermos should not change sharply. For example, a hot bottle suddenly cools down and may burst. How long it takes to thaw depends on the temperature of the environment (generally refers to the temperature set by the refrigerator). The higher the temperature, the faster it is, and the lower the temperature, the slower it is.
It is not recommended to put juice in a thermos. The environment of the thermos is sealed, which is more conducive to the growth of bacteria. Add fruit juice, and the thermos will soon be occupied by bacteria. It is recommended to drink it now, and try to drink it within 65,438+0 hours. Because fruit juice is stored for 1-4 hours, bacteria increase and metabolism is active, which is easy to produce toxic metabolites. After 6-8 hours, the number of bacteria will increase in a logarithmic straight line and enter a period of mass reproduction.
If fruit juices such as watermelon juice need to be preserved, it is suggested to be refrigerated as soon as possible, but refrigeration can only inhibit the reproduction of bacteria, but can not freeze pathogenic bacteria, and even some bacteria can reproduce and grow in the refrigerator.