Friends who like outdoor adventure and outdoor camping. For experienced veterans, the tools that need to be used outdoors, the items that need to be carried, and how to perform safe outdoor operations are all familiar. However, for some newcomers, in addition to insufficient tools and items, the most critical thing is that there are many irregularities and even irregularities in outdoor operations. Contains certain dangers.
Regarding the fact that thermos cups and stew pots cannot be directly heated externally, we have a special explanation in the previous article, but recently when I was watching a short video, I found that some people even used stew pots to directly heat the outside when camping outdoors. Heating was used. In the video, the other party was still confused as to why the outside had been heated for 5 minutes, but the inside still did not heat up. Fortunately, the other party finally gave up using the stew pot for heating and did not cause danger.
Today I will explain in detail again why thermos cups and stew pots cannot be heated directly externally.
The thermos cup and the stew pot are both made of double-layered stainless steel, and both adopt a vacuuming process. After vacuuming, the vacuum state between the double-layered stainless steel acts as a thermal insulation and prevents temperature conduction.
The vacuum insulates the temperature, so heating from the outside is also isolated. So the friend in the video said that the inside is still not hot after heating for 5 minutes. This not only shows that the vacuum of this water cup is thorough, but also shows that the heat preservation performance of this water cup is good.
Why is it said that it may still cause danger? If you continue to heat the outside of the thermos cup or stew pot at high temperatures, there is a professional term in the industry called dry burning. However, if the external temperature is too high or the high temperature heating time is too long, it will cause the outer wall of the thermos cup or stew pot to expand and deform due to high temperature. The interlayer is in a vacuum state. Once the outer wall is deformed or the material tension is reduced due to continuous heating at high temperature, the internal pressure will be released. The released pressure is huge, and the destructive force generated at the moment of release is also huge, so the thermos cup and The stew pot can be heated directly from the outside.
So some fans and friends asked, if the stainless steel water cups or utensils that are not vacuumed between the double layers can be heated externally? The answer is also no. First of all, even if there is air between the double layers without vacuuming, heating from the outside will greatly reduce the temperature conduction, increase carbon emissions, and is a waste of heat energy.
Secondly, there is air between the double layers. The externally heated interlayer air will continue to expand as the temperature of the outer wall increases. When the expansion reaches a certain level, the pressure generated by the expansion is greater than the pressure that the outer wall can withstand. It will also explode, causing considerable harm.
Finally, it is recommended that outdoor sports friends, in addition to the thermos cup, if you want to use one thing with multiple functions, you can bring a single-layer stainless steel lunch box or a single-layer stainless steel water cup, so that you can meet the needs of external heating.
Post time: Jan-19-2024