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Flasks in thermoses

• Publicado por Domonick Lars 8 de agosto de 2020 - Arquivado em Arte & Cultura - 43 visualizações

  Inside any thermos there is a special flask in which food is placed, intended for storage. A vacuum is maintained between the flask and the outer walls, which neutralizes the transfer of heat from what is inside the flask.

  Some manufacturers use thermal insulation materials instead of vacuuming, but this can affect the mass of the thermos, as well as its ability to maintain the temperature at the desired level.

  Another cheap technology is to fill the space between the outer walls and the bulb with regular air. It is clear that long-term preservation of food temperature is out of the question.

  In short: so far nothing has been invented better than a vacuum.

  Flasks are made of two types of materials: glass and stainless steel. Both have their own merits and demerits.

  • Glass flasks aremainly used in thermos flasks for storing liquids. The bulb itself is covered with a special reflective compound that reduces heat loss. And glass itself has a lower thermal conductivity than steel. You can check it yourself by touching a metal mug with tea with your hand, and then touching a glass one: the latter burns less.

  Of course, glass is less durable than metal, but not enough to be afraid for its safety. After all, bulletproof glass also exists, and a regular light bulb can handle the mass of an adult.

  Another advantage of the glass bulb is its low inertness. This means that glass is less likely to chemically react with different media than the same metals.

  Glass flasks do not tolerate temperature changes. If an ice-cold liquid is poured into a flask in which tea with a temperature of 90 ° C has just been stored, then there is a possibility of force majeure. The flask will simply burst.

  • Metal flasksare still stronger, and it is much more convenient to store food in such devices. Thermos flasks with such flasks are suitable for short trips, but taking a vessel with a metal flask with you to the mountains, when every gram in a backpack responds with pain in the legs is not a very deliberate decision.

  Another drawback of a metal flask is its inertness. Even stainless steel does not like an acidic environment, so pouring your favorite juices, lemon juice and other interesting drinks into such thermoses is not an option. Metals also absorb odors and are more difficult to clean.

  They retain heat worse than glass bulbs due to the peculiarities of thermal conductivity and a more violent reaction with gases.

  Body material

  In this case, the advantages and disadvantages of each thermos are obvious.

  Plastic thermoses are much lighter and more convenient to carry, but you have to pay for it in durability. Careless movement, and now your thermos flies to the ground with an echoing "grunt!" at the end. All! The vacuum is broken, the thermos is unusable.

  It is likely that the plastic will simply spring back from the impact, withstanding it, but because of the heartless physics, the bulb inside is more likely to suffer.

  Metal cases are much more durable, they hardly come into contact with aggressive media, so you don't have to worry about the possibility of corrosion how speaks https://bestvacuumflask.com/. The downside to metal is that it loves dents very much. One careless blow, and it will not be possible to restore the former beauty of the case.

  Corks in thermoses

  According to the manufacturers of thermoses themselves, almost a third of the heat is lost through the lids, so they need to be given special attention.

  • The lid is the most common type of thermos plug. As a rule, it does not go alone and is used in a duet with an additional stopper. However, in food thermoses, the cork is not always provided for in the design for more convenient access to food.

  Also, a simple thermos can be equipped with an opening lid, most often it is used in thermo mugs and cheap devices that are not designed to keep warm for a very long time.

  In thermoses with an additional stopper, the lid can be used as a cup.

  • Pump plugs include a dedicated fluid supply valve and a pneumatic pump. Vacuum flasks with these plugs are usually large enough and not suitable for hiking.
  • Valve plugs are quite easy to handle. To pour liquid into a glass, you do not need to unscrew the lid, just press the button. Heat loss is minimal.
    Of the minuses of this design, one can single out the fact that over time, in a cheap thermos, the valve can begin to leak, therefore, it is not worth saving vessels with this system.
  • The stopper with a tongue is used in sports thermoses and thermo mugs. To start drinking from such a vessel, it is enough to move the "tongue" to the side without unscrewing the lid.

  • The twist-off plugs are easy to handle, but because you have to unscrew them over and over again, there is a significant loss of fluid heat. Manufacturers correct this drawback by using plugs that do not need to be unscrewed to the end.