What is a thermos?
The thermos is a unique development of mankind, which allows us to preserve food at a certain temperature for up to a day. This applies to both hot and chilled products.
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Thermos - what is it and what is it used for?
A household appliance is a container with double walls, between which there is a vacuum. Most modern devices have an additional layer of insulation and a tight lid for more secure closure.
Thermoses are produced in various sizes. Allowed to store, carry and prepare various dishes.
Purpose of the device
The main purpose of the device is to preserve food fresh and at a certain temperature. If the dish is hot, it retains its attractive taste and aroma for a long time. A cold dish does not spoil over a long period of time and can always be reheated.
It is noteworthy that in ancient Greek mythology Thermos is the god of heat and wind.
The thermos is also often used for preparing “lazy” dishes. For example, it’s easy to make porridge in the evening or brew compote or decoction. They turn out tasty and rich thanks to the enclosed space in which the products are placed.
Device and main characteristics
The thermos was first invented by a resident of Munich (Germany) in 1904.The device, unique in its structure, was a flask with double walls and a mirror surface inside, which well retained the heat of the products placed in it.
The flask is the main element of the container. It is made of glass or stainless steel with double walls, between which air is pumped out. The vacuum is created to reduce thermal conductivity and convection between the environment and the internal contents of the flask.
Mirror coating covers the inner surface of the flask. The housing is usually made of metal or durable plastic. Also, most modern models have a layer of insulation and a tight lid made of safe plastic.
The device retains heat for 8–10 hours. After this time, a person has the opportunity to enjoy the still hot tea, as if it had just been brewed. This is especially convenient when it is not possible to use a regular kettle.
To keep the temperature longer, the flask is filled completely with liquid. So it will be hot for a long period.
The only “weak” point is the lid. When choosing a model, you need to pay attention to this detail. It must be made of durable and thick plastic and fit securely to the neck.
Classification of thermoses
Previously, devices were made only for liquids. It was rare to find a wide flask for carrying first courses on sale. But they didn't keep the food warm for long. Today everything has changed. There are a lot of options for thermoses.
According to the material of manufacture
Products made from different materials are available for sale. The most popular thermoses are:
- stainless steel;
- glass
Stainless steel products are traditional. It is customary to take them on long hikes, fishing, and walks in nature.Glass ones are good for home use, as they are more fragile. There is also an option for a plastic thermos. Its body is light and original. Suitable for outdoor sports and hiking. But it is worth remembering that plastic is not very durable.
By nature of storage
Previously, thermoses were intended exclusively for hot liquids. But not so long ago they began to be subdivided, taking into account the nature of the use of the container. For example:
- for tea, coffee and other hot drinks;
- for food;
- universal.
Moreover, each type of thermos has its own subspecies. For example, many people now buy a thermal mug for a pleasant morning every day. This item allows you to enjoy homemade coffee on your way to work.
There are also thermal flasks for hiking and active sports, special bottles for cold water and other options. For food, thermoses are divided into containers with different volumes. Some are intended for first courses, while others can withstand only solid food.
How to choose?
The choice of thermos is based on the principle of integrity and visual appeal. When going to the store, it’s worth remembering a few basic rules that will protect you from buying low-quality items:
- When examining, shake the thermos. If a soft ringing sound is heard, this means that the bulb is damaged or is not securely secured inside.
- A visual inspection of the inside of the device will allow you to assess its integrity and the absence of chips or cracks.
- There should be no sharp, unpleasant odors inside. If there are any, they will not disappear even after a thorough wash.
When you come home with your purchase, fill it with boiled hot water. If the outer walls heat up, it means the thermos is defective.It is worth returning it to the store as a low-quality item.
A thermos is a worthy purchase for all occasions. It’s good to go on hikes and trips with, or even take it with you on a long walk. Thermal mugs are ideal for a great start to the day and hot coffee. It’s convenient to take home-made lunch with you in containers if you can’t have lunch in a cafe or canteen.
