Thermos Flask: How It Keeps Things Hot and Cold

A thermos flask is a useful bottle that helps in maintaining the temperature of liquids for a long time. It is commonly used to keep drinks hot or cold during travel, school, or daily use.

It works by reducing heat transfer and helps in keeping hot liquids hot and cold liquids cold for a longer duration. This makes it an important example of how science is used in everyday life. In this article, we will understand the working of a thermos flask and its structure.

Table of Contents

1. What is a Thermos Flask?
2. How Does a Thermos Flask Work?
3. Uses of a Thermos Flask in Daily Life

What is a Thermos Flask?

A thermos flask is a special type of bottle or flask that does not allow heat loss or heat gain by the material stored in it. It keeps a hot substance hot and a cold substance cold for a very long time when placed inside it.

How Does a Thermos Flask Work?

Now, let’s understand how a thermos flask works. Just have a look at the thermos flask diagram given below so that you can understand the internal structure of that bottle. 

The outer casing of a thermos flask is made up of plastic (or metal). 

Plastic, being a poor conductor of heat, acts as an insulator, preventing the heat loss through conduction. Inside it, there is a double-walled container made of glass or stainless steel. Both the walls are polished so they are shiny.

The space between the two walls is a vacuum; this prevents the heat loss through convection since there are no air particles to carry out the transfer of heat. 

The shiny surface of the walls also prevents heat loss through radiation.

Uses of a Thermos Flask in Daily Life

A thermos flask is commonly used in everyday life to maintain the temperature of liquids for a long time.

•  It is used to keep tea, coffee, or milk hot during travel or at work.
• It helps in storing cold drinks like juice or water and keeps them cool.
• It is also used in hospitals to store liquids at a required temperature.

In this article, we understood what a thermos flask is and how it helps in preventing heat loss and heat gain. We also explored how conduction, convection, and radiation are controlled inside the flask to maintain temperature.