Thermoflask

Thermoflask – How It Keeps Things Hot or Cold

A thermoflask, also known as a vacuum flask or thermos, is a special container designed to maintain the temperature of liquids, keeping them hot or cold for extended periods. It is widely used at home, school, during travel, and in hospitals. Whether you want to enjoy hot tea in winter or cold juice in summer, a thermoflask makes it possible.

Structure of a Thermoflask

• Inner container: Usually made of glass or stainless steel, it holds the liquid.
• Outer container: Made of plastic or metal, it protects the inner part.
• Vacuum layer: The space between the inner and outer containers has no air, preventing heat transfer through conduction and convection.
• Reflective surface: The inside is often shiny to reflect heat and reduce radiation.
• Tight lid: Seals the flask and prevents heat from escaping or entering.

How It Works

• Prevents conduction: The vacuum layer doesn’t allow heat to pass easily.
• Prevents convection: No air means no convection currents.
• Reduces radiation: The shiny surface reflects heat away or back inside, depending on whether the liquid is hot or cold.

Uses of a Thermoflask

• Carrying hot tea, coffee, or soup while traveling.
• Keeping milk warm for babies.
• Storing cold drinks like water or juice during summer.
• Used in science labs to keep chemicals at stable temperatures.

Fun Fact

The thermoflask was invented in 1892 by Sir James Dewar, a Scottish scientist. That’s why it is also called the Dewar Flask.

A thermoflask is a smart use of science that helps us in our daily lives. It works by stopping heat transfer through conduction, convection, and radiation, keeping liquids hot or cold for hours. It is a great example of how science makes our life easier.