The thermos is a cleverly designed container used to maintain the temperature of liquids, whether they are hot or cold beverages.

It helps prevent the transfer of heat or cold, thereby keeping the liquid's temperature constant over an extended period.

The invention of the thermos can be traced back to the early 20th century. The earliest thermos was invented in 1892 by the German scientist and inventor, Sir James Dewar.

He was an expert in low-temperature physics and liquid gases. During his research, he discovered that placing a vacuum between two layers of glass effectively reduced the conduction of heat, preventing the rapid loss of the liquid's temperature in the container.

Although James Dewar did not commercialize his invention, he used the design to create containers for storing liquid gases, later known as "Dewar bottles." However, others later improved this design and applied it to the manufacturing of thermoses.

In 1929, the first real thermos was invented by the German engineer Reinhold Burger. His design incorporated a vacuum layer between the inner and outer cups, which improved the thermos' ability to maintain the liquid's temperature.

This invention received an enthusiastic response, and thermoses gradually gained popularity worldwide.

As science and technology continued to advance, the design and materials of thermoses were continuously improved to provide better heat preservation and more convenience.

Modern thermoses have become indispensable items in people's daily lives, offering the convenience of enjoying hot or cold drinks anytime and anywhere, whether they are on the go, at work, or traveling.

1. Construction and working principle:

Inner cup body: The main container inside the thermos, is usually made of stainless steel, ceramic, or glass. Stainless steel is a common choice due to its good insulation properties and durability.

Vacuum layer: A gap exists between the outside of the inner cup and the outer cup, forming a vacuum layer. The vacuum layer reduces heat conduction since there is no gas or solid particles to transfer heat.

Outer cup body: Typically made of plastic or metal, it acts as the thermos' outer shell. The design of the outer cup body helps maintain the outer surface's temperature, avoiding discomfort to the hands due to heat or cold.

The thermos works by reducing heat transfer through the combination of a thermal insulation layer (the vacuum layer) and insulating materials.

When a hot drink is placed in the thermos, the vacuum layer prevents heat from escaping, keeping the drink warm. Similarly, when a cold drink is placed in the thermos, the vacuum layer prevents cold from escaping, keeping the drink cool.

2. Features and advantages of the thermos:

Insulation performance: Thermoses effectively maintain the temperature of hot drinks for hours, and high-quality thermoses can even keep beverages warm for an entire day. Similarly, cold drinks remain chilled for a significant period.

Environmental protection and energy-saving: Using thermoses reduce the use of disposable cups, making them more environmentally friendly and energy-efficient since beverages don't need frequent reheating or cooling.

Portability: Thermoses are designed to be portable, easily fitting into backpacks or tote bags, allowing people to enjoy warm or cold drinks on the go.

Diversity: Thermoses come in various sizes, colors, and styles to cater to individual preferences and needs.

Safety: Most inner materials are food-grade, ensuring the thermos is safe to use and won't produce harmful substances.

The thermos is a practical and eco-friendly beverage container loved by many. By choosing a thermos that suits their needs, individuals can enjoy beverages at the perfect temperature wherever they may be.