A vacuum flask, also known as a insulated flask, is a commonly used container that can maintain the temperature of its contents for an extended period of time. It is widely used in daily life and work, providing convenience and comfort to people. This article will introduce the principles of the vacuum flask.
I. Structure of a vacuum flask
A vacuum flask typically consists of three parts: an inner cup, an outer cup, and a lid. The inner cup is responsible for storing the liquid and is usually made of stainless steel or glass, which has excellent insulation performance and durability. The outer cup is used to protect the inner cup and isolate it from the external environment, and is usually made of plastic or metal. The lid is used to seal the inner cup and is typically made of plastic or silicone material.
II. Principles of a vacuum flask
The insulation performance of a vacuum flask is mainly based on two principles: thermal conduction and radiant heat loss.
1. Thermal conduction
Thermal conduction is the transfer of heat through the internal movement of molecules. In a vacuum flask, a vacuum layer is formed between the inner and outer cups, and there are no molecules in the air that can conduct heat, thereby reducing thermal conduction. In addition, the inner cup is usually made of a material with a high thermal conductivity, which can quickly absorb and release heat, thereby reducing the transfer of heat inside.
2. Radiant heat loss
Radiant heat loss refers to the process by which an object transmits heat to the surrounding environment through radiation. In a vacuum flask, the inner wall of the outer cup is usually made of silver or copper-plated material, which can reflect radiant heat and reduce heat loss.
Combining the above two principles, a vacuum flask can effectively reduce heat loss and achieve long-term insulation.
