The principle of pressure cooker is very simple, because the boiling point of water is affected by air pressure, the higher the air pressure, the higher the boiling point. In the mountains, plateau, air pressure less than 1 atmospheric pressure, less than 100 ℃ water can boil, eggs with ordinary pots and pans is not cooked. In the air pressure is greater than 1 atmospheric pressure, the water will have to be higher than 100 ℃ to boil.

People commonly used pressure cooker is designed to use this principle. Pressure cooker to the water is quite tightly closed up, water evaporation of water heat produced by water vapor can not diffuse into the air, can only be retained in the pressure cooker, so that the pressure cooker inside the pressure is higher than 1 atmospheric pressure, but also so that the water to be higher than 100 ℃ when it boils.

This pressure cooker inside the formation of high-temperature and high-pressure environment, the rice will be easy to cook quickly, and quite crispy. Of course, the pressure inside the pressure cooker will not be unlimited, or it will explode. The use of pressure cookers need to be extra careful, turn off the fire in time to avoid accidents.