1. rice cooker (rice cooker, electric cooker): it is a cooker that converts electric energy into internal energy. It is convenient to use, clean and hygienic, and has many operating functions such as steaming, boiling, stewing and stewing food. Common rice cookers are divided into three types: automatic heat preservation type, timed heat preservation type and new microcomputer control type. Now it has become a daily household appliance, and the invention of the rice cooker has reduced the cooking time of many families. The result diagram and product diagram are as follows:
Schematic diagram of simple rice cooker
Schematic diagram of functional (reserved) rice cooker
2. Pressure cooker (also known as pressure cooker, generally using liquefied gas, artificial gas and natural gas): Pressure cooker is also known as pressure cooker (a sealed container consisting of pot body, pot cover, fusible piece, vent hole, safety valve and sealing apron), which uses the principle that the boiling point of water is affected by air pressure, and the higher the air pressure, the higher the boiling point. On mountains and plateaus, the air pressure is lower than 1 atmospheric pressure, and water can boil below 100℃. Eggs are not cooked in ordinary pots and pans. When the air pressure is greater than 1 atmospheric pressure, water will boil only when it is higher than 100℃. Nowadays, the pressure cooker widely used by people is designed by using this principle (invented by French physicist Dennis Papan in 1679). The water in the pressure cooker is closed tightly, so the steam generated by water evaporation can't diffuse into the air, and only stays in the pressure cooker, which makes the pressure in the pressure cooker higher than 1 atmospheric pressure, and also makes the water boil when it is higher than 100℃, thus forming a high-temperature and high-pressure environment in the pressure cooker. After the water in the pot is heated, the pressure will increase when it is closed. When the cooked food is pressed, it will be heated to above 100℃. With its unique function of high temperature and high pressure, it greatly shortens cooking time, saves energy and makes food loose. At the same time, the pressure cooker with high working pressure will cause great damage to nutrition.
But the pressure in the pressure cooker will not be infinite, or it will become a bomb. Therefore, there must be more than one safety device (fusible piece, vent and safety valve). The following figure shows the structure of the pressure cooker:
Schematic diagram of ordinary pressure cooker:
Third, electric pressure cooker (also known as electric pressure cooker, which uses electric energy to replace other energy sources): In addition to the different energy used, its principle is also different. Other principles are the same as those of ordinary pressure cookers. Its structural diagram is as follows:
Electric pressure cooker (pressure cooker) Figure: