Current location - Health Preservation Learning Network - Health preserving recipes - Why does the kettle scream when it boils?
Why does the kettle scream when it boils?
When the water does not boil, the lower water boils, the upper water does not boil, the bubbles below rise and contract, and burst when it is cold. It will make a sound, but when the water boils, the upper and lower layers are very hot, and the bubbles will not burst due to cold contraction, so the sound is not big.

When water reaches 100℃, it should react in the direction of offsetting this temperature rise. When water evaporates, it will absorb heat, which will make a sound. As the temperature rises, the burning water will form bubbles. When the foam bursts, it will make a squeaking sound. After boiling, the temperature is the same, reaching the boiling point. No more bubbles.

Extended data:

1, whistle electric kettle.

It is drawn from aluminum plate, and the electric heating element adopts immersed nickel-plated steel sealed electric heating tube. The electric heating tube is installed at the bottom of the kettle, and the joint with the kettle body is padded with a heat-resistant sealing ring to prevent water leakage. The lid of this kind of electric kettle is equipped with a strip vibrating spring self-buzzer (air flow buzzer). When the water temperature reaches 100℃, the air flow will ring. Because this kind of kettle is generally not equipped with a temperature limit controller, the power supply must be cut off manually. This kind of electric kettle is simple in structure, low in price and widely used in families.

2. Anti-dry whistle electric kettle.

Based on the design principle of whistle electric kettle, an automatic temperature limit controller (mainly bimetal thermostat or magnetic thermostat) is added. When the water boils, the generated steam deforms the bimetal of the temperature sensing element and drives the microswitch to cut off the power supply, which greatly improves the safety performance of the electric kettle.

The temperature limiting controllers in some high-quality electric kettles adopt a new type of heat-sensitive material (automatic constant temperature control switch) similar to memory alloy. When the water level in the kettle is lower than the electric heating pipe (the temperature of the electric heating pipe exceeds 100℃), the automatic constant temperature control switch will automatically cut off the power supply to protect the electric kettle from being scalded.

3. Plastic electric kettle.

The biggest feature of plastic electric kettle is portability, safety and reliability. The power signal indicator lamp arranged in the pot body can conveniently observe the electrified state, the upper and lower split structure can rotate 3600 degrees, and the melting point of the food-grade sanitary plastic material used in the pot body is above 200℃. This new electric kettle adopts hidden stainless steel electric heating plate and is equipped with steam induction control switch, which has multiple protection functions such as automatic power off, dry-burning power off prevention, thermal fuse protection and grounding protection.

Baidu encyclopedia-electric kettle

Baidu encyclopedia-boiled water