The role of the lid when boiling water 25

The boiling point of water rises with the increase of pressure, and the pressure in the pot can be relatively higher than that without the cap, so the temperature of the water boiling (boiling) is higher, and another reason is that the water vapor can not be dispersed, prevent heat loss, and reduce energy consumption. To put it bluntly, it is to save natural gas. The pressure cooker uses this principle, which increases the pressure in the pot is equivalent to increasing the temperature of the boiling water, so the pressure cooker can cook things that are not cooked in ordinary pots, and boil things that are not cooked in ordinary pots.

In plateau areas or very high places, ordinary pots cannot cook rice because of the low local atmospheric pressure, and the temperature of the relative water boiling will also be very low, not reaching 100 degrees, and in some places even more than 80 degrees. This is where the pressure cooker comes into play.

The first is that with the increase of the temperature in the pot, the gas in the pot expands and overflows, and the pressure in the pot will decrease, so as to achieve the purpose of speeding up the boiling The second is to let the steam return to the cage and increase the temperature of the water, that is, to increase the speed of boiling water!

You know the pressure cooker handle, why the pressure cooker has a lid, they have the same principle, but the lid does not have so much pressure, but it is also not negligible.

The addition of a lid blocks the dissipation of steam, reducing heat loss, thus allowing the water to boil faster.

It avoids heat loss, reduces heating time, and increases pressure to a certain extent.

It is easier to open with the cap, and it is not easy to enter the air (wind) after the cap and may bring bacteria in.

In addition, it is covered with anti-safety, so that it is not easy to collide or bathe out when boiling water.

1 In order to reduce the evaporation of water vapor and retain heat.

2. Increase the gap in the air pressure in the pot to force the water in the pot to reach the boiling point as soon as possible.

Let the steam return to the cage and raise the temperature of the water, which means that the boiling speed of the boiling water increases!

Avoid heat loss, reduce heating time and save energy.

Raise the air pressure, raise the boiling point, and the water is more boiling! Kill germs and stay healthy!

Why do you need to cover the pot when cooking?!

If it is tap water, open the lid and boil it for a while to help the gases (chlorine, odor, etc.) inside be discharged faster. In fact, as long as the water bubbles, it means that the water is basically boiling, and if you open the lid in advance, it will cause the heat generated by the heating to escape, resulting in a longer heating time and a slower boil. Once the water is boiling, of course, you can open the lid, as there is no need to heat it at this point.

Wait about 3 minutes after the water is boiling before turning off the heat

This is because after ordinary water is sent to the waterworks, it is chlorinated to remove impurities such as microorganisms. But at the same time, chlorine interacts with residual organic matter in water to form toxic carcinogenic compounds such as halogenated hydrocarbons and chloroform.

The contents of halogenated hydrocarbons and chloroform are closely related to the change of water temperature and the duration of boiling. When the water temperature reaches 90, the content of halogenated hydrocarbons rises from 53 micrograms per liter to 191 micrograms, and chloroform rises from micrograms per liter to 177 micrograms, both exceeding the national standard by two times. When the water temperature rises to 100 μg, the content of halogenated hydrocarbons and chloroform drops to 110 micrograms and 99 micrograms respectively, which still exceeds the national standard.

If it continues to boil, after 3 minutes, the halogenated hydrocarbons and chloroform levels drop to micrograms and micrograms, respectively, and it becomes safe drinking water. Of course, boiling water is not the longer it is boiled, the better, because the longer it is burned, there are no volatile harmful substances and nitrites in the water, and the content will be concentrated due to the evaporation of the water, and the content will be relatively high.

The lid needs to be opened when boiling water.

When the water is about to boil (80 -90), the lid should be opened, because there are more and more organic pollutants in the water now, and some substances are volatile, and they will volatilize with the water vapor when heated. Therefore, when the water is about to boil, the lid of the kettle should be opened to allow these substances to be volatilized to the maximum.

Usually boiling water only kills the microorganisms in the water, and boiling the water is the best sterilization method. However, the excrement of microorganisms in the water, especially the endotoxin released by the pathogenic bacteria after being killed, cannot be killed at 100, so the water should be boiled for 2 to 3 minutes before turning off the fire.

There are many harms of drinking raw water:

Don't drink raw water, drinking raw water has many harms, because the chlorine in tap water can interact with the residual organic matter in unboiled water, which increases the chance of bladder cancer and rectal cancer. Do not drink water that has been left out for too long, as it not only lacks various minerals, but may also contain some harmful substances and cause poisoning.

Water should be boiled for 3 minutes before drinking, because drinking water that is not thoroughly boiled is easy to get cancer. Boiling fresh water for 3 minutes is not only sterile, but also the chlorine and some harmful substances in the water have evaporated, while maintaining the essential nutrients in the water.

Studies have proved that the content of halogenated hydrocarbons and chloroform is closely related to the change of water temperature and the duration of boiling.

The above content refers to People's Daily Online-The correct way to boil water What are the health benefits of warm boiled water?

The correct way to live is: open the lid when the water is about to boil (80-90), wait for the water to boil for another 2-3 minutes, and then turn off the heat. Or open the lid as soon as the water is boiling and wait another 2-3 minutes.

This is because there are more and more organic pollutants in water nowadays, and some substances are volatile and will be volatilized with water vapor when heated. Therefore, opening the lid of the pot when the water is about to boil and boiling for another two or three minutes after the water is boiling can allow these substances to volatilize to the maximum. On the other hand, boiling water for too long will also cause the water to deteriorate and form harmful substances.

No, but don't overfill it, or the water will overflow when it's about to boil

Under what circumstances do we need to open the lid to boil water when boiling water?

No, otherwise it will be difficult for the water to boil.

It's best to close the lid. First of all, security is different. If the kettle is not covered with boiling water, it will not stop boiling water after boiling water, so it may keep boiling water, causing a short circuit and causing certain hazards to personal safety; After the lid is closed, the water will automatically stop when it boils, and it will not dry boil, which is more safe.

Second, the speed is different. When the kettle is closed, the heat is not easily dissipated. Water heats up faster.

Without a lid, the heat will be dissipated all the time. In contrast, the rate of boiling water will be very slow.

In addition, when boiling water, when the water temperature is close to 100, open the lid of the pot, volatile some residual volatile organic compounds in the water, and turn off the fire for 2 3 minutes after boiling water. Due to the secondary pollution of transmission and distribution pipelines and water storage tanks, the water stored in the tap water pipelines for too long should not be boiled directly for drinking. In the morning, turn on the tap, drain the water for 5-10 minutes, then boil and drink.

Tap water can be used to clean floors or toilets.

After the kettle is used for a long time, a layer of scale will appear inside the bottle, which is not easy to remove. If dilute hydrochloric acid is poured into the thermos, close the lid, shake gently a few times, then let it sit for 30 minutes, rinse it several times with clean water to remove limescale. You can also take a little tea, put it in a warm water bottle, fill it with boiling water, cover the bottle and drink the tea after 15-20 minutes.

Under the action of theophylline, the scale in the bottle will fall off and sink to the bottom of the bottle. Soak it a few times and the effect will be even better. You can also pour in about 500g of baking soda with a concentration of 1%, or heat alkaline water into a bottle and shake gently to remove limescale.

You can boil a little sweet potato with water and then keep the sweet potato with water for 8-10 hours. The limescale will gradually dissolve. You can also gently break two eggshells, put them in the bottle, then put half a bottle of cold water, plug the cork, press with your index finger, hold the neck of the bottle mouth with your thumb and other fingers, hold the bottom of the bottle with your other hand, and rotate it up and down, left and right.

For about 20 minutes, remove the cork, pour out the eggshells, and rinse twice with water.

It is better not to cover the lid, which can allow harmful substances to volatilize, can remove debris, and can make the water quality better.

Personally, I think it is correct to cover the high second boil when boiling water, because if you cover the lid to boil the water, it is safer, it will not cause burns, and the speed of boiling water is relatively fast.

It is better to close the lid, the pressure is very strong when the lid is closed, so the heat is very fast.

The lid refers to the covering object on top of the vessel, open object. It is generally round or square in shape to provide shelter from dust and contaminants.

1. After adding the lid, the slag in the pot will form an air cavity, and the air is a good heat insulator, so that the loss of heat can be reduced.

2. In order to reduce the evaporation of water vapor, heat is retained.

3. The branch brigade quietly increases the gap in the air pressure in the pot, forcing the water in the pot to reach the boiling point as soon as possible.

The lid refers to the covering utensils on top of the utensils, open mouths, and celery. It is generally round or square in shape to provide shelter from dust and contaminants.

1. After adding the lid, an air cavity will be formed in the pot, and the air is a good heat insulator, which can reduce the loss of heat.

2. In order to reduce the evaporation of water vapor and retain heat.

3. Increase the gap in the air pressure in the pot to force the water in the pot to reach the boiling point as soon as possible.

Under what circumstances do we need to open the lid to boil water when boiling water?

Because the water in the heat transfer pot is constantly accumulating in the military sales heat, and the water vapor has not escaped the order and has been accumulating in the pot, so the strengthening and temperature are constantly rising, resulting in the water boiling more violently, so the water with the lid closed is boiled stronger than the water with the lid opened.

Bring the water to a boil and close the lid. It boils more than when you open the lid, because the pressure inside the pot is higher and the water temperature is higher, so the boiling point of the water will be higher.

After the water is boiled, the water will boil faster, because after the lid is closed, it will form a sealed space, and the air pressure in this space will be greater than the atmospheric pressure, and after the atmospheric pressure is higher, its temperature will rise above 100 degrees, so the water will boil more intensely.

I think it should be boiled stronger when the lid is closed. Because water boils when it reaches a certain temperature at a certain air pressure. If the lid is closed, the temperature will continue.

In this life, every household will use a teapot or iron pot to boil water, but why do you open the lid after boiling the water and don't cover the lid to boil so much?When we open the lid after boiling the water, the heat will evaporate, which will cause the pressure in the pot to decrease. The loss of water vapor causes the temperature of the water to decrease a little bit, while the hot vapor is evaporated, resulting in an acceleration of air circulationAnd the pot with the lid can't be volatilized due to the hot steam

After the water is boiled, the lid will boil more intensely. For example, when we make dumplings, we can find this phenomenon.

I feel that the boiling is more intense when the lid is closed, because it is difficult for his gas to escape through the lid at this time, so its gas molecules will move more violently, which will cause the water to boil more violently.

When the water boils, the lid is closed and the boiling is more intense. Water vapor accumulates in a fixed range after the lid is closed, and when the lid is opened, the lid is closed more violently due to the decrease in temperature due to heat loss.