[Real-time] Anti-sputnik "Armycraft" who can top the list from fog cannons, indoor air purifiers to small masks

From December 16th to 22nd, the northern regions have encountered the largest regional heavy pollution since the winter, and Beijing has launched a red alert for heavy air pollution. Among them, haze components represented by PM2.5 pose a great threat to people's health. As a result, various types of equipment to resist smog emerge in an endless stream. This year's visibility of science and technology will take stock of the "arms spectrum" against them, and explore their working principles and anti-convulsion effects.

Fog car:

Against smog effects

Actually very limited

Due to its peculiar shape and cannon shape, the fog canopy was dubbed the "except artifact". In recent years, fog can also appear on the streets of many cities.

working principle:

The water is atomized into water mist particles (50-200 microns) with dust particle size by high pressure, and is ejected from the cannon-like air duct. The wind is strong, with a long range and a wide range. The dust is in contact with the water mist particles in the air. Settling settlement, and then to suppress dust, air purification purposes. Large spray guns can spray water mist of 120 meters and 70 meters high and cover an area of ​​more than 30,000 square meters.

Experts say:

Wang Yuesi, a researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said that a fog canister is a watering thing and it is the ability to spill water efficiently. He said that this tool is mainly used for construction on the construction site. Before the construction, a spray of water is sprayed to spray the wet work site. During construction, no ash is produced. It can also be used to dismantle old residential areas, factories, chimneys, etc. Road dust.

Wang Yuesi believes that the atmosphere is a super fluid, and the exchange rate is very fast. Some pollutants are sprayed down, and they are quickly added to other places. The so-called rule of blasphemy is not understood by the atmospheric sciences. If it is used to spray water around the monitoring point, it will affect the monitoring data of the monitoring point, resulting in unrealistic measured data.

Prof. Pan Xiaochuan of the School of Public Health of Peking University stated that smog was formed at an altitude of 2,000 meters, while the fog cannon reached 200 meters. Jiang Kejian, a researcher at the Energy Research Institute of the National Development and Reform Commission, believes that the sulfides and nitrides that originally belonged to the gas would react chemically with water to form fine particles and increase PM2.5.

Indoor air purifier:

Clean air efficiency

Unsatisfactory

The arrival of hazy days made more people choose to stay at home but the indoor air was not as clean. As a result, many people also purchased indoor air purifiers, but what about the real effects?

working principle:

The common air purifiers on the market are divided into three categories according to the working principle: passive purification, active purification, and double purification.

Passive purification air purifiers mainly rely on filter cleaning. The air is pumped into the machine by a fan, and the air is filtered through the built-in filter screen. It mainly serves to filter dust, odors, toxic gases, and kill some bacteria.

The active purification class does not rely on filters, but works through ion technology, photocatalyst technology, and plasmaclustering. The main principle is the use of electrostatic discharge of negative ions, adsorption of dust in the air play a role in dust reduction, but at the same time, negative ions also have ionization of ozone into ozone in the air, resulting in "ozone pollution", which is also relatively large for the human body hurt.

Double purging relies on filters and other technologies to clean the air.

Experts say:

According to Xie Huaqing, member of the National Environmental Protection Products Standardization Technical Committee, air purifiers have two important indicators. One is the amount of clean air, that is, the amount of air that is purified by the air purifier. The second indicator is “clean life”, which is how long it will be able to clean the indoor polluted air.

Xie Huaqing said that the air purifier used now has a relatively long time to clean out a certain amount of air. For example, it takes 5 to 6 hours to obtain a certain amount of purified air. “From this process, the role of the air purifier is It's relatively small. When the entire nature is hazy, the effect is almost all very weak."

N95 protective mask:

Static fiber material

Good protection

Anti-haze masks have become a must for travel. At present, the industry standard of mask protection level generally recognized in the world is: NIOSH (National Institute of Occupational Safety and Health) standards; European Union (EU) EN standard; China GB2626-2006 standard.

However, what is the working principle of anti-haze masks? Can it really protect you?

working principle:

The basic principle of a mask is to filter out harmful substances like a sieve. Masks that can protect against small dust are generally made of non-woven electrostatic materials that use electrostatic fibers to adsorb inhalable particles in the air.

Experts say:

The material room of the Beijing Medical Device Inspection Laboratory had conducted hermetic experiments on several types of masks in a hospital environment. The test results showed that ordinary gauze masks did not have a blocking effect on particulate matter below PM5. Ordinary medical masks have an effective effect on the protection of PM4. Medical surgical masks and medical disposable masks can block particles larger than 4 microns in diameter. The medical protective mask N95 can block most PM2.5 particles. When tested in a mask-sealing laboratory, over 99% of the particles were blocked by medical N95 masks.

However, Yue Weihua, director of the materials room at the Beijing Medical Device Inspection Institute, said that their tests are conducted in a sealed environment in a hospital environment. In cities, emissions such as vehicle exhaust are large, and many particles in the air are rendered oily. This will also reduce masks. Actual protection effect.

As the fine dust is also divided into two kinds of oily and non-oily, the more common 3M masks on the market are more commonly divided into KR and KN series. The KR series filters oily particles and the KN series filters non-oily particles.

Urban ventilation corridors:

Solve haze problems

Only assistive

Although the wind can blow away the haze, it is better to build several urban ventilation corridors than wait for the wind to come. Based on this consideration, the urban air ducts have also been placed in high hopes in the “fighting against flooding”.

For example, in February 2016, Beijing introduced a plan to build five grade one ventilation corridors with a width of 500 meters or more and multiple secondary ventilation corridors with a width of 80 meters or more; Roads will be strictly protected, and high-rise buildings will be prohibited in the “Wind Roads”; Fuzhou City has also planned a ventilation pattern with “one axis, ten corridors, and one more”, and is clearly written in the “Fuji Ecological Master Plan”.

Way of working:

Rely on the wind blowing into the city under high pressure to dispel fog.

Experts say:

“The main purpose of the ventilation corridor system is to improve the wind-heat environment in the dense urban areas and relieve the heat island effect in the central urban area. The pollution emissions are not reduced, the meteorological conditions,” Any Yong, deputy director of the Planning Research Office of the Beijing Urban Planning and Design Institute, said. Under the premise of being unchanged, the ventilation corridor alone cannot solve the problem of haze, but it is certain that the formation of a ventilation corridor network in the central urban area is effective for improving microclimate, and it has a certain role in promoting pollutant diffusion."

He Yong said that for large cities, re-planning of open space is no longer a condition. Therefore, we should try our best to make use of the areas with large ventilation potential and continue to use them. The ideal urban airway can best combine the natural corridors or natural elements in the city, such as rivers, lakes, and ditch green belts. The integration of various types of open spaces is conducive to the formation of urban air ducts with sufficient space width.