Shanghai Middle School Students Invented PM2.5 Air Purifier and Received Expert Recognition

Recently, Huang Siqi, a high school student at Xiangming Middle School, developed the prototype of the PM2.5 air purifier. In the recent innovation class, Huang Zengxin, a science and technology teacher from Xiao Huang, talked about PM2.5 particles, and he had the idea of ​​inventing a purifier to stop PM2.5 from entering the room. Today, the prototype of this instrument was born in the laboratory, and its scientific nature has also been recognized by experts.

"I hope to get a testing instrument and use the data to test the purification effect of this invention." Huang Sixi told reporters.

Innovation class ignites the passion for invention

In Xiangming Middle School, there is a course named "Innovation Lesson". Every time in class, the teacher of the Shanghai Invention Association Huang Zengxin will introduce students to the recent social hot spots and inspire their passion for invention. In a recent class, Huang Siqi learned the new term “PM2.5,” which refers to particles in the atmosphere that are less than or equal to 2.5 microns in diameter, and only 1/10th the diameter of a human hair. After being inhaled into the body, these particles directly enter the bronchus and cause diseases such as asthma, bronchitis, and cardiovascular diseases. Recently, China's environmental protection department put the "monitoring and publication of PM2.5" on the agenda, how to deal with PM2.5, has also been widely concerned by the public.

How can we reduce PM2.5 in the air? Xiao Huang began to explore. At home, she went online to access information and learn about various technologies and equipment for air purification. At the school, she often consulted Huang Zengxin to discuss the design of the invention.

“Have you ever seen the hookah? In the past, many people took out the hookah. The smoke was filtered through the water. A lot of nicotine and tobacco tar were dissolved in the water.” In a discussion, Teacher Huang spoke of the hookah to Xiao Huang. Can you inject water into the air purifier and let the water filter out the PM2.5 in the atmosphere? Huang Siwei immediately inspires. However, after the air enters the water, the filtering effect is estimated to be limited. How to increase the efficiency of the purifier? Xiao Huang has invested in a new round of exploration.

Water, fog, ultrasonic filtration

Yesterday, the reporter walked into the laboratory of Xiangming Middle School and saw that Xiao Huang’s invention had taken shape. This air purifier consists of a shell and several devices. The transparent casing is filled with a lot of water. At the bottom of the "tank" are three submersible aerobic pumps. They are connected with three conduits. Through the conduit, the aeration pump draws the air around the purifier into the water and generates a lot of air bubbles. Huang Siqi said that the submersible oxygen pumps were originally used to raise ornamental fish. They were installed in air purifiers in order to pump large amounts of outdoor air into the water and allow air and water to fully contact. In this way, the device becomes an enlarged version of "water pipe", which dissolves a large amount of PM2.5 in the air in water.

Light water filtration method is not enough to deal with PM2.5, Xiao Huang also adopts fog filtration method. Fog is a crystal produced by the contact of water vapor with dust in the air. The fog has the effect of adsorbing dust particles. In order to create "artificial fog", Xiao Huang repeatedly searched the Internet and finally bought an "ultrasonic atomizer." This device was originally installed in an air humidifier. She installed three ultrasonic atomizers into the air purifier and "co-operated" with aeration pumps. When the ultrasonic nebulizer was energized, a water mist appeared in the water of the purifier, adsorbing PM2.5 in the air.

Under Huang's guidance, Huang Siqi also installed two high-voltage electrodes in the purifier. After the positive and negative electrodes are energized, they can play the role of electrostatic dust removal.

I hope to use the instrument to detect the purification effect.

Xiao Huang said that after the design of this device is mature, it can be installed on the indoor wall like a wall-mounted air conditioner, and the outdoor air can be drawn by the duct attached to the instrument, and the PM2.5-free air can be introduced into the room. This device can also be designed to be more compact, becoming a PM2.5 interior air purifier, so that people do not inhale contaminated gas when traveling by car.

Xiao Huang also envisaged the improvement of this invention as an outdoor air purification device. “The exhaust emissions of cars and the emission of coal from power plants are the two main sources of PM2.5 in the atmosphere. If we put 'water pipes' into cars and coal-fired power plants, we may be able to reduce the concentration of PM2.5 in the atmosphere. ”

Of course, in order for these ideas to become a reality, Huang Sixi uses experimental data to prove that her invention can remove a large amount of PM2.5 in the air. Preliminary experiments show that this device can remove the smoke in the introduced gas. During the winter vacation, she is preparing to do a more precise experiment: replace the water in the purifier with distilled water, let it work for a period of time, sample the water, evaporate and observe with an electron microscope, and check whether the water contains PM2.5 particles. If so, it proves that the device has the function of filtering PM2.5.

For this invention, Zhang Mingxu, deputy director of the Shanghai Environmental Monitoring Center, said that in principle, this “three-pronged approach” of water filtration, fog filtration, and electrostatic dust removal is scientific and should remove some of the PM2 in the air. 5, but how high its purification efficiency, you need a test report to judge. The instruments used by the Environmental Monitoring Center are used for outdoor PM2.5 testing and cannot detect the purification effect of the invention.

Huang Suiyu told reporters that she had found on the Internet that the price of an indoor PM2.5 testing device was 20,000 yuan, but the school lab had no funds to purchase. If funding is in place, or if an organization provides such testing, the road to research and development of the “water pipe” purifier can continue.