Innovative Course Sparks Enthusiasm for Invention
Little Huang also imagined improving this invention into an outdoor air purifying device. "The exhaust of cars and the waste gas emissions from coal-fired power plants are two major sources of PM2.5 in the atmosphere. If we could install 'water pipes' in cars and coal-fired power plants, it might reduce the concentration of PM2.5 in the atmosphere."
Of course, to turn these concepts into reality, Huang Simian needs to prove with experimental data that her invention can remove a large amount of PM2.5 from the air. Preliminary experiments indicate that this device can remove smoke from the introduced gas. During the summer vacation, she plans to conduct a more precise experiment: replacing the water in the purifier with distilled water, letting it work for some time, then taking water samples, evaporating them, and observing under an electron microscope to detect whether PM2.5 particles are present in the water. If they are, it would prove that the device has the ability to filter PM2.5.
How can we reduce PM2.5 in the air? Little Huang began exploring. At home, she looked up information online, understanding various techniques and equipment for air purification; at school, she often discussed with Teacher Huang Zengxin, designing and inventing schemes under his guidance.
Under the guidance of Teacher Huang, Huang Simian also installed two low-voltage electrodes on the outside of the purifier. Before the side electrodes are powered, electrostatic dust removal can be achieved.
Using Water, Mist, and Ultrasonic Waves for Filtration
Today, when the reporter walked into Xiangming Middle School's laboratory, Little Huang's invention had already taken shape. This air purifier consists of an outer shell and several devices. The transparent outer shell is filled with a lot of water. On top of the "water tank," there are three submersible oxygen pumps, which are connected to three tubes. Through these tubes, the oxygen pump draws the air around the purifier into the water, producing a large number of bubbles. Huang Simian said that submersible oxygen pumps were originally used for ornamental fish, but installing them in the air purifier was to draw a large volume of outdoor air into the water, allowing the air to fully contact the water. Thus, the device becomes a miniaturized "water pipe," dissolving a large amount of PM2.5 from the air into the water.
Using only water filtration to deal with PM2.5 is not enough, so Teacher Huang also adopted mist filtration. Mist is formed by the contact of water vapor in the air with dust, and mist has the effect of adsorbing dust particles. To create "artificial mist," Little Huang repeatedly searched online and eventually bought an "ultrasonic nebulizer." These devices were originally used in humidifiers, but she removed three ultrasonic nebulizers and installed them in the air purifier, coordinating with the oxygen pump. Once the ultrasonic nebulizer is powered, mist emerges from the water body of the purifier, adsorbing PM2.5 from the air.
Wishing to Test Purification Effects with Instruments
Little Huang indicated that once the design of this device matures, it could be wall-mounted indoors like a wall-mounted air conditioner, drawing indoor air through tubes connected to instruments and introducing clean air, free of PM2.5, back into the room. This device could also be designed to be more compact, becoming a PM2.5 car air purifier, allowing people to avoid inhaling contaminated gases while traveling by car.
Regarding this invention, Zhang Mingxu, the chief guest of the Shanghai Environmental Monitoring Center in China, stated that theoretically speaking, the scientific plan of water filtration, mist filtration, and electrostatic dust removal should be able to remove some PM2.5 from the air, but its purification efficiency still needs to be evaluated through test reports. The instruments used by the environmental monitoring center are for indoor PM2.5 detection and cannot test the purification effects of this invention.
Every day after arriving at school, Huang Simian, a first-year student at Xiangming Middle School, immediately dove into the laboratory to tinker with her invention - the PM2.5 air purifier. Not long ago, during an innovation class, Little Huang heard about PM2.5 particulate matter from technology mentor Huang Zenggu. She then came up with the idea of inventing a type of purifier to prevent PM2.5 from entering indoors. Now, the prototype of this instrument has been born in the laboratory, and its scientific nature has been recognized by experts. "I hope to get a testing instrument to verify the purification effect of this invention with data," Huang Simian told the reporter.
Huang Simian informed the reporter that she found online that the selling price of an outdoor PM2.5 testing instrument is 20,000 yuan, but the school laboratory does not yet have the funds to purchase it. If the funds are available or if an organization provides such testing, the research path of this "water pipe" purifier can continue.
At Xiangming Middle School, there is a course called "Innovation Class." Every week, Mr. Huang Zengxin, a member of the Shanghai Invention Association, introduces current social hot topics to the students and sparks their enthusiasm for invention. In a recent class, Huang Simian learned about "PM2.5," a new term referring to particulate matter in the atmosphere with a diameter less than or equal to 2.5 micrometers, only 1/10 the diameter of human hair. These particulates, when inhaled into the body, directly enter the bronchus, causing diseases including asthma, bronchitis, and cardiovascular disease. Recently, China's environmental protection department has placed "monitoring and publishing PM2.5" on the agenda, and how to manage PM2.5 has attracted widespread public attention.
"Have you ever seen a water pipe? In the past, many people smoked water pipes, where the smoke, filtered through water, would dissolve much nicotine and tar in the water." During a discussion, Teacher Huang mentioned water pipes to Little Huang. Could water be injected into an air purifier, allowing the water to filter out PM2.5 from the atmosphere? Huang Simian instantly had an idea. However, the filtering effect of air entering the water is likely to be limited. How can the efficiency of the purifier be improved? Little Huang embarked on a new round of exploration.