A “red alert” in Beijing means the pollution is so bad, one deep breath turns your face red before you pass out and lose your alertness – or worse. Now those red alerts may be followed by a “wet alert” warning residents they’re about to get soaked by water cannons attempting to blast the smog out of the sky. Will it work?
The technology comes from a place even more polluted than China – coal mines. Hunan Jiujiu Mining Safety Equipment developed the “Multi-Function Dust Suppressor” as a way to protect miners from the severe respiratory problems caused by working in coal and other dusty mines. The cannons work on the same principle as nebulizers, which are mist inhalers used to deliver drugs to patients suffering from cystic fibrosis, asthma and other lung diseases.
Rather than delivering drugs to save lungs, the mist cannons remove particles from the air before they can be inhaled. The tiny water droplets (10 microns in diameter) are blasted into the air where they attach themselves to the dust and dirt particles in the smog, making them heavy enough to fall to the ground – where they probably cause different problems and increased business for car washes.
There’s a lot of smog in China. Can these cannons handle it? According to the company, one Multi-Function Dust Suppressor can hold ten tons of water and spray a nebulized mist for 75 minutes. The spray will cover an area 100 meters (330 feet) wide and 60 meters (200 feet) high. The cannons can be mounted on the backs of trucks and driven around for even wider coverage.
The idea sounds so good, a number of cities (like Guigang, Changsha and Zhuzhou) have purchased the cannons at the low-low price of $12,400 for a stationary model or $92,700 for the truck-mounted. There’s talk of putting them on the roofs of buildings or even have helicopters fly over areas with their cannons blasting. What could possibly go wrong?
Well, the cities, already suffering from droughts that created some of the dust, could run out of water. The dirty water droplets can end up polluting streams and there aren’t any cannons that can fix that. There’s the concern that pumping so much water in the air will alter the weather. And there’s the indisputable fact that there’s a LOT of pollution in China.
It’s ironic that “Multi-Function Dust Suppressor” came from coal mines – the source of the leading contributor to air pollution in the first place. Is there a message here?