A tower that purifies city air

Posted on 13 July 2016.

Dutch designer Daan Roosegaarde has invented a giant vacuum cleaner that captures fine particles and so purifies city air.

The images are disturbing. Beijing’s skyline has disappeared, hidden in a toxic smog. Passersby, even those wearing masks, have the acrid taste of coal in their mouths. The air is so saturated it gives you the impression you could hold it. Among other things it is packed full of fine particles. In the Chinese capital, these can reach as much as 680 micrograms per cubic meter, nearly 30 times the maximum recommended by the World Health Organization. Fine particles are considered dangerous because they enter people’s lungs directly and once they reach a threshold of 300 micrograms per cubic meter they also enter the blood vessels.

So naturally Daan Roosegaarde’s invention wowed the mayor of a city with increasing numbers of "airpocalypse" days.

Depolluting ions

The Dutch designer has designed an electronic vacuum cleaner that captures the pollution clogging up the air – a tower that has been named the Smog Free Tower. The aim is to create pockets of clean air. Its principle? An electromagnetic field generated by copper coils extracts the fine particles suspended in the air. Thanks to a positive current, an electrode sends positive ions into the air to fix them. A negatively charged surface then attracts them into the tower. The polluted air entering the roof is recirculated as clean air via its six sides.

>> See the video

30,000 m3 of clean air per hour

In partnership with Delft University of Technology (Netherlands), Daan Roosegaarde has already launched a prototype and installed a 7 meter high structure in Rotterdam (Netherlands). The Smog Free Tower is able to generate 30,000 m3 of air cleansed of fine particles per hour using not much more energy than a kettle. It’s certainly nothing that would give Beijing the mass clean-up it needs... although a Smog Free Tower is now being delivered to the Chinese capital.