Connaught Place smog tower to restart today

Subject : Environment

Section: Pollution

Context:

Delhi government has ordered the Delhi Pollution Control Committee (DPCC) to restart the Connaught Place smog tower at full capacity.

About Smog Tower:

Setup in 2021 at the cost of 20crore
Designed and developed by: IIT-Bombay, Minnesota University of the USA and Tata Project limited.
The structure is 24 m high — an 18-metre concrete tower, topped by a 6-metre-high canopy. At its base are 40 fans,10 on each side.
Each fan can discharge 25 cubic metres per second of air, adding up to 1,000 cubic metres per second for the tower as a whole.
Inside the tower in two layers are 5,000 filters. The filters and fans have been imported from the United States.

How it works?

The tower uses a ‘downdraft air cleaning system’ developed by the University of Minnesota.
Polluted air is sucked in at a height of 24 m, and filtered air is released at the bottom of the tower, at a height of about 10 m from the ground. When the fans at the bottom of the tower operate, the negative pressure created sucks in air from the top. The ‘macro’ layer in the filter traps particles of 10 microns and larger, while the ‘micro’ layer filters smaller particles of around 0.3 microns.
The downdraft method is different from the system used in China, where a 60-metre smog tower in Xian city uses an ‘updraft’ system — air is sucked in from near the ground, and is propelled upwards by heating and convection. Filtered air is released at the top of the tower.
Efficiency of smog tower: It can reduce air pollution by 70%-80% within a 50-metre radius and by 15%-20% up to a radius of 300 metres.

Source of the article: The Hindu