As per the IRC: 90 – 2010 the plant can be fitted with following Pollution Control Units, which become an integral part of the asphalt hot mix plant:
- Primary Pollution Control Device :- It is the primary Dust Collection System capable of removal of Upto 90% dust from the dryer exhaust of the asphalt hot mix plant.
- Secondary Pollution Control Device:- The wet scrubber system will capture pollutant gases from asphalt hot mix plant namely: CO, NO2, SO2 and VOCs and has been designed for 95-99.9% removal of gases pollutants. The affluent generated from wet scrubber will be treated in a neutralization plant.
The salient features and specifications of this unit are as per the stipulations laid down by the MORTH (Ministry of Road Transport and Highways) and published in IRC: 90 – 2010. As per the IRC: 90 – 2010, Annex – C, the typical hot mix plant emission and their control is as per the given standards.
The plant, after mixing asphalt with aggregate, inducts the dust into the dry dust collector and hot air into the wet dust collector. The wet dust collector is fitted with very high pressure water nozzles. Through these nozzles, water is sprayed all around the drum onto the gases. As a result of this, the gases are converted into water. The air pressure remains very thin and the remaining air is discharged through the exhaust chimney, which contains almost no pollutants. The water from the dust collector can be discharged into a pond and could be recycled again. But the slug pond must be cleaned once every week.