• Control of Vehicular & Industry Emission

In zigzag kilns, bricks are arranged to allow hot air to travel in a zigzag path. The length of the zigzag air path is about three times that of a straight line, and this improves the heat transfer from the flue gases to the bricks, making the entire operation more efficient. In addition, better mixing of air and fuel allows complete combustion, reducing coal consumption to about 20 percent. The zigzag design also ensures uniform distribution of heat, increasing the share of Class I bricks to about 90 percent. It also reduces emissions considerably. The zigzag technology has two sub-types: natural and induced.

The induced draft uses fans to regulate air, while the natural draft has a chimney. The operational cost of the induced draft includes the cost of diesel and the maintenance of a generator to run the fan, which comes up to about Rs 250,000 a season. This cost is eliminated in the natural model, but it requires an initial investment in building a chimney. While natural zigzag is usually the first choice for brick kiln owners as running costs are lower, they are choosing induced zigzag as conversion costs are lower. The government order also promotes induced draft technology. Owners of brick kilns are in a frenzy to convert the existing manufacturing units to “induced draft zigzag” kilns, to comply with an order by the Central Pollution Control Board (CPCB). The recommended zigzag is cleaner and more efficient.

In June this year, CPCB asked brick kilns across the country to make this shift, after they were identified as a significant source of pollution. In Delhi-NCR, similar guidelines have existed since 2015, but the progress in conversion is slow. Brick kiln owners say a shortage of manpower and lack of demand for the bricks are roadblocks in adhering to the deadline.

The Delhi-NCR region is plagued by severe air pollution, especially during the winter season. In order to find a long-term solution of the issue, Environmental Pollution (Prevention and Control) Authority (EPCA) had asked the NCR states to work on Graded Response Action Plan to reduce the pollution emanating from different sources. The plan identified brick kilns as one of the major sources of air pollution in the region. The EPCA then ordered all brick kiln must use the zigzag technology to run during the winter of 2017-18.