Knowledge Brief

What are the advantages of converting a Fixed Chimney Bull’s Trench Kiln (FCBTK) to a Zigzag Kiln?

There are primarily two advantages that can accrue to a brick entrepreneur when a Fixed Chimney Bull’s Trench Kiln (FCBTK) is converted into a Zigzag Kiln.

1. Savings in fuel cost due to lower consumption of fuel.
2. Increase in revenue due to improvement in the quantity of good quality bricks.

In addition, there is reduction in air pollution, which helps in meeting air pollution regulations and reducing adverse environmental impacts.

How much fuel can be saved by shifting from an FCBTK to a Zigzag Kiln?

On an average, a properly constructed and properly operated Zigzag Kiln saves 20%-30% fuel as compared to an FCBTK. For a kiln producing 50 lakh bricks per year, the annual savings in coal could range from 150–200 tonnes per year or an annual savings of Rs 7.5 lakh to Rs 20 lakh.

What is the improvement in the quantity of good quality bricks produced in a Zigzag Kiln compared to an FCBTK?

Typically, only 50%-60% of the bricks produced in an FCBTK get classified as Class-1 bricks. On the other hand, 80%-90% of the bricks produced in a Zigzag Kiln can be classified as Class-1 bricks. For a kiln producing 50 lakh bricks per year, this means an additional 10-15 lakh Class-1 bricks. Class-1 bricks get higher price in the market and are easier to sell.

How much reduction in air pollution (suspended particulate matter [SPM] emissions) is possible by shifting from an FCBTK to a Zigzag Kiln?

Typically, SPM emissions from FCBTKs are in the range of 150–1250 mg/Nm³, while SPM emissions from Zigzag Kilns are in the range of 30–250 mg/Nm³. There is a visible difference in the colour of smoke. While the colour of smoke in an FCBTK is often black, the smoke from a properly constructed and operated Zigzag Kiln is light grey in colour.