Fixed Chimney Bull’s Trench Kiln (FCBTK) technology is the most popular technology for production of bricks in India, Bangladesh, Nepal, and Pakistan.
The main reasons for its popularity are:
Despite its popularity, the BTK technology has several shortcomings.
The three main shortcomings of a BTK are:
A large amount of the fuel used in a BTK is not utilised fully, and hence wasted, mainly due to incomplete combustion of the fuel and heat losses from the kiln.
About 25% of the fuel used can be saved through simple measures. For a typical BTK in North India having annual production of 40–50 lakh bricks, 25% fuel wastage means higher consumption of about 100–150 tonnes of coal in a year. This means you are incurring an additional expenditure of Rs 5 lakh to Rs 15 lakh every year due to fuel wastage. This is a huge loss!
Typically, only 60% of the bricks fired in a BTK are Class 1 bricks. The remaining 40% are under‑fired, over‑fired or broken bricks.
If you are a BTK owner in North India, you are losing revenue of Rs 10 lakh to Rs 30 lakh in a year due to the high percentage of low quality bricks. Further, as the sale of low quality bricks takes much more time compared to Class 1 bricks, your inventory cost increases and your capital gets locked.
Owing to incomplete combustion of a large amount of fuel in a BTK, it produces substantial quantities of particulate matter (PM), carbon dioxide (CO2), carbon monoxide (CO), etc. All of these cause air pollution. The quantity of black smoke coming out from the chimney of a BTK gives an indication of air pollution.
The harmful effects of air pollution are felt most in the immediate surrounding areas of the kiln. High air pollution adversely affects the health of persons working in your BTK and also the health of the local population. It also adversely affects the health, growth and yield of crops, plants, and trees. Emissions of CO2 and black carbon also contribute to global warming and climate change.