ENERGY EFFICIENCY OF DIFFERENT KILNS
The energy consumption varies signi?cantly between different types of kilns as is shown in the following table.
Overall, one can say that between 11 and 70 tons of coal is needed to ? re 100,000 bricks, or that every brick
( of 3 kg weight ) consumes between 110 to 700 grams of
coal. Most brick kilns in Asia are still operating as traditional industries with very limited investments.
Batch red clamp kilns are the most widespread kilns in rural areas and in South Asia the continuous ” Bull ‘s
Trench Kiln ” ( BTK) is very popular. It has either a moveable or a fixed chimney and is a moving kiln
whereby there moves through the brick stacked in an oval-shaped trench. Tunnel kilns are the most common kilns
in industrialised
countries and are also found in some Asian countries such
as China and Vietnam. They are usually highly mechan?ised and require substantial investments. In tunnel kilns,
the bricks move through a ” tunnel ” on a cart.