What are the Different Kiln Technologies?
Brick making is an ancient technology with many of the kiln technologies available today being the same as they were thousands of years ago.
The following table summarises the kilns currently used around the world:
|Clamp Kiln||An ancient primitive technology. This kiln is highly polluting, inefficient fuel use and labour intensive. Widely used in Asia, Latin America, Africa. Operate only in intermittent mode. HZZK replaced the South African Clamp kiln with a clean brick firing technology which brought an 82% fuel saving as compared to the South African Clamp Kiln.|
|Hoffman Kiln||Invented in Germany 1858. Designed with large, permanent masonry arches and expensive tall chimney approx. 30 metres tall. Kiln must operate in continuous mode.|
|Bull’s Trench Kiln – Movable Metal Chimney||Workers move hot metal chimneys as the fire moves through the kiln. There are very high emissions and hazardous working conditions. Now generally banned.|
|Fixed Chimney Bulls Trench Kiln (FCBTK)||Prevalent in South Asia (India, Bangladesh, Pakistan and Nepal) where pressure for low emission technology is mounting, due to highly polluted air and related health concerns. The FCBTK has a tall, expensive 30 metre brick chimney and is highly polluting. Used in the ‘dry’ season only. Operates only in continuous mode.|
|Tunnel Kiln||Highly mechanized and automated processes, expensive to construct, requires highly skilled workers, dependent on a reliable electricity supply.|
|Vertical Shaft Brick Kiln (VSBK)||Introduced into Asia early 1970’s. Has a limited production output & is very ‘clay specific’.|