What does traditional Brick Factory like? (Part two)
Traditional Brick ovens are baking all over Iran, but the largest organizations manually brick kilns in the past
two hundred years has always been around Tehran. other cities with this kind of factory are: Isfahan -yazd-ahvaz
and gonabad .
History
The oldest discovered bricks, originally made from shaped mud and dating to before 7500 B.C. were found at Tell
Aswad, and then later in the upper Tigris region and in southeast Anatolia close to Diyarbakir. Other more recent
findings, dated between 7,000 and 6,395 B.C., come from Jericho and Catal Hüyük. In the ancient Indus Valley city
of Mehrgarh, mud bricks have been found dating to 7000 BCE. (Kenoyer 2005) Ceramic bricks were used as early as
4500 BCE in early Indus Valley cities.
Methods of manufacture
“Bricks” for building may be made from mud.
Rail kilns
In modern brickworks, this is usually done in a continuously fired tunnel kiln, in which the bricks move slowly
through the kiln on conveyors, rails, or kiln cars to achieve consistency for all bricks. The bricks often have
added lime, ash, and organic matter to speed the burning.
Bull’s Trench Kilns
In India, brick making is typically a manual process. The most common type of brick kiln in use there are Bull’s
Trench Kiln (BTK), based on a design developed by British engineer W. Bull in the late 19th century.
An oval or circular trench, 6-9 meters wide, 2-2.5 meters deep, and 100-150 meters in circumference, is dug. A
tall exhaust chimney is constructed in the centre. Half or more of the trench is filled with “green” (unfired)
bricks which are stacked in an open lattice pattern to allow airflow. The lattice is capped with a roofing layer
of finished brick.
In operation, new green bricks, along with roofing bricks, are stacked at one end of the brick pile; cooled
finished bricks are removed from the other end for transport. In the middle the brick workers create a firing
zone by dropping fuel (coal, wood, oil, debris, and so on.) through access holes in the roof above the trench.
Gallery
Notable brickworks
*The London Brick Company
*Brickworks Limited – Australian brick manufacturer
*Evergreen Brickworks