Brick kilns

My brickworks will have 4 kilns with a stack between each pair.  These kilns are of the downdraft style where the fuel (in my case coal) is fired around the sides with the heat forced up to the rounded roof then down over the green (unbaked) bricks in the center.  The hot gases then move downward though grates in the floor and into the adjoining chimney.  The coal and firing is input through the ports in the side of the kiln.  The ashes are removed through lower ports.  More modern versions of these kilns had external gas piping around the outside of the kiln with burners projecting into the kiln.

After firing, the bricks are removed from the kiln for cooling.  The type of clay and any additives, along with the method of heating determine the coloration and characteristics of the brick.  The heating process  took about two weeks per batch, plus the time for cooling and curing.

My kilns are all commercial products from two different manufacturers with some modifications and added finish.