Main features of Fixed Chimney Kiln 3
In addition to air leakage in flue ducts, the air also leaks through –the cloth damper (tripal) provided to seal one end of the kiln; through
openings in the ash insulation and cracks in the wicket walls (please refer figure 5). It is important to plug all these points and keep the air
leakage to a minimum.
The resistance offered by the brick setting depends both on the density of setting as well as the length of the setting (number of chambers in
operation). At present in most of the kilns (kilns in Calcutta area) the length of the cooling zone is maintained at 200 -250 ft which is more
than desired and setting is also tighter. As a result the flow rate of air through the kiln is less and the fire travel rate is generally not more
then 5-6 m/ day. To reduce energy consumption, the length of the cooling zone should be reduced to 150 -180 ft (figure 6) and the setting
should be made more open so that a fire travel rate of at least 8 m per day is achieved.