Tunnel kiln - has combustion chambers in enlarged kiln mantle at the firing zone or at the transfer from the preheating zone

摘要

Heated combustion chambers are within the enlarged kiln mantle, of a tunnel kiln, at the firing zone or at the transfer between the preheating and firing zones. They have openings for gas inlet and outlet to take in the colder fuel gas for the kiln gas from the entry to the kiln. The gas channels run within the enlarged kiln mantle. Heat exchangers lie along the longitudinal direction of the kiln within the kiln mantle, on both sides of the preheating zone at its lower temp. section. They cool the hot kiln exhaust gases for lateral recirculation through fans. The heat exchangers are pitched at an angle to the axis of the firing channel, to give one or more V-shaped structures. At least part of the exhaust gas is passed to the inner combustion chambers, on its path through the heat exchangers in the enlarged mantle section of the preheating zone to the exhaust chimney. ADVANTAGE - The system does not require special thermal insulation provisions.