Method of increasing the CO2 and H2O content of the exhaust gas and rotary tubular kiln plant for carrying out the method

摘要

In a rotary tubular kiln 1 which is directly heated, by replacing some of the combustion air, in particular some of the excess combustion air, the flue-gas composition is influenced by the outflowing flue gas in such a way that the proportion emitting the heat radiation, such as, for example, the CO2 and H2O proportion, is increased. This measure results in a reduction in the length of the rotary tubular kiln 1 and in a reduction in the fuel demand. The additional constructional outlay is small and is restricted to a feed line 3 to a mixing chamber 4 in which the recycled flue gas is intermixed with the air heated in the cooler 5 for the hot kiln material upstream of the direct heating device 6. IMAGE