Aerodynamics and combustion in a fluidized bed furnace chamber

摘要

In determining the flow patterns of an entering fluid in a particular space, it is advantageous to separate th fluid into segments of different velocities. This is possible with, for example, the burning of fossil fuels by controlling he fuel/oxidant mixing ratio to decrease the emission of pollutants. In contrast with firing techniques developed earlier, which wer basically concerned with the problems of stable ignition and the burn-out times of fuel, contemporary firing methods need to consider the necessity for decreasing emissions of polluting combustion products. For example, during coal-firing, the quantity of nitrogen oxides originating from the nitrogen in the fuel can be considerably decreased by establishing zones which lack air during certain firing phases, that is, by introducing different stages for feeding of air and fuel, thus controlling the mixing ratio and thereby reducing emissions.