Experimental Studies Of NO_x Reduction By Reburning And Fouling And Corrosion In A Drop Tube Furnace

Pollutant NOx emission is an increasing threat to environment and human health, which becomes an urgent problem to be solved. As people pay more attention to the enviroment protection issue, it is an important task that people control the emission of NOX and study the theory of combustion of pulverized coal for low NOX emission in the field of pulverized coal burning. One of these is fuel reburning.The paper researched on the creation mechanism and control method of gas pollutants from pulverized coal-fired boilers. Especially researched on the creation mechanism and influential factors of NOx emission, and the principles to controll it. And some experimental which studies of the formation of SO2 and NOx and burnout ratio for kinds of coals and blending coals have been done in a tube furnace, The factors that influence the SO2 and NOx emission are studied ,such as the furnace temperature .excess air factors, the temperature of second wind, the ratio of the first wind and the second wind, and the quantity of coal powder etc.Coal reburning is a successful advanced technology for reducing NOx emission from utility coal-fired boilers. In this work, the experiments have been carried out to study the effect of coal rank and fineness on the NOx reduction efficiency by using an one-dimension drop-tube furnace-The minum burn-out height should be calculated to organize the coal reburning process to get a higher carbon burn-out efficiency, The analayze result show that the fine or superfine pulverized coal should be adopt in order to solve the problems of higher incomplete combustion loss and lower NOx reduction efficiency exiting in the reburningExperiments were carried out to study the NOx reduction efficiency of the SNCR(Selective no-catalystic NOx Reduction) technology using ammonia injection, A chemical kinetics simulation was also conducted to investigate the effects of the parameters on the NOx reduction efficiency. The comparison between experimental and numerical methods shows that the mixing between theammonia and the flue gas has a great effect on the NOx reduction. Large amounts of CO and less O2 lead to improving the NOX reduction efficiency.In the end, the experiments studies on slag and corrosion of slag-tap boiler which burning mixing with sodalime are carried out. The effects on the burning mixing with different ratio sodalime are discuss, such as ash-melting point, fouling velocity, the content of HC1 and SO2 in flue-gas, the ratio of chlorin in dregs. The discuss result provide a useful reference and instruction for industrial utility.