Experimental Study On The Formation Characteristics Of Cenosphere Influenced By Combustion Atmosphere

In recent years, the lower-nitrogen combustion developed due to the requirement of denitration is being vigorously promoted. The technology has many advantages, such as:widely adaptable coals, reducing the denitration investment, no running cost, cost effective and optimizing boiler combustion performance. However, the actual operation shows that the boiler can produce much microsphere been difficult to remove by deduster under low nitrogen combustion atmosphere. More and more stringent environmental regulations and a growing awakening environmental awareness prompted us further in-depth study of the coal combustion process of fine microsphere generated.This article describes a systematic study about an Indonesian coal that burned in a power plant NOx emission and microsphere generation under air staged combustion technology. I completed a variety of test in a drop tube furnace. The use of XRD、 SEM and flotation methods are described in detail whether staged combustion, excess air ratio and temperature affect the fly ash particles in phase and morphology.Firstly, the article researchs the experiments coal s NOx emission rules in various conditions under an air staged combustion drop tube furnace. No air staged combustion test shows NOx emission increased with excess air ratio, but the extent of increase is much little. The staged combustion test shows the bedstand can achieve staged combustion of pulverized coal, but the NOX reductions through using this technology is not obvious.Secondly, the article researchs the impacts of amount of grading air on microsphere generation during the high-ash content coal combustion. The change of the excess air ratio has had no discernible effect on amorphous vitreous and quartz content in fly ash. At 1500℃, the cenosphere shape is globe, whether or not with staged combustion and the variation of excess air ratio. Cenosphere yield increases when the excess air ratio of grade wind increases and reaches a maximum when the total excess air ratio is 1.3. Under the same excess air ratio, staged combustion yield is more than the no staged combustion.Finally, the article researchs the impacts of combustion temperature on microsphere generation. With the rise of the combustion temperature, the quartz content in fly ash decreased, the content of amorphous vitreous did not change significantly. Particle morphology became progressively round with increasing temperature. when the combustion temperature is between 1300～1420℃, Cenosphere yield changes little. Between 1430～1500℃, with the rise of the combustion temperature, Cenosphere yield rising sharply.