酸化蒸发法对亚微米细颗粒物团聚和脱除性能的影响

Effect of acidification evaporation on agglomeration and removal of submicron fine particulate matter

为了更好地反映燃煤粉尘的脱除效果,通过烟气温湿酸灰耦合试验台,采用酸化蒸发法,测试了模拟烟气在降温过程中耦合增湿、酸化及改变飞灰颗粒物浓度的不同工况下,除尘前后模拟烟气中颗粒物的脱除效率及粒径的变化,进行了亚微米细颗粒物的团聚及脱除性能试验研究。将绝对湿度4.20%、飞灰颗粒物质量浓度72.362μg/m^(3)、温度120℃的模拟烟气,降温冷凝到极限80℃工况的过程中,调节烟气湿度、酸度、飞灰颗粒物质量浓度分别为8.90%、4.183×10^(-6)、385.27μg/m^(3)的最佳工况下,亚微米细颗粒物体积分布平均粒径由20.370μm团聚为51.355μm;经脱除后,脱除效率达到99.63%,个数分布平均粒径由1.769μm减小至0.869μm,亚微米细颗粒物有效脱除。试验结果表明,烟气的温湿酸灰耦合蒸发,改善了飞灰颗粒物对雾化液滴的吸附,增强了亚微米细颗粒物间的相互黏附,加剧了亚微米细颗粒物的团聚,形成了被除尘器高效捕捉的团聚体粒径,促进了亚微米细颗粒物的脱除。

In order to further reflect the removal effect of coal dust,through the flue temperture coupling of wet acid ash experimental platform,the dust-containing flue gas dust removal efficiency and particle size of submicron fine particles in simulated flue gas before and after dust removal were tested under the different conditions of cooling,coupling humidification,acidificationan and the changes of the concentration by the acidification evaporation method.The agglomeration and removal performance of submicron fine particles matter were studied.When the temperature of simulated hot dust-containing flue gas is 120℃,the absolute humidity is 4.20%,the concentration of ash particles matter is 72.362μg/m^(3),during the process of cooling and condensing to the limit of 80℃,the humidity,acidity and the particle concentration of fly ash are adjusted to 8.90%,4.183×10^(-6),385.27μg/m^(3)under the optimum working condition,and the mean diameter of the volume distribution of submicron fine particles agglomerates from 20.370μm to 51.355μm;After the dust collector,the efficiency of dust collector reaches 99.63%,the submicron fine particles are effectively removed,the mean diameter of the number distribution is reduced from 1.769μm to 0.869μm.The experimental result shows that the adsorption of aerosol droplets by fly ash particles is improved,the mutual adhesion between submicron fine particles is enhanced,the agglomeration of submicron fine particles is intensified,and the agglomerate particle size is effectively captured by the dust collector,and the removal and enhancement of submicron fine particles are promoted after flue gas vaporized by temperature coupling humidity acid ash.