燃煤电厂冲灰水系统防垢技术研究

STUDY OF SCALE INHIBITION IN ASH WATER OF POWER STATION

研究了粉煤灰在水中的溶解行为,结果表明:(1)灰水混合液在不同转速下搅拌20m in后,pH值、电导率、碱度、Ca2+浓度等指标不再明显变化;(2)向混合液中加入Na2CO3可有效降低Ca2+的浓度,而且Na2CO3的投加量与Ca2+浓度之比(摩尔比)为0.8∶1时,混合液中Ca2+即可降至15mg.l-1以下;(3)向灰水分离后的清液中通入CO2(6m in)可将全部碱性物质转化为HCO-3,并溶入大量CO2,用此水冲灰可达到与投加Na2CO3相似的效果.

The dissolution behavior of coal ash was studied, and in order to reduce concentration of Ca^2＋ in composite solution of ash and water, Na2CO3 was added. CO2 was aerated in the solution after ash was separated, and new ash was dissolved again. It was found that ： 1 ） pH, conductance, alkalinity and Ca^2＋ achieved stability after composite solution was stirred for 20min ; 2） Concentration of Ca^2＋ in composite solution was reduced by addition of Na2CO3, and when the mol ratio of Na2CO3 and Ca^2＋ was 0. 8： 1, concentration of Ca^2＋ was reduced to less than 15 mg · l^-1; 3） All alkalinity was converted to HCO3-, and CO2 was dissolved in the solution in which ash was separated after CO2 was aerated for 6min. The effect of CO2 on ash dissolution resembled of Na2CO3.