有机污染物对石灰石-石膏法脱硫塔浆液起泡影响研究

发布时间：2019-02-13 00:16

【摘要】：石灰石-石膏湿法烟气脱硫运行中,常会出现吸收塔浆液起泡溢流现象,吸收塔内循环浆液起泡后,液位计显示液位远远超过真实液位,再加上其他因素影响,塔内循环浆液液位波动明显变大,从而导致吸收塔间歇性溢流。随着起泡现象的加重,吸收塔循环浆液溢流量过大,浆液不能通过溢流管及时排出,泡沫就会涌进原烟气烟道、增压风机,将带来脱硫效率降低、石膏品质下降、增压风机的运行安全受到威胁等问题,影响了脱硫系统的稳定和安全运行。吸收塔浆液起泡溢流现象不仅会降低脱硫效率,污染周围环境,而且还会造成周围设备的腐蚀,严重时整个脱硫系统将停运并置换吸收塔内的浆液。本文对吸收塔浆液溢流的现象、危害、原因分析等进行了分析,主要研究了有机污染物对浆液起泡的影响,通过浆液中的化学需氧量(COD)、总有机碳(TOC)和总碳(TC)来研究浆液起泡的影响,得出以下结论:1.浆液中的COD含量严重影响浆液的起泡,一般未起泡时的浆液COD低至几十毫克每升,而起泡后的浆液COD值都处于300-600mg/L;浆液COD不是唯一影响浆液起泡的因素,消泡剂的添加只是在一定程度上降低浆液中的COD值而不是明显的降低;起泡有一定的时间蓄积性,消泡剂的加入对消泡在一定程度有滞后性。浆液COD中的一部分是由石灰石浆液COD而决定的;脱硫系统一直在不停地运转,浆液中COD在不停的蓄积。2.吸收塔浆液总体的TOC在80 mg/L～310 mg/L之间,通过分析无法得出浆液TOC的值与浆液起泡的关系,可能的原因有加入的消泡剂影响了浆液TOC的值。相关性分析得浆液中的COD与TOC有中等相关性,浆液消泡剂添加量既浆液的起泡程度的影响因素不止浆液中的TOC,也可得消泡剂的添加只是在一定程度上降低浆液中的TOC值。吸收塔浆液TOC主要来源于处理的废气中夹带的未完全燃烧的有机颗粒。3.吸收塔浆液TC总体在113 mg/L～353.3 mg/L之间,浆液TC与消泡剂的添加量总体趋势图呈现一致性。二号吸收塔浆液COD、TOC和TC的值整体比一号吸收塔浆液的COD、TOC和TC值高相同;故可得出浆液中的COD、TOC和TC对浆液起泡是有一定的影响。吸收塔浆液TC大部分来源于烟气中的未完全燃烧颗粒,少部分来源石灰石浆液。
[Abstract]:In the operation of limestone gypsum wet flue gas desulphurization, the phenomenon of bubbling and overflow of slurry in absorption tower is often observed. After the circulating slurry in absorption tower is bubbled, the liquid level is far higher than the real liquid level, which is influenced by other factors. The liquid level fluctuation of circulating slurry in the tower increases obviously, which leads to the intermittent overflow of the absorption tower. With the aggravation of foaming phenomenon, the overflow amount of circulating slurry in absorption tower is too large, the slurry can not be discharged through the overflow pipe in time, the foam will pour into the original flue gas flue, pressurized fan, will bring about the reduction of desulphurization efficiency and the decline of gypsum quality. The operation safety of turbofan is threatened, which affects the stability and safety of desulfurization system. The phenomenon of bubbling and overflow of slurry in absorber will not only reduce the efficiency of desulfurization and pollute the surrounding environment, but also cause corrosion of the surrounding equipment. In serious cases, the whole desulfurization system will be shut down and the slurry in the absorber will be replaced. In this paper, the phenomenon, harm and cause analysis of slurry overflow in absorber are analyzed. The influence of organic pollutants on the bubbling of slurry is mainly studied. The chemical oxygen demand (COD),) in the slurry is studied by means of chemical oxygen demand (COD),). Total organic carbon (TOC) and total carbon (TC) were used to study the effect of slurry foaming, and the following conclusions were obtained: 1. The COD content in the slurry has a serious effect on the bubbling of the slurry. The COD of the slurry is as low as tens of mg / liter when it is not bubbling, while the COD value of the slurry after bubbling is in the range of 300-600mg / L; The addition of defoamer only reduced the value of COD in the slurry to a certain extent, but not obviously. Foaming has a certain time accumulation, defoamer has a lag in a certain extent. Part of the slurry COD is determined by limestone slurry COD; the desulphurization system has been running continuously, and the COD in the slurry is accumulating continuously. 2. 2. The total TOC of the size of the absorber is between 80 mg/L~310 mg/L. The relationship between the value of TOC and the bubbling of the slurry can not be obtained by analysis. The possible reason is that the addition of defoamer affects the value of the TOC of the slurry. The correlation analysis shows that the COD in the size has a moderate correlation with TOC, and the amount of defoamer not only affects the degree of foaming of the slurry, but also the addition of the defoamer can reduce the value of TOC in the size to a certain extent. The absorption column slurry TOC is mainly derived from incomplete combustion organic particles entrained in the treated waste gas. 3. The total TC of the absorber slurry is between 113 mg/L~353.3 mg/L, and the overall trend chart of the addition of TC and defoamer is consistent. The values of COD,TOC and TC in No. 2 absorber are higher than those of COD,TOC and TC in No. 1 absorber, so it can be concluded that the COD,TOC and TC in the slurry have a certain influence on the bubbling of the slurry. The absorption column slurry TC mostly comes from incomplete combustion particles in flue gas and a few from limestone slurry.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X773

【相似文献】