燃用麻家梁煤锅炉脱硫浆液中毒原因分析及治理

Reason analysis and treatment for desulfurization slurry poisoning during combustion of Majialiang coal

针对某电厂燃用麻家梁煤时脱硫浆液中毒失效的问题,进行了不同比例麻家梁煤与宁武煤田大混煤掺烧试验,通过对除尘器不同位置飞灰的成分、粒度分析发现,麻家梁煤与大混煤F,Al含量基本相同,飞灰成分无明显差异,但随麻家梁煤掺烧比例增加,飞灰粒度逐渐降低,微细颗粒所占比重逐渐上升,从而造成静电除尘器效率降低,使得更多微细粉尘进入脱硫塔,脱硫浆液中F-,Al 3+质量浓度偏高,导致脱硫浆液中毒失效。将静电除尘器改造为电袋除尘器后,解决了燃用麻家梁煤时脱硫浆液的中毒问题。但是,改造后随着掺烧麻家梁煤比例增加,电袋除尘器进出口压差的增加趋势更明显因此应适当控制麻家梁煤的掺烧比例,以控制压差的变化。

To find out the specific reason for desulfurization slurry poisoning when some power plants burn Majialiang coal,experiments about co-firing the Dahun coal with Majialiang coal of different proportions were carried out.The composition analysis and size analysis for fly ash collected from different locations of the precipitator show that,the Majialiang coal and Dahun coal has almost the same fluoride and aluminum content,their fly ash＇s composition has no obvious difference.However,with an increase in proportion of Majialiang coal in the mixture,the particle size of fly ash gradually decreased,and the proportion of fine particles gradually increased,which could cause a reduction in the efficiency of the electrostatic precipita-tor,resulting in more fine dust entering into the desulfurization tower.Thus,the fluoride and aluminum content in the desulfurization slurry increased,causing poisoning and deactivation of the slurry.After the e-lectrostatic precipitator was transformed into the electric-bag filter,the slurry poisoning problem of burn-ing Majialiang coal was successfully solved.However,when the proportion of Majialiang coal rose,the pressure difference in the electric-filter precipitator increased more significantly.Therefore,properly con-trolling the co-firing ratio fo Maj ialiang coal can keep the pressure difference within a reasonable range.