市政污泥热电厂循环流化床协同焚烧技术验证研究

Validation of municipal sludge incineration in circulation fluidized bed boiler from a thermal power plant

以市政污泥为原料,利用某热电厂循环流化床锅炉进行协同焚烧验证研究.试验表明,循环流化床锅炉热电厂污泥协同焚烧的泥煤质量比可在0～0.3之间根据用户需求调节,炉膛燃烧温度>850℃,烟气停留时间2.59s,符合《生活垃圾焚烧污染控制标准》(GB18485—2001)中850℃烟气停留时间>2s的要求;脱硫塔烟气进出口NOx、SO2浓度低于锅炉未掺烧污泥前浓度,粉煤灰重金属含量低于《农用粉煤灰中污染物控制标准》(GB8173-87)中粉煤灰农用标准限值(在酸性土壤上:Cd5mg·kg-1,Pb250mg·kg-1),粉煤灰烧失量满足掺混前Ⅱ级品质要求.因此,循环流化床锅炉污泥协同焚烧可有效解决当地城镇污水厂污泥出路,最终实现污泥妥善、安全处置需求.

Incineration of municipal sludge with coal was investigated in a circulation fluidized bed from a thermal power plant.The results show that sludge /coal mass ratio was adjustable between 0 and 0.3 in the circulating fluidized bed boiler according to customer demand.The operating condition of combustion temperature was over 850 ℃ and flue gas residence time was 2.59s under the conditions,which complied with the requirement of the flue gas residence time （ 2 s） at 850 ℃ as prescribed in the pollution control standard on the municipal solid waste incineration （GB18485—2001）.The smoke concentrations import and export of the desulfurization tower were lower than the pre-mixing sludge concentration.The heavy metal content in fly ash met the standard limit （Cd 5 mg·kg-1,Pb 250 mg·kg-1） in acid soil of control standards of pollutants in fly ash for agricultural use,and the fly-ash burning-loss amount met the Ⅱgrade quality requirements.Therefore,incineration of municipal sludge in the circulation fluidized bed was an effective way in municipal sludge treatment,which would finally achieve the safe disposal of sludge from local urban sewage plant.