脱水污泥的干化效果对污泥后续焚烧处置及资源化有重要影响。比较了生物沥浸处理后深度脱水污泥与常规脱水污泥的水分蒸发速率差异,以评价其干化效果。在此基础上,对城市污泥生物沥浸示范工程中得到的有机质含量为44%(干物质计),干基高位热值为9250kJ/kg,含水率≤32%,颗粒粒径≤8mm的污泥样品,采用小型循环流化床焚烧炉(内径600mm,高度6500mm,污泥给料量200kg/h)进行焚烧处置初步研究。结果表明,在同样干化时间下,生物沥浸后脱水污泥相对于常规脱水污泥有较快的水分蒸发速度。在保证污泥颗粒在流化床炉内达到较好的流化状态前提下,该生物沥浸污泥可以在流化床炉内实现自持焚烧,相应流化床炉温可以被恒定维持在850℃左右。焚烧后残渣热灼减率为2.36%。同时发现,污泥有机质含量、污泥含水率、污泥的颗粒破碎度、流化床布风板风量等因素共同决定着城市污泥的自持焚烧效果。此研究将为城市污泥生物沥浸后期焚烧资源化应用提供必要的参数支持及合适的运行建议。
The drying effect plays a decisive role on the subsequent incineration of dewatered sludge. The natural drying effect of bioleached dewatered sludge and conventional dewatered sludge was compared in this study. In addition, incineration experiments for dewatered sludge obtained in demonstration project were carried out in a fluidized bed incinerator (600 mm in internal diameter and 6 500 mm in height, feeding rate 200 kg/ h). The organic matter, higher heating value (d. b. ) , moisture content and particle diameter of dewatered sludge were 44% , 9 250 kJ/kg, ≤ 32% and ≤ 8 mm, respectively. The results showed that the dewatered sludge after bioleaching has the faster evaporation rate compared with conventional dewatered sludge under the same drying conditions. The sewage sludge could achieve self maintaining incineration on the basis of sludge par- ticles with a better flow state in combustor. The corresponding temperature of combustor could be maintained at about 850~C and the ignition loss content of burned residue was 2.36%. It is also found that the initial sludge organic matter content, moisture content, degree of particle size breakage and the air amount on the distribution plate determine the effect of sewage sludge incineration. This study will provide the necessary parameters and the operation propose for the dewatered sewage sludge incineration after bioleaching.