城市排水管网中通沟污泥沉降堆积行为及数学模型研究

Experimental and mathematical modeling studies on the sedimentation and accumulation behavior of sewer sludge in urban drainage networks

采用搭建的管网污泥沉降堆积设备平台展开研究,通过统计分析污泥在管道中的沉积平衡高度反应出各个影响因素的作用效果。结果表明,在影响因素不变的情况下,经过一段时间后,管网污泥的沉积会达到固定的平衡高度。当坡度从0.5°增加至1°和1.5°时,平衡高度从41.62 mm降低到36.37 mm和31.85 mm,说明污泥沉积平衡高度与坡度负相关。当质量分数从0.5%增加至1%和3%时,平衡高度从30.56 mm升高到36.37 mm和39.69 mm,表明管网污泥沉积平衡高度与质量分数成正比。当流量从0.8 L/s降至0.6 L/s和0.4 L/s时,平衡高度从38.74 mm升高到41.62 mm和46.56 mm,证明管网污泥的沉积平衡高度与污水的流量(流速)成反比,这可能是由于污水流量(流速)越大则伴随的冲刷强度越大。最后,基于试验结果和理论分析,建立并优化了污泥沉积平衡高度和各个影响因素间的数学模型,可快捷有效获取污泥沉积平衡高度,为管网养护提供基础数据。

In this paper,a self-built experimental platform was used to investigate the sedimentation and accumulation law of sludge,the effect of each influencing factor was revealed by statistically analyzing the deposition equilibrium height of sludge in pipes.The experimental results showed that the deposition of pipe sludge would reach a fixed equilibrium height after a period of time under constant influencing factors.When the pipe inclination angle increased from 0.5° to 1° and 1.5°,the equilibrium height decreased from 41.62 mm to 36.37 mm and 31.85 mm,indicating that the equilibrium height of sludge deposition was negatively correlated with the pipe inclination angle.When the mass fraction increased from 0.5% to 1% and 3%,the equilibrium height improved from 30.56 mm to 36.37 mm and 39.69 mm,demonstrating that the equilibrium height of sludge deposition was proportional to the mass fraction.When the flow rate decreased from 0.8 L/s to 0.6 L/s and 0.4 L/s,the equilibrium height enhanced from 38.74 mm to 41.62 mm and 46.56 mm,proving that the equilibrium height of sludge deposition was inversely proportional to the flow rate and flow velocity of sewage,which may be attributed to the strong scouring intensity caused by the high flow rate and flow velocity of sewage.Lastly,based on the experimental results and previous theories,this study established and optimized the mathematical model between the equilibrium height of sludge deposition and influencing factors,which can quickly and effectively obtain the equilibrium height of sludge deposition to provide basic data for pipe network maintenance.