污泥管道输送沿程阻力影响因素分析

Influencing factors of on-way resistance in sludge transportation pipelines

摘要:

为识别污泥管道输送过程中沿程阻力的变化及影响因素,以长春市某污水处理厂浓缩后储泥池污泥为对象,考察污泥质量分数、温度、减阻剂用量、平均流速等因素对污泥管道输送过程沿程阻力的影响效应,并进行机理分析．结果表明:污泥质量分数对沿程阻力影响显著,质量分数分别为2.38％,3.94％,5.39％时,沿程阻力随质量分数增加而增大,输送过程中控制污泥质量分数小于2.38％可达最佳输送效果;温度对沿程阻力有显著影响,适当升温或采取保温措施有利于减小沿程阻力;减阻剂用量对沿程阻力影响显著,用量过低减阻效果不明显,用量过高会降低减阻效果,实际使用中需测算减阻剂最佳用量,污泥质量分数为3.94％时的减阻剂最佳用量为0.588％;污泥管道输送应在平均流速略高于不淤流速的紊流条件下进行,质量分数为2.38％,3.94％,5.39％的3种污泥的输送平均流速分别为1.35～1.5,1.20～1.30及1.10～1.20 m/s．

Abstract:

To understand the changes and influencing factors of on-way resistance in sludge transportation pipelines, the influence effects of sludge concentration, temperature, drag reduction agent dosage and mean velocity on on-way resistance were investigated and the mechanisms were analyzed using the sludge concentrated in storage basin in a wastewater treatment plant in Changchun City as object. The results showed that the sludge concentration significantly affected the on-way resistance, and when the concentrations were 2.38％, 3.94％ and 5.39％, the resistance increased as the concentration increased, therefore, to achieve the best conveying effect, the sludge concentration should be controlled less than 2.38％ during transportation process. Temperature has significant effect on the on-way resistance, therefore, appropriate heating or insulation measures will be beneficial to the reducing of resistance; Drag reduction agent dosage significantly affects the on-way resistance. The drag reduction effect will both be reduced when the drag reduction agent dosage is too low or too high, therefore, the drag reduction agent optimum dosage should be calculated in the actual use, and the best dosage for 3.94％ concentration sludge is 0.588％; The mean transportation velocity of sludge should be slightly higher than the non-deposition velocities under turbulent conditions which are determined to be 1.35-1.45 m/s,1.20-1.30 m/s and 1.10-1.20 m/s for 2.38％, 3.94％ and 5.39％ concentration sludge respectively.