疏浚管道粗砂输送特性及最佳流态研究

Transportation characteristics and optimal flow pattern of coarse sand in dredging pipelines

在疏浚管道输送粗砂砾石等粗大颗粒时,由于粒径构成复杂、浓度和局部阻力波动较大等因素,容易造成输送效率低、淤积堵塞和施工操作困难等问题。为实现粗大颗粒物料的安全高效输送,以中值粒径0.82 mm的粗砂为研究对象,在不同浓度和流速下进行管道输送试验,对粗砂的流态、沿程阻力损失、临界流速和滑移比(输送效率)等特性进行研究,根据疏浚施工要求确定输送时的最佳流态及对应的流速区间,该流态具有不易堵塞、输送稳定性高、输送效率高和磨损较小等优点。泥沙输送特性研究成果及最佳流态确定方法对粗大颗粒的安全、稳定、高效输送具有一定的理论参考和实际应用价值。

When coarse particles such as coarse sand and gravel are transported by dredged pipelines,due to factors such as complex composition of particle size,large fluctuations in concentration and local resistance,it is easy to cause problems such as transportation efficiency,siltation blockage and difficult operation.To realize the safe and efficient transportation of coarse particle materials,the coarse sand with a median particle size of 0.82 mm is taken as the research object.To study the flow pattern,loss of frictional drag,critical velocity and slip ratio(transportation efficiency)of coarse sand,pipeline transportation experiments are carried out under different concentrations and flow rates.According to the requirements of dredging construction,the optimal flow pattern and velocity range are determined.The flow state has the advantages of not being easy block,low wear,high transportation stability and high transportation efficiency.The research results on the characteristics of mud and sand transportation and the method for determining the optimal flow pattern have theoretical reference and application value for the safe,stable and efficient transportation of coarse particles.