碟式离心机应用于泥水分离的试验研究

Experimental Study on Slurry Separation by Disc Centrifuge

近年来随着城市轨道交通的发展,泥水平衡盾构技术得到了广泛的应用。为了提高泥水的分离效率,增加水的循环使用率,减少废水排放,文章使用碟式离心机进行泥水分离试验,该种类型的离心机具有大量的碟片,可降低沉降高度、增大沉降面积。试验中首先进行清水和粘土、细砂的混合液分离试验,分析分离前后混合液的浊度、物料的去除率,然后通过配置盾构用泥浆并与粘土、细砂混合后进行分离,分析分离前后物料浊度、粒度并对添加盾构泥浆前后的混合液稳定性进行测定。研究结果表明:碟式离心机适用于泥水盾构的泥水处理,对粒径40~60μm的粒子去除效果良好;去除率均在90%以上且分离效果与分离时间呈正比;分离后物料的稳定性增强、浊度降低,中位径D50显著变小。研究成果为实现泥水高效分离提供了理论与实践基础。

With the development of urban rail transit in recent years, slurry shield technology has been widely used. To improve the efficiency of slurry separation, the water cycle utilization rate is increased and wastewater is reduced. A slurry separation test is conducted by a disc centrifuge, which has many discs to reduce the sedimentation height and increase the sedimentation area. At first, a separation test of a mixed liquid of water, clay and fine sand is carried out to analyze the turbidity and removal rate of the mixed liquid before and after separation, then a separa- tion of the mixed liquid composed of the shield slurry, clay and fine sand is performed to analyze the turbidity and granularity of the mixture before and after the separation, and the stability of the mixed liquid is tested before and af- ter adding the shield slurry. The results show that the disc centrifuge is very effective for the slurry separation and works well in respect to particles with a grain size of 40 μm to 60 μm; the average removal rate is above 90% and the separation effect is proportional to time; and after separation by disc centrifuge, the material stability is enhanced and the turbidity is decreased, and the median size Ds0 is decreased significantly. The research results provide a theoretical and practical foundation for higher efficiency of slurry separation.