卧式螺旋沉降离心机广泛应用于污泥脱水领域,其结构参数、操作参数以及物料性质均会对脱水效果造成影响。污泥脱水前对污泥进行调质非常重要,国内外广泛使用的污泥调质技术对污泥脱水特性具有极大的影响。为提高卧螺离心机在进行污泥脱水时的分离效果,针对卧螺离心机的基础理论、结构特点和污泥调质技术进行研究。运用FLUENT软件中的RSM模型和DPM模型对卧螺离心机内的三维流场进行计算流体力学(Computational fluid dynamics,CFD)数值模拟,分析卧螺离心机的结构参数、螺旋以及污泥调质技术对离心脱水效率的影响。研究结果表明,增加离心机的长径比可以改善固-液分离效果,同时污泥黏度的降低也有利于固-液分离;考察到螺旋的存在会对离心机分离效率产生显著影响。
The horizontal decanter centrifuge is widely used in the process of sludge dewatering, the dewatering efficiency of which is significantly influenced by structural and operating parameters, as well as material properties. Sludge modification is very important for sludge dewatering, and it has a greatly influence on sludge dewatering characteristics. The basic theory and the structural features of centrifuge and sludge modification technology are studied for the separating efficiency. The three-dimensional flow field in the centrifuge of structural parameters and spiral, and sludge modification on the dewatering efficiency are investigated numerically by using computational fluid dynamics(CFD) software FLUENT. The results show that improvement of separation efficiency can be achieved by not only increasing the length-diameter ratio, but also decreasing the sludge viscosity. In addition, the centrifuge with spiral or not with spiral has large impact on the simulation result, which should be noticed in the investigation.