Abstract:

In this paper, two structural models of three-phase horizontal screw decanter centrifuge for oil-water sand separation are proposed first. Through CFD numerical calculation, it is found that the structure model of three-phase decanter centrifuge with axial pipe flanges for fluid discharging has certain defects that there is sand blocking in pipe flanges and lower separation efficiency. Through the improved design, the structure model with adjustable overflow baffles is available. The model has high oil recovery rate and relatively drier solid phase, which is suitable for oil-water solid separation. The model also has several different fluid discharging methods such as water and oil-sand separation, oil-water and sand separation, or oil and water-sand separation. The three-phase decanter centrifuge was processed and manufactured, and an experimental platform was built. Through experimental research, it is found that the three-phase decanter centrifuge with this structure has a higher separation efficiency for the oil phase, and the distance from the center of the baffle arc to the center axis of the drum has different effects on the separation efficiency.

Key words: decanter centrifuge, three phase separation, centrifugation, multiphase flow, computational fluid dynamics, numerical simulation, separation efficiency

摘要：

首先提出了用于油水砂分离的三相螺旋沉降式离心机两种结构模型。通过CFD数值计算发现，带有轴向管法兰的三相卧螺离心机结构模型存在一定的缺陷，即管法兰上有堵砂的情况出现且分离效率较低。通过改进设计，可调溢流挡板的三相卧螺离心机结构模型是可取的。该模型有较高的油相回收率，且固相也相对较干燥，适用于油水固三相分离。该模型还具有水与油砂分离、油水与砂分离或油与水砂分离等几种不同的排液方式。对此三相卧螺离心机加工制造，搭建实验平台，通过实验研究发现，此种结构的三相卧螺离心机对油相的分离效率较高，挡板圆弧中心到转鼓中心轴的距离对分离效率有着不同的影响。

关键词: 卧螺离心机, 三相分离, 离心分离, 多相流, 计算流体力学, 数值模拟, 分离效率