4 200 r/min卧螺离心机转鼓和螺旋输送器结构参数优选

为满足钻井液高效分离的需求,亟需研制高转速卧螺离心机。针对中高转速卧螺离心机转鼓破裂、螺旋输送器叶片断裂的技术难题,以3 200 r/mim离心机的转鼓和螺旋输送器结构参数为基础,利用有限元法分析转速提高到4 200 r/mim时卧螺离心机转鼓和螺旋输送器的最优参数。为提高计算精度,首先对转鼓和螺旋输送器的网格进行无关性分析,推荐转鼓和输送器的网格数分别为250 000和600 000。另外,以应力变形和安全系数为评判依据,利用有限元法分析转鼓壁厚、螺旋叶片螺距、厚度和倾角的结构参数,得出螺距、厚度为螺旋输送器的敏感参数,建议优选螺距为116 mm、厚度为7.5 mm,其余结构参数影响不是特别明显。建议根据螺旋输送器的振动特性和固液分离特性进一步优选结构参数,为高速离心机研制提供参考。

Optimization of the Structure Parameters of the Drum andScrew Conveyor for 4200 r/min Decanter Centrifuge

In demand for efficient separation of drilling fluid, it is urgent to develop a high-speed decanter centrifuge. Aiming at the technical problems of the middle or high speed decanter centrifuge, like the rupture of drum and the fracture of screw conveyor blades, based on the structural parameters of the drum and screw conveyor of the 3 200 r/mim centrifuge, the finite element method was used to analyze the optimal parameters of drum and screw conveyor for the speed of 4 200 r/min. In order to improve the calculation accuracy, the grid independence of drum and screw conveyor was analyzed, and the final recommended grid number of drum and screw conveyor was 250 000 and 600 000 respectively. In addition, based on the evaluation of stress, deformation and safety factor, the finite element method was used to analyze the structural parameters of the drum wall thickness, screw blade pitch, thickness and inclination angle, and the blade pitch and thickness were the sensitive parameters of the screw conveyor. The preferred blade pitch is 116 mm and the thickness was 7.5 mm, and the influence of other structural parameters was not particularly obvious. It is suggested that the structural parameters should be further optimized according to the vibration characteristics and solid-liquid separation characteristics of the screw conveyor, whicn provide a reference for the development of high-speed centrifuges.