Mukhopadhyay N, Bose P K
Department of Mechanical Engineering, Jalpaiguri Government Engineering College, Jalpaiguri 735 102.
J Environ Sci Eng. 2009 Oct;51(4):283-94.
Soot particulate emission reduction from diesel engine is one of the most emerging problems associated with the exhaust pollution. Diesel particulate filters (DPF) hold out the prospects of substantially reducing regulated particulate emissions but the question of the reliable regeneration of filters still remains a difficult hurdle to overcome. Many of the solutions proposed to date suffer from design complexity, cost, regeneration problem and energy demands. This study presents a computer aided theoretical analysis for controlling diesel soot particulate emission by cyclone separator--a non contact type particulate removal system considering outer vortex flow, inner vortex flow and packed ceramic fiber filter at the end of vortex finder tube. Cyclone separator with low initial cost, simple construction produces low back pressure and reasonably high collection efficiencies with reduced regeneration problems. Cyclone separator is modified by placing a continuous ceramic packed fiber filter placed at the end of the vortex finder tube. In this work, the grade efficiency model of diesel soot particulate emission is proposed considering outer vortex, inner vortex and the continuous ceramic packed fiber filter. Pressure drop model is also proposed considering the effect of the ceramic fiber filter. Proposed model gives reasonably good collection efficiency with permissible pressure drop limit of diesel engine operation. Theoretical approach is predicted for calculating the cut size diameter considering the effect of Cunningham molecular slip correction factor. The result shows good agreements with existing cyclone and DPF flow characteristics.
降低柴油机的烟尘颗粒排放是与废气污染相关的最突出问题之一。柴油颗粒过滤器(DPF)有望大幅减少规定的颗粒排放,但过滤器可靠再生的问题仍然是一个难以克服的障碍。迄今为止提出的许多解决方案都存在设计复杂、成本高、再生问题和能源需求等问题。本研究提出了一种计算机辅助理论分析方法,用于通过旋风分离器控制柴油机烟尘颗粒排放——旋风分离器是一种非接触式颗粒去除系统,它考虑了外旋流、内旋流以及在涡旋探测管末端的填充陶瓷纤维过滤器。初始成本低、结构简单的旋风分离器产生的背压低,收集效率相当高,且再生问题减少。通过在涡旋探测管末端放置连续的陶瓷填充纤维过滤器对旋风分离器进行了改进。在这项工作中,考虑外旋流、内旋流和连续陶瓷填充纤维过滤器,提出了柴油机烟尘颗粒排放的分级效率模型。还考虑陶瓷纤维过滤器的影响提出了压降模型。所提出的模型在柴油机运行允许的压降极限下给出了相当好的收集效率。预测了考虑坎宁安分子滑移校正因子影响来计算切割粒径的理论方法。结果与现有的旋风分离器和DPF流动特性吻合良好。