新型滤筒除尘器性能的数值模拟

Numerical Simulation on Performances of a New Type Filter Cartridge

以常规滤筒和内部增加锥体结构的新型滤筒为研究对象,建立其三维几何模型,采用k??双方程湍流模型对其过滤与清灰性能进行数值模拟.结果表明,在相同风量下,常规滤筒的进出口压差为170 Pa,而新型滤筒的进出口压差为120 Pa,这是由于新型滤筒内部增加了锥体结构,总过滤面积增大,过滤风速小于常规滤筒的过滤风速,过滤效率提高,压差减小;清灰时常规滤筒的侧壁压力峰值沿滤筒方向增加,但上部压力峰值为?100 Pa,底部压力峰值为16000 Pa,上部过小而底部过大对清灰不利;新型滤筒的侧壁压力峰值沿滤筒方向自上而下从3500 Pa增至4000 Pa,滤筒清灰效果有明显改善,可延长其使用寿命.

The three-dimensional geometric models of conventional filter cartridge and new type one with pyramidal structure were established, and their performances of dust filtration and cleaning simulated with k-ε model. The results show that the pressure difference between the inlet and outlet of conventional filter cartridge is 170 Pa, and the new filter 120 Pa under the same flow rate. The difference can be attributed to the increase of the area of new type filter cartridge with pyramidal structure and the filtration velocity is smaller than that of conventional filter, leading to the increment of filtration efficiency. The pressure peak of conventional filter cartridge along the length direction of filter cartridge increases, but the upper pressure peak is ？100 Pa and the bottom pressure peak 16 000 Pa. The upper pressure peak is too small and the bottom pressure peak too big, which is disadvantageous to the filter cartridge. The pressure peak of new type filter cartridge also increases along the length direction of filter cartridge changing from 3 500 to 4 000 Pa, the pressure peak is moderate and the distribution the pressure uniform. So the efficiency of dust-cleaning system can be significantly improved, and the service life of the filter cartridge prolonged.