Study on the performance of a vortex mist eliminator for improving the separation efficiency of fine particles

In the process of natural gas purification, common baffle demister has the problem of low separation efficiency and incomplete separation of fine droplets with the particle size in the range of 5–25 μm. This situation not only affects the quality of natural gas, but also causes corrosion and damage to gas equipment, and even seriously affects normal production. In order to solve these problems, we have carried out an innovative design for its structure. Based on the single‐stage baffle, vortex blades are added at the first straight plate section from the inlet and the second straight plate section in the middle to enhance the turbulent vortex degree and complexity of the flow field in this area and improve the probability of collision of small particles with the wall, thus achieving the purpose of improving the demisting efficiency. In this paper, performance of the new mist eliminator is analyzed and evaluated by means of experimental study and computational fluid dynamics (CFD) numerical simulation. The results show that when the flow rate is 3.5–5.5 m/s, total separation efficiency of the new mist eliminator for fine particles with a particle size of 5–25 μm is about 51.72%–86.13%, which is about 38.57%–55.76% higher than ordinary baffled mist eliminator. The separation efficiency of particles with a diameter of 5 μm is about 31.79%, increased about 26.15%. The separation efficiency of particles with a diameter of 10 μm is about 52.09%, increased about 37.21%. In addition, when the flow rate is 3.5–5.5 m/s, the pressure drop is increased by about 41.68–135.97 Pa. It could be concluded that the new type of mist eliminator could effectively improve the demisting efficiency of fine droplets.