关键词:

旋风分离器, 旋涡尾端, 压力测量, 信号分析

Abstract:

The pressure signals at different axial and radial positions of a cylinder-on-cone cyclone were measured and analyzed by the fast Fourier transform（FFT）.The vortex end of the cyclone was also visualized with red ink tracer.The results show that the wall pressure keeps stable in the cylinder and decreases gradually in the cone.The pressure values are almost same at different azimuths，indicating an axisymmetrical wall pressure profile in the cyclone.However，in the upper part of dipleg，the wall pressure suddenly falls，becomes non-axisymmetrical，and comes to the minimum at about 270° azimuth.In the lower part，the wall pressure rises rapidly and returns to axisymmetry.The vortex end is bended to the wall and turns around in this region.It is considered as the evidence of the vortex end.The position determined by the pressure measurement is close to the position of rotating ring observed in the tracing experiment.It is also found that the frequency of inner vortex is different from that of outer vortex when the inlet gas velocity is larger than 5 m·s^-1.The inner vortex flow fluctuates stronger and faster than its outer partner and the frequency increases with the inlet velocity resulting from the increase in turbulence intensity，while the frequency of outer vortex keeps invariant.In the vortex tail zone，the vortex breaks and the inner vortex fluctuation is involved in the wall pressure signal.Therefore，the position and dynamic characteristics of the vortex end can be well identified from the pressure measurement.The measurement can provide some experimental basis for assessing the relation of natural vortex length.

Key words:

旋风分离器, 旋涡尾端, 压力测量, 信号分析