Experimental study of dynamic characteristics of solid holdup fluctuations in a gas-solid cyclone reactor

Local transient solid holdup signals were measured by using an optical fiber probe at different axial and radial positions in the gas-solid cyclone reactor. The chaotic time series analysis of transient solid holdup was adopted to characterize the dynamic characteristics. The maximum and minimum solid holdup indicates that the high variability of gas-solid interaction. With the increase of the gas / solid ratio, the frequency of solid holdup fluctuation increased while the mean value of amplitude decreased; besides, the level of detail in the power spectrum fluctuations increased. In the diffusion chamber, the overall Kolmogorov entropy (K entropy) and correlation dimension (Dc) were higher indicating the strong chaos characteristic of gas-solid flow. In the agglomeration chamber, higher solid holdup initially reduced gas-solid interaction, decreasing flow randomness, but a subsequent increase led to irregular particle collisions and an upturn of K entropy and Dc. In the annulus chamber, K entropy and Dc were lower around the inner wall and outer wall compared to the middle region. In the separation chamber, K entropy and Dc tended to increase and then decrease as the radial position increased. Finally, the relationship between K entropy, Dc, and time-averaged solid holdup was analyzed.