Multiscale analysis of solids flux signals measured in a high density circulating fluidized bed using wavelet transformation

Kirbas G., Ellis N.

8th International Conference on Circulating Fluidized Beds, Hangzhou, China, 10 - 13 May 2005, pp.75-82 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Hangzhou
  • Country: China
  • Page Numbers: pp.75-82
  • Middle East Technical University Affiliated: Yes


In order characterize the annulus thickness in a high density circulating fluidized bed, local instantaneous solids fluxes are measured using a three-fibre optical probe in a 0.20 m diameter, 5.9 m tall CFB riser operating at superficial gas velocity of 6 m/s and solids circulation flux of 330 kg/m(2)s, with FCC particles of mean diameter 70 mu m and density 1700 kg/m(3) as the bed material. Measurements obtained at three axial levels (z = 0.76, 1.27, 3.10 m) and six radial locations (r/R = 0.94, 0.88, 0.75, 0.50, 0.25, 0.00) are analyzed using wavelet transformation, resulting in performing a multiscale analysis of the decomposed signal. The results indicate a clear distinction between the dense suspension upflow (DSU) and fast fluidization regimes observed in the bottom and top section of the riser, and the radial uniformity of the wavelet energy in the DSU regime.