Conclusions 98

In this work, solids holdup of FCC particles with a Sauter mean diameter of 67 µm and a particle density of 1877 kg/m3 _{are measured by an alternative image calibration method}

and the optical fiber probe respectively. Both methods are taken in the riser of a rectangular CFB with a cross section of 0.019×0.114 m2 _{and at two axial positions (5.33}

and 3.60 m) under different operating conditions with Ug and Gs in the range of 3.0-12.0

m/s and 50-150 kg/m2_{s, respectively.}

Using the image calibration method, the obtained radial distribution profiles of the solids holdup exhibit similar trends with that of previous research, which reflects the feasibility of the newly developed method. The direct comparing of solids holdup data obtained between the image calibration method and the optical fiber probe under identical operating conditions shows excellent agreement, which clearly verifies the accuracy of the image calibration method.

Further comparing between the image calibration method results from the current study and the measurement results of the optical fiber probe from other researchers also shows an excellent agreement under the same operating condition. These comparisons verify that the image calibration methods is a good alternative method in measuring the solids holdup in the rectangular riser.

Acknowledgements

The authors acknowledge with gratitude the financial support of the National Science and Engineering Research Council of Canada (NSERC) and the China Scholarship Council (CSC).

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