Calibration of the method to measure bubble properties in 2D fluidized beds

Non-intrusive measurement and hydrodynamics characterization of gas–solid fluidized beds: a review

“…The optical axis of the imaging system is perpendicular to the laser sheet. It is noteworthy that some CCD imaging systems employ a spot light or a strobe light instead of the laser-sheet for illumination [71,74]. High-quality images were obtained by carefully adjusting the camera (focus) and selecting the laser intensity for different operation conditions.…”

“…CCD photography in combination with digital image analysis were employed to acquire the bubble-dynamics information, including the position, dimension, hold-up, velocity and bubble-splitting occurrence [71,74,75]. The original images were processed through thresholding, indexing, filtering of false bubbles and peripheral voids as well as property recording [71].…”

“…Each image was treated through these steps individually. If the field of camera view is smaller than the investigated section, a calibration method is required to reject the split bubbles [74]. Busciglio et al [71] introduced two approaches to measure the bubble velocity, known as the Eulerian velocimetry and Lagrangian velocimetry, respectively.…”

Simulation of 3D freely bubbling gas–solid fluidized beds using various drag models: TFM approach

“…Considerable efforts have, therefore, been devoted to understand the formation and behavior of gas bubbles in fluidized beds. In this regard, two-dimensional fluidized beds, in planar rectangular columns of very limited thickness, have been often used to investigate the fundamental basis of fluidization such as bubble specifications, flow patterns, and solids mixing [1][2][3][4][5][6][7].…”