Electrical capacitance tomography measurements on vertical and inclined pneumatic conveying of granular solids

On the electrostatic equilibrium of granular flow in pneumatic conveying systems

“…By the same reasoning, granular flow in the vertical pipe was found to be more complex than that at the horizontal pipe so that it takes more time for the former to reach the electrostatic equilibrium. 22,23,31,32 This statement can also be verified in Table 2. Henceforth, it can be deduced that the electrostatic equilibrium involving granulewall collisions shows high relevancy to the granules' behavior and local flow characteristics (such as fluid turbulence): the more complex the granular flow, the longer to reach the electrostatic equilibrium state.…”

“…The instantaneous value of the cross-sectional average particle concentration ␣ s ( z, t) is defined as 22,23 : and the time-average value of ␣ s ( z, t) is denoted by Ͻ␣Ͼ(z):…”

Comparison of experimental and Computational Fluid Dynamics (CFD) studies of slug flow in a vertical riser

“…A detailed description of theory behind the ECT technology can be found in [7], and [11][12]. In this study, a ring of two measurement electrodes were placed around the circumference of the riser at a given height above the injection portals at the bottom of the 6 m riser section.…”

Experimental study of the hydrodynamic behaviour of slug flow in a vertical riser

“…The data were obtained at an acquisition frequency of 1000 Hz over 60 seconds for each run. A detailed description of theory behind this technology is described by Hammer (1983), Huang (1995), Zhu et al (2003) and Azzopardi et al (2010). The method can image the dielectric components in the pipe flow phases by measuring rapidly and continually the capacitances of the passing flow across several pairs of electrodes mounted uniformly around an imaging section.…”