Influence of magnetic field on the fluidization characteristics of circulating fluidized bed

This work concerns with the evaluation of a scaled ‘magnetically assisted circulating fluidized bed’, with a circular cross-section. Flow behavior and solids distributions were determined in a riser (0.032 m i.d. × 1.5 m height) of magnetite particles (dp = 425 μm, Φ = 0.86, ρs = 4500 kg m−3), in the experimental range (Ug = 4.2–5.3 m s−1; Gs = 30.1–40.3 kg m−2 s−1), which covered the fast fluidization flow regime. A shutter arrangement was used to measure the solids circulation rate. The riser is equipped with a pressure tapping at an interval of 0.3 m to detect the axial pressure profile, which helps in calculating the apparent solids holdup in that section. The plots conditions were distinguished by variations of parameters (net solids circulation rate, flow velocity, magnetic field intensity) at various heights along the riser for presence and absence of magnetic field. It is predictable, that the magnetic field has a significant influence on fluidization phenomenon along the whole riser, especially for the dilute section. It appears that, for applied magnetic field, the solids holdup begins to increase, this most likely indicates the starts of a ‘transition’ towards much ‘denser’ suspension.