Conference Dates

May 1-5, 2011


Cyclone diplegs play a major role in the functioning of fluidized beds. Previous studies have shown that at certain operating conditions there can be severe gas bypassing (also referred to as jet streaming) of gas in deep beds of Geldart Group A materials which leaves significant portions of the fluid bed defluidized. If cyclone diplegs are immersed in these defluidized regions, solids discharge from the dipleg may be hindered, which can lead to the flooding of the dipleg and the cyclone. This could result in high solids losses from the fluidized bed. Tests were conducted to demonstrate that cyclone diplegs can flood when discharging into a bed with gas bypassing. Tests were also conducted to determine how gas bypassing affects the operation of cyclone diplegs that have a splash plate or a trickle valve. These tests were conducted in a 1.52-m-diameter semicircular column equipped with a Plexiglas faceplate to allow visual observation.