In order to study multi-phase distribution characteristics of slender particles in scrubbing-cooling chamber

an improved direct sampling method was used to simultaneously measure locally axial and radial distribution of solid concentration and gas holdup in a cold model apparatus at various operating conditions. The cold model apparatus was scaled down according to geometric dimensions of scrubbing-cooling chamber of industrial gasification system. The results showed that scrubbing-cooling chamber could be divided into two zones of the upper gas-liquid-solid mixing zone and the lower solid-liquid flowing zone with boundary at cross-section of the downcomer outlet. The gas-liquid-solid mixing zone was consisted of downcomer outlet

bubble-break plate and gas cap regions

while the solid-liquid flow zone was consisted of gas phase turbulence

recirculation

and secondary flow regions. Due to compounded effects of particle hindrance (slowed down sedimentation) and agglomeration (accelerated sedimentation)

the axial distribution of solid concentration exhibited wavy fluctuations. The increase of annular gas velocity

solid volume concentration and aspect ratio of length over diameter enhanced bed turbulence and promoted radial gas dissipation. Change of operating conditions altered particle drifting velocity and resulted in fluctuation of radial solid concentration distribution. Under the effects of gas turbulence and recirculation

the secondary flow region showed circular flow where the “wall effect” of fluids and particles forced solid concentration higher at center but lower near wall.