화학공학소재연구정보센터
Chemical Engineering Science, Vol.101, 56-68, 2013
Bubble-wall interaction for asymmetric injection of jets in solid-gas fluidized bed
A hydrodynamic model describing gas solid two phase flow has been used to numerically study the effect of wall on the bubble shape, size, detachment time and the bubble trajectory in a two-dimensional fluidized bed. Using the numerical model, the influence of the wall is analysed by moving the jet from the centre of the bed towards the wall. The bubble characteristics are compared for different nozzle locations, thus presenting the effect wall has on asymmetrical injection as compared to symmetrical injection. A 30% increase in the bubble detachment time for an asymmetric injection (jet velocity of 10 m/s) is found when the nozzle is displaced from the centre of the bed towards the wall (80 mm offset from wall). In addition, the bubble evolution reveals an asymmetric wake formation during detachment indicating an early onset of mixing process. The wall forces acts tangentially on the bubble and has a significant impact on the bubble shape, neck formation during detachment, holdup time near the wall and its trajectory through the bed. (C) 2013 Elsevier Ltd. All rights reserved.