关键词: 十字型挡板, 流化床, 液体循环速度, 摩擦阻力系数

Abstract:

An investigation was conducted to study the hydraulic characteristics of internal loop fluidized bed with crossshape baffle setting on the bottom of the reactorAccording to the properties of multiphase mixing and collision, the crossshape baffle leads to the transformation of chaotic to orderly, offering a new way for controlling hydrodynamicsThe liquid circulation velocity and mixing time of the reactor were measured by the conductivity method, and compared with the conventional fluidized bed to indicate the fact of promoting gasliquidsolids mixingIt was shown that the liquid circulation velocity in the riser and that in the downcomer were increased by 9.5%±1.0% and 11.8%±1.0% of those without the crossshape baffleWhen superficial gas velocity was less than 0.86 cm·s^-1, liquid mixing time increased with setting the crossshape baffleLiquid mixing time decreased when superficial gas velocity was above 0.86 cm·s^-1.Frictional loss coefficient at the bottom section reduced from 4.13 to 2.75 with setting the crossshape baffle, resulting in obvious decrease of energy dissipation due to flow collisionBased on an energy balance over the loop, a correlation equation between liquid circulation velocity and frictional loss coefficient was establishedFor the threephase system, the prediction values from the above correlation equation agreed .

Key words: 十字型挡板, 流化床, 液体循环速度, 摩擦阻力系数