三级碳化反应器中的气泡行为研究

Study on Bubble Behavior in a Three-Stage Carbonization Reactor

针对“钙化碳化法”处理低品位铝土矿及赤泥新方法的核心环节碳化过程,为实现碳化反应器内气泡微细化及均匀分布,提高碳化效率,提出了“三级错流文丘里式射流反应器”,并进行了冷态物理模拟研究,考察了反应器内的局部气含率和气泡上升速度.结果表明,气含率随表观气速的增大而增大,随表观液速的增大而减小,沿反应器轴向逐渐降低,后一级反应器的气含率大于前一级;气泡上升速度随表观气速和表观液速的增大而增大,沿反应器轴向逐渐降低,后一级反应器的气泡上升速度大于前一级,该结果为碳化反应器的设计和工业应用提供了依据.

Aiming at the carbonization process of the calcification-carbonization method for low-graded bauxite and red mud, a “three-stage cross-flow Venturi jet reactor” was proposed to make bubble disintegrate and disperse uniformly and to improve carbonization rate. Physical simulation in carbonization reactor was also carried out. Local gas holdup and bubble rising velocity under different operating conditions were investigated. The results showed that the gas holdup increases with increase of the superficial gas velocity and decreased with increase of the superficial liquid velocity, while it also decreased along the axial direction of the reactor. The gas holdup in the latter stage of the reactor was higher than that in the former one. The bubble rising velocity increased with increase of the superficial gas velocity and superficial liquid velocity, and it decreased along the axial direction of the reactor. The bubble rising velocity in the latter stage of the reactor was higher than that in the former one. The results provide a theoretical and experimental basis to design the carbonization reactor and to guide its applications in industry.