射流鼓泡反应器中液相体积传质系数的测定

摘要

Jet bubbling reactor is commonly used in the carbonylation reaction.This type of reactor uses the jet mixing rather than the mechanical way to achieve gas-liquid mixture.The main advantage of the jet bubbling reactor is its simple structure,low manufacture and maintenance cost.It is of great significance to study the liquid mass transfer coefficient of this type of reactor for its design,optimization and scale-up.In this paper,the necking type circular nozzle was used to determine the liquid volume mass transfer coefficient of jet bubble reactor by dynamic dissolved oxygen method.The effect of superficial gas velocity and jet Reynolds number on liquid phase mass transfer coefficient were investigated.The results showed that the liquid phase mass transfer coefficient first increased then remained unchanged with the increase of gas velocity.When the superficial gas velocity remained unchanged,liquid volumetric mass transfer coefficient increased with the increase of Reynolds number.However,the effect on mass transfer was greatly reduced when the gas velocity was less than 0.0012 m/s.The empirical correlation of liquid phase mass transfer coefficient was established.The mass transfer coefficient of liquid phase reached the maximum when gas power input was 56％ of total power and the synergistic effect of gas bubble and liquid jet was also the strongest.%羰基合成反应一般采用射流鼓泡反应器,该类反应器气液混合的方式采用射流而非机械搅拌,其主要优点是结构简单、制作简便、维护费用低.研究该类型反应器的传质系数对于其设计、优化及放大操作均具有重要意义.本研究采用缩颈式圆形喷嘴,以动态溶氧法对射流鼓泡反应器内的液相体积传质系数进行测定,考察了表观气速、射流雷诺数对液相体积传质系数的影响.研究发现,随气速增大液相体积传质系数的变化规律为先增大而后保持不变.维持表观气速不变,随雷诺数增加液相体积传质系数增大,但当表观气速小于0.0012 m/s时,雷诺数对传质改善较小.建立了液相体积传质系数的经验关联式,当气体输入功率占总功率56％时,液相体积传质系数最大,气体鼓泡和液体射流的协同作用最强.