机械搅拌反应器中挡板的结构设计

Performance and Design of Baffles in Mechanically Agitated Gas-liquid Reactor

研究了内径为0.786m的搅拌釜中挡板尺寸及结构对圆盘透平桨RT和翼型桨k5及其组合在气液两相中的气体分散与混合特性的影响.对不同形式的挡板的搅拌功率、气含率及气液混合特性进行了对比分析.研究结果表明:挡板尺寸结构应根据搅拌特性需要进行优化设计;挡板系数为0.12时,组合浆的功率输入已与同一转速下的全挡板系数时的功率输入相近,它同时可改善微观混合、提高混合效率;采用开槽挡板可提高复杂快反应的选择性,混合效率提高20%～25%.

The effects of baffle structure and size on gas dispersion and mixing for the impellers of Rushton turbine RT and six-blade hydrofoil 6k5 and their mixed impellers were systematically investigated in a multi-phase agitated reactor with inner diameter of 0.786 m. Fractional gas hold up, power consumption, mixing time and micromixing segregation index were measured in the case of different baffle structure and size. The results show that the baffle structure and size ought to be optimized according to the agitation purpose. For the mixed impellers in a reactor with slot baffles, the requirement of power consumption approaching to that of using perfact baffles(which KB=0.35) can be satisfied, the micromixing is improved and the mixing efficiency can be enhanced when the baffle coefficient KB of the used slot baffles is equal to 0.12. The selectivity of complex quick reaction is improved and the mixing efficiency is promoted about 20%-25% when the slot baffle is used.