波纹气分板流化床干燥玉米膏的热效率

Heat Efficiency of Drying Corn Paste in Fluidized Bed with Corrugated Gas Distributor

为提升玉米膏在惰性粒子流化床干燥生产过程中的热质传递性能,采用实验室自设计的波纹气分板替代了传统的平板气分板。通过实测热效率与进风速率、进风温度等参数间的对应关系曲线,获知了操作热效率的若干变化规律。在此基础上,借助极差分析的正交实验设计,开展了相应的参数影响水平及取值优化研究。结果发现:热效率随进料质量流量或惰性粒子静床高的提高而增大,随惰性粒子粒径的提高而减小,随进风速率或进风温度的提高而先增大后减小;与传统的平板气分板相比,新型波纹气分板有助于设备获得更高的操作热效率,增幅可达25%～40%;各参数对热效率影响的作用强弱依次为进料质量流量>进风速率>惰性粒子粒径>惰性粒子静床高>进风温度;在实验拟定的考察范围内,优化的参数组合为进风速率5.5 m/s、进风温度85℃、惰性粒子粒径1.5 mm、进料质量流量11.5 g/s及惰性粒子静床高40 mm,对应的操作热效率约可高达0.378。

To enhance the heat and mass transfer performance of drying corn paste in fluidized bed with inert particles,a novel gas distributor with corrugated surface structure is designed in our lab for replacing the traditional flat plate distributor,and several change laws concerning the drying operation are acquired by testing the effect relationship curves of the heat efficiency with respect to the gas intake rate,gas intake temperature and etc.With the help of the orthogonal experiment design with range analysis,the effect degrees of operation parameters on heat efficiency are analyzed and the relevant parameter optimization is subsequently performed.The results show：the heat efficiency increases with the increase of the feed mass flow or inert particle static bed height,decreases with the increase of the inert particle diameter,and increases firstly and decreases later with the increase of the gas intake rate or gas intake temperature.Meanwhile,compared with the traditional flat plate distributor,the novel corrugated gas distributor can bring higher heat efficiency and the corresponding increase amplitude is about 25%~40%.Besides,the effect degree order of operation parameters on heat efficiency is feed mass flowgas intake rateinert particle diameterinert particle static bed heightgas intake temperature,and in the scheduled parameter range of experiment investigation,the optimum technological combination is gas intake rate at 5.5 m/s,gas intake temperature at 85 ℃,inert particle diameter at 1.5 mm,feed mass flow at 11.5 kg/s and inert particle static bed height at 40 mm,while the value of heat efficiency can reach 0.378.