双通道气流式MTP反应喷嘴雾滴粒径分布的研究

摘要

The properties of atomizing nozzle are directly dependent on Sauter Mean Diameter (SMD),Particle Size Distribution (PSD) and Droplet-Covered Diameter (DCD).The properties of two-fluid airblast atomizing nozzles in MTP reactor were investigated by cold model experiment.The relationships between the structure of the nozzles and the atomizing properties were considered,simultaneously,the detailed investigations of SMD,PSD and DCD generated by the nozzles owned with different rotational structure under different gas-liquid ratios qmG/qmL were also carried out.The experimental results show that the size and structure of the rotational slots and the inside diameter of the liquid-phase channel (dL) have an apparent influence on SMD,PSD and DCD.Changing qmG/qmL from 8.70 to 20.32,the corresponding SMD decreased from 20.02 μm to 17.88 μm,PSD was between 9.91 μm and 48.8 μm,and characteristic mean diameter D0.5 was 21.45 μm,under rotational channel number n =2,dimension of rotational channel b ×h =0.5 mm ×1.0 mm,the inside diameter dL =1.0 mm.While n =3,b ×h =1.5 mm ×2.0 mm,2.0 mm × 2.0 mm,and dL =2.5 mm,SMD values decreased with qmG/qmL increasing,the values changing from 62.48 μm to 58.89 μm,and from 63.02 μm to 59.39 μm,respectively,PSD further broadened among 34.3 μm and 111.6 μm,and D0.5 reached 64.02 μm.When n =4,the other parameters of b × h and dL unchanged,PSD and D0.5 were also unchanged basically,but SMD varied from 64.07 μm to 60.65 μm with qmG/qmL increasing.Furthermore,DCD would increase from φ640 mm to φ800 mm.%雾化喷嘴的性能直接取决于索泰尔平均粒径SMD、雾滴粒径分布PSD和雾滴覆盖直径DCD.利用冷模实验,以双通道气流式MTP反应雾化喷嘴为研究对象,考察了喷嘴结构与雾化性能之间的关系,研究了具有不同旋流结构的喷嘴在不同气液比qmG/qmL下SMD,PSD及DCD之间的变化规律.结果表明,旋流槽尺寸与结构、液相通道内径dL对SMD,PSD和DCD具有显著地影响.当喷嘴结构参数为:旋流通道数n=2,旋流通道尺寸b×h=0.5mm×1.0 mm,液相通道内径dL=1.0 mm时,随着qmG/qmL由8.70增加至20.32,喷嘴对应SMD由20.02 μm降至17.88 μm,雾滴粒径分布介于9.91 μm和48.8 μm之间,特征中径D05达到21.45 μm.当n=3,b×h=1.5 mm×2.0 mm和2.0 mm×2.0 mm,dL=2.5 mm时,SMD随着qmG/qmL的增加分别由62.48 μm降至58.89 μm,由63.02μm降至59.39 μm,雾滴粒径分布变宽,介于34.3 μm和111.6 μm之间,D0.5达到64.02 μm.当n=4,b×h和dL保持不变时,PSD和D0.5基本不变,SMD随气液比qmG/qmL的增加由64.07 μm变至60.65 μm.而且,DCD由φ640mm增至φ800 mm.