短程射流共点交汇对撞阀超微细化作用强化与效果  

Enhanced Ultra-fine Pulverizing Effect in New Short Jet Collision Nozzle

作　　者：徐彦喆 王骁 吴雪[1] 刘斌[1] XU Yan-zhe;WANG Xiao;WU Xue;LIU Bin(School of Artificial Intelligence,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]北京工商大学人工智能学院,北京100048

出　　处：《食品研究与开发》2022年第23期34-41,共8页Food Research and Development

基　　金：国家重点研发计划(2016YFD0400305)。

摘　　要：阀体结构是高压均质过程影响食品原料超微细化效果的关键。该文应用多物理场仿真软件COMSOL,对新型的短程射流共点交汇对撞阀(简称交汇对撞阀)内流体的剪切、撞击、空化和湍动效应进行分析,并进行纤维素高压射流均质超微细化试验。结果表明,交汇对撞阀内剪切、湍动、摩擦作用更强;阀体内交汇撞击区附近,压力回升利于空泡向内溃灭造成冲击,空化效应更强;与直孔阀相比,阀体出口附近湍动能增加近10倍。经交汇对撞阀处理,纤维素水分散液固形物体积占比升至75%,且电镜观察纤维素微纤直径和长度明显减小。阀体内作用机理分析与试验结果的一致性表明,流体转向、短程射流、共点交汇的阀体设计强化撞击、空化、湍流效应等,从而提升交汇对撞阀的超微细化效果。Homogeneous valve serves as a key factor affecting the ultra-fine pulverizing effect of food materials.Multi-physics field simulation software COMSOL was applied to analyzing shear,impact,cavitation and turbulence of fluid inside short jet collision nozzle(short for collision nozzle)which was regard as a new-type high-pressure jet homogeneous valve. Furthermore,the ultra-fine pulverizing experiment for homogenizing cellulose through collision nozzle was launched. The results showed that fluid shear,turbulence,and friction effects were stronger in the collision nozzle. In the impacting area inside the collision nozzle,pressure rebound facilitated bubble inward collapse,which could violently impact surrounding region. Therefore,in the collision nozzle,cavitation effect was stronger. Turbulence energy around the collision nozzle outlet was about 10 times greater than that around the straight hole nozzle outlet. After collision nozzle treatment,solid volume ratio of cellulose aqueous dispersion increased to 75%,and the diameter and length of cellulose microfibrils were obviously reduced during the scanning electron microscope observation. The concordant conclusion between mechanism analysis and experimental results illustrated that collision nozzle designed by fluid steering,shortrange jets,and co-point intersection was beneficial to enhance impact,cavitation,and turbulence effects,thereby potentiating the ultra-fine pulverizing effect.

关 键 词：均质阀 交汇对撞阀 高压均质 超微细化 纤维素 

分 类 号：TS203[轻工技术与工程—食品科学]