Abstract: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.