Numerical Simulation And Study On The Flow Patterns And Disruption Efficiency Of Ultra-high Pressure Homogenizers

The development situations of ultra-high-pressure homogenizing equipment at present have been introduced. Numerical investigations of the flow patterns within a high-pressure homogenizing valve have been conducted for visualization and analysis by using a commercial Computational Fluid Dynamics code. The resulting information given by CFD modeling and simulation compare well to previous experimental and theoretical investigations. A simple expression on relations of pressure gradient versus valve gap is presented that allows ready calculation for homogenizer designing and operating. Genetic Algorithm and Non-linear Regression Algorithm is coordinately used to validate the mathematic model indicated by numerical calculated data. The modeling and computing results give detailed information on the mechanical stresses and visualize the flow patterns that are usually difficulty to demonstrate by using general physical tests in small disruption valves.Numerical simulation of the cavtation flow in a high-pressure homogenizing valve has been investigated using computational fluid dynamics package with RNGk-εturbulent model. This investigation involves cavitations to different extents under several pressures, which visually demonstrates the cavitation phenomena and locates their districts within the whole flow field. Based on data from this study, the effects of parameter setting on iteration residuals, of pressure on the cavitation and the axial force on the surface of the valve head have been analyzed.Based on the impingement of T-typed geometry structure compared with the APV-Gaulin valve, mechanisms in the high-pressure homogenizing process have been analyzed including especially the inertial forces which produce compressive forces on the particles while they are moving through at high speed. Circulation zones existing in flow patterns are demonstrated by simulation. All the conclusions in this investigation give constructive information to the designing of relative parts in homogenizing equipment and the further work on the study of the flow patterns.Yeast cell disruption experiment has been conducted under ultra-high-pressure according to the method of regressive orthogonal designing. Response mathematic model of yeast cell disruption has been constructed and supplemented by artificial neural net algorithm which simulates the relationship of disruption against operation parameters covering concentration, pressure and elapse time with more prophecy. The resulting information dedicate to the establishment of application database on homogenizer, and the improvement on the performance of equipment.