Research On Cavitation Characteristics And Effects In Orifice Plate Cavitator

In recent years,the use of energy generated in the cavitation process to enhance physical and chemical processes has achieved good results.Hydraulic cavitation is used in various fluid fields such as water purification,organic compound decomposition and solution mixing.At present,there is no fixed standard on how to quantitatively analyze the cavitation effect.And there is no breakthrough progress in how to improve the cavitation effect of cavitator s.Therefore,it is of great significance to research characteristics and effect of fluid cavitation.The orifice plate cavitation device is taken as the research object.The cavitation characteristics and effect of fluid in orifice plate cavitator are researched by theoretical analysis,numerical simulation and experimental research methods.The effects of orifice plate structural parameters and pressure difference on the cavitation effect is analyzed.Force analysis is carried out on a spherical bubble to get high temperature and pressure environment when bubble collapse s.The pressure drop system of fluid is established in the orifice plate cavitator.And the motion equation of spherical cavitation bubble is derived through the law of conservation of mass.Through the cavitation bubble kinetics,the equations of precipitation and dissolution of vapor are obtained in the orifice plate cavitator.And the equation for the change of vapor holdup of the aqueous solution is derived in the orifice plate cavitator.The geometric model of fluid is established in UG and meshed in ICEM-CFD.In the fluid simulation software FLUENT,the internal fluid of cavitator is simulated under the conditions of different structural parameters(orifice plate through-flow cross-sectional area,holes distribution mode,holes dispersion degree,orifice plate channel inner surface roughness)and pressure difference.Multiphase flow is analyzed.Vapor volume flow rate is taken as the criterion for judging cavitation effect,the relationship between the above factors and the fluid cavitation effect is obtained.The cavitation experiment of methylene blue solution is carried out,the absorbance of solution before and after cavitation is measured by spectrophotometer,and the cavitation effect of cavitator under different conditions is obtained.The cavitation experiment of Escherichia coli is carried out with an orifice plate cavitator.The cavitation effect and practical significance of orifice cavitator is analyzed.It is found that fluid cavitation in the orifice plate channel is stable.The vapor phase is in a dispersed state outside the channel(pressure recovery zone).Different orifice plate structural parameters and pressure difference have different effects on cavitation effect of cavitator.The cavitation effect significantly reduces absorbance of methylene blue solution.The orifice plate cavitator has a significant sterilization effect on Escherichia coli.