Research On Technology And Flow-stop Theory Of Sticky Materials In Filling Machinery

In the process of measurement and filling of packing viscous fluid, the accuracy of the measurement has to meet more demads. Especially for costly food, medicines and health protection, the accuracy of the measurement is very high.Flow-stop is the process of fluid form a unit fluid materiel by metering and filling in packing machinery.Fluid materiel usually make adhesion after the completion of metering and filling.Because of this,it can not disconnect between units of fluid materiel,or between fluid materiel and filling orifice entrance.Some times,it make the materiel glue to the seal of packaging,and impair the quality of sealing,especially for the filling of viscous fluid. The analyzed results indicate that one of the key factors of influencing the effect of flow-stop of viscous fluid in metering and filling is the characteristic of pipe orifice.This research is to explore the influence of orifice shape on the flow-stop result of viscous fluid.The pressure distribution and change of viscous fluid in filling pipe orifice will effect the flow-stop.the perssure distribution and change of fluid in pipe orifice is directly related to the shape of pipe orifice. Tests have shown that there will produce pressure drop in the pipe orifice by using different shapes of pipe orifice to meter. Filling pipe orifice with lower pressure drop is more beneficial for flow-stop.This is because lower pressure drop,shorter the residence time of materiel stay at pipe orifice,and pipe orifice is beneficial for flow-stop.And at the orifice flow,because of repeatedly pressure,fluid has flowed to fill,fluid produce laminar flow, turbulent flow and the energy loss.These flow characteristics control the formation of droplet at the exit,further effect the flow-stop of fluid while filling. There are many factors of influencing flow-stop,such as pore diameter, extrusion pressure of extender mechanism, surface tension of fluid in orifice wall,viscosity and temperature of fluid,capillary of fluid[and some other things.The research in this paper has a higher theoretical level.Buliding dynamic surface tension of fluid model and flow-stop pipe diameter mathematical model,and researching the internal relation between fluid characteristics and metering mechanism outflow pipe orifice,that is an entirely new explore.There already have three research methods,analytical method,experimental method,numerical method by the aid of fluid mechanics and mechanical rotation.This study mainly uses the combination of analytical method and experimental method,that also is a method has wide application prospects,and it can enrich content of existing fluid machinery theory and packaging machinery design theory.The first chapter discusses relative theory of fluid flow-stop into two phases,historical review of fluid mechanics research in relation to fluid flow-stop,and modern research of fluid flow-stop.The first phase mainly research fluid mechanics,include local content of fluid flow-stop.The second expound the conception of fluid flow-stop without systematic study.At the same time,this chapter elaborates on the problem,method,academically significance and application value intended to research in the task.In chapter two,accroding to the reseach method of reynolds experiment and the flow characteristic of fluid in pipe,this paper analyses the influence of fluid flow through the surface on the characteristic of pipe laminar flow,outflow characteristic of fluid at pipe orifice,physical significance of flow-stop,unit pressure of fluid and so on.And then, this paper designed flow-stop test system of viscous fluid,finally found flow-stop mathematical model of viscous fluid accroding to the balance problem of viscous fluid at outflow orifice.We get flow-stop pipe diameter mathematical model of round outflow pipe orifice on dynamical conditions in vertical direction,and flow-stop pipe diameter mathematical model on static conditions.Defined by reynolds number,the former adapted to high-speed filling packaging,the latter adapted to middle-low speed filling packaging.In chapter three,loss of viscous fluid in flowing is studied by energy method.This chapter respectively analyses the energy balance of ideal fluid and actual fluid in flowing,on-way loss of laminar flow in round tube, on-way loss of turbulent flow in round tube, on-way loss of flow in round tube, on-way loss of flow inside variable cross-section.At the same time,this chapter researches equivalent diameter of different variabe cross-section pipe hole.They all effect flow velocity and reynolds number,and the flow-stop of viscous fluid in flowing.Chapter four mainly researches outflow pressure of different pipe orifice.outflow state,influence and comparison of viscous fluid flow-stop in different shape of outflow orifice.This chapter makes a deep study of pressure equalizing square hole clearance flow,pressure equalizing parallel face radial flow,relationship between orifice clearance and power loss,influence of outflow orifice on flow-stop effect.They all influence flow characteristic and flow-stop of viscous fluid.The result showed that round hole is easier than square hole for flow-stop.Chapter five designed the experimental procedures,method and process,defined four kinds materials of different viscosity to test.To conduct flow-stop pipe diameter experiments by mathematical model,get related data,count the experimental data,collation and analysis.at last, the reliability of flow flow-stop pipe diameter is verified through the linear analysis of mathematical model.Chapter six give a summary and prospect of viscous fluid flow-stop theories and techniques.It systematically summarizes research work and give an overview of the work that hope to do but have not done.This chapter mainly summarizes from theory analysis and experiment and generalizes the innovations in the dissertation,at together,looks forward related structure of flow-stop pipe diameter,shape inside and quantitative analysis of high-speed filling.