Study On The Revoluaton Of In-situ Online Inspection Of Micron-sized Particle In Two-Phase Flow In Reactor

In the chemical process,it involves a very complex gas-liquid-solid three-phase reaction,especially in the fluidized bed and stirred kettle,the solid particle catalyst has the phenomenon of uneven distribution of solid,and the reaction process is often accompanied by the process of particle wear and breakage.It is of great significance to the optimization design of the reactor structure and the amplification design of the whole process how to obtain the hydrodynamic characteristics such as the fluid flow condition,the particle size distribution of the catalyst,the distribution of the dispersed phase and the accumulation condition on line.In order to obtain the information of solid-liquid two-phase in the stirred vessel in real time and online,this paper developed a micro-particle on-line monitor based on coulter's principle.The main technical feature is that the coulter keyhole tube is directly inserted into the solid-liquid suspension system to be tested to obtain the concentration(number)and particle size distribution of solid particles at the current position in real time.Compared with other contact measurement methods(sampling method,conductance method,optical probe method),this method has the characteristics of real-time,accuracy,and can obtain the concentration and particle size distribution of micro particles at the same time,which can be used as a scheme for monitoring the distribution of solid and liquid system micro particles in industrial production.The process of suspension and sedimentation of micro particles in liquid phase was quantitatively measured by a self developed real-time online monitor.First of all,through the comparison with commercial offline instrument Multisizer4e since the research of the micro particle monitor is verified the reliability of the real-time,on-line measurement.Then,choose the standard material latex microspheres of Al2O3 and ZrO2 three different kinds of density of the micron particles,suspension characteristics under the steady speed in the magnetic stirrer and stirring particles after stop online gravity settling process in real time observation and measurement point is obtained under the two circumstances of particle concentration and size distribution information.The experimental results show that even if the mixing speed exceeds the critical suspension speed,the Al2O3 particles in the mixing container still have different degrees of non-uniform distribution,showing a certain concentration and particle size distribution.In the transient process of gravity deposition,the particle size and density of solid particles play a significant role in the solid-liquid two-phase separation process.Experiments show that the monitor designed in this paper can be used to continuously monitor the particle size distribution in the reactor in real time.But if the chemical reaction is to be accurately detected,the structure of the instrument needs to be further optimized.