Structure Research Of The Slot Nozzle Used In The Continuous CVD Device

6.5%Si Steel is being used and developed in more and more modern industrial areas because of its superior magnetic properties. Among many 6.5%Si steel preparation process, CVD method is the only one that has been industrialized application. Nozzle is an important component in the continuous CVD device. The performance of nozzle determines the uniformity of Si distribution inside the steel which will further affect the magnetic properties of steel. A new type of nozzle is proposed in this article which can be used in the continuous CVD device. The velocity distribution of the nozzle is studied by numerical simulation and experimental method. The structure of the nozzle is optimized by response surface method.The performance requirements of the nozzle in the continuous CVD device for 6.5%Si steel preparation are analyzed by which the design requirements of the nozzle are obtained. A new type of slot nozzle is designed and proposed based on the design requirements. Qualitative analysis of the performance and velocity distribution of the nozzle has been done. The velocity distribution of the nozzle is numerically simulated by FLUENT. The simulation model and results are verified by experiment. The results of the experiment indicate that the simulation model can reflect the velocity distribution of the nozzle accurately which proved that it is feasible to study the velocity distribution of the nozzle by numerical simulation method. Both the simulation results and experiment results show that the velocity distribution on the steel surface of the slot nozzle is relatively uniform. The influence of the other process parameters in CVD method on the velocity distribution is analyzed. The simulation model is simplified based on the influence law of other process parameters obtained. The significant factors are obtained by full factorial design and fractional factorial design which influence the width direction velocity distribution on the steel surface greatly. The influence law of the significant factors of the velocity distribution on the steel is obtained by numerical simulation method. The structure parameters are optimized by response surface method. The regression equation of the significant factors and the velocity distribution uniformity of the steel are obtained. The velocity distribution on the steel surface under optimal structure parameters is analyzed by numerical simulation and experiment. Both the simulation results and experiment results show that the velocity distribution on the steel surface is very uniform which verifies the accuracy of the optimization results.