Simulation Study For Multiphase Flow Behavior Of Powder Injection In RH Up-snorkel

RH vacuum cycle refining is an important process of producing pure steel,and its powder spraying is the key to realize desulfurization and dephosphorization.Compared with other RH powder spraying methods,RH rising tube powder spraying has the advantages of high powder yield,good dephosphorization and desulfurization kinetic conditions,which is expected to become an effective method of desulfurization and dephosphorization.Based on the equipment parameters and process parameters of 180 t RH refining unit of a steel mill,this paper studies the multiphase flow behavior of the spray powder from RH riser by means of numerical simulation and physical simulation,which aims to provide some reference for the industrial production of this process.This paper establishes a physical model of 1:4 according to the principle of similarity,simulates the influence of RH riser powder spraying,vacuum chamber powder spraying and ladle powder spraying on powder mixing,and studies the influence of RH riser powder spraying process parameters on mixing,circulating flow and powder movement.Studies the influence of the flow field of molten steel,the movement trajectory of powder and the number of different holes of RH riser powder spraying on the movement of powder by numerical simulation.In the physical simulation experiment,the mixing time of powder for RH riser powder spraying is 196.0s,9.3% shorter than ladle powder spraying and 4.9% shorter than vacuum chamber powder spraying.The mixing time of powder spraying 5cm below the center of the RH rising is 180.0s,which is 8.2% shorter than that of powder spraying 5cm above.When the blowing volume is 2.52 m3/h(model),the penetration effect of powder gas bubble is the best;When the gas ratio of powder spraying in RH riser increases from 0.2 to 0.3,the circulation flow rate changes the most,increasing by16.5%.In the numerical simulation experiment,the distribution uniformity of powder of five-hole powder spraying is 56.1%,and that of single-hole powder spraying is 22.9%.Within 20.0s of RH rising tube powder spraying,46.1% powder enters the ladle through the descending tube,and 53.9% powder stays in the vacuum chamber.