Effect Of Fluid Physical Properties On The Emulsification

摘要

Slag entrainment during metallurgical processes is a common source of macro inclusions, existing in a final product. This is the main reason why emulsification of slag should be controlled during the steel making processes. The onset for emulsification during the metallurgical processes is a function of practice specific issues and properties of used melts. The objective of this research was to study the effect of fluid physical properties on the emulsification. The research was made with a water model, using oil simulating slag and water simulating metal. Critical fluid flow velocity needed for emulsification and diameter of entrained droplets were measured. Role of fluid physical properties, affecting critical fluid flow velocity and diameter of entrained droplet were studied with varying density difference, oil viscosity and interfacial tension. Thickness of oil layer was also varied. Use of dimensionless numbers were also studied as a criterion for droplet formation. The results of this research proved, that the increase in density difference, oil viscosity, interfacial tension and oil layer thickness increase the fluid flow velocity needed for emulsification. Entrained oil droplet diameter increased with increasing oil viscosity, interfacial tension and oil layer thickness. On the other hand, oil droplet diameter decreased with increasing density difference. Research proved also, that dimensionless numbers can be used as a criterion for emulsification but dimensionless numbers usually suffers from lack of necessary variables. Studied dimensionless numbers were also compared to the real ladle system.