Abstract
Behaviours of injected powder and characteristics of mixing in the powder injection refining have been investigated by water model experiments. The results obtained are as follows.
(1) The critical velocity of a particle for the penetration into liquid could be expressed by Engh's equation.
(2) The penetration distance of a particle is given by the parameter which is the ratio of the kinetic energy of a particle to the turbulent shearing force.
(3) The behaviour of floatation or sedimentation is decided by the parameter which is the ratio of the buoyancy force of a particle to the turbulent shearing force.
(4) Time for dispersion of particles is a function of stirring power and liquid volume, and is about a twentieth of mixing time.
(5) The formula for mixing time is affected by the method of tracer addition and the method of stirring. Mixing time is expressed as a function of stirring power for the tracer injection and as a function of both stirring power and liquid volume for the gas bubbling with tracer addition onto the liquid surface.
