In order to deeply understand the super fine crushing technology of rear-mixed high-speed water jet flow

the mixing and jetting behavior of gas-liquid-solid three phases in acceleration tube with various diameter were investigated by using numerical simulation and crushing experiment methods.Mixing mechanism and acceleration performance of multiphase mixture jet flow were explored

and particles distributions in acceleration space were obtained.The result showed that aeration and entrainment effects of jet flow turbulent motion were the inherent mechanism of mixed attached phase.There existed many partition zones in the rear-mixed jet flow for particle acceleration.Whereby the nearer to the potential flow zone

the stronger the impact energy.Accordingly

optimizing configuration of the optional nozzle diameter with the acceleration tube diameter could force the particles near or enter the potential flow zone

whereby effectively improving grinding yield efficiency.The particles in space distribution within the acceleration tube were in the highest contents in high-efficiency acceleration zones of the outer and inner layers.As a result

the nearer to the potential flow zone

the fewer the particles.The particle contents in the air flow zone increased with increasing acceleration tube diameter.It was difficult for the particles to enter the ideal acceleration zone so that most of the particles were accelerated by relying on the high-efficiency acceleration zone of the inner and outer layers.In the case of maintaining the flowing morphological state of free jet flow

the grinding yield efficiency decreased with increasing acceleration tube diameter.Accordingly small tube diameter was of better constraint and concentration functions for water jet flow energy and particle motion space.