Effect of the Geometry of the Working Chamber of a Cylindrical-Conical Hydrocyclone on the Non-Newtonian Fluid Dynamics

Abstract

Numerical simulation is used to study the dynamics of non-Newtonian free-surface flow in a cylindrical-conical hydrocyclone. For different angles of taper of the conical section of the hydrocyclone, the pressure and velocity distributions are calculated, together with the dependence of the fluid film thickness on the axial coordinate. The effect of the rheological properties of the fluid and the controlling similarity parameters on the flow dynamics is studied.

Selection of structural parameters of a cylindrical-conical hydrocyclone for separation of suspensions by dual-stage flotation

“…Owing to the high effective viscosity of non-Newtonian media, flow in the cylindrical-conical hydrocyclone is carried out in a film regime [3]; this ensures the stable bond of a particle-bubble complex, since no abrupt increase in the circumferential velocity component occurs near the axis of the hydrocyclone.…”

“…(2) will, on the assumptions made, take on the form (3) where v rc (r, z), v zc (r, z), and v rl (r, z) are, respectively, the radial and axial velocity components of a complex, and the radial velocity component of the disperse medium in m/sec; r and z are the radial and axial coordinates in m.…”

“…The flow of a non-Newtonian fluid in a hydrocyclone is characterized [3] by the centrifugal Froude number (separation factor) Fr = u 0 2 /(gr k ), which is a modified Reynolds number Re n = ρ l u 0 2-n r k n /k and the dimensionless flow rate Q = = q /(πr k 2 u 0 ) = ab /(πr k 2 ). The rheologic properties of the fluid are described by the indicator n of the nonlinear flow curve, and the consistency index k in Pa⋅sec n .…”

Effect of structural parameters of hydrocyclones on the extraction of solid suspension particles by pressurized flotation

“…Moreover, separation will take place over a greater thickness of suspension film in a cylindrical-conical hydrocyclone than in a cylindrical hydrocyclone [7,8]; this will contribute to increased efficiency of the pressurized-flotation process, preventing solid-phase particles from emerging onto the wall of the hydrocyclone housing.…”

“…The flow of a non-Newtonian liquid in a hydrocyclone is characterized [7] by the centrifugal Froude number Fr (separation factor), the modified Reynolds number Re n , and the nonlinearity indicator n of the flow curve, as well as by the dimensionless flow rate, as calculated from the formula (12) where q is the flow rate of the suspension in m 3 /sec and e is the height of the inlet pipe of the hydrocyclone in m.…”