Coalescence of coarsely dispersed concentrated emulsions with turbulent agitation

The coalescence of drops, larger than microscale vortices, induced by velocity pulsations in concentrated emulsions is examined based on the theory of locally isotropic turbulence.Notation n number of drops per unit volume of emulsion - t time - ₀ and L micro- and macroscales of turbulence - _e, _c, and _d densities of the emulsion, the continuous, and the disperse phases, respectively - interphase tension - W concentration of the dispersed phase - D_T diameter of the agitating turbine - N rate of rotation of the turbine - D and H diameter and height of the mixing volume - d₃₂ averaged volume-surface diameter of the drops - d_m maximum size of drops that are stable with respect to fragmentation - f(W) concentration dependence - ¯v and ¯v(W) averaged magnitudes of the pulsation velocity in finely dispersed and coarsely dispersed emulsions - ¯gq and rates of collisions and coalescence of drops - t_c and _c time and rate of circulation - Re_M Reynolds number of mixer - _e effective viscosity of the emulsion - K_v constant describing the efficiency of collisions drops induced by velocity pulsations - F_v(W) and F_g(W) functional relations between the rate of coalescence and concentration of drops in the inertial and gradient regimes Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 1, pp. 27–33, January, 1982.