Foam Breaking Characteristics of a Mechanical Foam-Breaker Using Shear Force Fitted to a Stirred-Tank Reactor

抄録

This study examined foam breaking characteristics of a mechanical foam-breaker using shear force (MFUS) between a fixed orifice plate and a rotating disk fitted to a stirred-tank reactor (STR). The effects of operating conditions on the liquid holdup in foam φ_L and the volumetric rate of foam flow Q_a, which reflect the foaming behavior of the STR, were revealed. The foam-breaking behavior of the MFUS was investigated from changes in the foam density after foam breaking (ρ_f)_c, which remained constant at a disk rotational speed N, transitional disk rotational speed N_t, and shearing power P_s. The value of (ρ_f)_c decreased concomitant with the increase in the mass flow rate of liquid in the foam flowing into the orifice, w_L. The N_t became larger concomitant with the lower average ascending velocity of the foam U_a and higher φ_L. The magnitude of P_s was related to that of w_L. Empirical equations for predicting (ρ_f)_c, N_t and P_s were obtained based on those results.