The use of acoustic agglomerators for the suppression of sodium-fire aerosols in the case of a hypothetical core disruptive accident of a liquid-metal fast breeder reactor is discussed. The basic principle for the enhancement of agglomeration of airborne particles under the influence of an acoustic field is first discussed, followed by theoretical predictions of the optimum operating conditions for such application. It is found that with an acoustic intensity of 160 dB (∼1 W/cm2), acoustic agglomeration is expected to be several hundred times more effective than gravitational agglomeration. For particles with a radius larger than ∼2 µm, hydrodynamic interaction becomes more important than the inertial capture. For radii between 0.5 and 2 µm, both mechanisms have to be included in the theoretical predictions of the acoustic agglomeration rate.