the dispersed phase 40 in the form of droplets into contact with the dispersing phase 44 after having passed through the porous body 42 the purpose of the case 23 is to prepare the dispersed phase 40 which will be forced through the porous body 24 and facilitate the vibrations of the porous body 24 without degrading it the sealing system 25 and 25 u2032 may advantageously be formed by two flexible seals which provide both leaktightness and mobility of the porous body with respect to the case 23 the embodiment represented in fig1 is a system 51 for vibration by magnetic excitation i e the system 51 is formed by the alternating current source 4 connected to the winding 27 the geometry of which makes it possible to exert an alternating magnetic field on the porous body 24 the porous body 24 thus exposed to an oscillating magnetic field vibrates and exerts the intended mechanical action on the interface of the two phases 40 and 44 owing to this mechanical action produced at the interface of the phases 40 and 44 the droplets thus formed are rapidly separated from the pore from which they originate and become mixed into the dispersing phase 44 with a very small droplet size the embodiment represented in fig2 illustrates a system 151 for vibration by electrical excitation those elements which are the same will be given the same references and will not be described again the active module 102 differs from that presented in fig1 only by the vibration system the vibration system 151 now.