Abstract: The invention relates to a method for mixing liquids into each other or different phases into liquid by employing a double loop circulation, created below the surface zone of a reactor. In order to maintain an intensive mixing, it is characteristic of this Bottom Toroidal Roll or BTR principle that the employed mixer has a strong bottom draft and presses obliquely downward, and that the mixer is installed according to the mixing method of this invention and that the flow pattern thereof is controlled in an exactly determined fashion. In our method the mixer jet hits the cylinder surface of the reactor, so that the jet is divided into two roughly equal parts by adjusting this distribution by means of a back-flow guiding member of the invention, which guiding member is located above the mixer. The rolling motion taking place in the reactor is controlled by means of specific baffles.