Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced at the circumference of the conduit {the conduit having a plurality of openings in the axial direction or in the circumferential direction with a plurality of perforations in the circumferential direction only and covering the whole circumference the perforations being a complete cut-out in the circumferential direction covering the whole diameter of the tube, i.e. having two consecutive tubes placed consecutively, the additional component being introduced between them}