Abstract: Apparatus for increasing the homogeneity of the mixture of fluids, e.g. petroleum products flowing together in a pipe. The apparatus operates by dividing the flow into multiple converging jets and comprises a tubular body (10) for insertion in the pipe. The tubular body (10) houses a cylindrical sheath (9) inside which two plates (21, 22) provided with perforations (23) define two inlet chambers (25, 26) between which the flow is distributed. The space (33) between the plates is partitioned by a plurality of partitions (36) which are substantially perpendicular to the axis of the sheath so as to constitute outlet cells in which jets from the perforations of the plates converge. Said outlet cells have openings (38) formed in the sheath for the lateral removal of the fluids which mix therein.