Abstract: A fluid injector for the introduction, dispersion and mixing of a first fluid into a second fluid flowing through a conduit. The injector comprises an elongated body mounted in fluid-tight fashion through an aperture in the side of the conduit so as to extend transversely of the interior of the conduit and transversely of the flow of the second fluid therein. The injector body has an axial bore connectable at one end to a source of the first fluid under pressure and leading to at least one outlet bore extending transversely of the injector body and located within the conduit. The injector body has a transverse inlet bore within the conduit. One end of the inlet bore faces the flow of the second fluid within the conduit and the other end thereof communicates with the axial bore of the injector body upstream of the at least one outlet bore.