Motionless mixer

A device for the mixing of two fluids in a conduit which device is located within said conduit substantially along its longitudinal axis, said device comprising an elongated body having an upstream end and a downstream end, said upstream end being characterized as having an entry port for the entry of a first fluid found in the conduit, said entry port being substantially shaped as a frustum of a cone, the upstream end of which having a relatively wide base which faces the oncoming flow of the first fluid and converging sidewalls, a hollow shaft having an upstream end and a downstream end whose diameter substantially equals the downstream end of said entry port, said hollow shaft containing a plurality of mixing elements for the mixing of said two fluids and a feed port for the introduction of a second fluid to be mixed with the first fluid, said feed port positioned to feed said second fluid into said hollow shaft proximate its upstream end.