Static mixers for viscous material

Claim 1

A static mixer for mixing at least two fluid streams comprising: a. a straight tubular hollow elongated body member providing a mixing passageway for said fluid streams and having an inlet end for receiving said streams and an outlet end for discharging said streams after mixing therein, said passageway having slot openings through the walls thereof; b. a first inlet means communicating with said inlet end of said body member for introducing a first fluid stream into said body member; c. a second inlet means communicating with said inlet end of said body member for introducing a second fluid stream into said body member; d. at least one pair of retractable mixing bLade means, each of said blade means disposed in a plane normal to the walls of said passageway and at an angle from the longitudinal axis thereof, each of said planes intersecting the other and defining a line of intersection passing through said longitudinal axis, said mixing blades being disposed to obstruct a straight line through said body member, but to provide a plurality of serpentine passageways therethrough; e. at least one pair of operator means connected to each pair of mixing blades of (d) for moving said blades normal to the adjacent walls of said body member into the abutting relationship of (d) and retracting said blades away from said abutting relationship through said slot openings of (a) provided in said body member walls whereby said blades may be entirely removed from obstructing the passageway through said body member.