Mixer-injectors with twisting and straightening vanes

In a mixer injector having a body with a first and a second end, a flow passage therethrough from end to end, said flow passage being defined by a circularly sectioned wall extending along a central axis from an inlet port at said first end to an outlet port at said second end, said wall forming:

• a. a substantially cylindrical entry portion;
• b. a constricting portion;
• c. a substantially cylindrical injection portion;
• and
• d. an expanding portion;
• said constricting portion interconnecting said entry portion and said injection portion, and being substantially frusto-conical,
• said expanding portion joining to said injection portion, and being substantially frusto-conical,
• an injector port entering said injection portion through said wall immediately adjacent to the intersection of said constricting portion and injection portion, the improvement comprising:
• a set of twisting vanes on said wall, each said twisting vane extending from a location in said entry portion to a location in said constricting portion, said vanes rising from said wall and having a crest forming an acute angle with a plane that includes said central axis and which passes through said twisting vanes, said crest being radially spaced from said central axis, there being a plurality of said twisting vanes angularly spaced apart from one another;
• and
• a set of straightening vanes on said wall, each said straightening vane extending along said wall in said expanding portion, said vanes being parallel to said central axis, there being a plurality of said straightening vanes angularly spaced apart from one another, said straightening vanes having a crest substantially parallel to and radially spaced from said central axis.