Fluid injector and mixer apparatus
View Patent ↗An improved injector which mixes a secondary fluid into a carrier fluid stream has (a) a body for directing the flow of the carrier fluid, this body having an internal wall forming a flow passage therethrough, a central axis, an inlet, an outlet, and a port for receiving the secondary fluid that is mixed with the carrier fluid, (b) a ramp-like restriction portion which is located downstream of the body's inlet and upstream of the secondary fluid port and configured so as to decrease the effective cross-sectional area of the flow passage in the direction of the flow of the carrier fluid, (c) a ramp-like expansion portion which is located downstream of the secondary fluid port and upstream of the body's outlet and configured so as to increase the effective cross-sectional area of the flow passage in the direction of the flow of the carrier fluid, (d) a throat portion which is situated between the restriction and expansion portions, and (e) a cavity in the throat that extends from its internal wall and into the body, with the port entering the flow passage at a location in the throat cavity, and wherein this cavity is configured so to promote a vortical flow of the secondary fluid in the cavity.
1. A fluid injector having improved fluid mixing capabilities, said injector comprising:
a body for directing the flow of a carrier fluid, said body having an internal wall forming a flow passage therethrough, said flow passage having a central axis, an inlet, an outlet, and a port for receiving a secondary fluid that is mixed with said carrier fluid,
a ramp-like restriction located downstream of said inlet and upstream of said port and extending from said body internal wall so as to decrease the effective cross-sectional area of said flow passage in the direction of the flow of said carrier fluid, said restriction having a downstream end at which is located a rear surface that extends abruptly down to said flow passage internal wall,
a ramp-like expansion located downstream of said port and upstream of said outlet and extending from said body internal wall so as to increase the effective cross-sectional area of said flow passage in the direction of the flow of said carrier fluid, said expansion having an upstream end at which is located a front surface that extends abruptly upward from said flow passage internal wall,
wherein said restriction and expansion being situated on said internal wall so as to form between said restriction rear surface and expansion front surface a cavity, and
wherein said port located in said cavity.
2. The fluid injector as recited in claim 1 , wherein:
said restriction having a portion that slopes with respect to the inlet portion of said passage internal wall at an angle in the range of 25-35 degrees, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.
3. The fluid injector as recited in claim 2 , wherein:
said expansion having a portion that slopes with respect to the outlet portion of said passage internal wall at an angle in the range of 2-8degrees.
4. The fluid injector as recited in claim 2 , wherein:
the cross-sectional area of said flow passage at the location of said expansion downstream end is in the range of 28-72percent of said cross-sectional area of said passage inlet.
5. The fluid injector as recited in claim 1 , wherein:
said expansion having a portion that slopes with respect to the outlet portion of said passage internal wall at an angle in the range of 2-8degrees, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.
6. The fluid injector as recited in claim 1 , wherein:
the cross-sectional area of said flow passage at the location of said expansion downstream end is in the range of 28-72percent of said cross-sectional area of said passage inlet, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.
7. The fluid injector as recited in claim 1 , wherein:
said cavity having an effective width of “w” and an effective depth of “h”, and said flow passage having an effective inlet diameter of “d”,
the ratio of “w/d” is in the range of 100-200%, and
the ratio of “hid” is in the range of 30-70%.
8. A method for injecting a secondary fluid into a carrier fluid that flows through a body that directs the flow of said carrier fluid, said body having an internal wall forming a flow passage therethrough, said flow passage having a central axis, an inlet, an outlet, and a port for receiving said secondary fluid that is mixed with said carrier fluid, said method comprising the steps of:
providing a ramp-like restriction located downstream of said inlet and upstream of said port and extending from said body internal wall so as to decrease the effective cross-sectional area of said flow passage in the direction of the flow of said carrier fluid, said restriction having a downstream end at which is located a rear surface that extends abruptly down to said flow passage internal wall,
providing a ramp-like expansion located downstream of said port and upstream of said outlet and extending from said body internal wall so as to increase the effective cross-sectional area of said flow passage in the direction of the flow of said carrier fluid, said expansion having an upstream end at which is located a front surface that extends abruptly upward from said flow passage internal wall,
wherein said restriction and expansion being situated on said internal wall so as to form between said restriction rear surface and expansion front surface a cavity, and
wherein said port located in said cavity.
9. The method as recited in claim 8 , wherein:
said restriction having a portion that slopes with respect to the inlet portion of said passage internal wall at an angle in the range of 25-35 degrees, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.
10. The method as recited in claim 9 , wherein:
said expansion having a portion that slopes with respect to the outlet portion of said passage internal wall at an angle in the range of 2-8 degrees.
11. The method as recited in claim 9 , wherein:
the cross-sectional area of said flow passage at the location of said expansion downstream end is in the range of 28-72percent of said cross-sectional area of said passage inlet.
12. The method as recited in claim 8 , wherein:
said expansion having a portion that slopes with respect to the outlet portion of said passage internal wall at an angle in the range of 2-8degrees, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.
13. The method as recited in claim 12 , wherein:
said cavity having an effective width of “w” and an effective depth of “h”, and said flow passage having an effective inlet diameter of “d”,
the ratio of “w/d” is in the range of 100-200%, and
the ratio of “h/d” is in the range of 30-70%.
14. The method as recited in claim 8 , wherein:
the cross-sectional area of said flow passage at the location of said expansion downstream end is in the range of 28-72percent of said cross-sectional area of said passage inlet, and
said cavity having an effective width of “w”, and said flow passage having an effective inlet diameter of “d”, and the ratio of “w/d” is in the range of 100-200%.