Devices for producing vacuum using the venturi effect having a plurality of subpassageways and motive exits in the motive section
Devices for producing vacuum using the Venturi effect are disclosed that have a motive passageway converging toward a suction chamber, a discharge passageway diverging away from the suction chamber, and a suction passageway, all of which are in fluid communication with the suction chamber. The motive passageway has a single entrance, and subdivides downstream thereof into a plurality of subpassageways, one each leading to one of the plurality of motive exits, which are spaced apart from a discharge entrance of the discharge passageway to define a Venturi gap. The fletch having a plurality of ribs extending between an exterior surface of the generally conically-shaped main body thereof and an interior surface of the motive passageway is disposed in the motive passageway. The ribs divide the motive passageway into the plurality of sub-passageways, each converging fluid flow over the exterior surface thereof toward one of the plurality of motive exits.
1. A device for producing vacuum using the Venturi effect comprising:
a housing defining a suction chamber, a motive passageway converging toward the suction chamber and in fluid communication therewith, a discharge passageway diverging away from the suction chamber and in fluid communication therewith, and a suction passageway in fluid communication with the suction chamber;
wherein the motive passageway has a single entrance and a plurality of motive exits, and
a fletch in the motive passageway to subdivide the motive passageway downstream of the single entrance into a plurality of subpassageways, one each converging toward one of the plurality of motive exits;
wherein the plurality of motive exits are aligned with and spaced apart from a discharge entrance of the discharge passageway to define a Venturi gap;
wherein the fletch further comprises a tail positioned within the suction chamber in alignment with the plurality of motive exits for fluid flow from the plurality of motive exits to flow over an exterior surface of the tail.
2. The device of claim 1 , wherein the fletch has a conically-shaped main body positioned with a base of the main body proximate the plurality of motive exits, and a plurality of ribs extending between an exterior surface of the conically-shaped main body and an interior surface of the motive passageway, thereby defining the plurality of subpassageways.
3. The device of claim 2 , wherein the conically-shaped main body converges toward its base following a straight, parabolic, hyperbolic, or polynomial curve function.
4. The device of claim 2 , wherein the interior shape of the motive passageway proximate the plurality of motive exits and the exterior shape of the base of the conically-shaped main body are both circular or elliptical.
5. The device of claim 2 , wherein the plurality of ribs protrude from the exterior surface of the conically-shaped main body.
6. The device of claim 1 , wherein the cross-sectional area of the plurality of motive exits, collectively, is smaller than the cross-sectional area of the discharge entrance.
7. A device for producing vacuum using the Venturi effect comprising:
a housing defining a suction chamber, a motive passageway converging toward the suction chamber and in fluid communication therewith, a discharge passageway diverging away from the suction chamber and in fluid communication therewith, and a suction passageway in fluid communication with the suction chamber;
wherein the motive passageway has a single entrance and a plurality of motive exits, and subdivides downstream of the single entrance into a plurality of subpassageways, one each leading to one of the plurality of motive exits; and
wherein the plurality of motive exits are aligned with and spaced apart from a discharge entrance of the discharge passageway to define a Venturi gap;
wherein the discharge entrance protrudes into the suction chamber a distance thereby providing suction flow around the entirety of an exterior surface of the discharge entrance.
8. The device of claim 2 , wherein fluid flow from the plurality of motive exits flows over the exterior surface of the tail toward an apex of the tail; wherein the apex of the tail is positioned inside the discharge entrance of the discharge passageway.
9. The device of claim 7 , wherein the suction chamber has a rounded interior bottom below the discharge entrance.
10. The device of claim 7 , wherein the suction chamber has an internal width of a 10 mm to a 25 mm.
11. The device of claim 1 , wherein the motive passageway and the discharge passageway both diverge in cross-sectional area away from the suction chamber as a hyperbolic or parabolic function.
12. The device of claim 1 , wherein each subpassageway is rectangular in cross-section proximate one of the plurality of motive exits.
13. The device of claim 12 , wherein each subpassageway converges toward one of the plurality of motive exits from a main passageway with an outer interior wall, when viewed from a top, longitudinal cross-section, as a hyperbolic function.
14. The device of claim 13 , wherein each subpassageway converges toward one of the plurality of motive exits from the main passageway with an inner interior wall, when viewed from a top, longitudinal cross-section, as a hyperbolic function.
15. A system comprising:
the Venturi device of claim 1 ;
a source of pressure fluidly connected to the motive passageway;
a device requiring vacuum fluidly connected to the suction passageway; and
a pressure lower than the source of pressure is fluidly connected to the discharge passageway.
16. The system of claim 15 , wherein the source of pressure is atmospheric pressure or is boost pressure from a compressor of a turbocharger or supercharger.