Noise attenuation in a Venturi device and/or check valves
Venturi devices for producing vacuum are disclosed that include a housing defining a motive port, a suction port, a discharge port, a first flow passage between the motive port and the discharge port, and a second flow passage into and through the suction port and into fluid communication with the first flow passage, a first check valve incorporated into the housing and positioned to control fluid flow through the suction port, and a sound attenuating wrap about the outer surface of the housing. The Venturi devices may also include a sound attenuating member disposed in the first flow passage downstream of the intersection of the second flow passage and the first flow passage, in the portion of the second flow passage leading into the suction port, in the first check valve, or combinations thereof.
1. A Venturi device for producing vacuum comprising:
a housing defining a motive port, a suction port, a discharge port, a first flow passage between the motive port and the discharge port comprising a first tapering portion aligned end to end with a second tapering portion and spaced a distance apart from the second tapering port to define a fluid junction in fluid communication with the suction port, and a discharge section downstream of the second tapering portion, wherein the first tapering portion converges toward the fluid junction and the second tapering portion diverges from the fluid junction, and the housing further defining a second flow passage comprising an inlet port, a first port in fluid communication with the suction port, and a second port in fluid communication with the discharge section of the first flow passage, wherein the housing has an exterior surface;
a first check valve incorporated into the housing and positioned to control fluid flow through the suction port;
a second check valve incorporated into the housing and positioned to control fluid flow between the second port and the discharge section;
a first sound attenuating member disposed downstream of the first check valve within the second tapering portion; and
a sound attenuating material seated against the exterior surface of the housing, thereby encapsulating the first check valve and all or a portion of the housing defining the first flow passage and the second flow passage.
2. The Venturi device of claim 1 , further comprising a second sound attenuating member disposed in the second flow passage or in the second check valve.
3. The Venturi device of claim 2 , wherein the first and second sound attenuating members comprise a plug of porous sound attenuating material.
4. The Venturi device of claim 3 , wherein the first and second sound attenuating members comprise metals, plastics, ceramics, or glass.
5. The Venturi device of claim 3 , wherein the first and second sound attenuating members comprise wire, woven or matted, sintered particles, woven or matted fibers, and combinations thereof.
6. The Venturi device of claim 1 , further comprising a second sound attenuating member disposed in the first flow passage proximate to or in the discharge port.
7. The Venturi device of claim 1 , wherein the sound attenuating material about the outer surface of the housing includes a first member conformed to the contours of the exterior surface of the housing and a second member surrounding the first member, wherein the first member is interposed between the housing and the second member.
8. The Venturi device of claim 7 , wherein the first member is a foamable material.
9. The Venturi device of claim 7 , wherein the first member is molded to the contours of the exterior surface of the housing, and defines a more uniform outer surface once molded thereto.
10. The Venturi device of claim 7 , wherein the first member and the second member comprise different materials.
11. The Venturi device of claim 1 , wherein the sound attenuating material about the outer surface of the housing is molded to the contours of the exterior surface of the housing, and defines a seamless sleeve having a more uniform outer surface than the housing.
12. The Venturi device of claim 1 , wherein the sound attenuating material comprises a plurality of molded portions each having an inner surface contoured to match the contours of a portion of the exterior surface of the housing, wherein the plurality of molded portions are seated against the exterior surface of the housing and are connected together and/or to the housing by a retention mechanism.