Means and method for noise suppression

Claim 2

A noise suppressor comprising: an outer foam barrier; an inner perforate foam barrier positioned wiThin said outer barrier and spaced from the wall of said outer foam barrier; a radially enclosed axially extending passageway defined by the inner wall of said inner barrier, said passageway extending axially completely through said noise suppressor; and means for substantially filling the space between said inner and outer barriers with foamed liquid.

Claim 3

A noise suppressor of claim 1 wherein the outer foam barrier is a liquid pervious cylindrical member and the perforate inner foam barrier is a cylindrical member positioned concentrically within said outer foam barrier, the means for substantially filling the annular space between said inner and outer barriers with foamed liquid including a foam discharge header adapted to discharge liquid foam uniformly throughout said annular space, said header being connected to a means for providing liquid foam, a liquid collection tray positioned to receive liquid passing through the wall of said liquid pervious outer foam barrier, said noise suppressor being mounted on a movable supporting structure.

Claim 4

A noise suppressor comprising: means for radially surrounding an unconfined noise-radiating stream of high-velocity gas with a blanket of liquid foam from a location adjacent the origin of said stream of gas for an axial distance at least equal to the diameter of said stream of gas at its origin.

Claim 5

A noise suppressor comprising: means for radially surrounding an unconfined noise-radiating stream of high-velocity gas with a blanket of liquid foam from a location adjacent the origin of said stream of gas for an axial distance at least equal to the diameter of said stream of gas at its origin.

Claim 6

A noise suppressor of claim 4 including perforate means defining an axial passageway, said passageway being adapted to receive said stream of gas, said passageway having a diameter at least twice as great as the diameter of the stream of high-velocity gas at the origin of said stream.

Claim 7

A noise suppressor of claim 4 including perforate means defining an axial passageway, said passageway being adapted to receive said stream of gas, and means for generating said blanket of liquid foam including means for regulating the size of the bubbles in said foam to predetermined values which are less than the size of the perforations in said perforate means.

Claim 8

A process of suppressing noise comprising: radially surrounding an unconfined stream of high-velocity gas with a blanket of foamed liquid, said blanket extending axially rearward from a location adjacent the origin of the unconfined stream of gas for a distance at least as great as the diameter of the unconfined stream of gas at its origin, providing an axial passage for said stream of gas through said blanket of foamed liquid.

Claim 9

A process of suppressing noise comprising: radially surrounding an unconfined stream of high-velocity gas with a blanket of foamed liquid, said blanket extending axially rearward from a location adjacent the origin of the unconfined stream of gas for a distance at least as great as the diameter of the unconfined stream of gas at its origin, providing an axial passage for said stream of gas through said blanket of foamed liquid.

Claim 10

A process of claim 7 including regulating the size of the bubbles in said foamed liquid blanket to predetermined values.

Claim 11

A process of claim 7 wherein the unconfined stream of high-velocity gas is the exhaust from a jet engine and the inner diameter of the axial passageway in the blanket of foam is established at a value at least one and one-half times greater than the diameter of said exhaust at the point where said exhaust is ejected from said jet engine.

Claim 12

A process of suppressing noise according to claim 7 including continuously maintaining the blanket of foamed liquid radially around said unconfined stream of high-velocity gas for a predetermined period of time.

Claim 13

A noise suppressor of claim 1 wherein said inner and outer foam barriers are generally cylindrical and are mounted on a movable supporting structure.