Silencer for suction or discharge of fluids under pressure

Claim 2

A silencer for suction or discharge of a fluid due to a pressure difference comprising: an inlet pipe for said fluid having the consTruction of an increaser pipe; an outer shell made of a rigid plate material having a sound shielding characteristic, said outer shell having the shape of a hollow truncated cone with an outwardly divergent angle and contiguously connected at the small-diameter end thereof to the inlet pipe, the inner surface of the outer shell being covered with a sound absorbing layer of a specific thickness; at least one intermediate shell having the shape of a hollow truncated cone and supported within and coaxially with the outer shell by at least one supporting member; and an inner shell disposed coaxially at the centerline of the outer shell, the combination of the outer shell, said at least one intermediate shell, and the inner shell constituting a noise-reducing mechanism.

Claim 3

The silencer as claimed in claim 1 in which each intermediate shell is covered over the inner and outer surfaces thereof with respective sound absorbing layers filled with sound absorbing material.

Claim 4

The silencer as claimed in claim 1 in which the inner shell has a hollow interior space filled with a sound absorbing material

Claim 5

The silencer as claimed in claim 1 in which the outer shell, each intermediate shell, and the inner shell have respective outwardly divergent angles within the range of from 7* to 33*.

Claim 6

The silencer as claimed in claim 1 in which the outer, large-diameter end of the entire silencer is cut off along a plane at an angle of from 30* to 60* relative to the silencer centerline.

Claim 7

A silencer for an axial flow fan for causing flow of a fluid, comprising an outer shell and an inner shell disposed within the outer shell, each shell having the shape of a hollow truncated cone or pyramid with a divergent angle in the outward, discharge direction and having sound absorbing material on surfaces thereof along which said fluid is to flow, said shells being disposed and supported in respective positions coaxial with said axial flow fan, the inner shell being a hollow vessel structure closed at the end thereof in the outward, discharge direction and having an open opposite end covered by a porous sound absorbing structure, the outer surface of the inner shell being covered with a sound absorbing material.

Claim 8

A silencer for an axial flow fan for causing flow of a fluid, comprising an outer shell and an inner shell disposed within the outer shell, each shell having the shape of a hollow truncated cone or pyramid with a divergent angle in the outward, discharge direction and having sound absorbing material on surfaces thereof along which said fluid is to flow, said shells being disposed and supported in respective positions coaxial with said axial flow fan, the inner shell being a hollow vessel structure closed at the end thereof in the outward, discharge direction and having an open opposite end covered by a porous sound absorbing structure, the outer surface of the inner shell being covered with a sound absorbing material.

Claim 9

A silencer for an axial flow fan having a propeller driven by a shaft on the upstream side thereof and disposed coaxially within a cylindrical structure, said silencer comprising, in combination: a downstream silencer structure disposed coaxially with and downstream from the propeller and consisting, essentially, in concentric arrangement, an outer shell connected at its upstream end to the downstream end of said cylindrical structure, an inner shell closed at its downstream end and having an open upstream end covered by a porous sound absorbing structure, and at least one intermediate shell disposed between the outer and inner shells, each of said shells having the shape of a hollow truncated cone with a divergent angle in the downstream direction and having sound absorbing material on surfaces thereof along which said fluid is to flow; and an upstream silencer structure disposed coaxially with and upstream from the propelled and consisting, essentially in concentric arrangement, an outer shell connected at its downstream end to the upstream end of said cylindrical structure, an inner shell disposed around the propeller shaft, and at least one intermediate shell disposed between the outer and inner shells, each of said shells having the shape of a hollow truncated cone with a divergent angle in the upstream direction and having sound absorbing material on surfaces thereof along which said fluid is to flow.

Claim 10

A silencer for an axial flow fan having a propeller driven by a shaft on the upstream side thereof and disposed coaxially within a cylindrical structure, said silencer comprising, in combination: a downstream silencer structure disposed coaxially with and downstream from the propeller and consisting, essentially, in concentric arrangement, an outer shell connected at its upstream end to the downstream end of said cylindrical structure, an inner shell closed at its downstream end and having an open upstream end covered by a porous sound absorbing structure, and at least one intermediate shell disposed between the outer and inner shells, each of said shells having the shape of a hollow truncated cone with a divergent angle in the downstream direction and having sound absorbing material on surfaces thereof along which said fluid is to flow; and an upstream silencer structure disposed coaxially with and upstream from the propelled and consisting, essentially in concentric arrangement, an outer shell connected at its downstream end to the upstream end of said cylindrical structure, an inner shell disposed around the propeller shaft, and at least one intermediate shell disposed between the outer and inner shells, each of said shells having the shape of a hollow truncated cone with a divergent angle in the upstream direction and having sound absorbing material on surfaces thereof along which said fluid is to flow.