Silencer duct having silencing element extending therethrough

Abstract

A silencer duct that may be part of, for example, a turbomachine inlet may include a duct body. A first perforated wall extends within the duct body and substantially parallel to an interior surface of the duct body. A first acoustic absorbing material may be positioned between the duct body and the first perforated wall. A silencer element may extend axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.

What is claimed is: 
     
         1 . A silencer duct, comprising:
 a duct body;   a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body;   a first acoustic absorbing material positioned between the duct body and the first perforated wall; and   a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.   
     
     
         2 . The silencer duct of  claim 1 , wherein at least one of the first and second acoustic absorbing materials includes at least one of: foam, mineral wool, rock wool and fiberglass. 
     
     
         3 . The silencer duct of  claim 1 , wherein at least one of the duct body, the first perforated wall and the second perforated wall is made of plastic. 
     
     
         4 . The silencer duct of  claim 1 , wherein the second perforated wall has a hollow interior, and the second acoustic absorbing material is positioned within the hollow interior; and
 further comprising at least one support rib extending from at least one of the duct body and the first perforated wall to support the second perforated wall.   
     
     
         5 . The silencer duct of  claim 4 , further comprising an inner support axially positioned within the hollow interior, and at least one of the plurality of support ribs couples to the inner support for supporting the silencer element. 
     
     
         6 . The silencer duct of  claim 1 , wherein the duct body has a substantially hexagonal cross-section. 
     
     
         7 . The silencer duct of  claim 1 , wherein the silencer element includes a septum including a plurality of partitioning portions partitioning the duct body into at least two chambers, each partitioning portion including a pair of the second perforated walls having the second acoustic absorbing material positioned therebetween; and
 further comprising an inner support extending between the pairs of the second perforated walls of at least one of the partitioning portions to support the silencer element.   
     
     
         8 . The silencer duct of  claim 7 , wherein each of the second perforated walls couples to the first perforated wall. 
     
     
         9 . The silencer duct of  claim 7 , wherein the silencer duct includes a first, axially curved portion curving from an upstream end to a downstream end thereof such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof. 
     
     
         10 . The silencer duct of  claim 9 , wherein the first portion has an elongated S-shape. 
     
     
         11 . The silencer duct of  claim 9 , further comprising a second, axially linear portion extending from at least one of the downstream end of the first, axially curved portion and the upstream end of the first, axially curved portion. 
     
     
         12 . The silencer duct of  claim 8 , wherein the silencer element spirals from an upstream end to a downstream end of duct body such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof. 
     
     
         13 . A turbomachine inlet, comprising:
 an intake frame forming a working fluid flow, the intake frame operatively coupled to a compressor; and   a silencer duct positioned within the intake frame, the silencer duct including:
 a duct body, 
 a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body, 
 a first acoustic absorbing material positioned between the duct body and the first perforated wall, and 
 a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto. 
   
     
     
         14 . The turbomachine inlet of  claim 13 , wherein at least one of the duct body, the first perforated wall and the second perforated wall is made of plastic. 
     
     
         15 . The turbomachine inlet of  claim 13 , wherein the second perforated wall has a hollow interior, the second acoustic absorbing material is positioned within the hollow interior; and
 further comprising a plurality of support webs extending from the duct body to support the second perforated wall.   
     
     
         16 . The turbomachine inlet of  claim 15 , further comprising an inner support axially positioned within the hollow interior, and at least one of the plurality of support webs couples to the inner support for supporting the silencer element. 
     
     
         17 . The turbomachine inlet of  claim 13 , wherein the silencer element includes a septum including a plurality of partitioning portions partitioning the duct body into at least two chambers, each partitioning portion including a pair of the second perforated walls having the second acoustic absorbing material positioned therebetween; and
 further comprising an inner support extending between the pairs of the second perforated walls of at least one of the partitioning portions to support the silencer element.   
     
     
         18 . The turbomachine inlet of  claim 17 , wherein the silencer duct includes a first, axially curved portion curving from an upstream end to a downstream end thereof such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof. 
     
     
         19 . The turbomachine inlet of  claim 18 , further comprising a second, axially linear portion extending from at least one of the downstream end of the first, axially curved portion and the upstream end of the first, axially curved portion. 
     
     
         20 . The turbomachine inlet of  claim 17 , wherein the silencer element spirals from an upstream end to a downstream end of duct body such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof.