Exhaust treatment devices and methods for reducing sound using the exhaust treatment devices

Abstract

Exhaust treatment devices and methods for reducing sound using the exhaust treatment devices are provided. In one exemplary embodiment, the exhaust treatment device includes a housing and a catalyst disposed in the housing. The exhaust treatment device further includes a first end cone having a first inner wall and a first outer wall. The first outer wall is secured to the first inner wall at one end. The first outer wall is secured to the housing at another end. The first inner wall is spaced from the first outer wall at the other end such that the first inner wall and the first outer wall define a first cavity therebetween. The first inner wall is spaced from the catalyst at the other end such that an inlet is defined that communicates with the first cavity, wherein exhaust gases flowing through the inlet into the first cavity attenuate sound within the first end cone and the housing.

1 . An exhaust treatment device, comprising:
 a housing;   a catalyst disposed in the housing; and   a first end cone having a first inner wall and a first outer wall, the first outer wall secured to the first inner wall at one end, the first outer wall being secured to the housing at another end, the first inner wall being spaced from the first outer wall at the other end such that the first inner wall and the first outer wall define a first cavity therebetween, the first inner wall being spaced from the catalyst at the other end such that an inlet is defined that communicates with the first cavity, wherein exhaust gases flowing through the inlet into the first cavity attenuate sound within the first end cone and the housing.   
   
   
       2 . The exhaust treatment device of  claim 1 , wherein the exhaust gases flowing through the inlet into the first cavity attenuate sound at a predetermined frequency in the first end cone and the housing. 
   
   
       3 . The exhaust treatment device of  claim 1 , wherein the predetermined frequency is based on a volume of the first cavity, an area of the inlet, and a length of the inlet. 
   
   
       4 . The exhaust treatment device of  claim 1 , further comprising:
 a second end cone disposed on the housing on an end of the housing opposite the first end cone, the second end cone having a second inner wall and a second outer wall, the second outer wall secured to the second inner wall at a first end, the second outer wall being secured to the housing at a second end, a portion of the second inner wall being spaced from the second outer wall such that the second inner wall and the second outer wall define a second cavity therebetween, the second inner wall having at least one aperture extending therethrough, wherein exhaust gases flowing through the at least one aperture into the second cavity attenuate sound within the second end cone and the housing.   
   
   
       5 . The exhaust treatment device of  claim 4 , wherein exhaust gases flowing through the inlet into the first cavity attenuate sound at a first predetermined frequency and exhaust gases flowing through the at least one aperture into the second cavity attenuate sound at a second predetermined frequency, the second predetermined frequency differing from the first predetermined frequency. 
   
   
       6 . A method for reducing sound in an exhaust treatment device, the exhaust treatment device having a housing, a first end cone, and a catalyst, the catalyst being disposed in the housing, the first end cone having a first inner wall and a first outer wall, the first outer wall being secured to the first inner wall at one end, the first outer wall being secured to the housing at another end, the first inner wall being spaced from the first outer wall at the other end such that the first inner wall and the first outer wall define a first cavity therebetween, the first inner wall being spaced from the catalyst at the other end such that an inlet is defined that communicates with the first cavity, the method comprising:
 receiving exhaust gases in the first end cone such that a portion of the exhaust gases flow through the inlet into the first cavity of the first end cone; and   attenuating sound within the first end cone and the housing utilizing the portion of the exhaust gases flowing through the inlet into the first cavity of the first end cone.   
   
   
       7 . An exhaust treatment device, comprising:
 a housing;   a catalyst disposed in the housing; and   a first end cone having a first inner wall and a first outer wall, the first outer wall secured to the first inner wall at one end, the first outer wall being secured to the housing at another end, the first inner wall being spaced from the first outer wall at the other end such that the first inner wall and the first outer wall define a first cavity therebetween, the first inner wall being spaced from the catalyst at the other end such that an inlet is defined that communicates with the first cavity, the first inner wall having at least one aperture extending therethrough, wherein exhaust gases flowing through the inlet and the at least one aperture of the first inner wall into the first cavity attenuate sound within the first end cone and the housing.   
   
   
       8 . The exhaust treatment device of  claim 7 , wherein the exhaust gases flowing through the inlet and the at least one aperture of the first inner wall into the first cavity attenuate sound at a predetermined frequency in the first end cone and the housing. 
   
   
       9 . The exhaust treatment device of  claim 8 , wherein the predetermined frequency is based on a volume of the first cavity, a combined area of the inlet and the aperture, a length of the inlet, and a thickness of the first inner wall proximate the aperture. 
   
   
       10 . The exhaust treatment device of  claim 7 , further comprising:
 a second end cone disposed on the housing on an end of the housing opposite the first end cone, the second end cone having a second inner wall and a second outer wall, the second outer wall secured to the second inner wall at a first end, the second outer wall being secured to the housing at a second end, a portion of the second inner wall being spaced from the second outer wall such that the second inner wall and the second outer wall define a second cavity therebetween, the second inner wall having at least one aperture extending therethrough, wherein exhaust gases flowing through the at least one aperture of the second inner wall into the second cavity attenuate sound within the second end cone and the housing.   
   
   
       11 . The exhaust treatment device of  claim 10 , wherein exhaust gases flowing through the inlet and the at least one aperture of the first inner wall into the first cavity attenuate sound at a first predetermined frequency and exhaust gases flowing through the at least one aperture of the second inner wall into the second cavity attenuate sound at a second predetermined frequency, the second predetermined frequency differing from the first predetermined frequency. 
   
   
       12 . A method for reducing sound in an exhaust treatment device, the exhaust treatment device having a housing, a first end cone, and a catalyst, the catalyst being disposed in the housing, the first end cone having a first inner wall and a first outer wall, the first outer wall being secured to the first inner wall at one end, the first outer wall being secured to the housing at another end, the first inner wall being spaced from the first outer wall at the other end such that the first inner wall and the first outer wall define a first cavity therebetween, the first inner wall being spaced from the catalyst at the other end such that an inlet is defined that communicates with the first cavity, the first inner wall having at least one aperture extending therethrough, the method comprising:
 receiving exhaust gases in the first end cone such that a portion of the exhaust gases flow through the inlet into the first cavity of the first end cone and another portion of the exhaust gases flow through the at least one aperture of the first inner wall into the first cavity; and   attenuating sound within the first end cone and the housing utilizing the portion of the exhaust gases flow through the inlet into the first cavity of the first end cone and the portion of the exhaust gases flowing through the at least one aperture of the first inner wall into the first cavity.