Outlet silencer for cooling tower, evaporator cooler or condenser

Abstract

A sound attenuating apparatus for mounting on a heat exchanging apparatus such as a cooling tower, this apparatus having an attenuator housing with vertically extending sides, a top cover and a bottom adapted for mounting on the tower. There is an annular air inlet in the bottom and an air outlet is formed in at least one of the sidewalls. Perforated interior walls are mounted in the housing and define an /airflow passageway that extends from the air inlet to the air outlet. These walls include a first annular wall section extending about and defining an outer circumferential portion of the airflow passageway and a second wall section with that is annular and extends about a substantially vertical central axis. The latter wall section defines an inner circumferential portion of the passageway. The second wall section extends generally upwardly and outwardly from the air inlet. Sound absorbing material is arranged behind the perforated walls.

We claim:  
     
         1 . A sound attenuating apparatus for mounting on a heat exchanging apparatus such as a cooling tower, evaporative cooler, condensing unit, and the like, said apparatus comprising: 
 an attenuator housing having vertically extending sides defined by exterior sidewalls, a cover defined by an exterior, substantially unbroken top wall, and a bottom adapted for mounting on said heat exchanging apparatus, an annular air inlet being formed in said bottom and a main air outlet being formed in at least one of said sidewalls;    perforated interior walls mounted in said housing and defining an airflow passageway that extends from said air inlet to said main air outlet, said interior walls including a first annular wall section extending about and defining an outer circumferential portion of said airflow passageway and a second wall section that is substantially annular, extends about a substantially vertical central axis, and defines an inner circumferential portion of the airflow passageway, said second wall section extending generally upwardly and outwardly from said annular air inlet; and    sound absorbing material arranged behind said perforated interior walls on the sides thereof opposite said airflow passageway.    
     
     
         2 . A sound attenuating apparatus according to  claim 1  wherein said second wall section is substantially conical in shape and diverges upwardly and outwardly about its circumference.  
     
     
         3 . A sound attenuating apparatus according to  claim 2  including a sound reducing resonator located at said air inlet and extending about the outer circumference of said air inlet.  
     
     
         4 . A sound attenuating apparatus according to  claim 2  wherein said housing has four of said vertically extending sides and said air inlet extends substantially about a horizontal perimeter of said housing so as to be located in the four vertically extending sides.  
     
     
         5 . A sound attenuating apparatus according to  claim 2  wherein said sound absorbing material comprises compressed fibreglass batting.  
     
     
         6 . A sound attenuating apparatus according to  claim 1  wherein said second wall section includes a lowermost portion having a cylindrical shape, an intermediate portion which is substantially conical in shape and slopes upwardly and outwardly, and a top portion that extends substantially horizontally and outwardly.  
     
     
         7 . A sound attenuating apparatus according to  claim 6  including an annular sound reducing resonator located at said air inlet and extending about the outer circumference of said air inlet, said resonator having a plurality of holes formed in an inwardly facing wall thereof and distributed about its circumference.  
     
     
         8 . A combined cooling tower and sound attenuating apparatus, said combination comprising: 
 a cooling tower system including a tower structure, a fan unit mounted in said tower structure and arranged to circulate an airflow through said tower system for exit through an opening located in a top of said tower structure, and a liquid circulation system mounted in said tower structure and capable of circulating a liquid in said tower system so that liquid can be cooled by said air flow;    an attenuator housing having a vertically extending wall portion, a top cover, and a bottom, said housing being mounted on said top of said tower structure and having an air inlet formed in said bottom and arranged and aligned to receive said air flow from said opening, said housing further having an air outlet formed in said vertically extending wall portion;    perforated interior walls mounted in said housing and defining an airflow passage that extends from said air inlet to said air outlet, said interior walls including inner and outer annular wall sections extending around a substantially vertical central axis, said inner wall section extending generally upwardly and outwardly from said air inlet; and    sound absorbing material arranged behind said perforated interior walls on sides thereof opposite said airflow passage.    
     
     
         9 . A combination according to  claim 8  wherein said inner annular wall section is substantially conical in shape and diverges upwardly and outwardly about its circumference.  
     
     
         10 . A combination according to  claim 9  wherein said fan unit comprises an axial fan rotatable about a substantially vertical axis and said fan unit is located adjacent said top of the tower structure and wherein said air flow enters said tower system through one or more tower inlets located in one or more sides of said tower system.  
     
     
         11 . A combination according to  claim 9  including a sound reducing resonator located at said air inlet and extending about the circumference of said air inlet.  
     
     
         12 . A combination according to  claim 9  wherein said sound absorbing material is compressed fiberglass batting.  
     
     
         13 . A combination according to  claim 9  wherein said outer annular wall section is substantially cylindrical and extends upwardly to said air outlet, which extends about a horizontal perimeter of said housing.  
     
     
         14 . A sound attenuating apparatus for mounting on a heat exchanging apparatus such as a cooling tower, evaporative cooler, condensing unit, and the like, said sound attenuating apparatus comprising; 
 an attenuator housing arrangement having a top cover section, a bottom adapted for mounting on said heat exchanging apparatus and exterior sides defined by sidewalls extending upwardly from said bottom, said housing arrangement also including annular air inlets formed in said bottom and at least one air outlet formed in said exterior sides;    perforated interior walls mounted in said housing arrangement and defining air flow passageways that extend from said air inlets to said at least one air outlet, said interior walls including inner wall sections and outer wall sections arranged in pairs so that each pair comprises one of the inner wall sections and one of said outer wall sections, the wall sections of each pair extending around a substantially vertical central axis, each inner wall section extending generally upwardly and outwardly from a respective one of said air inlets, each outer wall section extending about its respective inner wall section and spaced therefrom; and    sound absorbing material arranged behind said perforated interior walls or sides thereof opposite said airflow passageways.    
     
     
         15 . A sound attenuating apparatus according to  claim 14  wherein each inner wall section is substantially conical in shape and diverges upwardly and outwardly about its circumference.  
     
     
         16 . A sound attenuating apparatus according to  claim 15  including a sound reducing resonator located at each air inlet and extending about the circumference of its respective air inlet.  
     
     
         17 . A sound attenuating apparatus according to  claim 15  wherein said sound absorbing material comprises compressed fibreglass batting.  
     
     
         18 . A sound attenuating apparatus according to  claim 14  wherein said at least one air outlet extends along all of said exterior sides of said housing arrangement and is adjacent said top cover section.  
     
     
         19 . A sound attenuating apparatus according to  claim 14  wherein each outer wall section includes a lower wall portion that tapers inwardly and upwardly and an upper wall portion that diverges outwardly and upwardly.  
     
     
         20 . A sound attenuating apparatus according to  claim 19  wherein each airflow passageway includes an upper passage section that extends to said at least one air outlet and that slopes radially outwardly and upwardly.  
     
     
         21 . A combined condenser unit and sound attenuating apparatus, said combination comprising: 
 a condenser system including a condenser housing forming an airflow passageway and an air outlet opening located in a top of said housing, a fan unit mounted in said housing and arranged to circulate an airflow through said housing for exit through said outlet opening, and a fluid circulation system capable of circulating a heat exchanging fluid in said condenser system so that said fluid can be cooled by said airflow;    an attenuator housing having a vertically extending wall portion, a top cover, and a bottom end, said attenuator housing being mounted on top of said condenser system and having an air inlet formed in said bottom end and arranged to receive said airflow from said outlet opening, said attenuator housing having an attenuator air outlet formed in said vertically extending wall portion;    perforated interior walls mounted in said attenuator housing and defining an airflow passage that extends from said air inlet to said attenuator air outlet, said interior walls including inner and outer annular wall sections extending around a substantially vertical central axis, said inner wall section extending generally upwardly and outwardly relative to said central axis; and    sound absorbing material arranged behind said perforated interior walls on sides thereof opposite said airflow passage.    
     
     
         22 . A combination according to  claim 21  wherein inner annular wall section is substantially conical in shape and diverges upwardly and outwardly about its circumference.  
     
     
         23 . A combination according to  claim 22  wherein said fan unit comprises an axial fan rotatable about a substantially vertical axis and said fan unit is located in a top section of the condenser housing and wherein said airflow enters said condenser housing through one or more openings located in a bottom of said condenser housing.  
     
     
         24 . A combination according to  claim 23  wherein said attenuator air outlet extends horizontally along at least two vertically extending sides of the attenuator housing.  
     
     
         25 . A combination according to  claim 21  wherein said top cover extends over a top end of said attenuator housing and prevents any of said airflow from passing upwardly through said top end.