Fan shroud for heat exchange tower fans

Abstract

A heat exchange tower which has at least one fan having fan blades and a fan shroud, and the fan shroud has a sound absorbing portion including an outer ring structure and a sound absorbing material disposed inside the outer ring structure and outside of the circle of rotation of the fan blades. A flared inlet portion is provided leading to the sound absorbing portion.

1 . A heat exchange tower, comprising:
 at least one fan having fan blades with outer tips rotating in a circle of rotation; and   a fan shroud, the fan shroud comprising:
 an outer ring structure; and 
 a sound absorbing material mounted to the outer ring surface and disposed radially inside the outer ring structure and outside of the circle of rotation of the tips of the fan blades. 
   
   
   
       2 . The heat exchange tower of  claim 1 , wherein the fan shroud comprises a flared inlet portion leading into the outer ring structure. 
   
   
       3 . The heat exchange tower of  claim 2 , wherein the inlet portion is integral with the outer ring structure. 
   
   
       4 . The heat exchange tower according to  claim 1 , further comprising an inner structure that sandwiches the sound absorbing material between the inner structure and the outer ring structure. 
   
   
       5 . The heat exchange tower according to  claim 4 , wherein the inner structure comprises a metal screen. 
   
   
       6 . The heat exchange tower according to  claim 1 , wherein the outer ring comprises a plurality of arcuate sections. 
   
   
       7 . The heat exchange tower according to  claim 1 , wherein the outer ring comprises at least one C-shaped arcuate metal band. 
   
   
       8 . The heat exchange tower according to  claim 1 , wherein the outer ring comprises at least one molded fiberglass arcuate section that forms at least one pocket that receives the sound absorbing material. 
   
   
       9 . The heat exchange tower according to  claim 1 , wherein the sound absorbing material is fiberglass batting. 
   
   
       10 . The heat exchange tower according to  claim 1 , wherein the sound absorbing material is foam. 
   
   
       11 . The heat exchange tower according to  claim 4 , wherein the outer ring comprises at least one C-shaped arcuate metal band. 
   
   
       12 . The heat exchange tower according to  claim 4 , wherein the outer ring comprises at least one molded fiberglass arcuate section that forms at least one pocket that receives the sound absorbing material. 
   
   
       13 . The heat exchange tower according to  claim 4 , wherein the sound absorbing material is fiberglass batting. 
   
   
       14 . The heat exchange tower according to  claim 4 , wherein the sound absorbing material is foam. 
   
   
       15 . A heat exchange tower, comprising:
 at least one fan having fan blades with outer tips rotating in a circle of rotation; and   a fan shroud, the fan shroud comprising:
 an outer supporting means; and 
 a sound absorbing means mounted to the outer supporting means disposed radially inside the outer supporting means and outside of the circle of rotation of the tips of the fan blades. 
   
   
   
       16 . The heat exchange tower of  claim 15 , wherein the fan shroud comprises a flared inlet portion leading into the outer supporting means. 
   
   
       17 . The heat exchange tower according to  claim 15 , further comprising an inner supporting means that sandwiches the sound absorbing material between the inner and the outer supporting means. 
   
   
       18 . A heat exchange tower, comprising:
 at least one fan having fan blades with outer tips rotating in a circle of rotation; and   a fan shroud, the fan shroud comprising:
 an outer ring structure formed of at least one molded section, the section forming at least one pocket; and 
 a sound absorbing material disposed inside the pocket and radially outside of the circle of rotation of the tips of the fan blades. 
   
   
   
       19 . A heat exchange tower according to  claim 18 , wherein the molded section includes at least two axially spaced pockets separated by a rib in between the pockets, with sound absorbing material disposed in each pocket. 
   
   
       20 . A method for reducing sound emitted by a heat exchange tower, the tower having at least one fan blade with outer tips rotating in a circle of rotation, and a fan shroud surrounding the circle of rotation of the tips, comprising the step of:
 providing a sound absorbing material on an inner surface of the shroud between the inner surface of the shroud and the circle of rotation of the blade tips.   
   
   
       21 . An air cooled condenser, comprising:
 a plurality of condenser coils;   a fan deck disposed below the condenser coils, the fan deck comprising a plurality of fans having fan blades with outer tips rotating in a circle of rotation, and a plurality of fan shrouds each surrounding a respective fan, each fan shroud comprising:
 an outer ring structure; and 
 a sound absorbing material mounted to the outer ring surface and disposed radially inside the outer ring structure and outside of the circle of rotation of the tips of the fan blades.