Evaporative cooling device

Abstract

An evaporative cooler for cooling a fluid contained in an array of spaced heat exchange elements by heat transfer to a cooling liquid flowing downwardly around the elements in counter current flow to an upwardly flowing gas is provided. The evaporative cooler includes a casing ( 1 ) housing the array ( 2 ) of spaced heat exchange elements, the gas flowing upwardly through the casing, and humid gas leaving the casing at an upper end; a restrictor ( 3 ) comprising a series of apertures ( 3 a ) located below the array of spaced heat exchange elements; the spaces between the heat exchange elements being aligned with the apertures, to provide substantially straight upwardly directed gas-flow channels through the heat exchange array; gas being drawn into the casing through the restrictor apertures and producing a pressure drop sufficient to inhibit loss of cooling liquid from a lower end of the cooler; and a coalescer ( 6 ) located above the heat exchange array, such that liquid droplets entrained in the upward gas flow are captured and coalesced to a size whereby coalesced liquid droplets falls down onto the heat exchange array.

1 . An evaporative cooler for cooling a fluid contained in an array of spaced heat exchange elements by heat transfer to a cooling liquid flowing downwardly around the elements in counter current flow to an upwardly flowing gas; which comprises
 a casing housing the array of spaced heat exchange elements, the gas flowing upwardly through the casing, and humid gas leaving the casing at an upper end;   a restrictor comprising a series of apertures located below the array of spaced heat exchange elements; the spaces between the heat exchange elements being aligned with the apertures to provide substantially straight upwardly directed gas-flow channels through the heat exchange array; gas being drawn into the casing through the restrictor apertures and producing a pressure drop sufficient to inhibit loss of cooling liquid from a lower end of the cooler; and   a coalescer located above the heat exchange array, so that liquid droplets entrained in the upward gas flow are captured and coalesced to a size whereby coalesced liquid droplets falls down onto the heat exchange array.   
     
     
         2 . A cooler according to  claim 1 , wherein the upwardly directed gas channels have a height up to at least 50% of the height of the heat exchange array. 
     
     
         3 . A cooler according to  claim 1 , wherein the elements in the uppermost row of the heat exchanger array are positioned in said channels, so that the upwardly flowing entrained liquid droplets impinge upon these uppermost elements. 
     
     
         4 . A cooler according to  claim 1 , wherein the gas inlet velocity through the restrictor apertures is at least 9 m/s. 
     
     
         5 . A cooler according to  claim 4 , wherein the restrictor apertures are in the form of slots or holes. 
     
     
         6 . A cooler according to  claim 1 , which further comprises a fan attached to the casing to provide the upwardly flowing gas. 
     
     
         7 . A cooler according to  claim 1 , wherein the fluid in the heat exchanger array is a volatile refrigeration fluid. 
     
     
         8 . A cooler according to  claim 7 , wherein the fluid is supercritical carbon dioxide. 
     
     
         9 . A cooler according to  claim 1 , wherein the heat exchange elements are in the form of tubes. 
     
     
         10 . A cooler according to  claim 1 , wherein the heat exchange elements are in the form of hollow plates. 
     
     
         11 . A cooler according to  claim 1 , which further comprises means for providing make-up liquid to compensate for evaporated liquid and other liquid losses. 
     
     
         12 . A cooler according to  claim 11 , wherein the means for providing make-up liquid comprises a series of liquid sprays at a lower end of the cooler. 
     
     
         13 . A cooler according to  claim 1 , which further comprises means for bleeding a portion of the cooling liquid from the cooler. 
     
     
         14 . A closed circuit liquid chiller, which includes the evaporative cooler of  claim 1 . 
     
     
         15 . A refrigeration apparatus, which includes the evaporative cooler of  claim 1 . 
     
     
         16 . A closed circuit liquid chiller, which includes the evaporative cooler of  claim 3 . 
     
     
         17 . A closed circuit liquid chiller, which includes the evaporative cooler of  claim 3 . 
     
     
         18 . A closed circuit liquid chiller, which includes the evaporative cooler of  claim 11 . 
     
     
         19 . A closed circuit liquid chiller, which includes the evaporative cooler of  claim 11 .