Heat exchanger

Abstract

The present disclosure provides for a heat exchanger. The heat exchanger generally comprises a duct and substantially parallel tubes having an outer wall and arranged in the duct to define gaps therebetween. An air flow is directed through the duct to deliver heat through the gaps and over the outer walls of the tubes. A second means directs an air flow that receives heat through the tubes. The air flow that delivers heat generally comprises air that is moist, saturated, or near its saturation curve. The heat exchanger also comprises collecting means arranged in the duct for collecting the condensate flowing along the outer walls of the tubes upon exiting from the duct at the outlet.

1 . A heat exchanger, comprising:
 a duct:   a plurality of substantially parallel tubes, each having an outer wall, arranged in said duct to define gaps therebetween;   first means for directing an air flow through said duct that delivers heat through the gaps and over said outer walls of said tubes;   second means for directing an air flow that receives heat through said tubes;   an inlet at a first region of said duct and an outlet a second region of said duct disposed distal from said first region such that in said duct, the air flow that delivers heat flows from said inlet to said outlet and condensate forms on said outer wall of said tubes and flows toward said outlet, the air flow that delivers heat comprising air that is moist, saturated, or near its saturation curve; and,   collecting means arranged in said duct for collecting said condensate flowing along said outer walls of said tubes upon exiting from said duct at said outlet.   
     
     
         2 . The heat exchanger of  claim 1  further comprising spray means for spraying an aqueous medium in an atomized phase into the air flow that delivers heat before the air flow that delivers heat enters into said inlet. 
     
     
         3 . The heat exchanger of  claim 1  wherein said tubes further comprise members projecting into the gaps to increase the external surface area of said tubes over which the air flow that delivers heat passes. 
     
     
         4 . The heat exchanger of  claim 1  wherein said substantially parallel tubes are provided in a tube bundle assembly. 
     
     
         5 . The heat exchanger of  claim 4  wherein a plurality of tube bundle assemblies are assembleable into an array within said duct to define said gaps. 
     
     
         6 . The heat exchanger of  claim 1  wherein each tube of said substantially parallel tubes has an inlet in fluid communication with an inlet of at least another substantially parallel tube. 
     
     
         7 . The heat exchanger of  claim 6  wherein each inlet of said substantially parallel tubes are in fluid communication through a plenum. 
     
     
         8 . The heat exchanger of  claim 1  wherein each tube of said substantially parallel tubes has an outlet in fluid communication with an outlet of at least another substantially parallel tube. 
     
     
         9 . The heat exchanger of  claim 8  wherein each outlet of said substantially parallel tubes are in fluid communication through a plenum. 
     
     
         10 . The heat exchanger of  claim 1  wherein each of said substantially parallel tubes are corrugated. 
     
     
         11 . The heat exchanger of  claim 1  further comprising a spray system, said spray system being adapted to clean said outer walls of said substantially parallel tubes. 
     
     
         12 . The heat exchanger of  claim 1  further comprising a spray system, said spray system being adapted to saturate said air flow before said air flow contacts said outer wall of said tubes. 
     
     
         13 . The heat exchanger of  claim 1  wherein said air flow that receives heat through said tubes is directed toward a manufacturing process that produced said airflow that delivers heat. 
     
     
         14 . The heat exchanger of  claim 1  wherein said air flow that receives heat through said tubes is recycled by being directed toward a manufacturing process that produced said airflow that delivers heat. 
     
     
         15 . The heat exchanger of  claim 14  wherein said air flow that receives heat is directed toward a drying section of a papermaking process. 
     
     
         16 . The heat exchanger of  claim 1  wherein said air flow that receives heat is directed to provide recycled heated room air. 
     
     
         17 . The heat exchanger of  claim 1  wherein said condensate is recycled by being directed toward a manufacturing process that produced said airflow that delivers said condensate. 
     
     
         18 . The heat exchanger of  claim 17  wherein said condensate is re-cycled by being directed toward a papermaking process. 
     
     
         19 . The heat exchanger of  claim 1  wherein said tubes are manufactured from a metal selected from the group consisting of copper alloy, stainless steel, carbon steel, non-ferrous copper alloy, Inconel, nickel, Hastelloy, titanium, high conductivity coppers, brasses, wrought Martensitic stainless steel, aluminium bronzes, 90/10 aluminium bronze, cold wkd (wrought), 92/8 aluminium bronze, hard (wrought), 93/7 aluminium bronze, hard (wrought), 95/5 aluminium bronze, 1/2 hard (wrought), 95/5 aluminium bronze, hard (wrought), nickel iron aluminium bronze, as extruded (wrought), combinations thereof, and the like. 
     
     
         20 . The heat exchanger of  claim 1  wherein said heat exchanger has a log mean temperature difference of at least about 40 percent.