Heat exchanger

Abstract

In one aspect, an indirect heat exchanger comprising a plurality of fins having openings and a plurality of tubes connecting the fins. The indirect heat exchanger has spacings between the fins that permit a first fluid to flow therethrough. The fins have outer portions outward of the tubes to be contacted by the first fluid as the first fluid flows through the spacings. The tubes have interiors aligned with the openings of the fins to permit a second fluid to flow through the tubes and the openings of the fins. The fins have inner portions extending about the openings to be contacted by the second fluid. The fins are configured to transfer heat between the first fluid and the second fluid via direct contact between the outer portions of the fins and the first fluid and direct contact between the inner portions of the fins and the second fluid.

What is claimed is: 
     
         1 . An indirect heat exchanger comprising:
 a plurality of fins having openings;   a plurality of tubes connecting the fins;   spacings between the fins that permit a first fluid to flow therethrough;   outer portions of the fins outward of the tubes to be directly contacted by the first fluid as the first fluid flows through the spacings between the fins;   the tubes having interiors aligned with the openings of the fins to permit a second fluid to flow through the tubes and the openings of the fins; and   inner portions of the fins extending about the openings to be directly contacted by the second fluid, the fins configured to transfer heat between the first fluid and the second fluid via direct contact between the outer portions of the fins and the first fluid and direct contact between the inner portions of the fins and the second fluid.   
     
     
         2 . The indirect heat exchanger of  claim 1  wherein the tubes include a plurality of pairs of tubes, each pair of tubes comprising a first tube and a second tube on opposite sides of one of the fins with the interiors of the first and second tubes aligned with one of the openings of the one of the fins. 
     
     
         3 . The indirect heat exchanger of  claim 1  wherein the inner portions of the fins include projecting portions extending from the outer portions of the fins; and
 wherein the tubes extend about the projecting portions. 
 
     
     
         4 . The indirect heat exchanger of  claim 1  wherein the inner portions of the fins include collar portions that define at least a portion of the openings of the fins; and
 wherein the tubes extend about the collar portions. 
 
     
     
         5 . The indirect heat exchanger of  claim 1  wherein the inner portions of the fins include flat portions and collar portions upstanding from the flat portions;
 wherein the tubes extend about the collar portions; and 
 wherein the tubes have end portions secured to the flat portions of the fins. 
 
     
     
         6 . The indirect heat exchanger of  claim 1  wherein the outer portions of the fins have a surface pattern. 
     
     
         7 . The indirect heat exchanger of  claim 1  wherein the tubes are connected to the fins by at least one of welds and adhesive. 
     
     
         8 . The indirect heat exchanger of  claim 1  further comprising o-rings between the tubes and the fins. 
     
     
         9 . The indirect heat exchanger of  claim 1  wherein the tubes are made of a first material and the fins are made of a second material, the second material having a higher thermal conductivity than the first material. 
     
     
         10 . The indirect heat exchanger of  claim 1  wherein the tubes are made of a plastic material and the fins are made of a metallic material. 
     
     
         11 . The indirect heat exchanger of  claim 1  wherein the connected fins and tubes are configured to withstand an internal pressure of the second fluid of at least 100 pounds per square inch. 
     
     
         12 . A method of manufacturing an indirect heat exchanger, the method comprising
 forming an opening of a fin, the fin having an inner portion extending about the opening;   connecting tubes to opposite sides of the fin with interiors of the tubes aligned with the opening of the fin to permit a fluid to flow through the interiors of the tubes and the opening of the fin; and   wherein connecting the tubes to the opposite sides of the fin comprises positioning the inner portion of the fin to be contacted by the fluid as the fluid flows through the opening of the fin.   
     
     
         13 . The method of  claim 12  wherein forming the inner portion of the fin comprises forming a collar portion of the fin; and
 wherein connecting the tubes to the opposite sides of the fin comprises positioning one of the tubes to extend about the collar portion of the fin. 
 
     
     
         14 . The method of  claim 13  wherein connecting the tubes to the opposite sides of the fin comprises securing the one tube to the fin via at least one of a weld and adhesive. 
     
     
         15 . The method of  claim 12  further comprising connecting the tubes to fins on opposite sides of the fin so that there are spacings between the fins that permit another fluid to flow between the fins. 
     
     
         16 . The method of  claim 12  wherein forming the opening of the fin comprises forming a plurality of openings of the fin; and
 wherein connecting the tubes to opposite sides of the fin comprises connecting a plurality of pairs of tubes to opposite sides of the fin so that the interiors of each pair of tubes are aligned with one of the openings of the fin. 
 
     
     
         17 . The method of  claim 12  wherein forming the opening of the fin comprises drawing a portion of the fin to form a projecting portion of the fin that defines at least a portion of the opening of the fin. 
     
     
         18 . The method of  claim 12  further comprising imparting a surface pattern to the fin. 
     
     
         19 . The method of  claim 18  wherein imparting the surface pattern to the fin comprises imparting the surface pattern to the fin before forming the opening in the fin. 
     
     
         20 . The method of  claim 18  further comprising forming a flattened portion in the fin that interrupts the surface pattern; and
 wherein forming the opening of the fin comprises forming the opening in the flattened portion. 
 
     
     
         21 . The method of  claim 20  wherein forming the opening in the flattened portion comprises forming an initial opening in the flattened portion and drawing a collar portion of the fin away from the flattened portion, the collar portion defining at least a portion of the opening. 
     
     
         22 . The method of  claim 12  wherein connecting the tubes to the fin comprises securing the tubes to the fin using at least one of:
 welding; 
 adhesive; 
 a bimetallic transition joint; 
 cold metal transfer; and 
 explosion welding.