heat exchanger for a boiler

Abstract

A heat exchanger for a boiler comprises a central chamber for receiving a combustion gas. A baffle divides the central chamber into a first section and a second section. The baffle also restricts the combustion gas from flowing directly from the first section of the central chamber to the second section of the central chamber. There is a plurality of spaced-apart flues disposed about a periphery of the central chamber. The flues allow for communication between the first section of the central chamber and the second section of the central chamber, in particular, the flues allow for combustion gas to flow from the first section of the central chamber to the second sections of the central chamber.

1 . A heat exchanger for a boiler, the heat exchanger comprising:
 a central chamber for receiving a combustion gas;   a baffle dividing the central chamber into a first section and a second section, the baffle restricting the combustion gas from flowing directly from the first section of the central chamber to the second section of the central chamber; and   a plurality of spaced-apart flues disposed about a periphery of the central chamber, the flues allowing for communication between the first section of the central chamber and the second section of the central chamber, and the flues allowing for combustion gas to flow from the first section of the central chamber to the second sections of the central chamber.   
     
     
         2 . The heat exchanger as claimed in  claim 1  wherein a fin extends between the central chamber and a corresponding one of the flues allowing for communication between the central chamber and said flue. 
     
     
         3 . The heat exchanger as claimed in  claim 2  wherein a width of the fin is longitudinally graduated. 
     
     
         4 . The heat exchanger as claimed in  claim 2  wherein the fin is provided with turbulators to enhance heat flux. 
     
     
         5 . The heat exchanger as claimed in  claim 2  wherein the fin is provided with a plurality of divider stays extending radially from the central chamber to maintain laminar flow of the combustion gas. 
     
     
         6 . The heat exchanger as claimed in  claim 1  wherein the central chamber and flues have a unitary structure and are formed from a single blank. 
     
     
         7 . The heat exchanger as claimed in  claim 1  wherein at least a portion of the central chamber and the flues disposed about said portion of the central chamber are formed from a single blank. 
     
     
         8 . A boiler comprising:
 a unitary heat transfer structure formed from a single blank, the blank being stamped and formed from a strip pulled from a slit coil of stainless steel, and the blank being pulled around to form a central chamber and longitudinal seamed to form a plurality of spaced-apart flues disposed about a periphery of the central chamber, the flues being in communication with the central chamber;   a baffle dividing the central chamber into a first section and a second section, the baffle restricting combustion gas from flowing directly from the first section of the central chamber to the second section of the central chamber;   an outer cylindrical boiler housing surrounding the unitary heat transfer structure, the housing having upper and lower with provisions for receiving and exhausting combustion gases; and   wherein a fluid being heated flows outside the unitary heat transfer structure and combustion gases flow within the unitary heat transfer structure in a counter flow direction as compared to the fluid being heated.   
     
     
         9 . The heat exchanger as claimed in  claim 8  wherein the flues are longitudinally and laterally graduated.