Heat Exchanger

Abstract

A heat exchanger suitable for long term use in the unfiltered hot exhaust gas of an aluminum smelter is disclosed. In one embodiment, the heat exchanger comprises fluid carrying tubes connected together with web members to form a cylindrical shell. A header located at each end of the cylindrical shell is provided for feeding fluid to and from the tubes of the heat exchanger. Shrouds can be placed over the headers to affect hot gas turbulence and help minimize scaling. The surfaces of the cylindrical shell, when in un-scrubbed exhaust gas of an aluminum smelter, will be in contact with particles and/or dust and possibly caustic fumes and, therefore, may be treated with a relevant slip coating selected, for example, from the Teflon family.

1 . An apparatus comprising:
 at least two parallel positioned tubes each having a first end and a second end for conducting a fluid;   web members coupled between the at least two parallel positioned tubes; and   a header located at each of the first and second ends of the at least two parallel tubes;   wherein the apparatus is adapted for use as a heat exchanger in the exhaust gas of an aluminum smelter.   
   
   
       2 . The apparatus of  claim 1  wherein the apparatus is configured so that exhaust gas of an aluminum smelter flows substantially parallel to the at least two parallel positioned tubes. 
   
   
       3 . The apparatus of  claim 2  wherein the apparatus is configured so that fluid flows through the two parallel positioned tubes in a first directions and so that the exhaust gas flows in a second direction opposite to the first direction. 
   
   
       4 . An apparatus comprising:
 a plurality of parallel tubes each having a first end and a second end for conducting a fluid in a first direction, wherein the plurality of parallel tubes is adapted to be surrounded by exhaust gas from a smelter so that the exhaust gas flows in a second direction parallel to the plurality of parallel tubes and opposite the first direction; wherein the apparatus is adapted for use as a heat exchanger in the exhaust gas of a smelter.   
   
   
       5 . The apparatus of  claim 4  wherein the smelter is an aluminum smelter. 
   
   
       6 . The apparatus of  claim 4  further comprising web members connecting the tubes together so that the tubes and the web members form a first cylindrical shell. 
   
   
       7 . The apparatus of  claim 5  further comprising a header located at each of the first and second ends of the parallel tubes. 
   
   
       8 . The apparatus of  claim 6  further comprising a coating over the first cylindrical shell.