Advanced waste heat recovery in industrial fired-heaters

Abstract

A piping system for recovery heat energy from an exhaust gas in a heat recovery furnace, the piping system comprising a piping inlet, where the piping inlet transects a wall of a stack zone of the heat recovery furnace, a piping run, the piping run fluidly connected to the piping inlet, and a piping outlet, the piping outlet fluidly connected to the piping run, where the piping outlet transects the wall of the stack zone of the heat recovery furnace, where the piping system is positioned in a stack zone of the heat recovery furnace between a stack inlet and a stack outlet.

That which is claimed is: 
     
         1 . A piping system for recovery heat energy from an exhaust gas in a heat recovery furnace, the piping system comprising:
 a piping inlet, where the piping inlet transects a wall of a stack zone of the heat recovery furnace;   a piping run, the piping run fluidly connected to the piping inlet; and   a piping outlet, the piping outlet fluidly connected to the piping run, where the piping outlet transects the wall of the stack zone of the heat recovery furnace,   where the piping system is positioned in a stack zone of the heat recovery furnace between a stack inlet and a stack outlet.   
     
     
         2 . The piping system of  claim 1 , where the piping run is spiral piping comprising helix-shaped pipe,
 where the piping inlet transects the wall proximate to the stack outlet of the heat recovery furnace,   where the piping outlet transects the wall proximate to the stack inlet of the heat recovery furnace, and   where there is a gap between the spiral piping and the wall.   
     
     
         3 . The piping system of  claim 2 , where the gap is less than 2 inches. 
     
     
         4 . The piping system of  claim 1 , where the piping run is wraparound piping, the wraparound piping comprising:
 a piping rise, the piping rise fluidly connected to the piping inlet, where the piping rise has a rise height;   a piping loop, the piping loop fluidly connected to the piping rise, where the piping loop is located adjacent to the wall, where the piping loop has a length; and   a piping down-run, the piping down-run fluidly connected to the piping loop and further fluidly connected to the piping outlet, where the piping down-run has a down-run height.   
     
     
         5 . The piping system of  claim 4 , where the rise height is less than the distance between the stack inlet and the stack outlet. 
     
     
         6 . The piping system of  claim 4 , where the length of the piping loop is less than the perimeter of the stack zone. 
     
     
         7 . The piping system of  claim 4 , where the down-run height is less than the distance between the stack inlet and the stack outlet. 
     
     
         8 . The piping system of  claim 1  further comprising two piping runs. 
     
     
         9 . A method of recovering heat from an exhaust gas in a stack zone of a heat recovery furnace, the method comprising the steps of:
 introducing a process gas through a piping inlet, where the piping inlet transects a wall of the stack zone;   allowing the process gas to flow through a piping run physically connected to the piping inlet, where the piping run is positioned in the stack zone between a stack inlet and a stack outlet, where the piping run is positioned adjacent to the wall such that the exhaust gas flows through the piping run;   transferring heat from the exhaust gas to the process gas as the process gas flows through the piping run; and   allowing the process gas to flow through a piping outlet physically connected to the piping run.   
     
     
         10 . The method of  claim 9 , where the piping run is spiral piping comprising helix-shaped pipe,
 where the piping inlet transects the wall proximate to the stack outlet of the heat recovery furnace,   where the piping outlet transects the wall proximate to the stack inlet of the heat recovery furnace, and   where there is a gap between the spiral piping and the wall.   
     
     
         11 . The method of  claim 10 , where the gap is less than 2 inches. 
     
     
         12 . The method of  claim 9 , where the piping run is wraparound piping, the wraparound piping comprising:
 a piping rise, the piping rise fluidly connected to the piping inlet, where the piping rise has a rise height;   a piping loop, the piping loop fluidly connected to the piping rise, where the piping loop is located adjacent to the wall, where the piping loop has a length; and   a piping down-run, the piping down-run fluidly connected to the piping loop and further fluidly connected to the piping outlet, where the piping down-run has a down-run height.   
     
     
         13 . The method of  claim 12 , where the rise height is less than the distance between the stack inlet and the stack outlet. 
     
     
         14 . The method of  claim 12 , where the length of the piping loop is less than the perimeter of the stack zone. 
     
     
         15 . The method of  claim 12 , where the down-run height is less than the distance between the stack inlet and the stack outlet. 
     
     
         16 . The method of  claim 9 , where the process gas is an acid gas feed. 
     
     
         17 . The method of  claim 9 , where the process gas is an air feed. 
     
     
         18 . The method of  claim 9 , where the piping outlet is fluidly connected to a convection section of the heat recovery furnace.