Waste heat recovery

Abstract

There is provided a method for pre-heating a fluid ( 140, 240, 340 ) by heat transfer from combustion gases ( 101 ) flowing through an exhaust duct ( 100 ) of a furnace, wherein the fluid ( 140, 240, 340 ) is supplied to a heat transfer device ( 120, 200, 300 ) which is in heat transfer contact with the combustion gases ( 101 ). At least a portion of the heat transfer device ( 120, 200, 300 ) is movably arranged relative to the exhaust duct ( 100 ) such that it can be moved into and out of the exhaust duct.

1 - 12 . (canceled) 
     
     
         13 . In a method for pro-heating a fluid ( 140 ,  240 ,  340 ) by heat transfer from combustion gases ( 101 ) flowing through an exhaust duct ( 100 ) of a furnace, wherein the fluid ( 140 ,  240 ,  340 ) is supplied to a heat transfer device ( 120 ,  200 ,  300 ) in heat transfer contact with the combustion gases ( 101 ), the improvement comprising:
 the heat transfer device ( 120 ,  200 ,  300 ) comprising a double pipe ( 200 ) having an inner pipe ( 201 ,  301 ) and an outer pipe ( 202 ,  302 );   passing the fluid ( 240 ) first through the inner pipe ( 201 ) and subsequently through the outer pipe ( 202 ); and   arranging at least a portion of the heat transfer device ( 120 ,  200 ,  300 ) relative to the exhaust duct ( 100 ) for moving that at least a portion of the heat transfer device into and out of the exhaust duct ( 100 ).   
     
     
         14 . The method of  claim 13 , wherein the fluid ( 140 ,  240 ,  340 ) comprises a substance selected from the group consisting of an oxygen-containing gas, an oxygen-containing gas comprising at least 90% by volume oxygen, a fuel, and a gaseous fuel. 
     
     
         15 . The method of  claim 13 , wherein the furnace comprises a glass furnace. 
     
     
         16 . In a furnace having an exhaust duct ( 100 ) to exhaust combustion gases ( 101 ) from the furnace, and a heat transfer device ( 120 ,  200 ,  300 ) for pre-heating a fluid ( 140 ,  240 ,  340 ) by heat transfer from the combustion gases ( 101 ), the heat transfer device ( 120 ,  200 ,  300 ) including an inlet ( 204 ,  304 ) for the fluid ( 140 ,  240 ,  340 ) to be pre-heated and an outlet ( 206 ) for pre-heated fluid, the improvement comprising:
 the heat transfer device ( 200 ,  300 ) comprising at least one double pipe ( 200 ,  300 ), and at least a portion of the heat transfer device ( 120 ,  200 ,  300 ) is arranged relative to the exhaust duct ( 100 ) and movable for movement into and out of the exhaust duct ( 100 ).   
     
     
         17 . The furnace of  claim 16 , further comprising an automated retraction system for moving at least a portion of the heat transfer device ( 120 ,  200 ,  300 ) into and out of the exhaust duct ( 100 ). 
     
     
         18 . The furnace of  claim 16 , further comprising the heat transfer device ( 120 ,  200 ) being oriented vertically with respect to the exhaust duct ( 100 ). 
     
     
         19 . The furnace of  claim 16 , wherein a portion of the double pipe ( 200 ,  300 ) movable into the exhaust duct ( 100 ) has a length selected from the group consisting of at least 0.25 m, at least 1.0 m, and at least 1.5 m. 
     
     
         20 . The furnace of  claim 16 , wherein a portion of the double pipe ( 200 ,  300 ) movable into the exhaust duct ( 100 ) has a maximum length selected from the group consisting of a maximum of 1.0 m, a maximum of 1.5 m, and a maximum of 2.0 m. 
     
     
         21 . The furnace of  claim 16 , wherein the double pipe ( 200 ,  300 ) comprises:
 an inner pipe ( 201 ,  301 ); and   an outer pipe ( 202 ,  302 ) closed at one end ( 303 ),   wherein the inner pipe ( 301 ) is reset with respect to the closed end ( 303 ) of the outer pipe ( 302 ).   
     
     
         22 . The furnace of  claim 16 , further comprising an inert gas supply line ( 245 ) connected to the heat transfer device ( 120 ,  200 ,  300 ). 
     
     
         23 . The furnace of  claim 16 , further comprising at least one additional heat transfer device ( 120 ,  200 ,  300 ), and at least one burner, wherein the outlet of each of the heat transfer devices ( 120 ,  200 ,  300 ) is connected to a corresponding same one of the at least one burner. 
     
     
         24 . The furnace of  claim 23 , wherein the at least one additional heat transfer device ( 100 ,  200 ,  300 ) is an amount selected from the group consisting of between 1 and 30 heat transfer devices per burner, and less than 20 heat transfer devices per burner. 
     
     
         25 . The furnace of  claim 16 , further comprising the heat transfer device ( 120 ,  200 ,  300 ) being located upstream of other waste heat recovery devices and emission control devices of the furnace.