Double fired u-tube fired heater

Abstract

A fired heater is provided with u-shaped coils is provided. The coils have at least one inlet, at least one inlet section, at least one outlet and at least one outlet section. Burners are provided in both the center of the end wall of the fired heater and on the floor of the side wall. The fired heater is more compact and provides more even heat distribution compared to prior art heaters.

1 . A fired heater comprising a firebox comprising:
 a plurality of coils comprising inlet sections and outlet sections, with outlet sections of the coils positioned in at least one lane and with inlet sections of the coils positioned in at least two lanes; and   at least two sets of burners,   wherein one set of burners is located in a center portion of an end wall of said fired heater and one set of burners is located on a floor next to a side wall of said fired heater.   
     
     
         2 . The fired heater of  claim 1  wherein the lanes are about parallel to each other. 
     
     
         3 . The fired heater of  claim 1  wherein the outlet sections and the inlet sections are positioned about vertically, at least during use. 
     
     
         4 . The fired heater of  claim 1  wherein the inlet sections in each lane of the at least two lanes and the outlet sections in the at least one lane are arranged in an inline arrangement or in a staggered arrangement, and the inlet sections in each lane of the at least two lanes are positioned in a staggered configuration with respect to outlet sections present in an adjacent parallel lane. 
     
     
         5 . The fired heater of  claim 1  wherein the burners on the floor have a flame that is directed in a vertical direction. 
     
     
         6 . The fired heater of  claim 1  wherein the burners on the floor have a flame that is directed in a horizontal direction. 
     
     
         7 . The fired heater of  claim 1  wherein there are at least one set of burners above said burners on the floor. 
     
     
         8 . The fired heater of  claim 1  wherein said burners next to said side walls are immediately adjacent to said side walls. 
     
     
         9 . The fired heater of  claim 1  wherein said burners next to said side walls are extended away from said side walls. 
     
     
         10 . A method of improving heat distribution in a fired heater comprising providing a fired heater comprising a firebox comprising:
 a plurality of coils comprising inlet sections and outlet sections, with outlet sections of the coils positioned in at least one lane and with inlet sections of the coils positioned in at least two lanes; and   at least two sets of burners,   wherein one set of burners is located in a center portion of an end wall of said fired heater and one set of burners is located on a floor next to a side wall of said fired heater.