High-performance cracker

Abstract

A furnace for thermally cracking hydrocarbon process fluid is provided. The furnace comprises a convection section including a plurality of convection sub-sections, a radiant section comprising a plurality of radiant sub-sections, and an enclosure defining a plurality of discrete sectors. Each discrete sector of the enclosure includes a convection sub-section having at least one convection conduit for carrying hydrocarbon process fluid, at least one radiant sub-section having at least one radiant conduit connected to receive preheated hydrocarbon process fluid from the convection conduit, and a heat source configured to deliver heat into the discrete sector. Adjacent sectors of the furnace are segregated from each other, such that the heat delivered from the heat source is substantially localized in the discrete sector of the enclosure.

1 . A furnace for thermally cracking hydrocarbon process fluid, said furnace comprising:
 a convection section comprising a plurality of convection sub-sections, each convection sub-section configured for preheating hydrocarbon process fluid;   a radiant section comprising a plurality of radiant sub-sections, each radiant sub-section configured for cracking preheated hydrocarbon process fluid;   an enclosure defining a plurality of discrete sectors; and   each discrete sector of said enclosure including a convection sub-section having at least one convection conduit for carrying hydrocarbon process fluid, at least one radiant sub-section having at least one radiant conduit connected to receive preheated hydrocarbon process fluid from said convection conduit of said convection sub-section, and a heat source configured to deliver heat into said convection sub-section for preheating the hydrocarbon process fluid within said convection conduit of said convection sub-section and into said radiant sub-section for cracking hydrocarbon process fluid within said radiant conduit of said radiant sub-section,   wherein adjacent sectors of the furnace are segregated from each other, such that the heat delivered from said heat source is substantially localized in said discrete sector of said enclosure.   
     
     
         2 . The furnace of  claim 1  wherein the discrete sectors of the furnace are arranged in a side-by-side relation. 
     
     
         3 . The furnace of  claim 2  wherein the discrete sectors of the furnace are spaced apart from each other within said enclosure. 
     
     
         4 . The furnace of  claim 2  wherein the discrete sectors of the furnace are at least partially separated by partition walls positioned between adjacent sectors of the furnace. 
     
     
         5 . The furnace of  claim 1 , wherein at least one of said discrete sectors is maintained within a single enclosure. 
     
     
         6 . The furnace of  claim 1 , wherein at least one of said discrete sectors of said furnace further comprises at least one shutter positioned between said convection sub-section and said radiant sub-section of said discrete sector, said shutter being movable for adjusting the transfer of heat from said heat source into said convection sub-section. 
     
     
         7 . The furnace of  claim 1 , wherein said heat source of each of said discrete sectors is independently operable for selectively delivering heat into a respective one of said discrete sectors. 
     
     
         8 . The furnace of  claim 1 , wherein said convection conduit of said convection sub-section is contained entirely within a respective sector of said enclosure. 
     
     
         9 . The furnace of  claim 1 , wherein at least one discrete sector of said furnace comprises a single convection sub-section and at least two radiant sub-sections, said at least two radiant sub-sections each having a radiant conduit being connected to receive hydrocarbon process fluid from a convection conduit in said single convection sub-section. 
     
     
         10 . The furnace of  claim 1 , wherein the at least one convection conduit comprises a coil. 
     
     
         11 . The furnace of  claim 1 , wherein the at least one radiant conduit comprises a coil. 
     
     
         12 . The furnace of  claim 1 , wherein the heat source comprises one or more burners. 
     
     
         13 . A pyrolytic furnace for hydrocarbon cracking, said furnace comprising:
 an enclosure having a longitudinal axis;   a convection section divided into convection sub-sections in side-by-side relation along the longitudinal axis of said enclosure;   a radiant section divided into radiant sub-sections in side-by-side relation along the longitudinal axis of said enclosure, each of said radiant sub-sections corresponding to one of said convection sub-sections together forming a furnace sector;   at least one convection conduit positioned in each of said convection sub-sections for carrying hydrocarbon process fluid, and at least one radiant conduit positioned in each of said radiant sub-sections for carrying preheated hydrocarbon process fluid, wherein each convection conduit is contained entirely within its respective convection sub-section and is coupled for fluid flow communication with said at least one radiant conduit; and   plural heat sources positioned to introduce heat into said radiant section and said convection section of said furnace, wherein each heat source is positioned to deliver heat into a single sector of said furnace.   
     
     
         14 . The pyrolytic furnace of  claim 13 , wherein deactivation of one of said heat sources associated with one of said furnace sectors reduces the heat introduced into that sector, while the heat delivered into an adjacent furnace sector remains substantially constant. 
     
     
         15 . The pyrolytic furnace of  claim 13 , wherein at least two of the sectors of said furnace are adjacent and are at least partially separated by a partition wall positioned between the adjacent sectors of the furnace. 
     
     
         16 . The pyrolytic furnace of  claim 13 , wherein at least one sector of said furnace further comprises a shutter positioned between said convection sub-section and said radiant sub-section, said shutter being movable for controlling the flow of heat from said heat source of said sector into said convection sub-section of said sector. 
     
     
         17 . The pyrolytic furnace of  claim 13 , wherein said heat source of each sector is independently controllable for delivering heat into said sector. 
     
     
         18 . The pyrolytic furnace of  claim 13 , wherein at least one sector of said furnace comprises a single convection sub-section and at least two radiant sub-sections configured to receive hydrocarbon process fluid from said single convection sub-section. 
     
     
         19 . A method of operating a pyrolytic furnace comprising the steps of:
 (a) distributing hydrocarbon process fluid into a convection section of a discrete sector of the furnace;   (b) transferring pre-heated hydrocarbon process fluid from the convection section of the discrete sector into at least one corresponding radiant section of the discrete sector; and   (c) delivering heat into the at least one radiant section of the discrete sector of the furnace to crack the pre-heated hydrocarbon process fluid within the radiant section of the discrete sector and into the convection section of the discrete sector to pre-heat the hydrocarbon process fluid within the convection section of the discrete sector, wherein the heat is substantially concentrated in the discrete sector of the furnace.   
     
     
         20 . The method of  claim 19 , further comprising the step of performing steps (a) through (c) for plural discrete sectors of the pyrolytic furnace. 
     
     
         21 . The method of  claim 20 , further comprising the step of reducing a quantity of heat delivered to a selected one of said discrete sectors of the furnace, while maintaining a quantity of heat delivered to an adjacent one of said discrete sectors of the furnace, such that the internal temperature of the selected discrete sector of the furnace is substantially reduced while the internal temperature of the adjacent sector of the furnace remains substantially constant. 
     
     
         22 . The method of  claim 19 , further comprising the step of at least partially isolating the heat delivered within the radiant section and the convection section of the discrete sector of the pyrolytic furnace from an adjacent discrete sector. 
     
     
         23 . The method of  claim 22 , wherein the isolating step comprises the sub-step of at least partially retaining the heat within the discrete sector using a partition wall positioned between the discrete sector and the adjacent discrete sector of the furnace.