RSC external downcomer arrangement

Abstract

An RSC external downcomer arrangement system includes a radiant syngas cooler that receives and cools syngas generated in a gasifier. The radiant syngas cooler includes a housing of the radiant syngas cooler defining an annular space of the radiant syngas cooler, and heat exchange tubes of the radiant syngas cooler positioned within the annular space and configured to flow a cooling medium. The heat exchange tube enables heat exchange between the syngas and a cooling medium to cool the syngas. The radiant syngas cooler includes a downcomer of the radiant syngas cooler that supplies a cooling medium to the heat exchange tube, wherein the downcomer includes a lower flow portion positioned outside an annular space of the radiant syngas cooler.

Description

Technical Field

[0001] The present invention relates to radiant syngas coolers and, more particularly, to radiant syngas coolers configured to generate steam. Background Art

[0002] Conventional radiant syngas coolers are designed with tubes arranged in an interior, annular space of the radiant syngas cooler. Tubes arranged in the annular space of the radiant syngas cooler do not face the syngas and therefore do not necessarily participate in heat transfer. In addition, arranging the tubes in the annular space of the radiant syngas cooler can increase the costs associated with constructing the radiant syngas cooler by increasing the diameter of the cooler. Summary of the invention

[0003] Certain embodiments comparable in scope to the original claims of the present invention are summarized below. These embodiments are not intended to limit the scope of the claims of the present invention, but rather these embodiments are intended only to provide a brief overview of possible forms of the present invention. In fact, the present invention may encompass various forms that may be similar or different from the embodiments set forth below.

[0004] In a first embodiment, a system of the present invention includes a radiant syngas cooler that receives and cools syngas generated in a gasifier. The radiant syngas cooler includes a shell of the radiant syngas cooler that defines an annular space of the radiant syngas cooler, and a heat exchange tube of the radiant syngas cooler that is positioned within the annular space and through which a cooling medium flows. The heat exchange tube enables heat exchange between the syngas and the cooling medium to cool the syngas. The radiant syngas cooler includes a downcomer tube of the radiant syngas cooler that supplies a cooling medium to the heat exchange tube, wherein the downcomer tube includes a downflow portion that is positioned outside the annular space of the radiant syngas cooler. The downflow portion is fluidly connected to a header, and the header fluidly connects the downcomer to the heat exchange tube.

[0005] The downcomer comprises a third downcomer branch pipe fluidically connecting the downcomer to an additional panel header, and the additional panel header is fluidically connected to the additional plurality of panel tubes.

[0006] The first downcomer branch pipe and the second downcomer branch pipe extend from the downcomer in opposite directions.

[0007] Wherein, the first downcomer branch pipe and the second downcomer branch pipe extend from the concentric reducing pipe of the downcomer.

[0008] wherein the downflow portion of the downcomer includes an expansion joint configured to allow expansion and contraction caused by thermal fluctuations; wherein the downcomer includes a downflow portion and a crossflow portion extending from the downflow portion into an annular space of the radiant syngas cooler, wherein a region of the crossflow portion positioned within the annular space is constructed of one or more materials that can withstand higher temperatures than the material of the downflow portion.

[0009] Wherein the downcomer comprises a bleed line positioned outside of the shell of the radiant syngas cooler.

[0010] wherein the downcomer is a first downcomer, and the radiant syngas cooler comprises a second downcomer, wherein the first and second downcomers respectively comprise a first downcomer branch pipe and a second downcomer branch pipe, wherein the first downcomer branch pipe fluidically couples the first downcomer to a first panel header, the second downcomer branch pipe fluidically couples the second downcomer to a second panel header separated from the first panel header, and the first and second downcomer branches overlap each other

[0011] Wherein, the first downcomer branch pipe includes a curved portion allowing the second downcomer branch pipe to enter the second panel tube header.

[0012] In a second embodiment, a system of the present invention includes a radiant syngas cooler, the radiant syngas cooler including a plurality of platen tubes extending from one or more platen headers within an annular space of the radiant syngas cooler, and a plurality of downcomers having a vertical portion circumferentially arranged around an exterior of the radiant syngas cooler and a horizontal portion extending into the annular space. The horizontal portion includes an inner portion arranged within the annular space and an outer portion arranged outside the annular space, and a first plurality of elbow joints coupled between the vertical portion and the outer portion of the plurality of downcomers. The system includes a second plurality of elbow joints coupled to the inner portion and a plurality of concentric reducers coupled to the second plurality of elbow joints. The system includes a plurality of downcomer branches extending from the concentric reducers, wherein at least a portion of the plurality of downcomer branches are coupled to the one or more platen headers, and a cage bottom header disposed below the one or more platen headers, wherein at least one of the plurality of downcomer branches is coupled to the cage bottom header.

[0013] In a third embodiment, a system of the present invention includes a gasifier that generates syngas that is fluidly coupled to a radiant syngas cooler. The radiant syngas cooler includes a plurality of panel tubes extending from one or more panel tube headers within the cooler and a plurality of downcomers arranged circumferentially around the cooler, wherein the plurality of panel tubes are configured to cool the syngas flowing through the cooler. The system includes a first plurality of elbow joints coupled between a vertical portion of the downcomer and a horizontal portion of the downcomer, wherein the elbow joint is configured to extend the horizontal portion of each downcomer in a radially inward direction relative to the cooler. The radiant syngas cooler includes a cooler wall, wherein the horizontal portion of each downcomer includes an inner portion and an outer portion. The cooler includes a second plurality of elbow joints coupled between each inner portion of each downcomer and a plurality of concentric reducers. The cooler includes a plurality of downcomer branches extending from each concentric reducer, wherein one or more of the branches are coupled to an adjacent panel tube header. The cooler includes a cage bottom header disposed below the panel tube header, wherein at least one of the plurality of downcomer branches is coupled to the cage bottom header. The hot syngas transfers heat to a cooling fluid flowing through the plurality of panel tubes and cage tubes. A syngas processor configured to process the flow of cooled syngas is disposed downstream of the radiant syngas cooler. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features, aspects and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like reference numerals represent like parts throughout the several views, and in which:

[0015] Figure 1 is a block diagram of an embodiment of an IGCC power plant including a radiant syngas cooler, wherein steam generated by the radiant syngas cooler is directed to a heat recovery steam generator;

[0016] Figure 2 yes Figure 1 A partial schematic diagram of an embodiment of a radiant syngas cooler of , depicting a top view of the cooler at a bottom section;

[0017] Figure 3 yes Figure 1 A partial schematic diagram of an embodiment of a radiant syngas cooler of , showing a downcomer extending through the cooler, wherein a portion of the downcomer extends inside a wall of the cooler and a portion of the downcomer remains outside of the wall of the cooler;

[0018] Figure 4 It is along Figure 3 A schematic diagram of an embodiment of an expansion bellows of a downcomer arrangement;

[0019] Figure 5 yes Figure 1 A partial cross-sectional view of an embodiment of a radiant syngas cooler showing components disposed within a wall of the RSC;

[0020] Figure 6 yes Figure 1 A partial schematic diagram of an embodiment of a radiant syngas cooler showing an external view of a plurality of cage tubes coupled to a cage bottom header;

[0021] Figure 7 yes Figure 1 A partial schematic diagram of an embodiment of a radiant syngas cooler showing an interior view of a plurality of cage tubes coupled to a cage bottom header; and

[0022] Figure 8 yes Figure 1 A partially schematic side elevational view of an embodiment of a radiant syngas cooler showing a portion of a plurality of cage tubes modified and coupled to a cage bottom header. DETAILED DESCRIPTION

[0023] One or more specific embodiments of the present invention will be described below. In order to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may differ between implementations. Moreover, it should be appreciated that such development work may be complex and time-consuming, but will be a routine task of design, production, and manufacturing for a person of ordinary skill who benefits from this disclosure.

[0024] When introducing elements of various embodiments of the present invention, the articles "a," "an," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0025] As described below, the disclosed embodiment includes a radiant syngas cooler (RSC) having a plurality of downcomers positioned circumferentially around the wall (which may also be referred to as a shell) of the RSC. Arranging the downcomers around the periphery of the RSC can reduce the inner diameter of the RSC compared to when the downcomers are arranged in the annular space of the RSC. Reducing the inner diameter of the RSC enables the RSC to be moved from one position to another more easily by reducing the overall size of the RSC. Moreover, arranging the downcomers outside the RSC simplifies the piping in the dome section portion of the RSC. Arranging a portion of the downcomers outside the RSC also enables the portion of the downcomers arranged outside the RSC to be made of a material of lower cost. In one example, the portion of the downcomers inside the RSC can be made of a high nickel alloy together with the downcomer branches, the inner elbow and any other components inside the RSC. The portion of the downcomers outside the RSC and the components (e.g., outer elbow, bleedline) can be made of carbon steel (e.g., SA106 pipe).

[0026] As further described below, the downcomer extends axially and externally relative to the wall of the RSC, and a portion of the downcomer extends through the wall into the annular space of the RSC. The downcomer is configured to flow cooling water downward around the periphery of the RSC. As the syngas flows through the RSC, the hot syngas generated in the gasifier is initially cooled using cooling water supplied by the downcomer to a plurality of panel tubes and cage tubes positioned closer to the hot gas path of the RSC. The downcomer of the present invention can include a number of features that facilitate stable operation of the RSC over time.

[0027] For example, an expansion joint (e.g., an expansion bellows) of the downcomer can enable the downcomer to expand or contract (e.g., in response to temperature changes) in response to a cooling fluid (e.g., water) flowing through the downcomer. The downcomer can also have a discharge line configured to discharge excess water (e.g., high-pressure steam).

[0028] Inside the RSC wall, the downcomer is coupled to an inner elbow. The inner elbow forms an angle and is coupled to a pipe fitting, such as a concentric reducer. Downcomer branches arranged along the side of the concentric reducer may have an elbow configured to couple the downcomer branches to the panel header, while downcomer branches extending from the bottom of the concentric reducer have an elbow at an angle of about 45 degrees configured to couple the downcomer branches to the cage bottom header. These configurations are described in further detail below.

[0029] Now referring to the accompanying drawings, Figure 1is a block diagram of an embodiment of an IGCC power plant 10 including a radiant syngas cooler, wherein steam generated by a radiant syngas cooler (RSC) 12 is directed to a heat recovery steam generator 14. The RSC 12 has an external downcomer, as described in further detail below.

[0030] Other elements of the IGCC system 10 may include a fuel source 16, which may be solid or liquid, which may be used as an energy source for the IGCC power generation unit 10. The fuel source 16 may include coal, petroleum coke, petroleum, biomass, wood materials, agricultural waste, tar, coke oven gas and asphalt, or other carbon-containing items. The fuel of the fuel source 16 may be passed to a feedstock preparation unit 18. The feedstock preparation unit 18 may generate feedstock, for example, by chopping, grinding, shredding, crushing, agglomerating or pelletizing to adjust the size or shape of the fuel source 16. In addition, water 20 or other suitable liquids may be added to the fuel source 16 in the feedstock preparation unit 18 to produce a slurry feedstock (and / or for separate introduction into the gasifier 22). In other embodiments, no liquid is added to the fuel source 16, thus producing dry feedstock. In other embodiments, if the fuel source 16 is a liquid, the feedstock preparation unit 18 may be omitted. The gasifier 22 is coupled to the RSC 12.

[0031] The IGCC power plant 10 may also include an air separation unit (ASU) 24. The ASU 24 may operate to separate air into component gases by, for example, distillation techniques. The ASU 24 may separate oxygen 28 from air supplied to it by a supplemental air compressor 26, and the ASU 24 may transfer the separated oxygen 28 to the gasifier 22.

[0032] The feedstock may be passed from the feedstock preparation unit 18 to the gasifier 22. The gasifier 22 may convert the feedstock into a syngas 30, which is primarily a combination of carbon monoxide (CO) and hydrogen. The conversion may be achieved by subjecting the feedstock to controlled amounts of steam and oxygen at high pressure (e.g., about 20 bar to 85 bar) and high temperature (e.g., about 700 degrees Celsius to 1600 degrees Celsius), depending on the type of gasifier 22 used. The gasification process may include the feedstock undergoing a pyrolysis process, whereby the feedstock is heated. The temperature inside the gasifier 22 may be in the range of about 150 degrees Celsius to 700 degrees Celsius during the pyrolysis process, depending on the fuel source 16 used to generate the feedstock.

[0033] The gasifier 22 utilizes steam and oxygen 28 to allow some of the feedstock to be burned to produce CO and release energy that drives the conversion of additional feedstock into hydrogen and additional CO. 2 In this manner, the gasifier 22 produces a synthesis gas 30. The synthesis gas 30 may include about 85% CO and hydrogen in equal proportions, as well as CH 4 , HCl, HF, COS, NH3 , HCN, and H 2 S (based on the sulfur content of the feedstock). Synthesis gas 30 may be referred to as untreated synthesis gas because it includes, for example, H 2 The gasifier 22 may also generate waste, such as slag 32, which may be a wet ash material. The slag 32 may be removed from the radiant syngas cooler (RSC) 12 and disposed of.

[0034] The syngas 30 is cooled in the RSC 12 as described in further detail below. The syngas 30 is cooled in a radiation transfer type heat exchanger and steam 34 is generated in a plurality of cage tubes and platen tubes. The cooled syngas 30 may exit the RSC 12 and enter a gas purifier 38.

[0035] In one embodiment, the gas purifier 38 may be a syngas scrubber and / or a water-gas shift reactor. The gas purifier 38 may scrub the untreated syngas to remove HCl, HF, COS, HCN, and H from the untreated syngas 30. 2 S, which may include separating sulfur in a sulfur processor 40. Additionally, the gas purifier 38 may separate salts from the untreated syngas 30 via a water treatment unit 42, which may utilize water purification techniques to generate usable salts from the untreated syngas.

[0036] The processed syngas 44 may be delivered as a combustible fuel to a combustor 46, such as a combustion chamber, of a gas turbine engine 48. The gas turbine engine 48 may include a turbine 50, a drive shaft 52, and a compressor 54, as well as the combustor 46. The combustor 46 may receive a fuel, such as syngas, that may be injected under pressure from a fuel nozzle.

[0037] The drive shaft 52 can connect the turbine 50 to the compressor 54. The compressor 54 can include blades coupled to the drive shaft 52. Therefore, the rotation of the turbine blades in the turbine 50 can cause the drive shaft 52 connecting the turbine 50 to the compressor 54 to rotate the blades within the compressor 54. This rotation of the blades in the compressor 54 causes the compressor 54 to compress the air received via the air intake in the compressor 54. The compressed air can then be fed to the combustor 46 and mixed with fuel and compressed nitrogen to allow for more efficient combustion. The drive shaft 52 can also be connected to a load 58, which can be a fixed load, such as a generator for generating electricity, for example, in a generator set. The load 58 can be any suitable device powered by the rotational output of the gas turbine engine 48.

[0038] Returning to the discussion of the RSC 12, the steam 34 generated by the RSC 12 can be directed to a heat recovery steam generator (HRSG) 14. The HRSG 14 can be coupled to a steam turbine engine 60 that can drive a second load 62. The second load 62 can also be a generator for generating electricity. However, both the first and second loads 58, 62 can be other types of loads that can be driven by the gas turbine engine 48 and the steam turbine engine 60. In addition, although the gas turbine engine 48 and the steam turbine engine 60 can drive independent loads 58 and 62, as shown in the illustrated embodiment, the gas turbine engine 48 and the steam turbine engine 60 can also be used in tandem to drive a single load via a single shaft. The specific configuration of the steam turbine engine 60 and the gas turbine engine 48 can be implementation specific and can include any combination of sections.

[0039] As mentioned above, you can refer to Figure 2 Further understanding of the configuration of the downcomer 36. More specifically, Figure 2 yes Figure 1 Schematic top view of an embodiment of the bottom section of the RSC 12. It should be noted that the bottom portion of the RSC 12 can be connected to a slag pile to collect slag, or other equipment. As shown, the RSC 12 can be circumferentially surrounded by a plurality of downcomers 36. Cooling water can be fed from a cooling water source (e.g., boiler feed water available in the unit) through the downcomers 36. In general, high-pressure steam can be generated from a cooling water flow through the downcomers 36 arranged around the periphery of the RSC 12. When the syngas 30 flows through the RSC 12, the hot syngas 30 is initially cooled in the radiant heat transfer type features (e.g., internal heat transfer tubes, walls, etc.) of the RSC 12. The steam 34 generated by the heat transfer can then be directed to another area of ​​the unit, such as the HRSG 14.

[0040] As described above, arranging the downcomers 36 around the perimeter of the RSC 12 can reduce the inner diameter of the RSC 12 as compared to when the downcomers 36 are arranged within the annular space of the RSC 12. Although only two downcomers 36 are shown, multiple downcomers 36 are externally disposed around the RSC 12 along the perimeter of the RSC 12. The downcomers 36 may be spaced substantially equidistantly around the perimeter of the RSC 12. For example, a pair of downcomers 36 may be spaced apart from adjacent tubes 36, which in turn are separated from another pair by an equal distance. In certain embodiments, the downcomers 36 may be spaced at different intervals along the perimeter of the RSC 12, or may be clustered in one area in other embodiments. The downcomers 36 extend from the exterior of the RSC 12 and into the annular space of the RSC 12 defined by the wall 64, as described below with reference to FIG. Figure 3 Detailed explanation.

[0041] Other equipment is also arranged in the annular space of the RSC 12, including but not limited to a cage bottom header 66, a plurality of panel tubes 67, one or more panel tube headers 68, one or more concentric reducers 70, and a plurality of downcomer branches 72. Figure 3 As shown in the schematic side view of FIG. , the elbow joint 74 can connect the drop tube 36 to the concentric reducer 70, which is further referred to in FIG. Figure 8 Shown and described. A plurality of downcomer branches 72 extend from the concentric reducer 70 on one end and are connected to a header on the other end. Some of the downcomer branches 72 are connected to the cage bottom header 66, while other downcomer branches 72 are connected to the panel header 68. Each downcomer 36 can be associated with one or more downcomer branches 72. For example, each downcomer 36 can be associated with between 1 and 10 downcomer branches (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 branches). In addition, a plurality of downcomer branches 72 can be arranged in the same or different orientations to facilitate coupling the downcomer branches to various features, including the cage bottom header 66 and the panel header 68.

[0042] As described above, the downcomer 36 is disposed circumferentially around the outer wall 64 of the RSC 12 and extends into the annular space of the RSC 12. Figure 3 As shown in FIG, a majority of the drop tube 36 remains within the exterior region of the RSC 12. An expansion joint (e.g., an expansion bellows) 78 is utilized along the drop tube 36 to enable the drop tube 36 to expand or contract in response to thermal expansion and contraction (e.g., differential thermal expansion between the RSC 64 and the drop tube assembly 36). Figure 6 Further understanding of the details of the expansion joint 78. The downcomer 36 may also include an outer elbow 80. The outer elbow 80 forms an angle and transitions the downcomer 36 from being generally parallel to the outer wall 64 of the RSC 12 above the elbow (e.g., a downflow portion) to being generally perpendicular to the outer wall 64 of the RSC 12 (e.g., a crossflow portion). The downcomer 36 may be coupled to the RSC 12 via a nozzle sleeve 86. The inner diameter of the nozzle sleeve 86 may be greater than the outer diameter of the downcomer 36 and may have any suitable geometry. In certain embodiments, a purge gas is injected into the annular space between the nozzle sleeve 86 and the downcomer 36 via line 82.

[0043] The drop tube 36 may also include a flange assembly 84 (eg, one or more flange plates) to couple a nozzle sleeve 86 to the drop tube 36. The nozzle sleeve 86 may be welded or otherwise coupled to the flange assembly 84. The nozzle sleeve 86 is welded to the RSC wall 64 at the other end.

[0044] From the nozzle 86, the down tube 36 extends into an interior region 87 of the RSC 12, which is separated from the exterior region 76 by the RSC wall. Inside the RSC wall, the down tube 36 is coupled to an inner elbow 88. The inner elbow 88 forms an angle and is coupled to the concentric reducer 70 via welding, fusion, brazing or some other connection method.

[0045] The downcomer branches 72 may have a smaller diameter than the downcomer 36. For example, the diameter of the downcomer branches 72 may be a percentage of the diameter of the downcomer 36, such as between 25 and 75%, 33 and 65%, 40 and 50%, and all percentages therebetween. The downcomer branches 72 arranged along the sides of the concentric reducers 70 may have elbows 92 that angle the downcomer branches toward the panel header 68. The downcomer branches 72 extending from the bottom of the concentric reducers 70 may have elbows 94 that angle the downcomer branches 72 toward the cage bottom header 66.

[0046] The portions and components of the downcomer 36 outside the RSC wall 64 may be made of a different material than the portions and components of the downcomer 36 inside the RSC wall 64. The portions and components of the downcomer 36 outside the RSC 12 are subjected to lower temperatures than the portions of the downcomer inside the RSC 12. Thus, the portions of the downcomer inside the RSC are different from the downcomer branches 72, the inner elbows 88, and any other components inside the RSC 12 (e.g., Figure 6-7 The cage tube, or nozzle 86 described in the RSC 12 can be made of any suitable material, such as a superalloy configured to have excellent temperature strength, ductility and oxidation resistance relative to the portion of the downcomer 36 outside the RSC wall 64. In a non-limiting example, the portion of the downcomer 36 inside the RSC 12 can be made of a high nickel alloy together with the downcomer branch 72, the inner bend 88 and any other components inside the RSC 12. In this example, the portion and components of the downcomer 36 outside the RSC 12 (e.g., the outer bend, the discharge line) can be made of a material that is generally less expensive and does not necessarily have the same material properties as the material used for the downcomer 36 inside the RSC 12. Non-limiting examples of such materials include carbon steel (e.g., SA 106 pipe). Between the nozzle 86 and the portion of the downcomer 36 adjacent to the nozzle 86 and closer to the RSC 12, a transition material can be used to mitigate the deformation of the joint caused by welding of different materials. For example, the transition material can include Inconel available from Special Metalscorporation of Hartford, New York. TM 625 high nickel alloy.

[0047] As described above, the expansion joint 78 (eg, an expansion bellows) is positioned along the downcomer 36 and is configured to enable the downcomer 36 to expand or contract in response to thermal fluctuations. Figure 4 It is along Figure 3 Schematic diagram of an embodiment of an expansion joint 78 arranged in a downcomer 36. The expansion joint 78 is made of carbon steel and stabilizes the portions of the downcomer 36 above and below the expansion joint 78. The expansion joint 78 enables thermal expansion of the downcomer 36 as fluid flows through the tube 36. The expansion bellows includes a plurality of ridges 98. On either side of the ridges 98, the expansion joint 78 may include a flange 100 that is welded, fused, brazed, or otherwise coupled to an adjacent downcomer 36. Reference may be made to Figure 5 The position of the expansion joint 78 relative to the downcomer 36 is further appreciated.

[0048] Figure 5 6 is a partial cross-sectional view of components arranged outside the RSC and components arranged inside the RSC. A cooling medium (e.g., water) flows from the downcomer 36 to the downcomer branch 72 (e.g., heat exchange tubes). The cooling medium (e.g., water) flows from the downcomer branch 72 to the cage bottom header 66 and the panel header 68. The water flows through the panel tubes 67 (from the panel header 68) and from the cage bottom header 66 through the cage tubes (not shown). As shown, the panel header 68 provides the cooling medium to the plurality of panel tubes 67. The panel tubes 67 may also have a cooling fluid (e.g., water) flowing through the panel tubes 67 (e.g., heat exchange tubes).

[0049] As described above, the RSC 12 is configured such that the downcomer 36 extends axially along the RSC 12 on its exterior and transitions inwardly through the RSC wall 64. The downcomer 36 also extends through openings in a plurality of cage tubes 102 extending from the cage bottom header 66, as shown in FIG. Figure 6-8 as shown in . Figure 6 yes Figure 1 FIG. 1 is a partial schematic diagram of an embodiment of an RSC 12 showing an external view of a plurality of cage tubes 102 coupled to a cage bottom header 66. The cage tubes 102 may be made of a high nickel alloy as may other components disposed within the RSC 12. The cage tubes 102 may be disposed circumferentially around the panel tubes 67. Generally speaking, for each downcomer 36, a set of cage tubes 102 may be coupled to the cage bottom header 66.

[0050] The receiving plate 104 may be positioned against some of the plurality of cage tubes 102 and configured to seal against the downcomer 36 to maintain the internal pressure of the RSC 12. The receiving plate 104 includes a downcomer receptacle 106 for receiving the downcomer 36 and, in some embodiments, is sized to receive the nozzle 86. The receiving plate 104 may be welded, fused, brazed, or otherwise coupled to some of the plurality of cage tubes 102 and may form or seal a portion of the RSC wall 64. The receiving plate 104 may be made of a material capable of withstanding the high temperatures of the RSC 12. Many of the cage tubes 102 extend generally parallel to the wall of the RSC wall 64. However, the shape of some of the cage tubes 102 may be modified to accommodate the receiving plate 104. As shown in FIG. Figure 7 As shown in FIG. 1 , the portion 108 of the cage tube 102 adjacent to the receiving plate 104 may be modified to have a bend 109. The modified cage tube 108 provides a gap or space suitable for the cartridge seal, as shown in FIG. Figure 8 explain.

[0051] Figure 8 yes Figure 1 1 is a partially schematic side view of an embodiment of an RSC 12, showing a bend 109 in a modified cage tube 108 that accommodates a box seal 110. The box seal 110 may be welded, fused, brazed, or otherwise coupled to the receiving plate 104. In other embodiments, the box seal 110 may simply be placed against the modified cage tube 108 and the receiving plate 104 to form a compression seal. In general, the box seal 110 helps reduce the escape of hot syngas from the RSC 12. Additionally, the box seal is designed to accommodate differential thermal expansion between the cage tube and the vessel wall. As described above, the downcomer 36 is coupled to the concentric reducer 70 to which the downcomer branches 72 are coupled.

[0052] The technical effect of the present invention is to arrange a plurality of downcomers circumferentially outside the wall of the RSC. Compared with when the downcomers are arranged in the annular space of the RSC, the downcomers arranged around the periphery of the RSC can reduce the inner diameter of the RSC. Moreover, arranging the downcomers outside the RSC simplifies the pipeline in the dome-shaped cross-section part of the RSC. Arranging the downcomers outside the RSC can also make the part of the downcomers arranged outside the RSC made of lower cost materials. A part of each downcomer is retained outside the wall of the RSC. Inside the RSC wall, the downcomer is connected to the inner elbow and connected to the concentric reducer. The downcomer branches arranged along the side of the concentric reducer can have an elbow at an angle of about 90 degrees, and the elbow is configured to connect the downcomer branches to the screen tube header, and the downcomer branches extending from the bottom of the concentric reducer have an elbow at an angle of about 45 degrees, and the elbow is configured to connect the downcomer branches to the cage bottom header.

[0053] This specification uses examples to disclose the present invention, including the best mode, and also enables any person skilled in the art to implement the present invention, including making and using any device or system and performing any included method. The patent scope of the present invention is defined by the claims, and may include other examples that occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims as long as they have structural elements that do not differ from the literal language of the claims, or as long as they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. A system comprising: a radiant syngas cooler configured to receive and cool syngas produced in the gasifier; a housing of the radiant syngas cooler defining an annular space of the radiant syngas cooler; heat exchange tubes of the radiant syngas cooler positioned within the annular space and configured to flow a cooling medium, wherein the heat exchange tubes are configured to enable heat exchange between the syngas and the cooling medium to cool the syngas; as well as A downcomer of the radiant syngas cooler configured to supply a cooling medium to the heat exchange tubes, wherein the downcomer includes a downflow portion positioned outside of an outer shell of the radiant syngas cooler, wherein the downflow portion of the downcomer extends axially along the length of the outer shell of the radiant syngas cooler to at least a bottom portion of the outer shell, such that the downflow portion is fluidly connected to a header, and the header fluidly connects the downcomer to the heat exchange tubes.

2. The system according to claim 1, characterized in that The downcomer includes a first downcomer branch and a second downcomer branch, wherein the first downcomer branch fluidly couples the downcomer to the header, and the second downcomer branch fluidly couples the downcomer to an additional header.

3. The system according to claim 2, characterized in that The header is a panel header that fluidly couples the first downcomer branch to a plurality of panel tubes configured to flow a cooling medium, and the additional header is a cage header that fluidly couples the second downcomer branch to a plurality of cage tubes configured to flow a cooling medium.

4. The system according to claim 3, characterized in that The plurality of cage tubes surround the plurality of panel tubes, and the radiant syngas cooler includes an additional panel tube header fluidly coupling an additional plurality of panel tubes to additional downcomers, wherein the additional downcomers each have a respective lower flow portion positioned outside of an annular space of the radiant syngas cooler.

5. The system according to claim 3, characterized in that The downcomer includes a cross-flow portion extending from the lower flow portion into an annulus of the radiant syngas cooler, wherein the cross-flow portion extends through openings in the plurality of cage tubes.

6. The system according to claim 5, characterized in that The plurality of cage tubes have curved portions that accommodate the containers of the drop tubes.

7. The system according to claim 3, characterized in that The downcomer includes a third downcomer branch fluidly coupling the downcomer to an additional panel header, the additional panel header being fluidly coupled to an additional plurality of panels.

8. The system according to claim 2, characterized in that The first downcomer branch pipe and the second downcomer branch pipe extend from the downcomer in opposite directions.

9. The system according to claim 2, characterized in that The first downcomer branch pipe and the second downcomer branch pipe extend from a concentric reducer of the downcomer.

10. The system according to claim 1, characterized in that The lower flow portion of the downcomer includes an expansion joint configured to allow for expansion and contraction caused by thermal fluctuations.

11. The system according to claim 1, characterized in that The downcomer includes a downflow portion and a crossflow portion extending from the downflow portion into an annular space of the radiant syngas cooler, wherein a region of the crossflow portion positioned within the annular space is constructed of one or more materials that can withstand higher temperatures than the material of the downflow portion.

12. The system according to claim 1, characterized in that The downcomer includes a blowdown line positioned external to the shell of the radiant syngas cooler.

13. The system according to claim 1, characterized in that The downcomer is a first downcomer, and the radiant syngas cooler includes a second downcomer, wherein the first and second downcomers include a first downcomer branch and a second downcomer branch, respectively, wherein the first downcomer branch fluidly couples the first downcomer to a first panel header, the second downcomer branch fluidly couples the second downcomer to a second panel header separated from the first panel header, and the first and second downcomer branches overlap each other.

14. The system according to claim 13, characterized in that The first downcomer branch pipe includes a curved portion allowing the second downcomer branch pipe to enter the second panel header.

15. A system comprising: a radiant syngas cooler comprising a plurality of panels extending from one or more panel headers within an annular space of the radiant syngas cooler, and a plurality of downcomers having vertical portions disposed circumferentially around an exterior of the radiant syngas cooler and horizontal portions extending into the annular space, wherein the horizontal portions include an inner portion disposed within the annular space and an outer portion disposed outside the annular space; a first plurality of elbow fittings coupled between the vertical portions and the outer portions of the plurality of drop tubes; a second plurality of elbow fittings coupled to the interior portion and a plurality of concentric reducers coupled to the second plurality of elbow fittings; a plurality of downcomer branches extending from the concentric reducer, wherein at least a portion of the plurality of downcomer branches are coupled to the one or more panel headers; as well as A cage bottom header is arranged below the one or more panel headers, wherein at least one downcomer branch of the plurality of downcomer branches is coupled to the cage bottom header.

16. The system according to claim 15, characterized in that The first plurality of elbow fittings, the vertical portion, and the outer portion each comprise carbon steel.

17. The system according to claim 15, characterized in that The concentric reducer, the second plurality of elbow fittings, and the inner portion each comprise a superalloy.

18. The system according to claim 15, characterized in that The first plurality of elbow fittings, the vertical portion, and the outer portion are each constructed of a material that is more heat resistant than a material used to construct the first plurality of elbow fittings, the vertical portion, and the outer portion.

19. The system according to claim 15, characterized in that The diameter of the downcomer is approximately twice the diameter of the plurality of downcomer branches.

20. A system comprising: a gasifier configured to generate syngas fluidly coupled to a radiant syngas cooler; The radiant syngas cooler includes a plurality of panels extending from one or more panel headers within the cooler and a plurality of downcomers arranged circumferentially around the cooler, wherein the plurality of panels are configured to cool syngas flowing through the cooler; a first plurality of elbow fittings coupled between the vertical portion of the downcomer and the horizontal portion of the downcomer, wherein the elbow fittings are configured to extend the horizontal portion of each downcomer in a radially inward direction relative to the cooler; a cooler wall of the radiant syngas cooler, wherein the horizontal portion of each downcomer includes an inner portion inside the cooler wall and an outer portion outside the cooler wall; a second plurality of elbow fittings coupled between each interior portion of each dropper and the plurality of concentric reducers; a plurality of downcomer branches extending from each concentric reducer, wherein one or more of the branches are coupled to an adjacent panel header; a cage bottom header arranged below the panel header, wherein at least one of the plurality of downcomer branches is connected to the cage bottom header; and wherein the hot syngas is configured to transfer heat to a cooling fluid flowing through the plurality of panel tubes and cage tubes; as well as A syngas processor is disposed downstream of the radiant syngas cooler and is configured to process a flow of cooled syngas.

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