Gasifier throat cooling

Abstract

A gasifier for converting a carbonaceous feedstock to produce syngas, the gasifier comprising a cone section and a throat section; wherein the throat section comprises a throat refractory material having an interior surface and a substantially cylindrical cooling element having an inner face and an outer face in a radial direction and a top face and a bottom face in a vertical direction wherein the inner face, the outer face, the top face and the bottom face define a cooling cavity; and wherein the cooling element is in thermal contact with the throat refractory material on the inner face, the top face and the outer face.

Description

[0001] Cross-reference to related applications This application claims priority to U.S. Nonprovisional Application No. 18 / 477,815, filed September 29, 2023, which is incorporated herein by reference. Background Technology

[0002] The partial combustion or gasification of solid carbonaceous fuels such as coal to produce gases valuable as fuels for domestic and industrial use, as starting materials for synthetic chemicals and fuels, and as energy sources for power generation has long been recognized and practiced worldwide on varying scales. The high-temperature and corrosive chemical environment within gasifiers necessitates the protection of the external pressure vessel walls by refractory materials, particularly in the narrow throat at the reactor outlet. These refractory materials degrade during operation and must be periodically removed and replaced. Summary of the Invention

[0003] The present invention relates to a system for cooling the throat of a vaporizer in which a cooling chamber is located using one or more substantially cylindrical cooling coils, the one or more substantially cylindrical cooling coils being surrounded by refractory material on the inner surface, top surface and outer surface of the cooling chamber.

[0004] Aspect 1: A gasifier for converting carbonaceous feedstock to produce syngas, the gasifier comprising a conical section and a throat section; wherein the throat section comprises a throat refractory material and a substantially cylindrical cooling element having an inner surface and an outer surface in a radial direction and a top surface and a bottom surface in a vertical direction, wherein the inner surface, the outer surface, the top surface, and the bottom surface define a cooling cavity; and wherein the cooling element maintains thermal contact with the throat refractory material on the inner surface, the top surface, and the outer surface.

[0005] Aspect 2: According to the vaporizer of aspect 1, the vaporizer includes a coolant inlet conduit in fluid communication with the cooling element and a coolant outlet conduit in fluid communication with the cooling element; wherein the coolant inlet conduit is in fluid communication with a coolant source outside the vaporizer; and wherein the coolant outlet conduit is in fluid communication with a coolant tank outside the vaporizer.

[0006] Aspect 3: The vaporizer according to aspect 2, wherein the coolant inlet conduit and the coolant outlet conduit include sections oriented perpendicular to the centerline of the vaporizer in the radial direction.

[0007] Aspect 4: The gasifier according to any one of Aspects 1 to 3, wherein the throat refractory material comprises refractory bricks.

[0008] Aspect 5: A vaporizer according to any one of Aspects 1 to 4, wherein the throat section has an inner surface and an inner radius defined as the distance from the centerline of the vaporizer to the inner surface of the throat section; wherein the minimum value of the inner radius of the throat section is within 2% of the maximum value of the inner radius of the throat section.

[0009] Aspect 6: A vaporizer according to any one of Aspects 1 to 4, wherein the throat section has an inner radius that gradually increases with depth.

[0010] Aspect 7: The vaporizer according to any one of Aspects 1 to 6, the vaporizer further comprising a refractory support base plate attached to the bottom surface of the cooling element.

[0011] Aspect 8: A method of operating a vaporizer, the method comprising indirectly transferring heat from a refractory material having a refractory temperature to a coolant having a coolant temperature and a liquid stability limit; wherein the method comprises a drying mode characterized by raising the refractory temperature from ambient temperature to about 100°C, and a heating mode characterized by raising the refractory temperature from about 100°C to the liquid stability limit of the coolant; wherein during the drying mode, the coolant temperature is maintained between a lower limit of the drying mode temperature and an upper limit of the drying mode temperature; wherein during the heating mode, the coolant temperature is maintained between a lower limit of the heating mode temperature and an upper limit of the heating mode temperature.

[0012] Aspect 9: According to the method of aspect 8, wherein the lower limit of the drying mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the drying mode temperature is less than or equal to 5°C higher than the refractory temperature.

[0013] Aspect 10: The method according to aspect 8 or aspect 9, wherein the lower limit of the heating mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the heating mode temperature is less than or equal to 10°C lower than the liquid stability limit of the coolant.

[0014] Aspect 11: The method according to any one of Aspects 8 to 10, wherein the coolant has a coolant pressure; wherein the coolant pressure is kept constant at a value greater than the vapor pressure of the coolant under the liquid stability limit.

[0015] Aspect 12: The method according to any one of Aspects 8 to 10, wherein the coolant has a coolant pressure; wherein the coolant pressure is maintained at a value greater than the vapor pressure of the coolant at the temperature of the coolant.

[0016] Aspect 13: The method according to any one of Aspects 8 to 12, the method further comprising a cooling mode characterized by reducing the refractory temperature from the operating temperature of the gasifier to a value equal to the ambient temperature; wherein during the cooling mode, the coolant temperature is maintained between a lower limit of the cooling mode temperature and an upper limit of the cooling mode temperature.

[0017] Aspect 14: According to the method of aspect 13, wherein the lower limit of the cooling mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the cooling mode temperature is less than or equal to the smaller of 10°C lower than the liquid stability limit of the coolant and 5°C higher than the refractory temperature.

[0018] Aspect 15: The method according to any one of Aspects 8 to 14, wherein the coolant temperature is controlled by exchanging heat with a quenching bath before indirectly transferring heat from the refractory material.

[0019] Aspect 16: A gasifier for converting carbonaceous feedstock to produce syngas, the gasifier comprising: a reactor section configured to react the carbonaceous feedstock with an oxidant to produce syngas; a quenching section configured to contact the syngas with a quenching bath; and a throat section configured to convey the syngas from the reactor section to the quenching section, wherein the throat section includes a throat refractory material and a cooling element in thermal contact with the throat refractory material; wherein the quenching section includes a suction pipe having... The device has an inlet in fluid flow communication with the throat section and an outlet in fluid flow communication with the quenching bath; wherein the quenching section further includes a low liquid level located above the outlet of the extraction tube; wherein the quenching bath has a liquid level at or above the low liquid level; wherein the quenching section further includes a quenching heat exchanger in thermal contact with the quenching bath; wherein the cooling element includes an inlet in fluid flow communication with the outlet of the quenching heat exchanger; and wherein at least a portion of the quenching heat exchanger is located above the outlet of the extraction tube and below the low liquid level.

[0020] Aspect 17: The vaporizer according to aspect 16, wherein at least a portion of the quenching heat exchanger is configured to reduce liquid level and flow instability in the quenching bath.

[0021] Aspect 18: The vaporizer according to aspect 17, wherein at least a portion of the quenching heat exchanger is configured to reduce the liquid level and flow instability in the quenching bath, forming a conical truncated surface.

[0022] Aspect 19: A method of operating a gasifier, the method comprising: reacting a carbonaceous feedstock with an oxidant to generate a syngas stream; cooling a refractory material in thermal contact with the syngas stream by indirect heat exchange with a heat transfer fluid; contacting the syngas stream with a quenching water stream to generate a quenched syngas stream; and partially condensing the quenched syngas stream to generate a process condensate stream; wherein the heat transfer fluid includes at least a portion of the process condensate stream.

[0023] Aspect 20: According to the method of aspect 19, the quenching water stream includes at least a portion of the process condensed material stream. Attached Figure Description

[0024] The invention will now be described in conjunction with the accompanying drawings, wherein like reference numerals denote like elements. Furthermore, reference numerals for similar elements shared in the drawings may be indexed in multiples of one hundred. For example, in Figure 2 The changes that have occurred Figure 1 Component 1xx in the code can be referred to as component 2xx.

[0025] Figure 1 A cross-section of a vaporizer according to the prior art is shown.

[0026] Figure 2 A cross-section of a gasifier with cooling elements behind the refractory material in the throat is shown.

[0027] Figure 3 A cross-section of the vaporizer is shown, in which the cooling element is in fluid flow communication with a coolant source outside the vaporizer and a coolant tank outside the vaporizer.

[0028] Figure 4 The control scheme for the closed-loop cooling system is shown.

[0029] Figure 5A A control scheme for an open-loop cooling system is shown.

[0030] Figure 5B It shows Figure 5A A variant in which the pressure of the coolant is also controlled.

[0031] Figure 6 A cross-section of a gasifier including a reactor section and a quenching section is shown, wherein the quenching heat exchanger is integrated into the quenching section.

[0032] Figure 7 It shows Figure 6 The modified cross-section, wherein at least a portion of the quenching heat exchanger is integrated into the quenching liquid level stabilizer.

[0033] Figure 8 It shows Figure 7A variant in which the quenching heat exchanger and cooling elements are integrated with the downstream process condensate system. Detailed Implementation

[0034] The following detailed description provides only preferred exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the subsequent detailed description of preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the invention. As set forth in the appended claims, various changes may be made to the function and arrangement of the elements without departing from the spirit and scope of the invention.

[0035] When applied to any feature of the embodiments of the invention described in the specification and claims, the articles “a” and “an” as used herein mean one or more. The use of “a” and “an” does not limit the meaning to a single feature unless such limitation is explicitly stated. The article “the” preceding a singular or plural noun or noun phrase indicates one or more specific designated features and may have a singular or plural meaning depending on the context in which it is used.

[0036] The phrase "at least a portion" means "a portion or all of". "At least a portion of the material stream" has the same composition as its derived material stream, with the same concentration of each substance in the material.

[0037] The term “and / or” placed between the first entity and the second entity includes any one of the following meanings: (1) only the first entity, (2) only the second entity, or (3) both the first entity and the second entity. The term “and / or” placed between the last two entities in a list of three or more entities means at least one entity in the list, including any particular combination of entities in the list. For example, “A, B and / or C” has the same meaning as “A and / or B and / or C” and includes the following combinations of A, B and C: (1) only A, (2) only B, (3) only C, (4) A and B but not C, (5) A and C but not B, (6) B and C but not A, and (7) A and B and C.

[0038] The adjective "any" means one, some, or all, without distinguishing the quantity.

[0039] "Downstream" and "upstream" refer to the intended flow direction of the process fluid being transferred. If the intended flow direction of the process fluid is from the first unit to the second unit, then the second unit is downstream of the first unit. In the case of a circulating flow, downstream and upstream refer to the first passage of the process fluid.

[0040] The term "indirect heat exchange" refers to a process in which sensible heat and / or latent heat is transferred between two or more fluids without physical contact between them. Heat can be transferred through the walls of the heat exchanger or using an intermediate heat transfer fluid. The term "hot feed" refers to any feed stream that leaves the heat exchanger at a temperature lower than its entry temperature. Conversely, "cold feed" is a feed stream that leaves the heat exchanger at a temperature higher than its entry temperature.

[0041] Figure 1 A cross-section of a vaporizer 100 according to the prior art is shown. A container wall 102 maintains the pressure of the vaporizer and is protected by a layer of insulating refractory material 104 and wall support bricks 106. One or more refractory support shelves 108 may extend inward from the container wall 102 toward the centerline of the vaporizer to improve structural integrity and / or simplify the installation of the refractory material. A refractory support base plate 110 extends from the container wall 102 to support the weight of the refractory material, and one or more refractory support shelves 108 may also extend inward from a portion of the refractory support base plate 110. An insulating base plate refractory material 112, which may comprise bricks and / or castable materials, can be found on the refractory support base plate 110. Throat support bricks 114 can be found on the inner portion of the refractory support base plate 110. The inner surface of the vaporizer is formed by refractory bricks 116, which form sidewalls 118, cones 120, and throats 122. The larynx 122 can be in such a position as Figure 1 The stepped configuration shown has an inner radius of throat 122 that gradually increases with depth to improve slag flow out of the gasifier, wherein the inner radius is defined as the distance from the centerline of the gasifier to the inner surface of throat 122.

[0042] The refractory bricks 116 in the cone 120 and throat 122 are susceptible to damage from slag, requiring frequent replacements and necessitating costly shutdowns and closures of the gasifier. Damage can occur by any means, such as erosion, corrosion, penetration, and spalling. One way to increase the lifespan of the refractory is by introducing cooling elements, such as heat exchanger tubes carrying a coolant (e.g., water), behind the refractory. Figure 2A cross-section of a gasifier 200 with cooled refractory material according to an embodiment of the present invention is shown. A throat-external refractory material 214 forms a cooling cavity 236 between the refractory material 116 and the refractory material support base plate 110, in which a substantially cylindrical cooling element 230 is positioned. The cooling element 230 has an inner surface closest to the centerline of the gasifier, an outer surface closest to the container wall 102, and a top and bottom surface in the vertical direction. In at least some embodiments, the cooling element 230 is attached to the refractory material support base plate 110. In at least some embodiments, the throat-external refractory material 214 may comprise a refractory material different from the insulating base plate refractory material 212. The cooling element 230 maintains thermal contact with the refractory brick 116 and the throat-external refractory material 214 through a cooling cavity material 232, which may comprise one or more refractory materials, such as refractory paper and / or castable refractory materials, such as silicon carbide. The cooling chamber material 232 can be arranged to maintain thermal contact with the refractory material as it expands and contracts with the thermal circulation within the gasifier. In at least some embodiments, the throat 122 can have, for example, Figure 1 The stepped configuration is shown. In at least some other embodiments, the throat 222 can be positioned as follows: Figure 2 The configuration shown is essentially cylindrical. For some gasifiers, the essentially cylindrical configuration allows for better slag flow through the throat compared to a stepped configuration. When the throat 222 is new, the variation between the widest and narrowest inner radii of the throat 222 can be less than 2%, less than 1%, or less than 0.5%. When the throat 222 is nearing replacement, the variation between the widest and narrowest inner radii of the throat 222 can be less than 50% or less than 25%.

[0043] The insulating base plate refractory material 212 may include bricks instead of castable materials or a combination of both to make installation and replacement easier.

[0044] Improved heat transfer via the refractory brick 116, the outer refractory material 214 of the throat, and the refractory support base plate 110 to the cooling element 230 reduces the temperature within the refractory brick 116, thereby extending the overall lifespan. In at least some embodiments, the bottom of the cooling element 230 may be attached to the refractory support base plate 110 to maintain its position relative to the refractory support base plate 110 and to conduct heat to the cooling element 230. Surprisingly, extended lifespan can be achieved without active cooling within the cone 120. In at least some embodiments, there is no cooling element within or behind the cone 120.

[0045] The refractory support base plate 110 may include a refractory support shelf 234 to support the refractory bricks 116 in the throat 222. The refractory support shelf may be formed as a continuous ring or segmented into multiple tabs to reduce the risk of cracking due to circumferential stress caused by uneven thermal expansion.

[0046] Cooling element 230 may include conduits for carrying a coolant such as water. The conduits may be in the radial direction (…). Figure 2 One or more layers are formed in the horizontal direction of the cooling element 230. The conduits in the cooling element 230 may be circumferentially oriented within the cooling cavity 236 to form a cylindrical path, or they may be oriented in a serpentine path within the cooling cavity 236. In at least some embodiments, the serpentine path may include straight segments in the vertical direction while changing the direction circumferentially by 180 degrees to create a serpentine path with vertical bends. In at least some other embodiments, the serpentine path may include curved segments in the circumferential direction while changing the direction vertically by 180 degrees to create a serpentine path with horizontal bends. The cooling element 230 may include multiple segments that may be installed individually and subsequently welded together by expansion joints in series and / or parallel.

[0047] Figure 3 A cross-section of the vaporizer 300 is shown, in which the cooling element 230 is in fluid flow communication with a coolant source 340 and a coolant tank 342 outside the vaporizer. In at least some embodiments, the coolant source 340 is in fluid flow communication with the coolant tank 342 and dissipates heat into the environment incorporated into the coolant circuit. The cooling element 230 may include a coolant inlet conduit 344 and a coolant outlet conduit 346, both of which may travel through the throat refractory material 214, the insulating base plate refractory material 212, and / or the refractory support base plate 110 while passing through the container wall 102. The pressure and flow rate of the coolant may be controlled by one or more devices located upstream or downstream of the cooling element 230. For example, the coolant inlet conduit 344 may include a pressure regulating device 352, such as a valve or orifice, to allow the coolant within the cooling element 230 to operate at the same, higher, or lower pressure than the vaporizer. Similarly, the coolant outlet conduit 346 may include a flow regulating device 350, such as a valve, to allow the coolant within the cooling element 230 to flow at a desired rate. The cooling element 230 may include a single loop in which coolant flows in series from the coolant source 340 to the coolant tank 342, or the cooling element 230 may include multiple loops connected via manifolds to the coolant source and coolant tank, in which coolant flows in parallel. The coolant may include any suitable heat transfer fluid, such as water.

[0048] Even when the gasifier is not producing syngas, its temperature is typically maintained at a high level. However, the gasifier temperature can periodically cycle between high and ambient temperatures to save fuel or for maintenance purposes. Under typical conditions, the heating and cooling profiles as a function of time are steep because the operator wants to maximize the amount of time the gasifier is at its normal operating temperature, primarily constrained by the thermal expansion and contraction of the refractory material. However, when starting the gasifier after replacing refractory materials such as the insulating base plate refractory 212 or the throat exterior refractory 214, a slower heating profile allows moisture in the refractory material to be slowly drained in dry mode. Rapid evaporation of liquid water within the refractory material can damage the material due to the large volumetric expansion of the resulting steam. To maintain the heating profile at a safe rate, the coolant can be kept between the lower limit of the dry mode coolant temperature and the upper limit of the dry mode coolant temperature for an extended period during dry mode operation. In at least some embodiments, the lower limit of the dry mode coolant temperature is defined relative to the refractory temperature, for example, less than or equal to 5°C lower than the refractory temperature. In at least some embodiments, the upper limit of the coolant temperature during the drying mode is defined relative to the refractory temperature, for example, less than or equal to 5°C higher than the refractory temperature. One advantage of maintaining the coolant temperature near the refractory temperature during drying is better control over the rate of moisture removal from the refractory material. Another advantage is minimizing strain caused by the thermal expansion of the different materials in the refractory material and coolant conduits.

[0049] During dry operation, the coolant can operate at a pressure sufficient to ensure it remains in the liquid phase. One method of pressure control is to maintain a constant pressure greater than the coolant's saturation pressure at the maximum coolant temperature throughout all modes of vaporizer operation. Another method is to gradually increase the coolant pressure as the coolant temperature increases, while always maintaining the coolant pressure above its saturation pressure at the current coolant temperature. During dry operation, the coolant may include cooling water, process condensate, and / or boiler feedwater.

[0050] The drying operation ends when the temperature of the refractory material reaches the final drying refractory temperature and is maintained at that temperature for a specified period of time (also known as the holding time). In at least some embodiments, the final drying refractory temperature can be approximately 100°C (the boiling point of water at ambient pressure), and the holding time can range from 12 hours to 24 hours. At this point, the cooling system enters a heating mode, in which the refractory temperature rises from the drying refractory temperature to the ignition temperature of the gasifier. In at least some embodiments, the ignition temperature of the gasifier ranges from 950°C to 1400°C.

[0051] During heating mode, the coolant temperature can be maintained between the lower limit of the heating mode coolant temperature and the upper limit of the heating mode coolant temperature. In the case of drying mode, the lower limit of the heating mode coolant temperature can be defined relative to the refractory temperature, for example, less than or equal to 5°C lower than the refractory temperature, and / or the upper limit of the heating mode coolant temperature can be defined relative to the refractory temperature, for example, less than or equal to 5°C higher than the refractory temperature.

[0052] When the temperature of the refractory material approaches the liquid stability limit of the coolant, the cooling system switches from heating mode to normal operating mode. When the cooling system is in normal operating mode, the vaporizer can be in any number of modes, including switching from the preheating burner to the feed injector, starting, generating syngas, shutting down, entering standby, performing thermal maintenance, or switching from the feed injector to the preheating burner. During normal operating mode, the coolant temperature can be maintained between the lower limit and the upper limit of the normal operating mode coolant temperature. The upper limit of the normal operating mode coolant temperature can be defined as less than or equal to 5°C below the liquid stability limit, or less than or equal to 10°C below the liquid stability limit. The liquid stability limit of the coolant is defined as the temperature at which the coolant begins to boil or thermally decompose. When syngas is being generated, the lower limit of the normal operating mode coolant temperature can be defined as less than or equal to 5°C above the dew point of the syngas, or less than or equal to 10°C above the dew point of the syngas, or less than or equal to 25°C above the dew point of the syngas, to prevent condensation.

[0053] When the vaporizer must be cooled to or near ambient temperature, similar to the heating mode, strain due to thermal contraction can be minimized by maintaining the coolant temperature between the lower limit and the upper limit of the cooling mode temperature. In at least some embodiments, the lower limit of the cooling mode temperature may be defined relative to the refractory temperature, for example, less than or equal to 5°C lower, or less than or equal to 10°C lower, or less than or equal to 25°C lower, and the upper limit of the cooling mode coolant temperature may be defined relative to the refractory temperature, for example, less than or equal to 5°C higher, or less than or equal to 10°C higher, or less than or equal to 25°C higher, provided that it does not exceed the upper limit of the normal operating mode coolant temperature.

[0054] Typically, liquid coolant is maintained at a constant temperature with varying flow rates to alter the cooling load provided. Operating a vaporizer with coolant temperature tracking the refractory temperature requires redesigning the coolant control loop to allow for variations in coolant temperature while simultaneously altering or maintaining a constant coolant flow rate. This is possible in both open-loop and closed-loop cooling systems.

[0055] Figure 4A control scheme for a closed-loop cooling system 400 is illustrated. In this example, a supplemental coolant 402 (such as boiler feedwater) is fed into container 410, where it is pressurized with nitrogen 404. The flow rate of the supplemental coolant 402 is controlled by a level controller LC1 in container 410, and the pressure of the nitrogen in container 410 is controlled by a pressure controller PC1, which sends an electrical signal to the nitrogen supply valve and / or vent valve 406. If necessary, container 410 may be equipped with a drain pipe (not shown) to remove excess water. Pump 420 delivers coolant from container 410 to line 422, where temperature controller TC1 can control the temperature by feeding back an electrical signal to heater 430 in container 410, such as during drying and heating modes or when the coolant temperature in container 410 or line 422 is below a desired value. However, most of the time, the coolant in line 422 will be hotter than expected due to heat removed from the refractory material (such as refractory 116) via cooling element 230. Therefore, line 422 delivers the coolant to cooler 440 (e.g., a fan cooler) to dissipate the heat absorbed by the coolant during operation of the cooling system. For example, cooler 440 can be used to dissipate heat absorbed by boiler feedwater as it passes through the gasifier, while the gasifier is producing syngas under steady-state conditions. The required cooling load in cooler 440 will increase as the gasifier cools. Coolant is delivered to line 442, where temperature controller TC2 can control the temperature by feeding back an electrical signal to cooler 440, for example, via speed controller SC1 on the fan cooler. Coolant is delivered to cooling element 230 via line 442 and exits cooling element 230 via line 446. In at least some embodiments, the flow rate of coolant through cooling element 230 will be constant. In other embodiments, the flow rate of the coolant through cooling element 230 can be variable. For example, temperature controller TC3 and flow controller FC1 can control the temperature and flow rate of the coolant in line 446 by sending an electrical signal from TC3 to flow controller FC2, which operates control valve 450 before returning the coolant water to container 410, or control valve 450 can be operated directly by temperature controller TC3. In other embodiments, the flow rate and temperature of the coolant water in line 446 can be controlled by adjusting the speed of pump 420 and / or by adjusting the opening of valves such as valve 452.

[0056] Figure 5A A control scheme for an open-loop cooling system 500A is shown to supply at least one of a hotter coolant 502 (such as boiler feedwater) and a colder coolant 504 (such as cooling water) to the cooling element 230 via line 512. In at least some embodiments, such as at the start of a dry mode, the coolant may be limited to cooling water. As in Figure 4In the closed-loop example, the temperature of the coolant in pipeline 512 can be increased or decreased according to the needs of the current operating mode. Figure 5A In this process, the temperature can be controlled by changing the relative flow rates of the hotter coolant 502 and the colder coolant 504. In at least some embodiments, methods such as... Figure 4 The coolant temperature is lowered by a cooler in the heat exchanger 510. The coolant temperature can be increased by heating the coolant through indirect heat exchange with a heat transfer fluid 506 (such as steam) in the heat exchanger 510. When the coolant is heated by steam, the heated coolant exits via line 512 and condensate 514 exits from the hot side of the heat exchanger 510. The temperature controller TC3 on line 512 can control the coolant temperature by sending an electrical signal back to the control valve 520 that regulates the flow rate of the heat transfer fluid 506. The coolant is delivered to the cooling element 230 via line 512 and exits via line 546. The temperature controller TC4 on line 546 and / or the flow controller FC4 on line 512 can be used to control the coolant temperature and flow rate by sending an electrical signal to actuate the control valve 550 before returning the coolant to the condensate system 552 and / or the drain line 554. For example, when plant cooling water is the source of coolant, the drain line 554 may be a preferred destination for the coolant, such as during at least a portion of the dry mode. In at least some embodiments, the flow controller FC4 may be placed on line 546 instead of line 512. In at least some embodiments, the temperature controller TC4 may directly control the temperature and flow rate of the coolant in line 546. In at least some embodiments, a valve located upstream of exchanger 510 may be used to control the flow rates of the hotter coolant 502 and the colder coolant 504. In at least some embodiments, Figure 5A The cooling system in the middle can eliminate the steam heating section including heat exchanger 510, valve 520, TC3 and condensate line 514.

[0057] Figure 5B It shows Figure 5A A variation of the control scheme in which the pressure of the hotter coolant 502 is controlled by a pressure controller PC4 on line 512, which feeds back an electrical signal to control valve 560.

[0058] For both open-loop and closed-loop cooling systems, a variety of coolants can be used. In at least one embodiment, process condensate is used as a coolant while the gasifier is running, allowing switching to an alternative coolant (such as boiler feedwater) when process condensate is unavailable. Those skilled in the art will understand that the flow rate of the process condensate produced by the gasifier may, in some cases, exceed the flow rate of the desired coolant. When this occurs, at least a portion of the process condensate can bypass either the open or closed cooling loop.

[0059] Figure 6 A cross-section of the gasifier, including reactor section 600 and quenching section 650, is shown. Syngas and slag exit the gasifier throat 222 and contact a water-containing quenching feed stream delivered by a quenching ring 651 at the bottom of the gasifier throat 222. The syngas, slag, and quenching feed stream travel downwards along the intake pipe 653 and contact a water-containing quenching bath. The level of the quenching bath is maintained above the low level 655. The syngas and slag travel downwards through the quenching bath through the outlet of the intake pipe 653, where the syngas separates from the slag and rises upwards through the annular space formed between the intake pipe 653 and the guide pipe 657. The syngas then exits via the quenched syngas outlet port 659. Quenching water can exit the quenching section 650 via the water discharge outlet 661. Slag can exit the quenching section 650 via the slag outlet 663.

[0060] The quenching heat exchanger 671 can be positioned in fluid flow communication with the coolant inlet conduit 344 and in thermal contact with the quenching bath. Allowing indirect heat exchange between the quenching bath and the coolant in the quenching heat exchanger provides several advantages. In normal operating mode, the coolant in the cooling element 230 must be maintained within a narrow temperature range: below an upper limit typically set by the coolant saturation temperature, the coolant thermal destructive limit, and / or structural material, and above a lower limit typically set by the syngas dew point. The quenching bath provides thermal inertia to better control the coolant temperature in the cooling element 230, particularly preventing the coolant from dropping below the lower limit when the vaporizer is operating. For further control of the coolant temperature, at least a portion of the coolant leaving the quenching heat exchanger 671 can be separated and delivered via the external heat exchanger conduit 673 to an external heat exchanger (not shown). The external heat exchanger can heat or cool the coolant as needed, wherein the coolant is returned via the external heat exchanger return 675 in fluid flow communication with the coolant inlet conduit 344.

[0061] In at least some embodiments, the quenching heat exchanger 671 is positioned such that at least a portion of the heat exchange area is located above the outlet of the draw tube 653 and below the low liquid level 655. This ensures that the quenching bath will be able to provide thermal inertia to the coolant during vaporizer operation, while minimizing thermal contact between the quenching heat exchanger 671 and the quenching bath during vaporizer shutdown, when the liquid level in the quenching bath is much lower and typically maintained below the bottom of the draw tube 653.

[0062] Figure 7 It shows Figure 6The modified cross-section of the quenching heat exchanger 771 is integrated into the quenching level stabilizer 780. The quenching level stabilizer reduces the possibility of level and flow instability in the quenching bath, which could otherwise lead to incomplete quenching of the syngas and excess quenching bath water residue downstream. In at least some embodiments, the quenching level stabilizer 780 forms a conical truncated surface. At least a portion of the quenching heat exchanger 771 may be attached to the solid surface of the quenching level stabilizer 780, and / or at least a portion of the quenching heat exchanger 771 may be welded to form the solid surface of the quenching level stabilizer 780. The quenching level stabilizer 780 may be connected to the wall of the quenching section 650 via one or more support brackets 781. The quenching level stabilizer may be positioned above, at, or below the low liquid level 655. In at least some embodiments, the quenching level stabilizer may be positioned above the low liquid level 655.

[0063] Figure 8 It shows Figure 7A variant of the process condensate system, in which the quenching heat exchanger 771 and cooling element 230 are integrated with the process condensate system 800 downstream of the gasifier. At least a portion of the process condensate stream 802, formed by condensing water from the downstream syngas feed stream, is separated to form a process condensate coolant fraction 804, which enters the quenching heat exchanger 771. The heated process condensate stream 806 exits the quenching heat exchanger 771 and enters the cooling element 230, exiting as a hot process condensate stream 808, which combines with the quenched syngas feed stream 812 exiting the gasifier. The quenched syngas feed stream 812 is further contacted with the nozzle scrubber water stream 814 in the nozzle scrubber 820 before entering the syngas scrubber 830. In the syngas scrubber 830, the quenched syngas stream 812 contacts a water stream including at least a portion of process condensate 802 and / or ash water stream 832 to produce a scrubbed syngas stream 834 with a reduced concentration of entrained solid particles. A water stream 841 with an increased concentration of solid particles exits the syngas scrubber 830, is pumped in a quenching pump 840, and enters the quenching ring 651 as quenching water stream 842. At least a portion of the quenching water stream 842 can be split to form a nozzle scrubber water stream 814. At least a portion of the process condensate coolant fraction 804 can bypass the quenching heat exchanger 671 to form a process condensate bypass 852, which can be combined with the quenched syngas stream 812. At least a portion of the heated process condensate stream 806 can bypass the cooling element 230 to form a heated process condensate bypass stream 854, which can be combined with the quenched synthesis gas stream 812. In at least some embodiments, the quenching cooler 771 can be omitted, and the process condensate 804 can be supplied to the cooling element 230.

[0064] Although the principles of the invention have been described above in conjunction with preferred embodiments, it should be clearly understood that the description is by way of example only and not as a limitation on the scope of the invention.

Claims

1. A gasifier for converting carbonaceous feedstock to produce syngas, the gasifier comprising a conical section and a throat section; The throat section includes a throat refractory material and a substantially cylindrical cooling element having an inner and outer surface in the radial direction and a top and bottom surface in the vertical direction, wherein the inner surface, the outer surface, the top surface, and the bottom surface define a cooling cavity; and The cooling element is in thermal contact with the throat refractory material on its inner surface, top surface, and outer surface.

2. The vaporizer according to claim 1, comprising a coolant inlet conduit in fluid communication with the cooling element and a coolant outlet conduit in fluid communication with the cooling element; The coolant inlet conduit is in fluid communication with a coolant source outside the vaporizer; and The coolant outlet conduit is in fluid communication with the coolant tank outside the vaporizer.

3. The vaporizer according to claim 2, wherein the coolant inlet conduit and the coolant outlet conduit include sections oriented perpendicular to the centerline of the vaporizer in the radial direction.

4. The gasifier according to claim 1, wherein the throat refractory material comprises refractory bricks.

5. The vaporizer of claim 1, wherein the throat section has an inner surface and an inner radius, the inner radius being defined as the distance from the centerline of the vaporizer to the inner surface of the throat section; The minimum value of the inner radius of the throat segment is within 2% of the maximum value of the inner radius of the throat segment.

6. The vaporizer according to claim 1, wherein the throat section has an inner radius that gradually increases with depth.

7. The vaporizer according to claim 1, further comprising a refractory support base plate attached to the bottom surface of the cooling element.

8. A method of operating a vaporizer, the method comprising: Heat is indirectly transferred from refractory materials with refractory temperatures to coolants with coolant temperatures and liquid stability limits. The method includes a drying mode and a heating mode, the drying mode being characterized by raising the refractory temperature from ambient temperature to about 100°C, and the heating mode being characterized by raising the refractory temperature from about 100°C to the liquid stability limit of the coolant. During the drying mode, the coolant temperature is maintained between the lower limit of the drying mode temperature and the upper limit of the drying mode temperature. During the heating mode, the coolant temperature is maintained between the lower limit of the heating mode temperature and the upper limit of the heating mode temperature.

9. The method according to claim 8, wherein the lower limit of the drying mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the drying mode temperature is less than or equal to 5°C higher than the refractory temperature.

10. The method of claim 8, wherein the lower limit of the heating mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the heating mode temperature is less than or equal to 10°C lower than the liquid stability limit of the coolant.

11. The method of claim 8, wherein the coolant has a coolant pressure; wherein the coolant pressure is kept constant at a value greater than the vapor pressure of the coolant under the liquid stability limit.

12. The method of claim 8, wherein the coolant has a coolant pressure; wherein the coolant pressure is maintained at a value greater than the vapor pressure of the coolant at the coolant temperature.

13. The method of claim 8, further comprising a cooling mode characterized by reducing the refractory temperature from the operating temperature of the gasifier to a value equal to the ambient temperature; During the cooling mode, the coolant temperature is maintained between the lower limit of the cooling mode temperature and the upper limit of the cooling mode temperature.

14. The method of claim 13, wherein the lower limit of the cooling mode temperature is less than or equal to 5°C lower than the refractory temperature, and wherein the upper limit of the cooling mode temperature is less than or equal to the smaller of 10°C lower than the liquid stability limit of the coolant and 5°C higher than the refractory temperature.

15. The method of claim 8, wherein the coolant temperature is controlled by exchanging heat with the quenching bath before indirectly transferring heat from the refractory material. o 15 • According to the method of claim 8, the coolant temperature is controlled by heating with at least one of resistance heating, steam, and heated heat transfer fluid before indirectly transferring heat from the refractory material.

16. A gasifier for converting carbonaceous feedstock to produce syngas, the gasifier comprising: A reactor section configured to react the carbonaceous feedstock with an oxidant to produce syngas; Quenching section, wherein the quenching section is configured to bring the synthesis gas into contact with the quenching bath; And a throat section configured to deliver the synthesis gas from the reactor section to the quenching section: The throat section includes throat refractory material and a cooling element that is in thermal contact with the throat refractory material; The quenching section includes a suction pipe having an inlet in fluid communication with the throat section and an outlet in fluid communication with the quenching bath. The quenching section further includes a low liquid level located above the outlet of the extraction tube; The quenching bath has a liquid level at or above the low liquid level; The quenching section further includes a quenching heat exchanger that comes into thermal contact with the quenching bath; The cooling element includes an inlet that is in fluid flow communication with the outlet of the quenching heat exchanger; and At least a portion of the quenching heat exchanger is located above the outlet of the extraction tube and below the low liquid level.

17. The vaporizer of claim 16, wherein at least a portion of the quenching heat exchanger is configured to reduce liquid level and flow instability in the quenching bath.

18. The vaporizer of claim 17, wherein the quenching heat exchanger is configured such that at least a portion thereof forms a conical truncated surface to reduce the liquid level and flow instability in the quenching bath.

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