Fluidized bed reactor system for extracting particles during reaction

Abstract

To provide a fluidized bed reactor configured to allow particle sample recovery without interrupting an ongoing reaction.SOLUTION: A fluidized gas reactor includes: a reaction chamber 1 including a fluidized bed; a gas distribution plate 3 having a plurality of openings 9 opening toward the reaction chamber; a plurality of fluidizing gas inlet tubes 4 each being in communication with one of the openings in the gas distribution plate; a fluidizing gas source configured to provide a stream of the fluidizing gas individually to each of the fluidizing gas inlet tubes; a coolant system which has a fluid inlet, a coolant flow path in communication with the fluid inlet, the coolant flow path being configured to cool each of the fluidizing gas inlet tubes; and a fluid outlet in fluid communication with the coolant flow path. Each of the fluidizing gas inlet tubes is configured to receive a fluidizing gas and transport the fluidizing gas to the reaction chamber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to fluidized bed reactors. In various embodiments, the present disclosure relates generally to systems for withdrawing particle samples from a fluidized bed reactor without interrupting an ongoing reaction. In various embodiments, the present disclosure relates to systems for supplying a coolant to a fluidizing gas supply line in a fluidized bed reactor. [Background technology]

[0002] It is known to use a fluidized bed reactor system connected to a locally cooled gas distribution plate, where the cooling channels allow for the transport of a cooling fluid through a jacket configured around the gas distributor. The locally cooled gas distribution plate is effective in preventing deposition on the walls around the orifices of the gas distribution plate. However, the gas distributor can only transport gas from the plenum chamber to the reaction chamber, and it is not possible to collect particle samples while continuing to emit gas. Furthermore, because the gas distributor cools the flowing gas near the gas distribution plate, it may not be able to effectively prevent the reaction of the reacting gas within the plenum chamber.

[0003] It is also known to use a fluidized bed reactor having a fluidizing gas flow path emerging from an ejector and a particle removal passageway adjacent to the ejector, where the airflow into the reactor may be used to prevent or reduce particle flow through the particle removal passageway. Particle removal can be initiated by introducing fluidized reaction gas into the bottom of the reactor and reducing the airflow through the particle removal passageway. However, this configuration only allows extraction of particles from a portion of the fluidized bed. It would be desirable to be able to selectively remove particles from any of multiple portions of the fluidized bed.

[0004] The present disclosure describes a system for withdrawing particle samples from a fluidized-bed reactor without interrupting an ongoing reaction. The present disclosure further describes a system for supplying a coolant to a fluidizing gas supply line in a fluidized-bed reactor. These systems can be realized by various embodiments disclosed herein. These embodiments are not intended to be exhaustive or limiting of the advantages that may be realized based on the teachings of the present disclosure. Various objects and advantages of the various embodiments disclosed herein will be apparent from the description herein or may be learned from the practice of the various embodiments, both as described herein or as modified in light of any variations apparent to those skilled in the art. The present invention, therefore, resides in the novel methods, arrangements, combinations, and improvements disclosed in the various embodiments herein. Summary of the Invention [Means for solving the problem]

[0005] In light of the current need for improved methods of removing entrained particles from exhaust streams, a brief summary of various exemplary embodiments is presented. It is intended to highlight and introduce certain aspects of the various exemplary embodiments, but is not intended to limit the scope of the present invention. Additionally, certain simplifications and omissions may be made in the summary that follows. Detailed descriptions of preferred exemplary embodiments sufficient to enable one skilled in the art to make and use the inventive concepts follow.

[0006] Various embodiments disclosed herein relate to a fluidized bed reactor configured to allow for the withdrawal of particle samples without interrupting an ongoing reaction. In various embodiments, the fluidized bed reactor includes a reaction chamber containing a particle bed and a gas distribution plate having a plurality of openings therethrough, each opening opening into the reaction chamber. The reactor also includes a plurality of fluidizing gas inlet tubes, each of which communicates with one of the openings in the gas distribution plate. Each of the fluidizing gas inlet tubes is configured to receive a fluidizing gas and deliver it to the reaction chamber through the gas distribution plate. A fluidizing gas source is configured to supply a flow of fluidizing gas to the fluidizing gas inlet tubes. Various embodiments of the reactor include a plurality of particle outlets, each of which is located at the bottom of one of the fluidizing gas inlet tubes. The flowing gas source is configured to selectively stop the flow of flowing gas in any one of the flowing gas inlet pipes, and each particle outlet is configured to receive particles from the particle bed while the flow of flowing gas in the corresponding flowing gas inlet pipe is stopped.

[0007] In various embodiments, the flow gas source is configured to selectively stop the flow of flow gas through one of the flow gas inlet pipes without interrupting the flow of flow gas through the other of the flow gas inlet pipes. In various embodiments, the flow gas source comprises a plurality of flow gas supply pipes, each flow gas supply pipe in communication with a corresponding flow gas inlet pipe, each flow gas supply pipe including a valve configured to selectively stop the flow of flow gas through the corresponding flow gas inlet pipe.

[0008] In various embodiments, the flow gas source comprises a plurality of flow gas supply lines, each of which is in communication with a corresponding flow gas inlet line, and each of which includes a first valve configured to be in a first position.

[0009] Here, the first position selectively stops the flow of fluid gas to the corresponding fluid gas inlet pipe.

[0010] Also, wherein when the first valve is in a first position, the corresponding flowing gas inlet pipe includes a second valve configured to allow particles to flow from the particle bed to the particle outlet. Similarly, in various embodiments, the first valve is also configured to adopt a second position, the second position allowing a flow of flowing gas into the corresponding flowing gas inlet pipe, and the second valve configured to prevent flow of particles from the particle bed to the particle outlet when the first valve is in the second position. In various embodiments, the first and second valves allow flow of the flowing gas from the corresponding flowing gas inlet pipe or allow flow of particles from the particle bed to the particle outlet through the flowing gas inlet pipe. The flow of the flowing gas and the flow of particles through the flowing gas inlet pipe are not allowed simultaneously.

[0011] In various embodiments, the flowing gas reactor comprises a coolant system including a fluid inlet, a coolant flow path in communication with the fluid inlet, the coolant flow path configured to cool each of the flowing gas inlet pipes, and a fluid outlet in communication with the coolant flow path. The fluid inlet may have an inlet manifold. The coolant flow path may include a plurality of cooling jackets, each surrounding one of the flowing gas inlet pipes, each cooling jacket in communication with the inlet manifold. The fluid outlet may have an outlet manifold in communication with each of the cooling jackets.

[0012] In various embodiments, the flowing gas reactor includes a coolant system including a fluid inlet, a coolant flow path in communication with the fluid inlet, and a fluid outlet in communication with the coolant flow path. The coolant flow path may include multiple cooling jackets, each surrounding one of the flowing gas inlet tubes, and the coolant flow path may be configured to flow coolant from the fluid inlet to the fluid outlet, with the coolant flowing sequentially through the multiple cooling jackets. In various embodiments, the coolant flow path includes multiple cooling jackets, each surrounding one of the flowing gas inlet tubes, and the coolant flow path is configured to flow coolant from the fluid inlet to the fluid outlet, with the coolant flowing in parallel through the multiple cooling jackets.

[0013] In some embodiments, the fluidized gas reactor may include a disentrainment chamber disposed above the reaction chamber and a conical velocity reduction chamber disposed therebetween. In various embodiments, the diameter of the disentrainment chamber is 1.5 to 10 times, 2 to 5 times, 2.25 to 4 times, or about 2.5 times larger than the diameter of the reaction chamber.

[0014] In various embodiments, the flowing gas reactor comprises a graphite-walled reaction chamber configured to be heated to a temperature between about 600° C. and about 2200° C., or between 800° C. and about 2000° C., or between 1250° C. and about 1800° C. The flowing gas reactor may comprise a graphite-walled reaction chamber configured to be heated to a temperature between about 600° C. and about 2200° C., and may comprise at least one of a velocity reduction chamber and a de-entrainment chamber configured to be heated to a temperature between about 600° C. and about 2200° C.

[0015] Various embodiments disclosed herein relate to a flowing gas reactor including a reaction chamber having a particle bed, a gas distribution plate having a plurality of openings therethrough, each opening opening into the reaction chamber, and a plurality of flowing gas inlet pipes, each of the plurality of flowing gas inlet pipes communicating with one of the openings in the gas distribution plate. Each of the flowing gas inlet pipes may be configured to receive a flowing gas and deliver the flowing gas to the reaction chamber. The reactor may include a flowing gas source configured to supply a flow of the flowing gas to the flowing gas inlet pipes and a coolant system. In various embodiments, the coolant system includes a fluid inlet, coolant channels in communication with the fluid inlet, the coolant channels configured to cool each of the flowing gas inlet pipes, and a fluid outlet in communication with the coolant channels.

[0016] Various embodiments disclosed herein relate to a fluidized-gas reactor configured to allow for the withdrawal of particle samples without interrupting an ongoing reaction, the fluidized-gas reactor comprising: a reaction chamber having a particle bed; a gas distribution plate having a plurality of openings therethrough; and a plurality of fluidized-gas inlet tubes communicating with one of the cones in the gas distribution plate. In various embodiments, each of the fluidized-gas inlet tubes has a gas inlet opening and a particle outlet opening. A fluidized-gas source may be configured to provide a flow of fluidized gas to the gas inlet openings of the fluidized-gas inlet tubes. In various embodiments, the reactor includes a valve system configured to selectively stop the flow of fluidized gas into the gas inlet opening of any one of the fluidized-gas inlet tubes and allow particles to flow from the particle bed to the particle outlet opening while the flow of fluidized gas into the gas inlet opening is stopped. The valve system may be configured to selectively stop flow of flowing gas to the gas inlet opening of any one of the flowing gas inlet pipes without interrupting flow of flow of flowing gas to the gas inlet openings of the other flowing gas inlet pipes. The valve system may be configured to prevent flow of particles from the particle bed to the particle outlet opening unless flow of flowing gas to the gas inlet opening is stopped.

[0017] For a better understanding of various exemplary embodiments, reference is made to the accompanying drawings. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 illustrates a fluidized bed reactor with multiple gas inlet tubes, each configured to deliver a fluidizing gas into the reaction chamber. [Figure 2] 2 shows a fluidized bed reactor with multiple gas inlet pipes according to FIG. 1, one gas inlet pipe being configured to allow for the withdrawal of a particle sample from the fluidized bed. [Figure 3] 2A-2C show various embodiments of a fluidized bed reactor according to FIG. 1 with multiple gas inlet pipes, the gas inlet pipes being equipped with a coolant system. [Figure 4]2A-2C show various embodiments of a fluidized bed reactor according to FIG. 1 with multiple gas inlet pipes, the gas inlet pipes being equipped with a coolant system. [Figure 5] 2A-2C show various embodiments of a fluidized bed reactor according to FIG. 1 with multiple gas inlet pipes, the gas inlet pipes being equipped with a coolant system. [Figure 6] 1 shows four different views of a system for providing a gas inlet pipe for a fluidized bed reactor, the gas inlet pipe being equipped with a system of cooling jackets. [Figure 7] 1 shows four different views of a system for providing a gas inlet pipe for a fluidized bed reactor, the gas inlet pipe being equipped with a system of cooling jackets. [Figure 8] 1 shows four different views of a system for providing a gas inlet pipe for a fluidized bed reactor, the gas inlet pipe being equipped with a system of cooling jackets. [Figure 9] FIG. 9 shows a gas distribution plate connected to the system according to FIGS. 6 to 8. [Figure 10A] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 10B] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 10C] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 10D] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 10E] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 10F] 10A-10C show various arrangements of gas inlet pipes connected to the gas distribution plate shown in FIG. 9. [Figure 11] FIG. 1 shows an apparatus for use in connection with a fluidized bed reactor for de-entraining fine particles from the fluidizing gas. [Figure 12] FIG. 10 shows the apparatus of FIG. 10 in use in connection with a fluidized bed reactor. DETAILED DESCRIPTION OF THE INVENTION

[0019]

[0013] In the drawings, wherein like numerals indicate like components or steps, broad aspects of various exemplary embodiments are disclosed. Figure 1 illustrates a fluidized bed reactor configured to allow for the withdrawal of particle samples without interrupting an ongoing reaction.

[0020] 1. Collection of particles in a flow The fluidized bed reactor shown in FIG. 1 includes a reaction chamber 1 having a bed of particles 2 disposed therein. A gas distribution plate 3 forms the floor of the reaction chamber 1 and has conical gas inlet openings 9 therein. A plurality of fluidizing gas inlet pipes 4 deliver fluidizing gas into the reaction chamber 1. The plurality of fluidizing gas inlet pipes 4 may be vertically oriented, and each of the fluidizing gas inlet pipes 4 is in communication with one of the openings 9 in the gas distribution plate 3. The fluidizing gas is delivered from a fluidizing gas source to each of the fluidizing gas inlet pipes 4 through fluidizing gas supply pipes 5. Each of the fluidizing gas supply pipes 5 is in communication with a corresponding one of the fluidizing gas inlet pipes 4 and is configured to supply a flow of fluidizing gas to the corresponding one of the fluidizing gas inlet pipes 4. The fluidized bed reactor of FIG. 1 also includes a plurality of particle outlets 8, each of which is disposed or connected to one of the fluidizing gas inlet pipes 4.

[0021] In various embodiments, the fluidizing gas source is configured to selectively stop the flow of fluidizing gas to one of the fluidizing gas inlet pipes 4. Each particle outlet is configured to receive particles from the particle bed while no fluidizing gas is flowing to the corresponding fluidizing gas inlet pipe. Referring to FIG. 1 , each particle outlet 8 is connected to one of the fluidizing gas inlet pipes 4 via a valve 7. Here, each valve 7 is closed. Each fluidizing gas supply pipe 5 is connected to one of the fluidizing gas inlet pipes 4 via a valve 6. In FIG. 1 , each valve 6 is open and each valve 7 is closed. Fluidizing gas is supplied to the fluidizing gas inlet pipes 4 through pipe 5 in the direction of arrow A. Fluidizing gas is also transported from a first portion 5a of the fluidizing gas supply pipe 5 through valve 6 to a second portion 5b of the fluidizing gas supply pipe 5 to the fluidizing gas inlet pipe 3. The fluidizing gas then travels through the fluidizing gas inlet pipe 4 in the direction of arrow A and enters the reaction chamber 1 through an opening 9 to fluidize the bed of particles 2 .

[0022] In various embodiments, the flowing gas includes a reactive gas that forms a carbon or ceramic coating on the particles 2. In such cases, it is desirable to be able to withdraw a sample of the particles in the bed for analysis of the coating layer. Furthermore, it is desirable to be able to withdraw a sample of the particles in the bed without interrupting the deposition reaction. Referring to Figure 2, the valve system in the apparatus of Figure 1 allows for this sample to be withdrawn.

[0023] In FIG. 2, fluidizing gas is supplied from two pipes 5 through valves 6 to fluidizing gas inlet pipe 4 in the direction of arrow A. The fluidizing gas then travels through fluidizing gas inlet pipe 4 in the direction of arrow A, enters reaction chamber 1 through opening 9, and fluidizes the bed of particles 2. When fluidizing gas inlet pipe 4 receives fluidizing gas from pipe 5, valve 7 is closed. As shown in FIG. 2, in third fluidizing gas inlet pipe 4, valve 6a (corresponding to one of valves 6 in FIG. 1) is closed, blocking the flow of fluidizing gas from pipe 5a and preventing fluidizing gas from being received. In this third fluidizing gas inlet pipe 4, valve 7a, located between particle outlet 8 and fluidizing gas inlet pipe 4, is open. This causes a sample of particles 2 in reaction chamber 1 to fall through fluidizing gas inlet pipe 4 into particle outlet 8 in the direction of arrow C, allowing a sample of particles in the fluidized bed to be recovered from particle outlet 8. The flowing gas continues to enter the reaction chamber in the direction of arrow B through another tube 4 so that collection of the particle sample does not interrupt the ongoing deposition reaction in reaction chamber 1. Furthermore, as the flowing gas enters the reaction chamber in the direction of arrow B through tube 4, positive pressure within the reaction chamber may blow the particles in the direction of arrow C, facilitating particle collection.

[0024] FIG. 3 shows a fluidized bed reactor having a reaction chamber 1 with a bed of particles 2 therein. A gas distribution plate 3 has a conical gas inlet opening 9. A plurality of fluidizing gas inlet pipes 4 (two are shown in FIG. 3, but more may be used) deliver fluidizing gas into the reaction chamber 1 in the direction of arrow B. Each fluidizing gas supply pipe 5 communicates with a corresponding fluidizing gas inlet pipe 4 and is configured to supply a flow of fluidizing gas to the corresponding fluidizing gas inlet pipe 4. The fluidized bed reactor of FIG. 1 also includes a plurality of particle outlets 8, each disposed or connected to one of the fluidizing gas inlet pipes 4.

[0025] In Figure 3, reaction chamber 1 has walls 10 made of a conductive material, such as conductive carbon, typified by graphite. The graphite walls of the reaction chamber are electrically resistive (represented as resistor 10a in Figure 3). Power supply 11 applies current to resistive graphite walls 10 via circuit 12, heating reaction chamber 1 to a temperature between about 600°C and about 2200°C.

[0026] In various embodiments, various materials may be deposited on the primary particles in the reaction chamber. Fluidized Bed Chemical Vapor Deposition (FBCVD) may be used to deposit monocrystalline, polycrystalline, and amorphous coating materials on the primary particles in a fluidized bed. These coatings include silicon, silicon dioxide, silicon carbide, silicon nitride, silicon oxynitride, pyrolytic carbon, diamond, graphite, fluorocarbons, tungsten, titanium nitride, and high-dielectric-constant materials.

[0027] In various embodiments, pyrolytic carbon (PyC) may be deposited on the primary particles using FBCVD, using acetylene or an acetylene / propylene mixture and a deposition temperature of 1250-1450°C. Silicon may be deposited on the primary particles using FBCVD, using a temperature of 650°C and a pyrolytic deposition of silane with silicon deposition formed in a fluidized bed. Silicon carbide (SiC) may be deposited on the primary particles using FBCVD of CH3SiCl3, using a temperature of 1500°C and a hydrogen carrier gas.

[0028] In various embodiments, primary particles may be sequentially coated with multiple beds. For example, nuclear fuel particles may be produced by sequentially coating primary particles made of UO. The UO particles may be coated with a porous carbon layer by depositing carbon from ethylene in an inert carrier gas at 1250°C, followed by a dense carbon layer by depositing carbon from an acetylene / propylene mixture in an inert carrier gas at 1300°C. A silicon carbide layer is deposited on the dense carbon layer from CHSiCl using a hydrogen carrier gas at 1500°C. Finally, an outer layer of dense carbon is deposited from an acetylene / propylene mixture in an inert carrier gas at 1300°C. The resulting particles are known as tri-isostructural (TRISO) coated particles.

[0029] In various embodiments, the fluidized bed in the fluidized-bed reactor of claim 1 may contain primary particles. Fluidizing gas containing reactants may flow into the reaction chamber 1 from various inlet tubes 4 through openings 9 in the gas distribution plate 3, as shown in FIG. 1 . After the reaction has proceeded for a certain period of time, one valve 6 (shown as valve 6a in FIG. 2 ) may be closed to block the flow of fluidizing gas through one inlet tube 4 without interrupting the fluidization of the particle bed from the flow of fluidizing gas through the remaining inlet tubes 4. As shown in FIG. 2 , one of the valves 7 (shown as valve 7a in FIG. 2 ) on the inlet tube connected to valve 6a may be opened, allowing a particle sample to fall through the inlet tube 4 into the particle outlet 8, enabling collection and analysis of the particle sample. For example, if pyrolytic carbon is deposited on primary particles, after the reaction has proceeded for a specified period of time, a sample of the carbon-coated particles may be collected through the inlet tube 4 and the particle outlet 8 without interrupting fluidization through the remaining inlet tubes 4. If analysis reveals uneven or incomplete coverage of the particle sample, deposition of pyrolytic carbon within the reaction chamber can be continued. If the particles are found to be completely coated, deposition can be stopped and the particles can be recovered.

[0030] If particles are coated sequentially in multiple beds, the particles may be collected and analyzed at each coating step without interrupting fluidization.

[0031] 2. Coolant system When performing high-temperature FBCVD reactions, heating the interior of reaction chamber 1 to temperatures between about 600°C and about 2200°C can have the undesirable side effect of heating the flowing gas in flowing gas inlet tube 4 before it enters reaction chamber 1. If the flowing gas contains reactant gases, this can cause reaction products, such as a carbon or ceramic layer, to deposit on the inside of tube 4, reducing or completely stopping the flow of the flowing gas. This can be mitigated or prevented by an appropriate coolant system.

[0032] Such a coolant system is shown in FIG. 3. Each flow gas inlet tube 4 enters a plenum chamber 17 located below the gas distribution plate 3. Each flow gas inlet tube 4 is surrounded by a hollow jacket 14. A coolant fluid, such as water or steam, is introduced into the first jacket 14 through the coolant inlet tube 13. After the first jacket 14 is filled, the coolant exits the jacket 14 through the coolant flow tube 15 and travels to the second jacket 14. After the second jacket 14 is filled, the coolant exits the second jacket 14 through the coolant outlet tube 16. In the embodiment of FIG. 3, the coolant travels through multiple cooling jackets 14 in series with each other. This reduces the possibility of the hot gases inside the reaction chamber 1 overheating the flow gas inlet tubes 4 or the flow gas within those tubes. This also reduces the rate at which carbon or ceramic reaction products deposit on the inner surfaces of the tubes 4.

[0033] Another coolant system is shown in FIG. 4. Each flowing gas inlet tube 4 enters a plenum chamber 17 located below the gas distribution plate 3. The coolant fluid is preferably a gas 18, such as steam. The coolant fluid is introduced into the plenum chamber 17 through the coolant inlet tube 13a. After the plenum chamber 17 is filled, the coolant exits the plenum chamber 17 through the coolant outlet tube 16. This reduces the possibility of excessive heating inside the plenum chamber 17 and prevents the hot gas inside the reaction chamber 1 from excessively heating the flowing gas in the flowing gas inlet tube 4. This also reduces the rate at which reaction products deposit on the inner surface of the tubes 4.

[0034] A third coolant system is shown in FIG. 5 . The flowing gas inlet pipes 4 are housed in a plenum chamber 17. Each flowing gas inlet pipe 4 is surrounded by a hollow jacket 14. A coolant, such as water or steam, enters the coolant inlet pipes 13 into an inlet manifold 19, which distributes the coolant flow to each jacket 14 (although two jacketed gas inlet pipes are shown in FIG. 5 , more jacketed gas inlet pipes may be used if desired). After the jackets 14 are filled, the coolant exits the jackets 14 and enters an outlet manifold 20. From the outlet manifold 20, the coolant exits the plenum chamber 17 through the coolant outlet pipes 16. In the embodiment of FIG. 5 , the coolant travels through the cooling jackets 14 in parallel. This may allow for more even distribution of heat within the plenum chamber than traveling the coolant through the cooling jackets 14 in series. When the coolant travels through the cooling jackets in series, the coolant has less time to absorb heat from the flowing gas inlet pipe 4 when it is introduced into the first cooling jacket than when it is introduced into the last cooling jacket, so as the distance from the coolant inlet increases, the efficiency of absorbing heat from the flowing gas inlet pipe 4 decreases. When the coolant travels through the cooling jackets in parallel, the coolant arrives at each cooling jacket 14 at approximately the same time, so the efficiency of absorbing heat from each flowing gas inlet pipe 4 is similar.

[0035] 3 and 5, each flowing gas supply pipe 5 may pass through a cooling jacket 14 before intersecting with the corresponding flowing gas inlet pipe 4. This allows the flowing gas to be cooled before being introduced into the inlet pipe 4, preventing reactants in the flowing gas from reacting and forming solid carbon or ceramic material at the opening between the supply pipe 5 and the inlet pipe 4. This reduces the possibility of obstructing the flow of the flowing gas introduced into the inlet pipe 4.

[0036] 3, the flowing gas inlet pipes 4 may also extend downwardly beyond the lower surface of the plenum chamber 17. For each inlet pipe 4, a valve 7 is located below the plenum chamber 17 at the junction between the inlet pipe 4 and the particle outlet 8.

[0037] As can be seen in Figure 3, each flow gas supply pipe 5 has a valve 6 that allows the flow of flow gas to be stopped to the corresponding inlet pipe 4. Each valve 6 is independently operated. The flow of flow gas to any inlet pipe 4 can be stopped by closing the valve 6 of the corresponding supply pipe 5 without interrupting the flow of flow gas to each of the remaining inlet pipes.

[0038] After selecting an inlet tube 4 and shutting off the flow of fluid to the selected inlet tube, valve 7 at the lower end of the selected inlet tube is opened, allowing a particle sample from the particle bed to fall from the selected inlet tube through the open valve 7 and into particle outlet 7. While the particles are being collected, they fall through a region of inlet tube 4 cooled by cooling jacket 5, slowing the reaction rate between any reaction gas within tube 4 and the particle surface. After the particle sample is collected, valve 7 is closed and valve 6 is opened, restoring the flow of fluid through the selected inlet tube 4. This arrangement therefore allows fluid gas to continue flowing through all remaining inlet tubes into reaction chamber 1 while a particle sample for analysis is collected from particle outlet 8 connected to the first inlet tube 4. In this way, the reaction between the fluid gas and the particle bed in chamber 1 is not interrupted during particle sample collection.

[0039] Figures 6 and 7 show an assembly including a set of flowing gas inlet pipes and a coolant system located below a gas distribution plate designed to fit into the plenum chamber of a flowing gas reactor. In the embodiment of Figures 6 and 7, there are two cooling jackets 14. Flowing gas inlet pipes 4 (shown in Figure 7) deliver flowing gas through each cooling jacket and into the reaction chamber via openings 9 through the distribution plate 3 (not shown in Figures 6 and 7). Plate 22 (shown in Figure 7) stabilizes the cooling jackets and holds them in a fixed relative orientation. Plate 22 may also be fixed to the inner wall of the plenum chamber.

[0040] As shown in FIGS. 6 and 7 , the coolant inlet 13 delivers coolant fluid to the first cooling jacket 14. The coolant fluid then travels from the first cooling jacket 14 to the second cooling jacket 14 before exiting the plenum through the coolant outlet 16. The coolant then travels between the cooling jackets 14 through the tube 15. As shown in FIGS. 6 and 7 , the flowing gas may be delivered to each flowing gas inlet tube 4 via the corresponding flowing gas supply tube 5 and pass through the cooling jacket 14 before intersecting with the inlet tube 4. Alternatively, as shown in FIG. 7 , the flowing gas supply tube 5 may pass through a solid pillar 14c before intersecting with the inlet tube 4. Here, the pillar 14c is located below the coolant inlet 13. Valve 6 allows the flowing gas supply to each inlet tube to be temporarily stopped, allowing particle samples to be collected in the corresponding sample chamber 24 by opening valve 7.

[0041] Figure 8 shows the assembly of Figure 7 as viewed in the direction of arrow 8. In Figure 8, cooling jackets 14 can be seen above the sample chamber 24. The first cooling jacket 14 has a fluid inlet 13, which conveys a coolant fluid into the jacket 14. The coolant fluid exits the first cooling jacket 14 via pipe 15 and enters the second cooling jacket 14. The coolant fluid then exits the second cooling jacket through a coolant fluid outlet 16. Each cooling jacket 14 has a flowing gas supply pipe 4 at its center, which regulates the temperature of the flowing gas by indirect heat exchange with the coolant fluid. Each flowing gas supply pipe 4 is supplied with flowing gas from pipe 5b via supply pipe 5a, which is connected to valve 6.

[0042] Figure 9 shows a cross section of the device according to Figure 7 in combination with a gas distribution plate 3. As shown in Figure 9, the plate 3 may have a cylindrical wall 3a and a conical gas distribution surface 9 surrounding the opening of the flowing gas supply pipe 4. Adjacent gas distribution holes 9 may contact each other at a raised edge 9a. The surface of the conical gas distribution hole 9 may intersect with the cylindrical wall 3a at an edge 9b.

[0043] 10A-10F show various configurations of gas distribution plates 3 for use with three flow gas supply pipes 4 (FIGS. 10A and 10B), four flow gas supply pipes 4 (FIGS. 10C and 10D), or five flow gas supply pipes 4 (FIGS. 10E and 10F). Each plate has a plurality of openings, each corresponding to an opening at the top of a flow gas supply pipe 4, and a conical surface 9 at the bottom of the plate 3 surrounding each opening. Each pair of adjacent conical surfaces 9 intersects at a raised edge 9a.

[0044] Referring again to FIG. 3 , the reaction chamber 1 has walls 10 made of a conductive material, such as conductive carbon, e.g., graphite. A fluidizing gas flows through the reaction chamber 1 in the direction of arrow B and exits the reaction chamber through outlet tube 1a. The flow of the fluidizing gas through the reaction chamber 1 fluidizes particles 2 in the particle bed. Typically, particle beds contain particles of various sizes, including coarse and fine particles. As the fluidizing gas flows through the particle bed, the gas flow moves the coarse particles within the particle bed without separating them from the surface. However, fine particles have greater buoyancy in the fluidizing gas flow and may become entrained in the flow. These fine particles may break away from the surface of the fluidized bed and exit the reaction chamber 1 through tube 1a. This reduces the yield of the reaction between the particles in the fluidized bed and the reactants in the fluidized bed. Therefore, a device must be installed at the outlet of tube 1a to recover or recycle the entrained fine particles. It would be advantageous to prevent the entrained fine particles from entering the fluidizing gas outlet tube 1a.

[0045] 3. De-entrainment of fine particles FIG. 11 illustrates an apparatus 25 for recovering fine entrained particles from a flowing gas stream passing through a tubular fluidized gas reactor. The apparatus 25 is configured to be positioned above the tubular fluidized gas reactor chamber 1. The apparatus 25 includes a lower end having an opening 26 of diameter x configured to receive the flowing gas from the reactor chamber, and a tubular de-entrainment chamber 30 of diameter nx located above the opening 26, where n is between 1.5 and 10. In various embodiments, the inner diameter of the de-entrainment chamber is 1.5 to 10 times (n is between 1.5 and 10), 2 to 5 times, 2.25 to 4 times, or about 2.5 times the diameter of the reactor chamber. In various embodiments, a conical velocity reduction chamber 29 interfaces between the opening 26 and the velocity reduction chamber such that the angle y between the plane m defining the lower boundary of the de-entrainment chamber 30 and the conical inner wall of the velocity reduction chamber 29 is between 15° and 75°, 25° and 65°, 30° and 60°, 40° and 50°, or about 45°. Two openings 31 in the wall of the de-entrainment chamber 30 allow the flowing gas to exit the de-entrainment chamber 30 after entering the velocity reduction chamber through the openings 26.

[0046] The periphery of opening 26 is defined by a raised lip 28. An indentation 27 is defined by the vertical outer surface of lip 28 and the horizontal surface of the lower edge of the outer surface of the wall of velocity reduction chamber 29. Lip 28 and indentation 27 are used to secure device 25 to the upper edge of reaction chamber 1.

[0047] As shown in Figure 12, apparatus 25 can be used in combination with a fluidized gas reactor, generally as shown in Figure 1. The fluidized gas reactor includes a reaction chamber 1 having an opening 35 at its upper end. Around the periphery of opening 35, reaction chamber 1 has a raised lip 34 that secures to indentation 27 of apparatus 25. Reaction chamber 1 also has an indentation 33 that receives raised lip 28 of apparatus 25. The opening at the top of apparatus 1 may be closed by a lid 32.

[0048] As shown in FIG. 11, fluidizing gas travels from fluidizing gas supply pipe 5a through fluidizing gas inlet pipe 4 and enters reaction chamber 1 through opening 9 in gas distribution plate 3. The fluidizing gas then exits reaction chamber 1 through opening 26 and enters apparatus 25. In apparatus 25, the fluidizing gas carries fine entrained particles from the fluidized bed in reaction chamber 1 and enters velocity reduction chamber 29 at a first velocity. As the fluidizing gas passes through the velocity reduction chamber, the cross-sectional area across which the gas crosses increases. As the fluidizing gas exits velocity reduction chamber 29, the gas velocity decreases until it enters de-entrainment chamber 30, where it reaches a second velocity less than the first velocity. In the apparatus of FIG. 12, the cross-sectional area of ​​reaction chamber 1 is x, and the cross-sectional area of ​​de-entrainment chamber 30 is 2.5x. As the fluidizing gas travels from reaction chamber 1 through velocity reduction chamber 29 and into de-entrainment chamber 30, the gas velocity decreases by a factor of ten.

[0049] Because the velocity of the flowing gas decreases in the de-entrainment chamber 30, the buoyancy of the fine particles entrained in the flowing gas as it passes through the reaction chamber 1 is reduced in the de-entrainment chamber 30. Therefore, the fine particles fall from the flowing gas stream before the gas stream enters the outlet opening 31. That is, they tend to become de-entrained. The de-entrained particles then fall through the velocity reduction chamber 29 into the reaction chamber 1. The conical inner surface of the velocity reduction chamber 29 is useful for transporting the de-entrained particles from the de-entrainment chamber 30 to the reaction chamber 1. After de-entraining the fine particles, the flowing gas is introduced into the outlet pipe 1a through the outlet opening 31 and discharged from the de-entrainment chamber. The outlet pipe 1a may transport the flowing gas directly from the de-entrainment chamber 30, as shown in FIG. 12. Alternatively, the opening 31 may transport the flowing gas from the de-entrainment chamber 30 to an outer housing chamber surrounding the reaction chamber 1 and the apparatus 25. The flowing gas may then be exhausted from the outer housing chamber through a set of outlet tubes.

[0050] While various embodiments have been described in detail with particular reference to certain aspects thereof, it should be understood that the invention is capable of other embodiments and its details are susceptible to modification in various obvious respects. As will be readily apparent to those skilled in the art, variations and modifications are possible while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are illustrative and in no way limiting of the invention, which is defined solely by the claims.

Claims

1. A fluidized bed reactor in which a particle bed containing particles is fluidized by a fluidizing gas, comprising: a reaction chamber configured to hold the particle bed therein; a gas distribution plate having a plurality of openings opening toward the reaction chamber; a plurality of flowing gas inlet pipes, each of which communicates with one of the openings in the gas distribution plate; a flowing gas source configured to individually supply a flow of the flowing gas to each of the flowing gas inlet pipes; a coolant system including a fluid inlet, a coolant flow passage communicating with the fluid inlet and configured to cool each of the flowing gas inlet pipes, and a fluid outlet communicating with the coolant flow passage; each of the fluidizing gas inlet pipes configured to receive the fluidizing gas and deliver the fluidizing gas to the reaction chamber to fluidize the bed of particles; the flowing gas source comprises a plurality of flowing gas supply pipes communicating with the plurality of flowing gas inlet pipes, respectively; each of the plurality of flowing gas supply pipes comprises a valve configured to selectively stop the flow of the flowing gas to the flowing gas inlet pipe communicating with each of the plurality of flowing gas supply pipes; A fluidized bed reactor configured such that the coolant system does not excessively heat the fluidizing gas in the fluidizing gas inlet pipe.

2. 2. The fluidized bed reactor of claim 1, the fluid inlet having an inlet manifold; the coolant flow passages have a plurality of cooling jackets; each of the cooling jackets surrounds one of the flowing gas inlet pipes; each of the cooling jackets in communication with the inlet manifold; a fluidized bed reactor, wherein said fluid outlet has an outlet manifold communicating with each of said cooling jackets;

3. 2. The fluidized bed reactor of claim 1, the coolant flow passages have a plurality of cooling jackets; each of the cooling jackets surrounds one of the flowing gas inlet pipes; the coolant flow passages are configured to provide a flow of coolant from the fluid inlet to the fluid outlet; A fluidized bed reactor, wherein a coolant flows through a plurality of said cooling jackets in sequence.

4. 2. The fluidized bed reactor of claim 1, the coolant flow passages have a plurality of cooling jackets; each of the cooling jackets surrounds one of the flowing gas inlet pipes; the coolant flow passages are configured to provide a flow of coolant from the fluid inlet to the fluid outlet; A fluidized bed reactor, wherein the coolant flows through a plurality of said cooling jackets in parallel.

5. 2. The fluidized bed reactor of claim 1, a de-entrainment chamber provided above the reaction chamber; a conical velocity reduction chamber disposed between the reaction chamber and the de-entrainment chamber; A fluidized bed reactor wherein the diameter of the deentrainment chamber is 1.5 to 10 times the diameter of the reaction chamber.

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