Tubular fixed bed reactor

Abstract

The invention relates to the field of chemical equipment, in particular to a tubular fixed bed reactor which comprises an upper end cover, a lower end cover, a shell pass cylinder, an upper tube plate, a lower tube plate and a plurality of reaction tubes, a tube pass inlet is formed in the upper end cover, a tube pass outlet is formed in the lower end cover, and a shell pass inlet and a shell pass outlet are formed in the shell pass cylinder; the gas distribution assembly is arranged inside the upper end cover; the lower distribution cylinder is positioned in the shell pass cylinder and surrounds the periphery of at least part of the reaction tubes; and a plurality of overflowing through holes are uniformly distributed in the side peripheral wall of the lower distribution cylinder. The gas distribution assembly is arranged, so that the catalyst in each reaction tube can be utilized more uniformly; by arranging the lower distribution cylinder, the shell pass medium at the shell pass inlet can be uniformly distributed, and the situation that part of reaction heat in the reaction tube cannot be taken away in time is avoided. The gas distribution assembly and the lower distribution cylinder are arranged in a combined manner, so that the tubular fixed bed reactor is good in reaction stability and high in product yield.

Description

Technical Field

[0001] This application relates to the field of chemical equipment, and more specifically, to a tubular fixed-bed reactor. Background Technology

[0002] In chemical production processes, synthesis reactions are frequently involved, such as the production of syngas from coal or natural gas and the production of liquid fuels (hydrocarbons, alcohols, aldehydes, acetic acid series products, etc.) from syngas in the coal chemical industry. All of these reactions are exothermic. Due to the large amount of heat released, localized overheating of the catalyst bed often occurs, leading to reduced selectivity and catalyst coking. To achieve high selectivity and effectively remove the heat of reaction, a tubular fixed-bed reactor can be used, with the catalyst packed inside the reaction tubes and the heat extraction medium outside the tubes.

[0003] Current tubular fixed-bed reactors suffer from several problems: some reactor tubes have low catalyst utilization, while others have excessive catalyst load leading to premature deactivation. Additionally, the heat extraction from the reactor tubes is uneven, meaning that the heat of reaction in some tubes cannot be carried away in time, resulting in coking, poor reaction stability, and low product yield. Summary of the Invention

[0004] The purpose of this application is to provide a tubular fixed-bed reactor, which aims to solve the technical problems of uneven catalyst utilization and uneven heat extraction in each reaction tube of the existing tubular fixed-bed reactor, resulting in poor reaction stability and low product yield.

[0005] To achieve this objective, the technical solution adopted in this application is as follows: a tubular fixed-bed reactor is provided, comprising an upper end cover, a lower end cover, a shell-side cylinder disposed between the upper end cover and the lower end cover, an upper tube sheet disposed at the top of the shell-side cylinder, a lower tube sheet disposed at the bottom of the shell-side cylinder, and a plurality of reaction tubes disposed between the upper tube sheet and the lower tube sheet. The upper end cover has a tube-side inlet, the lower end cover has a tube-side outlet, and the shell-side cylinder has a shell-side inlet and a shell-side outlet. The tubular fixed-bed reactor further comprises: a gas distribution assembly disposed inside the upper end cover and used to uniformly distribute the reactant gas at the tube-side inlet; and a lower distribution cylinder located inside the shell-side cylinder and surrounding at least a portion of the reaction tubes. A plurality of flow holes are uniformly distributed on the side wall of the lower distribution cylinder to uniformly distribute the shell-side medium at the shell-side inlet.

[0006] In some embodiments, the gas distribution assembly includes N flow guide shells and N flow guide plate groups, where N is a positive integer greater than 1; the N flow guide shells are all cylindrical, and the inner diameter of each flow guide shell is set to increase along the air intake direction; the N flow guide shells are sequentially nested from the outside to the inside, and the inner diameter of the top surface and the inner diameter of the bottom surface of the N flow guide shells decrease from the outside to the inside; the innermost flow guide shells enclose to form a central flow guide channel communicating with the tube inlet, and two adjacent flow guide shells enclose to form a peripheral flow guide channel communicating with the tube inlet; the N flow guide plate groups are divided into a central plate group and N-1 peripheral plate groups; the central plate group includes at least one central flow guide plate, and each central flow guide plate extends spirally along the air intake direction and is arranged in the central flow guide channel; the peripheral plate groups are arranged one-to-one in the peripheral flow guide channels, and each peripheral plate group includes at least one peripheral flow guide plate, and each peripheral flow guide plate extends spirally along the air intake direction.

[0007] In some embodiments, all N flow guide shells are frustum-shaped, and the N flow guide shells are arranged coaxially around the central axis of the tube inlet with their top surfaces flush. The height of the N flow guide shells increases from the outside to the inside.

[0008] In some embodiments, the extension lines of the generatrices of the N guide shells intersect the central axis of the tube inlet at the same point, and the difference between the apex angles of the two cones corresponding to two adjacent guide shells is the same as the apex angle value of the cone corresponding to the innermost guide shell.

[0009] In some embodiments, the set of extensions of the outermost guide shell’s generatrix toward the upper tube sheet covers the openings of all the reaction tubes on the upper tube sheet.

[0010] In some embodiments, each of the N flow guide shells corresponds to one of the N cones, and the generatrix lengths of the N cones are all the same and are 1.5-2.0 times the inner diameter of the top surface of the outermost flow guide shell.

[0011] In some embodiments, the number of central guide vanes in the central plate group is the same as the number of peripheral guide vanes in each peripheral plate group, and is n, where n is a positive integer greater than 1.

[0012] In some embodiments, n central guide plates are spaced apart around the central axis of the tube inlet and connected to each other on the central axis of the tube inlet, and the side of each central guide plate facing away from the central axis of the tube inlet is connected to the innermost guide shell; each peripheral guide plate in each peripheral guide channel is spaced apart around the central axis of the tube inlet and connected between two adjacent guide shells used to enclose the peripheral guide channel.

[0013] In some embodiments, the n central guide plates in the central plate group and the n peripheral guide plates in each peripheral plate group are rotationally symmetric structures with a rotation angle of 2π / n and a rotation axis of the central axis of the tube inlet.

[0014] In some embodiments, the collection of all cross-sections of all the central guide vanes and all the peripheral guide vanes cut by the same plane perpendicular to the central axis of the tube inlet constitutes n line segment structures, and the n line segment structures extend radially outward from the same center point.

[0015] In some embodiments, each central guide plate in the central plate group extends from the top surface flush to the bottom of the innermost guide shell, and each peripheral guide plate in each peripheral plate group extends from the top surface flush to the bottom of the two adjacent guide shells that enclose the peripheral guide channel corresponding to the peripheral plate group.

[0016] In some embodiments, a connecting fitting is provided at the tube inlet; the gas distribution assembly further includes a cylindrical extension section connected to the top of the outermost flow guide shell, the extension section having a flow channel, the flow channel being connected to the tube inlet, the central flow guide channel and each of the peripheral flow guide channels respectively; a connector is provided on the extension section, the connector being fixedly installed on the connecting fitting.

[0017] In some embodiments, the tubular fixed-bed reactor further includes an upper distribution cylinder located within the shell-side cylinder and surrounding at least a portion of the reaction tubes; the upper distribution cylinder is also uniformly provided with a plurality of flow holes for uniformly distributing the shell-side medium flowing toward the shell-side outlet.

[0018] In some embodiments, both the upper distribution cylinder and the lower distribution cylinder have a connecting end; the connecting end of the lower distribution cylinder is disposed on the lower tube sheet, and the lower distribution cylinder and the shell-side cylinder form a lower distribution cavity communicating with the shell-side inlet, and the plurality of flow holes on the lower distribution cylinder are all communicating with the lower distribution cavity; the connecting end of the upper distribution cylinder is disposed on the upper tube sheet, and the upper distribution cylinder and the shell-side cylinder form an upper distribution cavity communicating with the shell-side outlet, and the plurality of flow holes on the upper distribution cylinder are all communicating with the upper distribution cavity.

[0019] In some embodiments, the upper distribution cylinder and the lower distribution cylinder each have an extended end opposite to their respective connecting ends; the shell-side inlet is directly opposite the side peripheral wall of the lower distribution cylinder, and the distance between the outer end face of the extended end of the lower distribution cylinder and the center of the shell-side inlet is the inner diameter of the shell-side inlet.

[0020] In some embodiments, the shell-side outlet is directly opposite the side peripheral wall of the upper distribution cylinder, and the distance between the outer end face of the outer extension end of the upper distribution cylinder and the center of the shell-side outlet is the inner diameter of the shell-side outlet.

[0021] In some embodiments, the upper distribution cylinder and the lower distribution cylinder each have a plurality of drainage notches formed at the circumferential edge of their respective connecting ends.

[0022] In some embodiments, the inner peripheral walls of the upper distribution cylinder and the lower distribution cylinder are both in contact with the outermost reaction tube.

[0023] In some embodiments, the plurality of flow holes on the upper distribution cylinder are arranged in at least one row along the circumference of the upper distribution cylinder, and the plurality of flow holes on the lower distribution cylinder are arranged in at least one row along the circumference of the lower distribution cylinder; the flow holes in each row are arranged at equal intervals.

[0024] In some embodiments, the positions of two adjacent rows of flow holes are staggered.

[0025] In some embodiments, the number of the flow holes in each row on the lower distribution cylinder is not less than four times the number of the shell-side inlets.

[0026] In some embodiments, the number of the flow holes in each row on the upper distribution cylinder is not less than four times the number of the shell-side outlets.

[0027] In some embodiments, the sum of the flow areas of the plurality of flow holes on the lower distribution cylinder is not less than twice the sum of the flow areas of the shell-side inlet.

[0028] In some embodiments, the sum of the flow areas of the plurality of flow holes on the upper distribution cylinder is not less than twice the sum of the flow areas of the shell-side outlet.

[0029] In some embodiments, the nominal diameter of both the shell-side inlet and the shell-side outlet is 350 mm.

[0030] In some embodiments, the number of shell-side inlets and shell-side outlets are both 2-4.

[0031] In some embodiments, the tubular fixed-bed reactor further includes a lower baffle plate disposed between the lower distribution cylinder and the shell-side cylinder to enclose and form the lower distribution cavity.

[0032] In some embodiments, the tubular fixed-bed reactor further includes an upper baffle plate disposed between the upper distribution cylinder and the shell-side cylinder to enclose and form the upper distribution cavity.

[0033] One of the above technical solutions has the following advantages or beneficial effects: By setting a gas distribution component in the tubular fixed-bed reactor for uniformly distributing the gas to be reacted at the tube inlet, the gas to be reacted can be uniformly distributed into multiple essentially identical reaction gas branches to flow into each reaction tube in the reactor, thereby reacting with the internal catalyst. This allows for more balanced utilization of the catalyst in each reaction tube. Furthermore, by setting a lower distribution cylinder in the tubular fixed-bed reactor, which surrounds at least a portion of the reaction tubes, and with multiple flow holes uniformly distributed on the sidewall of the lower distribution cylinder, the shell-side medium (which can be a heat-extracting medium) at the shell-side inlet can be uniformly distributed. This allows the shell-side medium to flow uniformly from the outer periphery of the lower distribution cylinder into at least a portion of the reaction tubes within the lower distribution cylinder, thereby ensuring that the heat of reaction in these at least a portion of the reaction tubes is removed evenly and promptly, preventing coking. More importantly, by combining the gas distribution components and the lower distribution cylinder, the reaction gas in each reaction tube of the tubular fixed bed reactor can be evenly distributed, and the catalyst bed temperature can be uniform, thereby effectively improving the reaction stability, synthesis reaction conversion rate and product yield, achieving a beneficial effect of 1+1>2.

[0034] Other advantages of this application and the technical effects of preferred embodiments will be further described in the detailed embodiments below. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic longitudinal section of a tubular fixed-bed reactor provided in at least one embodiment of this application;

[0037] Figure 2 This is a schematic longitudinal section of a tubular fixed-bed reactor (partial) provided in at least one embodiment of this application;

[0038] Figure 3 This is a three-dimensional schematic diagram of a gas distribution component provided in at least one embodiment of this application;

[0039] Figure 4 This is a front view schematic diagram of a gas distribution component provided in at least one embodiment of this application;

[0040] Figure 5 This is a top view schematic diagram of a gas distribution assembly provided in at least one embodiment of this application;

[0041] Figure 6 This is a bottom view schematic diagram of a gas distribution assembly provided in at least one embodiment of this application;

[0042] Figure 7 This is a longitudinal cross-sectional schematic diagram of a gas distribution assembly provided in at least one embodiment of this application;

[0043] Figure 8 This is a three-dimensional schematic diagram of N flow guide plate assemblies (after assembly) provided in at least one embodiment of this application;

[0044] Figure 9 This is a front view schematic diagram of N flow guide plate assemblies (after assembly) provided in at least one embodiment of this application;

[0045] Figure 10 This is a top view schematic diagram of N guide vane assemblies (after assembly) provided in at least one embodiment of this application;

[0046] Figure 11 This is a cross-sectional schematic diagram of N flow guide plate assemblies (considering the plate width) provided in at least one embodiment of this application;

[0047] Figure 12 This is a schematic cross-sectional view of a tubular fixed-bed reactor provided in at least one embodiment of this application;

[0048] Figure 13 yes Figure 1 Enlarged view of section A;

[0049] Figure 14 This is a plan view of the lower distribution cylinder (after unfolding) provided in at least one embodiment of this application;

[0050] Figure 15 This is a longitudinal cross-sectional schematic diagram of the lower distribution cylinder provided in at least one embodiment of this application.

[0051] The following are the labeling elements in the figure:

[0052] 00: Gas distribution component 1: Flow guide shell

[0053] α: The apex angle of the cone corresponding to the outermost guide shell; 100°: the central guide channel.

[0054] R: Length of the conical generatrix corresponding to the outermost guide shell; 110: Outer guide channel.

[0055] 2: Deflector assembly d: Inner diameter of the top surface of the outermost deflector shell 22: Outer slab assembly; 21: Central slab assembly

[0056] 221: Peripheral deflector; 211: Central deflector

[0057] 20: Center point 200: Line segment structure

[0058] 3: Extension section 300: Flow channel

[0059] 31: Connector A: Intake direction

[0060] 4: Pipe inlet 41: Connecting parts

[0061] M: Centerline of the tube inlet; 52: Lower tube sheet

[0062] 51: Upper tube sheet; 7: Upper end cap

[0063] 6: Reaction tube; 9: Shell-side cylinder

[0064] 8: Lower end cover; 91: Shell side inlet

[0065] 70: Tube side outlet; 92: Shell side outlet

[0066] 201: Upper distribution cylinder; 202: Lower distribution cylinder

[0067] 1a: Connecting end; 1b: Extended end

[0068] 101: Upper distribution cavity; 102: Lower distribution cavity

[0069] 500: Through-flow hole; 600: Drainage notch

[0070] d1: Shell-side inlet inner diameter; d2: Shell-side outlet inner diameter

[0071] 301: Lower baffle plate; 61: Support plate Detailed Implementation

[0072] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0073] It should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0074] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0075] Furthermore, in the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0076] by Figures 1 to 15 Taking the tubular fixed-bed reactor provided in this application as an example, this application will be described and introduced. The tubular fixed-bed reactor provided in this application can be specifically used as a reactor for the catalytic hydrogenation of carbon dioxide to methanol, a methanation reactor, etc., in the field of coal chemical industry; no limitations are set here. Figure 1 As shown, the tubular fixed-bed reactor includes an upper end cover 7, a lower end cover 8, a shell-side cylinder 9 disposed between the upper end cover 7 and the lower end cover 8, an upper tube sheet 51 disposed at the top of the shell-side cylinder 9, a lower tube sheet 52 disposed at the bottom of the shell-side cylinder 9, and multiple reaction tubes 6 disposed between the upper tube sheet 51 and the lower tube sheet 52. The upper end cover 7 is provided with a tube-side inlet 4, the lower end cover 8 is provided with a tube-side outlet 70, and the shell-side cylinder 9 is provided with a shell-side inlet 91 and a shell-side outlet 92. The tubular fixed-bed reactor also includes a gas distribution assembly 00 and a lower distribution cylinder 202. It should be noted that the gas distribution assembly 00 and the lower distribution cylinder 202 of this disclosure can also be disposed individually or in combination on other types of reactors. If the structure and function of the gas distribution assembly 00 and / or the lower distribution cylinder 202 used in these other types of reactors are the same as those of this disclosure, and the technical problems solved and the technical effects achieved are basically the same, then these other types of reactors should also fall within the protection scope of this disclosure.

[0077] The gas distribution component 00 is located inside the upper end cover 7 and is used to uniformly distribute the gas to be reacted at the tube inlet 4. The gas to be reacted can be the raw material gas or other gases that need to participate in the reaction. By setting the gas distribution component 00 in the tubular fixed bed reactor to uniformly distribute the gas to be reacted at the tube inlet 4, the gas to be reacted can be uniformly distributed into multiple basically identical reaction gas branches to flow into each reaction tube 6 in the tubular fixed bed reactor, and then react with the internal catalyst. In this way, the catalyst in each reaction tube 6 can be utilized more evenly.

[0078] The lower distribution cylinder 202 can be a cylindrical structure, specifically a cylindrical cylinder, a frustum cylinder, or other regular or irregular shapes. It is located inside the shell-side cylinder 9 and surrounds the outer periphery of at least a portion of the reaction tube 6. Multiple flow holes 500 are evenly distributed on the sidewall of the lower distribution cylinder 202 to evenly distribute the shell-side medium at the shell-side inlet 91. The lower distribution cylinder 202 can be connected to the lower tube sheet 52 or fixed to the shell-side cylinder 9 by a component. The requirement is that the lower distribution cylinder 202, located inside the shell-side cylinder 9 and surrounding the outer periphery of at least a portion of the reaction tube 6, has multiple flow holes 500 that evenly distribute the shell-side medium from the shell-side inlet 91. The lower distribution cylinder 202 can be positioned near and directly opposite the shell-side inlet 91, or it can be positioned slightly off-center. The requirement is that the shell-side medium flowing to the lower distribution cylinder 202 is evenly distributed by it. By setting a lower distribution cylinder 202 in a tubular fixed-bed reactor, the lower distribution cylinder 202 surrounds the outer periphery of at least a portion of the reaction tubes 6. At the same time, multiple flow holes 500 are evenly distributed on the side wall of the lower distribution cylinder 202. On the one hand, the shell-side medium (which can be a heat-extracting medium) at the shell-side inlet 91 can be evenly distributed. On the other hand, the shell-side medium flows evenly from the outer periphery of the lower distribution cylinder 202 into the space between at least a portion of the reaction tubes 6 inside the lower distribution cylinder 202. This allows the heat of reaction in the at least a portion of the reaction tubes 6 to be removed evenly and in a timely manner, preventing coking.

[0079] It is worth noting that by combining the gas distribution component 00 and the lower distribution cylinder 202 in the tubular fixed bed reactor, this application can make the gas to be reacted in each reaction tube 6 in the tubular fixed bed reactor uniformly distributed and the catalyst bed temperature uniform, thereby effectively improving the reaction stability, synthesis reaction conversion rate and product yield, and achieving a beneficial effect of 1+1>2.

[0080] In one or more embodiments, the gas distribution component 00 may include N flow guide shells 1 and N flow guide plate groups 2, where N is a positive integer greater than 1; for example, if the gas distribution component 00 includes 5 flow guide shells 1, then the number of flow guide plate groups 2 is also 5.

[0081] All N guide shells 1 are cylindrical, and optionally, the central axis of each guide shell 1 extends along the air inlet direction A. This air inlet direction A can be understood as the direction in which the gas to be reacted flows into the gas distribution assembly 00; the inner diameter of the cross-section of each guide shell 1 is set to increase along the air inlet direction A, i.e., as shown below. Figure 2 As shown, if the air intake direction A is from top to bottom, then the inner diameter of the cross-section of each guide shell 1 increases from top to bottom. In this case, each guide shell 1 can be understood as a structure that is narrow at the top and wide at the bottom.

[0082] N flow guide shells 1 are sequentially nested from the outside in. If the outermost flow guide shell 1 is the first flow guide shell, the next outermost flow guide shell 1 is the second flow guide shell, and so on, the sequential nesting of N flow guide shells 1 from the outside in can be understood as the first flow guide shell being nested around the outer periphery of the second flow guide shell, the second flow guide shell being nested around the outer periphery of the third flow guide shell, and so on, with the (N-1)th flow guide shell being nested around the outer periphery of the Nth flow guide shell. It should be noted that the first flow guide shell being nested around the outer periphery of the second flow guide shell can be further understood as the second flow guide shell being completely located inside the first flow guide shell, or partially located inside the first flow guide shell. For example, both can be configured with their top surfaces flush, while the bottom of the second flow guide shell extends beyond the interior of the first flow guide shell. Figure 4 As shown, the flow guide shells 1 of other levels can be set up in the same way, which will not be described in detail here.

[0083] The inner diameter of the top surface of the N flow guide shells 1 decreases from the outside to the inside. This can be understood as the inner diameter of the top surface of the first flow guide shell being larger than that of the second flow guide shell, the inner diameter of the top surface of the second flow guide shell being larger than that of the third flow guide shell, and so on. Similarly, the inner diameter of the bottom surface of the N flow guide shells 1 decreases from the outside to the inside. This can be understood as the inner diameter of the bottom surface of the first flow guide shell being larger than that of the second flow guide shell, the inner diameter of the bottom surface of the second flow guide shell being larger than that of the third flow guide shell, and so on. Thus, a roughly cylindrical gap is formed between the first guide shell and the second guide shell, between the second guide shell and the third guide shell, ... between the (N-1)th guide shell and the Nth guide shell. This gap is the outer guide channel 110 formed by the enclosing of two adjacent guide shells 1, which is connected to the tube inlet 4. The Nth guide shell, that is, the innermost guide shell 1, can itself enclose and form a central guide channel 100 connected to the tube inlet 4. As can be seen from the above, the gas distribution component 00 has a roughly conical sleeve-shaped structure. After the reaction gas flows into the N-1 peripheral guide channels 110 through the tube inlet 4, it can flow out of the N-1 peripheral guide channels 110 at an angle away from the central axis M of the tube inlet 4 under the guidance of the corresponding guide shell 1. This helps to shorten the flow path length of the gas to the contact element, resulting in high gas velocity, low pressure drop, and rapid participation of the gas in the reaction, which accelerates the reaction efficiency and shortens the reaction cycle. At the same time, the gas flows out from the multi-layered annular channels, resulting in uniform gas distribution without the problem of insufficient distribution points, and excellent gas distribution effect.

[0084] The gas distribution component 00 can be connected to the tube inlet 4 via at least one flow guide shell 1. That is, at least one flow guide shell 1 can not only be used for flow guidance, but also for connection to the tube inlet 4, so as to ensure that the gas distribution component 00 is stably installed at the tube inlet 4 of the tubular fixed bed reactor.

[0085] The N guide vane groups 2 can be divided into a central plate group 21 located in the middle of the gas distribution assembly 00 and N-1 peripheral plate groups 22 located around the central plate group 21. The central plate group 21 may include at least one central guide vane 211. Each central guide vane 211 extends spirally along the inlet direction A and is arranged within the central guide channel 100. Thus, the gas to be reacted flowing into the central guide channel 100 can spirally flow out under the guidance of the spiral central guide vane 211, thereby increasing the gas velocity and further enabling the gas to participate in the reaction quickly. Simultaneously, the spiral central guide vane 211 changes the flow direction of the gas to be reacted flowing into the central guide channel 100, reducing the impact and wear of the airflow on the upper tube sheet 51 (or other components directly opposite the outlet side of the central guide channel 100), and improving the service life of the upper tube sheet 51. The aforementioned N-1 peripheral plate groups 22 are respectively arranged one-to-one within the N-1 peripheral guide channels 110, that is, one peripheral plate group 22 is arranged in each peripheral guide channel 110; each peripheral plate group 22 includes at least one peripheral guide plate 221, and each peripheral guide plate 221 extends spirally along the air intake direction A. It should be noted that the central guide plate 211 can extend along the entire central guide channel 100 or extend to a local position in the central guide channel 100, and the specific extension position and spiral size are not limited here; similarly, the peripheral guide plates 221 can extend along the entire corresponding peripheral guide channel 110 or extend to a local position in the peripheral guide channel 110, and the specific extension position and spiral size are also not limited here. By arranging both the central guide plate 211 and the peripheral guide plates 221 to extend spirally along the air intake direction A, the gas flow rate can be increased and the flow path length for the gas to reach the contact element can be shortened.

[0086] As can be seen from the above, the structure of the gas distribution component 00 can effectively control the gas pressure drop and flow rate, resulting in good gas distribution. At the same time, the guide shell 1 of the gas distribution component 00 only has a gas outlet at the bottom, which can promote the downward flow of all the gas to be distributed, thereby participating in the reaction as soon as possible. The structure is simple and easy to mass-produce, and it is suitable for reactors involving gas, such as methanol reactors and methanation reactors in the coal chemical industry, and has broad application prospects.

[0087] In some embodiments, such as Figures 3 to 7As shown, all N guide shells 1 are frustum-shaped and coaxially arranged around the central axis M of the tube inlet 4 with their top surfaces flush. This allows the reactant gas to simultaneously enter the central guide channel 100 and each of the peripheral guide channels 110, facilitating uniform gas distribution. Furthermore, this structure is easy to manufacture and facilitates the assembly of the guide shells 1 in the gas distribution assembly 00. In some embodiments, the height of the N guide shells 1 increases from the outside in, meaning the height of the innermost guide shell 1 is higher than that of its outermost counterpart. Further, the height of the first guide shell is less than the height of the second guide shell, the height of the second guide shell is less than the height of the third guide shell, and so on. This structure ensures that both the central guide channel 100 and the peripheral guide channels 110 have sufficient length to guide the gas within the channels. Simultaneously, it effectively shortens the flow path length for the distributed gas to reach the contact element, increasing the gas participation rate in the reaction and thus shortening the reaction cycle.

[0088] In some embodiments, see Figure 2 The extension lines of the generatrices of the N guide shells 1 intersect the central axis M of the tube inlet 4 at the same point. The difference between the apex angles of the two cones corresponding to any two adjacent guide shells 1 is the same as the apex angle of the cone corresponding to the innermost guide shell 1. In other words, if the apex angle of the outermost guide shell 1 is α, the apex angle of the next outermost guide shell 1 is α(N-1) / N, and so on, until the apex angle of the innermost guide shell 1 is α / N. For example, if N is 3, the apex angle of the outermost guide shell 1 is α, the apex angle of the next outermost guide shell 1 is 2α / 3, and the apex angle of the innermost guide shell 1 is α / 3; if N is 5, the apex angle of the outermost guide shell 1 is α, the apex angle of the next outermost guide shell 1 is 4α / 5, and so on, until the apex angle of the innermost guide shell 1 is α / 5. This structure facilitates gas distribution and positioning, and achieves pressure equalization, resulting in better fluid distribution uniformity and ease of manufacturing. The evenly spaced angles of the guide shells 1 ensure that when this gas distribution assembly 00 is applied to large-scale reactors, the gas can be distributed more uniformly.

[0089] In some embodiments, the line extension of the generatrix of the outermost guide shell 1 toward the upper tube sheet 51 should cover the openings of all reaction tubes 6 on the upper tube sheet 51. That is, when setting the shape of the outermost guide shell 1, the principle should be that its generatrix extends to the upper surface of the upper tube sheet 51 of the tubular fixed bed reactor and covers the openings of all reaction tubes 6. This structure allows the gas to flow into each reaction tube 6 along the extension direction of the guide shell 1 after being distributed by the gas distribution component 00, resulting in better gas distribution.

[0090] In some embodiments, each of the N flow guide shells 1 corresponds to one of the N cones, and the generatrix lengths of the N cones are all the same, and are approximately 1.5-2.0 times the inner diameter of the top surface of the outermost flow guide shell 1. For example... Figure 2As shown, the generatrix length of the N cones corresponding to the N guide shells 1 can be R. If the value of R is set too large, it will hinder the loading of catalyst and other contact components. In some embodiments, the gas distribution component 00 and the catalyst inlet can both be set on the upper end cover 7 of the tubular fixed bed reactor. The gas distribution component 00 is located between the tube inlet 4 and the catalyst inlet. The catalyst can be loaded into the reaction tube 6 from the inlet. In this case, if the value of R is larger, the catalyst inlet will be blocked more, which will be more detrimental to the loading of the catalyst. Conversely, if the value of R is set too small, the distributed gas will rapidly decrease in velocity due to the increased space, the flow channel will lengthen, and the flow rate will decrease, which will be detrimental to the reaction. Therefore, the setting of this structure and its proportional relationship can facilitate the arrangement of the gas distribution component 00 in the tubular fixed bed reactor without hindering the loading of catalyst and other contact components. At the same time, it helps to shorten the flow channel length of the distributed gas to the contact components, so that the distributed gas can quickly participate in the reaction, further optimizing the gas distribution effect.

[0091] It should be noted that although the numerical ranges and parameters described in this application are approximate and are limited by the word "about," the numerical values ​​described in the specific examples are reported as precisely as possible. However, any numerical value inherently contains some error, which may be caused by the standard deviation (including the standard deviation found in the measuring instrument) found in their respective test measurements. Similarly, it should be understood that any numerical range listed herein is intended to include all subranges contained therein. For example, the range "1.5-2.0" is intended to include all subranges between the listed minimum value of 1.5 and the listed maximum value of 2.0, and including both that minimum and maximum value; that is, the range having a minimum value equal to or greater than 1.5 and a maximum value equal to or less than 2.0. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values, such as 1.6, 1.8, etc. Unless otherwise expressly indicated, the numerical ranges specified in this application are approximate.

[0092] In some embodiments, please refer to the following: Figure 3 , Figure 5 and Figure 6The number of central guide plates 211 in the central plate group 21 is the same as the number of peripheral guide plates 221 in each peripheral plate group 22, and is n, where n is a positive integer greater than 1. The figure shows the case where n is 3, but the specific value of n can be selected according to the actual situation and is not uniquely limited here. By setting the number of central guide plates 211 and peripheral guide plates 221 to multiple, the direction of gas flow after being guided by multiple central guide plates 211 and multiple peripheral guide plates 221 can be more diverse, avoiding insufficient gas distribution points and making the gas distribution more uniform. Setting the number of central guide plates 211 and peripheral guide plates 221 to be the same can further improve the performance of the gas distribution component 00 in uniformly distributing gas.

[0093] In some embodiments, please continue reading Figure 3 , Figure 5 and Figure 6 n central guide vanes 211 are spaced apart around the central axis M of the tube inlet 4 and connected to each other on the central axis M. The side of each central guide vane 211 facing away from the central axis M of the tube inlet 4 is connected to the innermost guide shell 1, meaning the n central guide vanes 211 are connected as a whole, with the corresponding connecting lines collinear with the central axis M of the tube inlet 4. Furthermore, the outer sides of the n central guide vanes 211 facing away from the central axis M of the tube inlet 4 are all connected to the innermost guide shell 1. Thus, the n central guide vanes 211 can be stably installed inside the innermost guide shell 1; each outer... Each peripheral guide plate 221 within the surrounding guide channel 110 is arranged at intervals around the central axis M of the tube inlet 4 and connected between two adjacent guide shells 1 used to enclose the peripheral guide channel 110. In this way, each peripheral guide plate 221 within each peripheral guide channel 110 not only plays a guiding role, but also connects two adjacent guide shells 1. This structure allows the connection between each guide shell 1 to be achieved through the guide plate group 2, without the need for additional connecting parts 31, reducing production costs. The structure is reasonable and ensures the overall stability of the gas distribution assembly 00.

[0094] In some embodiments, see Figure 5 and Figure 6The n central guide plates 211 in the central plate group 21 and the n peripheral guide plates 221 in each peripheral plate group 22 are all rotationally symmetric structures with a rotation angle of 2π / n and the central axis M of the tube inlet 4 as the rotation axis. As shown in the figure, taking n=3 as an example, the three central guide vanes 211 in the middle are rotationally symmetric structures with a rotation angle of 2π / 3 (i.e., 120°) and the central axis M of the tube inlet 4 as the rotation axis. This means that the structure obtained after rotating the three central guide vanes 211 120° around the rotation axis is the same as the structure before rotation. Similarly, the three peripheral guide vanes 221 in each peripheral plate group 22 are also rotationally symmetric structures with a rotation angle of 2π / 3 (i.e., 120°) and the central axis M of the tube inlet 4 as the rotation axis. This means that the structure obtained after rotating the three peripheral guide vanes 221 belonging to the same peripheral plate group 22 120° around the rotation axis is the same as the structure before rotation. This structure further improves the distribution effect of the gas distribution assembly 00, resulting in a more uniform gas distribution. Optionally, the pitch of each central guide vane 211 and each peripheral guide vane 221 can be set to 5 times the diameter of the tube inlet 4, which results in better gas distribution.

[0095] In some embodiments, see Figures 8 to 10 If the thickness of the guide shell 1, the thickness of the central guide plate 211 and the thickness of the outer guide plate 221 are ignored, the structure shown in the figure can be formed by combining all the central guide plates 211 and all the outer guide plates 221. As can be seen from the figure, the structure is composed of three spiral plates, specifically a rotationally symmetric structure with a rotation angle of 2π / n (n is 3 in the figure, and the rotation angle is 120° at this time) and the central axis M of the tube inlet 4 as the rotation axis. In these embodiments, if the thickness of the guide shell 1, the thickness of the central guide plate 211, and the thickness of the peripheral guide plate 221 are taken into account, the collection of all cross-sections of all central guide plates 211 and all peripheral guide plates 221 cut by the same plane perpendicular to the central axis M of the tube inlet 4 can constitute n line segment structures 200. The n line segment structures 200 extend radially outward from the same center point 20, the center point 20 being located on the central axis M of the tube inlet 4, and the included angle between two adjacent line segment structures 200 is 2π / n; Figure 11 For example, in the diagram, n=3, meaning three line segment structures 200 extend radially outward from the same center point 20, with an included angle of 120° between adjacent line segment structures 200. The central guide plate 211 and peripheral guide plates 221 are arranged such that the width of each peripheral guide plate 221 at a cross-section is the radial distance between the two adjacent guide shells 1 connected thereto at that cross-section, and the width of each central guide plate 211 at a cross-section is the inner radius of the innermost guide plate at that cross-section. For example... Figure 6 , Figure 7As shown, if the radial distance between two adjacent guide shells 1 increases from top to bottom, then the width of the outer guide plate 221 located within the two adjacent guide shells 1 will also increase from top to bottom. This structure makes the guide plate assembly 2 easy to manufacture and facilitates the installation of the guide plate assembly 2 within the guide shell 1, resulting in a reasonable structure.

[0096] like Figure 11 As shown, the thickness of all central guide vanes 211 and all peripheral guide vanes 221 can be set to be the same, or they can be set to be different according to actual needs.

[0097] In some embodiments, see Figure 6 and Figure 7 Each central guide plate 211 in the central plate group 21 extends from its top surface to the bottom of the innermost guide shell 1, and each peripheral guide plate 221 in each peripheral plate group 22 extends from its top surface to the bottom of the two adjacent guide shells 1 that enclose the peripheral guide channel 110 corresponding to the peripheral plate group 22. This structure allows the central guide plate 211 and the peripheral guide plate 221 to extend throughout the entire channel, which can further increase the gas flow rate and thus improve the reaction efficiency.

[0098] In some embodiments, such as Figure 7 As shown, the gas distribution assembly 00 also includes a cylindrical extension 3 connected to the top of the outermost guide shell 1. The extension 3 has a flow channel 300, which is connected to the tube-side inlet 4, the central guide channel 100, and each peripheral guide channel 110. The extension 3 has a connector 31, which is fixedly installed on a connecting fitting 41 at the tube-side inlet 4. Optionally, the connector 31 and the connecting fitting 41 are bolted flange connections, meaning the connector 31 and the connecting fitting 41 can be flange structures, and they are fixed together by bolts. The flange structure can be a plate-type flat-face flange or a necked flat-face flange, such as... Figure 2 As shown, the height of the connector 31 is H, and the distance from the outer end of the connector 31 to the bottom end of the extension section 3 is L. Preferably, L ≥ (H + 25) mm, thereby avoiding the overlap between the weld circumferential seam of the extension section 3 and the outermost guide shell 1 and the circumferential seam of the extension section 3 and the connector 31, thus avoiding weld overlap and welding defects. Since the gas distribution assembly 00 adopts a bolted flange connection structure with the inlet, it does not need to be welded to the inner wall of the shell of the tubular fixed bed reactor. Therefore, the gas distribution assembly 00 is easy to replace, and the replacement of the gas distribution assembly 00 will not damage the inner wall of the shell of the tubular fixed bed reactor.

[0099] In some embodiments, the inner diameter of the top surface of the outermost guide shell 1, the inner diameter of the cross-section of the flow channel 300, and the diameter of the tube inlet 4 are all the same. For example... Figure 2As shown, if the diameter of the tube inlet 4 is d, then the inner diameter of the cross-section of the flow channel 300 is d, and the inner diameter of the top surface of the outermost guide shell 1 is also d. This structure ensures that the gas flowing out of the tube inlet 4 can smoothly enter the flow channel 300 and the gas distribution assembly 00, which helps to improve the gas distribution efficiency.

[0100] The following is a summary of the structure of the gas distribution component 00: Figure 2 As shown, the tubular fixed-bed reactor employs the aforementioned conical gas distribution assembly 00. In some embodiments, the gas distribution assembly 00 may specifically include a connector 31, an extension section 3, multiple nested guide shells 1, and a guide plate assembly 2. More specifically, one end of the extension section 3 is welded to the connector 31, and the other end of the extension section 3 is welded to the top of the outermost guide shell 1. The multiple nested guide shells 1 are connected and fixed by the guide plate assembly 2. The generatrix vertices of the multiple nested guide shells 1 are the same point and are located on the centerline of the gas distribution assembly 00 (i.e., the central axis M of the tube-side inlet 4). The extension length of the multiple nested guide shells 1 is preferably such that it does not obstruct the loading of the catalyst. The conical gas distribution assembly 00 and the connecting fitting 41 at the tube-side inlet 4 can be fixedly connected by bolts, nuts, and washers. The tubular fixed-bed reactor also includes an upper tube sheet 51 located on the outlet side of the gas distribution assembly 00 and multiple reaction tubes 6. The inlets of the multiple reaction tubes 6 are evenly distributed on the upper tube sheet 51. Gas enters the tubular fixed-bed reactor from the tube-side inlet 4, then flows downward at an angle between multiple nested guide shells 1, and then flows to the upper surface of the upper tube sheet 51 of the tubular fixed-bed reactor. Gas flows from one end of the reaction tube 6 through the catalyst bed inside the reaction tube 6, and after the reaction occurs, it flows out from the other end of the reaction tube 6 and is finally discharged from the reaction gas outlet. This conical gas distribution assembly 00 has a simple structure, is easy to replace, and will not damage the reactor shell during replacement. It has a short flow channel, high flow velocity, and uniform distribution of raw gas, which can accelerate the reaction efficiency and shorten the reaction cycle, thereby better controlling the pressure drop and flow velocity, and achieving a better gas distribution.

[0101] In one or more embodiments, the tubular fixed-bed reactor further includes an upper distribution cylinder 201, which may be a cylindrical structure, specifically a cylindrical cylinder, a frustum-shaped cylinder, or other regular or irregular shapes; the structure of the upper distribution cylinder 201 may be consistent with that of the lower distribution cylinder 202. The upper distribution cylinder 201 is located inside the shell-side cylinder 9 and surrounds at least a portion of the reaction tube 6; a plurality of flow holes 500 are also uniformly distributed on the upper distribution cylinder 201 to uniformly distribute the shell-side medium flowing to the shell-side outlet 92. The upper distribution cylinder 201 can be connected to the upper tube sheet 51 or fixed to the shell-side cylinder 9 by a component. The key is to ensure that the upper distribution cylinder 201 is located inside the shell-side cylinder 9 and surrounds at least part of the reaction tube 6, and that its multiple flow holes 500 can evenly distribute the shell-side medium flowing towards the shell-side outlet 92. The upper distribution cylinder 201 can be positioned near and directly opposite the shell-side outlet 92, or it can be positioned slightly off-center, as long as the shell-side medium is evenly distributed by the upper distribution cylinder 201 and can flow to the shell-side outlet 92. In one specific embodiment, two distribution cylinders can be arranged at the top and bottom of the shell-side cylinder 9, respectively. Of course, the specific arrangement can be determined according to actual conditions. By setting an upper distribution cylinder 201 in a tubular fixed-bed reactor, the upper distribution cylinder 201 surrounds the outer periphery of at least a portion of the reaction tubes 6. At the same time, multiple flow holes 500 are evenly distributed on the side wall of the upper distribution cylinder 201. On the one hand, the shell-side medium between at least a portion of the reaction tubes 6 inside the upper distribution cylinder 201 can pass evenly through the outer periphery of the upper distribution cylinder 201 and flow to the shell-side outlet 92. On the other hand, this structure can also ensure that the heat of reaction in at least a portion of the reaction tubes 6 can be removed evenly and in a timely manner, preventing coking.

[0102] In one or more embodiments, both the upper distribution cylinder 201 and the lower distribution cylinder 202 have a connecting end 1a. The connecting end 1a of the lower distribution cylinder 202 is located on the lower tube sheet 52, and the lower distribution cylinder 202 and the shell-side cylinder 9 enclose each other to form a lower distribution cavity 102 communicating with the shell-side inlet 91. Multiple flow holes 500 on the lower distribution cylinder 202 are all connected to the lower distribution cavity 102. The connecting end 1a of the upper distribution cylinder 201 is located on the upper tube sheet 51, and the upper distribution cylinder 201 and the shell-side cylinder 9 enclose each other to form an upper distribution cavity 101 communicating with the shell-side outlet 92. Multiple flow holes 500 on the upper distribution cylinder 201 are all connected to the upper distribution cavity 101. The connecting end 1a of the upper distribution cylinder 201 and the upper tube sheet 51, and the connecting end 1a of the lower distribution cylinder 202 and the lower tube sheet 52, can be connected by welding. Other connection methods are also possible and are not limited here. Thus, the lower distribution cylinder 202 is arranged at the bottom of the shell-side cylinder 9, allowing the shell-side medium to enter the lower distribution chamber 102 through the shell-side inlet 91. It then enters the central region of the shell-side cylinder 9 through multiple flow holes 500 on the lower distribution cylinder 202. This achieves uniform distribution of the shell-side medium and helps eliminate the flow dead zone in the central region of the shell-side cylinder 9, thereby improving the effective utilization of the equipment's space and preventing over-reaction of materials in the dead zone of the tubular fixed-bed reactor, which could lead to coking and other accidents. The shell-side medium flows from bottom to top, and the upper distribution cylinder 201 is arranged at the top of the shell-side cylinder 9. The shell-side medium enters the upper distribution chamber 101 through multiple flow holes 500 on the upper distribution cylinder 201 and then exits the shell-side cylinder 9 through the shell-side outlet 92. This structure also achieves uniform distribution of the medium, thus ensuring uniform temperature distribution within the tubular fixed-bed reactor.

[0103] It should be noted that both the lower distribution cavity 102 and the upper distribution cavity 101 described above can be open cavities; for example... Figure 13 The lower distribution cavity 102 shown has its bottom end connected to the lower tube sheet 52, and its top end is a free end. In this case, the lower distribution cavity 102 is an open cavity with an open top. Of course, the lower distribution cavity 102 can also be a closed cavity, for example... Figure 15The lower distribution cavity 102 shown has its bottom end connected to the lower tube sheet 52, and its top end connected to a plate (the lower baffle 301 in the figure). The lower distribution cavity 102 is thus formed by the lower distribution cylinder 202, the lower baffle 301, the shell-side cylinder 9, and the lower tube sheet 52, creating a relatively closed cavity. The lower baffle 301 can be a complete annular structure, resulting in a relatively closed lower distribution cavity 102. Alternatively, the lower baffle 301 can be at least one fan-shaped annular structure, in which case the lower distribution cavity 102 has an opening for the shell-side medium to overflow from the top. It should be noted that, besides the lower baffle 301 shown in the figure, other structures can be used between the lower distribution cylinder 202 and the shell-side cylinder 9 to form lower distribution cavities 102 of different shapes; this is not a limitation. The structure of the upper distribution cylinder 201 can be set with reference to the structure of the lower distribution cylinder 202, and the upper distribution cavity 101 can also be set with reference to the structure of the lower distribution cavity 102. It will not be described again here.

[0104] Furthermore, the thicknesses of the lower distribution cylinder 202 and the upper distribution cylinder 201 can be determined based on the medium flow velocity and impact force at the shell-side inlet and outlet. Optionally, when the lower distribution cylinder 202 is made of carbon steel or low-alloy steel, its thickness can be no less than 6 mm; when the lower distribution cylinder 202 is made of stainless steel, its thickness can be no less than 4 mm. Of course, the specific thickness value needs to be set according to the actual situation, and no specific limitation is made here. The thickness setting of the upper distribution cylinder 201 can also refer to that of the lower distribution cylinder 202, and will not be elaborated here.

[0105] As can be seen from the above, in a tubular fixed-bed reactor, a lower distribution cylinder 202 and an upper distribution cylinder 201 are arranged. Multiple flow passages 500 are formed on the sidewall of the lower distribution cylinder 202 and the sidewall of the upper distribution cylinder, resulting in a simple and easy-to-implement structure. Furthermore, this internally guided liquid distribution structure, with the flow passages 500 located on either the lower distribution cylinder 202 or the upper distribution cylinder 201, helps to achieve uniform distribution of the shell-side medium without damaging the complete shell-side cylinder 9 structure. The shell-side cylinder 9 using this liquid distribution structure, except for a few shell-side inlets 91 and shell-side outlets 92, basically does not require other cumbersome processing to coordinate with the shell-side medium distribution, effectively reducing the risk of loss and ensuring structural strength.

[0106] In the aforementioned tubular fixed-bed reactor, the positions of the shell-side inlet 91 and shell-side outlet 92 can be determined according to the requirements for perforation reinforcement and the needs of the process or piping. The height of the lower distribution cylinder 202 can be determined based on the position of the shell-side inlet 91, and the height of the upper distribution cylinder 201 can be determined based on the position of the shell-side outlet 92. The structures of the upper distribution cylinder 201 and the lower distribution cylinder 202 can be set to be the same. The following description uses the structure of the lower distribution cylinder 202 as an example.

[0107] Please refer to some specific embodiments of this application. Figure 13 and Figure 14 The lower distribution cylinder 202 can be rectangular when unfolded and cylindrical when closed. The lower distribution cylinder 202 has an extended end 1b opposite to the connecting end 1a. The height of the lower distribution cylinder 202 is the shortest distance from the connecting end 1a to the extended end 1b. When the connecting end 1a of the lower distribution cylinder 202 is connected to the lower tube sheet 52, the side wall of the lower distribution cylinder 202 is directly opposite the shell-side inlet 91. The fact that the side wall of the lower distribution cylinder 202 is directly opposite the shell-side inlet 91 can be understood as the projection point of the center of the shell-side inlet 91 along the medium flow direction onto the lower distribution cylinder 202 should be located between the connecting end 1a and the extended end 1b of the lower distribution cylinder 202. In this way, the lower distribution cylinder 202 can effectively block the impact of the shell-side medium flowing out of the shell-side inlet 91 on the reaction tube 6. In some embodiments, the distance between the outer end face of the extension end 1b of the lower distribution cylinder 202 and the center of the shell-side inlet 91 is the inner diameter d1 of the shell-side inlet 91. In this case, the height of the lower distribution cylinder 202 should be 1.5 times the inner diameter d1 of the shell-side inlet 91 and the distance between the bottom of the shell-side inlet 91 and the lower tube sheet 52. If the distance between the bottom of the shell-side inlet 91 and the lower tube sheet 52 is set to 0, the height of the lower distribution cylinder 202 is 1.5 times the inner diameter d1 of the shell-side inlet 91. If the distance between the bottom of the shell-side inlet 91 and the lower tube sheet 52 is greater than 0, the height of the lower distribution cylinder 202 is greater than 1.5 times the inner diameter d1 of the shell-side inlet 91. Therefore, the height of the lower distribution cylinder 202 is at least 1.5 times the inner diameter d1 of the shell-side inlet 91. This structure saves material in the lower distribution cylinder 202, reducing costs while ensuring that the shell-side medium flowing out from the shell-side inlet 91 can first contact the lower distribution cylinder 202 before flowing into the reaction tubes 6 inside the lower distribution cylinder 202. This results in better fluid distribution, faster distribution of the outflowing medium, and higher distribution efficiency. Figure 13 The lower distribution chamber 102 shown is an open-top lower distribution chamber 102. In this embodiment, by limiting the distance between the outer end face of the outer end 1b of the lower distribution cylinder 202 and the center of the shell inlet 91 to the inner diameter d1 of the shell inlet 91, more than 80% of the shell-side medium flowing out of the shell inlet 91 can be distributed to the reaction tubes 6 inside the lower distribution cylinder 202 through the evenly distributed regular small holes (through flow holes 500) on the lower distribution cylinder 202. Less than 20% overflows through the free end of the lower distribution cylinder 202 and then flows down to the reaction tubes 6 inside the lower distribution cylinder 202. At this time, the liquid distribution is relatively uniform and the distribution effect of the lower distribution cylinder 202 is good.

[0108] Similarly, in some embodiments, when the side peripheral wall of the upper distribution cylinder 201 is connected to the upper tube sheet 51 at its connecting end 1a, it is directly opposite the shell-side outlet 92, and the distance between the outer end face of its extension end 1b and the center of the shell-side outlet 92 is the inner diameter d2 of the shell-side outlet 92; the structure and function of the upper distribution cylinder 201 are similar to those of the lower distribution cylinder 202 when its connecting end 1a is connected to the lower tube sheet 52, and will not be described again here.

[0109] In some embodiments of this application, please refer to Figure 14 Multiple drainage notches 600 can be formed at the circumferential edges of both the connecting end 1a of the upper distribution cylinder 201 and the connecting end 1a of the lower distribution cylinder 202, facilitating the discharge of the shell-side medium inside the upper distribution cylinder 201 and the lower distribution cylinder 202. After being discharged into the upper distribution cavity 101 and the lower distribution cavity 102, the medium can be further discharged outside the tubular fixed bed reactor. For ease of manufacturing, the drainage notches 600 can be set as semi-circular notches, rectangular notches, triangular notches, etc., but are not limited to these and can be set according to actual needs.

[0110] Please refer to some embodiments of this application. Figure 14 For ease of manufacturing, the flow holes 500 on the upper distribution cylinder 201 and the lower distribution cylinder 202 can be set as regular holes such as circular holes, rectangular holes, waist-shaped holes or elliptical holes. Of course, they can also be set as irregular hole structures. Other structures that can allow the shell-side medium to flow through the lower distribution cylinder 202 (such as through grooves of various shapes) should also be within the protection scope of this application. The shapes of the flow holes 500 on the upper distribution cylinder 201 and the lower distribution cylinder 202 can be the same or different, and can be set as needed.

[0111] In one or more embodiments, the inner peripheral walls of both the upper distribution cylinder 201 and the lower distribution cylinder 202 abut against the outermost reaction tube 6. See also... Figure 1The lower distribution cylinder 202 surrounds all the reaction tubes 6 within the shell-side cylinder 9, with its inner circumferential wall abutting against the outermost reaction tube 6 within the shell-side cylinder 9. This structure effectively prevents the shell-side medium from impacting the reaction tubes 6, thus protecting them. By abutting the outermost reaction tube 6 against the inner circumferential wall of the lower distribution cylinder 202, the structural strength and deformation resistance of the lower distribution cylinder 202 are effectively improved. This structure is reasonable and will not affect the original layout or support of the reaction tubes 6 within the shell-side cylinder 9, nor will it affect the original manufacturing sequence and difficulty of the tubular fixed-bed reactor. The inner circumferential wall of the upper distribution cylinder 201 abuts against the outermost reaction tube 6, and its structure and function are similar, so they will not be described further here. It should be noted that the reaction tube 6 of this tubular fixed bed reactor can be a corrugated tube, finned tube, threaded tube, spiral groove tube, high-pass bright tube, or other heat transfer enhanced tube to improve the flow rate and heat transfer of the shell-side medium.

[0112] In one or more embodiments, a plurality of flow-through holes 500 on the upper distribution cylinder 201 are arranged in at least one row along the circumference of the upper distribution cylinder 201, and a plurality of flow-through holes 500 on the lower distribution cylinder 202 are arranged in at least one row along the circumference of the lower distribution cylinder 202; the arrangement of the plurality of flow-through holes 500 on the upper distribution cylinder 201 is similar to the arrangement of the plurality of flow-through holes 500 on the lower distribution cylinder 202, and the following description only describes the arrangement of the plurality of flow-through holes 500 on the lower distribution cylinder 202. Figure 14 As shown, multiple flow holes 500 are arranged in at least one row along the circumference of the lower distribution cylinder 202. Figure 14 The diagram shows three rows of flow-through holes 500, with adjacent rows of holes 500 staggered. This structure further enhances the medium distribution effect and efficiency of the lower distribution cylinder 202. See further details. Figure 14 Each row of flow-through holes 500 may include multiple flow-through holes 500, which may be arranged at equal intervals. Furthermore, in at least one row of flow-through holes 500 on the lower distribution cylinder 202, one row of flow-through holes 500 may exist such that the central axis of the shell-side inlet 91 is located in the plane containing this row of flow-through holes 500; that is, the center of each flow-through hole 500 in this row is at the same height as the center of the shell-side inlet 91. This structure helps to quickly and evenly distribute the shell-side medium flowing out of the shell-side inlet 91, improving distribution efficiency.

[0113] In one or more embodiments, the number of flow-through holes 500 in each row on the lower distribution cylinder 202 is no less than four times the number of shell-side inlets 91. In one or more embodiments, the number of flow-through holes 500 in each row on the upper distribution cylinder 201 is no less than four times the number of shell-side outlets 92. This structure ensures that the shell-side medium can quickly pass through the lower distribution cylinder 202 and the upper distribution cylinder 201, achieving uniform distribution, thus having high distribution efficiency, a reasonable structure, and being easy to implement.

[0114] In one or more embodiments, the sum of the flow areas of the plurality of flow-through holes 500 on the lower distribution cylinder 202 is not less than twice the sum of the flow areas of the shell-side inlet 91. In one or more embodiments, the sum of the flow areas of the plurality of flow-through holes 500 on the upper distribution cylinder 201 is not less than twice the sum of the flow areas of the shell-side outlet 92; specifically, the nominal diameter of both the shell-side inlet 91 and the shell-side outlet 92 can be 350 mm. Further, the number of both the shell-side inlet 91 and the shell-side outlet 92 can be 2-4. This structure can also ensure that the shell-side medium can quickly pass through the lower distribution cylinder 202 and the upper distribution cylinder 201, achieving uniform distribution, thereby having high distribution efficiency.

[0115] In some embodiments of this application, please refer to Figure 15 The tubular fixed-bed reactor may also include an upper baffle and a lower baffle 301. The two baffles are connected to the lower distribution cylinder 202 and the upper distribution cylinder 201 respectively. Their structures and functions are similar; therefore, the connection between the lower baffle 301 and the lower distribution cylinder 202 will be used as an example in the following description. The lower baffle 301 can be positioned between the lower distribution cylinder 202 and the shell-side cylinder 9 to enclose and form the lower distribution cavity 102. The lower baffle 301 can be connected to the lower distribution cylinder 202, the shell-side cylinder 9, or between the two. The connection method can be a fixed connection or a detachable connection, including but not limited to welding, snap-fitting, screwing, electromagnetic connection, etc. The connection method should be designed to facilitate operation and the disassembly and assembly of internal reactor components (such as support plates 61, baffles, etc.). The inner side of the lower baffle 301 can be connected to the outer end 1b of the lower distribution cylinder 202, or to other parts of the lower distribution cylinder 202. The lower baffle 301 can be configured as a regular structure such as annular or fan-shaped, or as other irregular structures. It can be arranged horizontally, inclined, or in a concave-convex arrangement. It should be noted that the specific structure, shape, and flow-blocking area of ​​the lower baffle 301 are not specifically limited. The lower baffle 301 may not have holes or slots, or it may be similar to the lower distribution cylinder 202, with multiple through holes evenly arranged. This is not limited here. By setting the lower baffle 301, the shell-side medium can be minimized or eliminated from overflowing from the top of the lower distribution cavity 102, thereby allowing the shell-side medium to be evenly distributed through the lower distribution cylinder 202 as much as possible, thus improving the distribution effect of the lower distribution cylinder 202.

[0116] In one or more embodiments, the structure supporting the reaction tube 6 of the tubular fixed bed reactor can be a support plate 61 or a baffle plate. This structure can be a structure well known to those skilled in the art, and since it is not part of the core improvement of this application, it will not be described in detail here.

[0117] It is worth noting that the support plates 61 or baffles can be modified to have few or no reaction tubes 6 arranged near the periphery of the shell-side cylinder 9, so that the outermost reaction tube 6 can be set slightly inward to provide sufficient space for the arrangement of the upper distribution cylinder 201 and the lower distribution cylinder 202; at the same time, the area without tubes can also meet the needs of shell-side medium flow, which can effectively reduce the pressure drop in the shell side. The multiple support plates 61 provided on the reaction tubes 6 can be full-support support plates 61 with openings between the tube holes. This structure can not only increase the rigidity of the reaction tubes 6 and prevent the reaction tubes 6 from vibrating, but also allow the shell-side medium to flow axially through the support plates 61 without shell-side flow dead zones, resulting in uniform catalyst bed temperature.

[0118] The following summary is made regarding the lower distribution cylinder 202 and the upper distribution cylinder 201: Using the lower distribution cylinder 202 and the upper distribution cylinder 201 for the shell-side cylinder 9, except for a few shell-side inlets 91 and shell-side outlets 92, eliminates the need for other complex processing related to shell-side medium distribution, effectively reducing the risk of loss and ensuring structural strength. Furthermore, by using the lower distribution cylinder 202 or the upper distribution cylinder 201, the number of shell-side inlets 91 or shell-side outlets 92 in this tubular fixed-bed reactor can be reduced. For example, without the lower distribution cylinder 202, the formation of the shell-side inlets 91 may require 6 to 8 pipes with a nominal diameter of 300 mm; with the lower distribution cylinder 202, the formation of the shell-side inlets 91 may only require 2 to 4 pipes with a nominal diameter of 350 mm. This reduction in the number of shell-side inlets 91 and shell-side outlets 92 facilitates the piping, manufacturing, heat treatment, and transportation operations of the tubular fixed-bed reactor. Conversely, a larger number of shell-side inlets 91 and shell-side outlets 92 not only increases the difficulty of reactor manufacturing and piping but also expands the reactor's width and height, increasing the difficulty of heat treatment and transportation. Conversely, a smaller number of shell-side inlets 91 and shell-side outlets 92 not only facilitates reactor piping and manufacturing but also allows the inlets 91 and outlets 92 to be arranged vertically, thereby reducing the reactor's width and facilitating heat treatment and transportation. By employing an internally guided lower distribution cylinder 202 and / or upper distribution cylinder 201, the shell-side medium distribution and catalyst bed temperature are uniform within the tubular fixed-bed distributor of this application.

[0119] The following is a summary of the tubular fixed-bed reactor: Currently, reactors for the catalytic hydrogenation of carbon dioxide to methanol in China are still in the research and development and pilot-scale stages, with few mature industrial-scale applications. Therefore, existing reactors for the catalytic hydrogenation of carbon dioxide to methanol also use syngas hydrogenation reactors. The methanol production reaction is highly exothermic; failure to remove this heat promptly will lead to high temperatures within the reactor, affecting the catalyst's performance. Simultaneously, the reaction temperature within the reactor cannot be too low, otherwise, it will hinder the forward reaction and affect methanol yield. In the methanol synthesis process, an ideal reactor should maintain a minimal temperature difference in the catalyst, achieving a homogeneous or isothermal state. The tubular fixed-bed reactor provided in this application, equipped with a gas distribution component and a lower distribution cylinder, can effectively ensure a homogeneous or isothermal state for the catalyst, thereby improving the stability and product yield of the catalytic hydrogenation of carbon dioxide to methanol reaction. Therefore, the tubular fixed-bed reactor provided in this application is suitable as a reactor for the catalytic hydrogenation of carbon dioxide to methanol. The tubular fixed-bed reactor proposed in this application, through the combination of gas distribution components and a lower distribution cylinder, achieves uniform gas distribution and high flow velocity at the tube inlet, uniform distribution of reactant gas within each reaction tube, uniform distribution of the heat exchange medium in the shell side, and uniform catalyst bed temperature. This effectively improves reaction stability, synthesis reaction conversion rate, and product yield, resulting in a synergistic effect greater than the sum of its parts. The overall structure of the tubular fixed-bed reactor is simple and compact, facilitating manufacturing, transportation, and installation, and allowing for easy catalyst loading and unloading. Furthermore, by incorporating heat-enhanced reaction tubes 6 and fully supported plates 61 within the tubular fixed-bed reactor, the heat transfer effect and rigidity of the reaction tubes 6 can be further improved, eliminating dead zones in the shell side flow. In this case, the reaction stability and product yield of the tubular fixed-bed reactor are even more ideal.

[0120] Obviously, the above embodiments of this application are merely examples for clear illustration and are not intended to limit the implementation of this application. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A tubular fixed-bed reactor, comprising an upper end cover, a lower end cover, a shell-side cylinder disposed between the upper end cover and the lower end cover, an upper tube sheet disposed at the top of the shell-side cylinder, a lower tube sheet disposed at the bottom of the shell-side cylinder, and a plurality of reaction tubes disposed between the upper tube sheet and the lower tube sheet, wherein the upper end cover has a tube-side inlet, the lower end cover has a tube-side outlet, and the shell-side cylinder has a shell-side inlet and a shell-side outlet, characterized in that... The tubular fixed-bed reactor also includes: A gas distribution assembly, disposed inside the upper end cap and used to uniformly distribute the reactant gas at the inlet of the tube; and A lower distribution cylinder is located inside the shell-side cylinder and surrounds at least part of the outer periphery of the reaction tube; a plurality of flow holes are evenly distributed on the side wall of the lower distribution cylinder to evenly distribute the shell-side medium at the shell-side inlet.

2. The tubular fixed-bed reactor according to claim 1, characterized in that, The gas distribution component includes N flow guide shells and N flow guide plate groups, where N is a positive integer greater than 1; All N flow guide shells are cylindrical, and the inner diameter of each flow guide shell is set to increase along the air intake direction; the N flow guide shells are sequentially nested from the outside to the inside, and the inner diameter of the top surface and the inner diameter of the bottom surface of the N flow guide shells decrease from the outside to the inside; the innermost flow guide shell encloses to form a central flow guide channel connected to the tube inlet, and the two adjacent flow guide shells enclose to form a peripheral flow guide channel connected to the tube inlet; The N deflector groups are divided into a central deflector group and N-1 peripheral deflector groups; the central deflector group includes at least one central deflector, each of which extends spirally along the air intake direction and is arranged in the central deflector channel; the peripheral deflector groups are arranged one-to-one in the peripheral deflector channels, each of which includes at least one peripheral deflector, each of which extends spirally along the air intake direction.

3. The tubular fixed-bed reactor according to claim 2, characterized in that, All N flow guide shells are frustum-shaped, and are arranged coaxially around the central axis of the tube inlet with their top surfaces flush. The height of the N flow guide shells increases from the outside to the inside.

4. The tubular fixed-bed reactor according to claim 3, characterized in that, The extension lines of the generatrices of the N guide shells intersect the central axis of the tube inlet at the same point, and the difference between the apex angles of the two cones corresponding to two adjacent guide shells is the same as the apex angle value of the cone corresponding to the innermost guide shell; and / or, the set of extension lines of the generatrices of the outermost guide shells toward the upper tube sheet covers the inlets of all the reaction tubes on the upper tube sheet.

5. The tubular fixed-bed reactor according to claim 4, characterized in that, Each of the N flow guide shells corresponds to one of the N cones. The generatrix lengths of the N cones are all the same and are 1.5-2.0 times the inner diameter of the top surface of the outermost flow guide shell.

6. The tubular fixed-bed reactor according to any one of claims 3-5, characterized in that, The number of central guide plates in the central plate group is the same as the number of peripheral guide plates in each peripheral plate group, and both are n, where n is a positive integer greater than 1.

7. The tubular fixed-bed reactor according to claim 6, characterized in that, The n central guide plates are arranged at intervals around the central axis of the tube inlet and connected to each other on the central axis of the tube inlet. The side of each central guide plate facing away from the central axis of the tube inlet is connected to the innermost guide shell. Each peripheral guide plate in each peripheral guide channel is arranged at intervals around the central axis of the tube inlet and connected between two adjacent guide shells used to enclose the peripheral guide channel.

8. The tubular fixed-bed reactor according to claim 7, characterized in that, The n central guide plates in the central plate group and the n peripheral guide plates in each peripheral plate group are all rotationally symmetric structures with a rotation angle of 2π / n and a rotation axis of the central axis of the tube inlet.

9. The tubular fixed-bed reactor according to claim 8, characterized in that, The collection of all cross-sections of all the central guide vanes and all the peripheral guide vanes cut by the same plane perpendicular to the central axis of the tube inlet constitutes n line segment structures, and the n line segment structures extend radially outward from the same center point.

10. The tubular fixed-bed reactor according to any one of claims 3-5, characterized in that, Each central guide plate in the central plate group extends from the top surface flush to the bottom of the innermost guide shell, and each peripheral guide plate in each peripheral plate group extends from the top surface flush to the bottom of the two adjacent guide shells that enclose the peripheral guide channel corresponding to the peripheral plate group.

11. The tubular fixed-bed reactor according to any one of claims 2-5, characterized in that, The inlet of the tube is provided with a connecting fitting; the gas distribution assembly also includes a cylindrical extension section connected to the top of the outermost flow guide shell, the extension section is provided with a flow channel, the flow channel is connected to the inlet of the tube, the central flow guide channel and each of the peripheral flow guide channels respectively; the extension section is provided with a connector, the connector is fixedly installed on the connecting fitting.

12. The tubular fixed-bed reactor according to claim 1, characterized in that, The tubular fixed-bed reactor further includes an upper distribution cylinder, which is located inside the shell-side cylinder and surrounds at least part of the outer periphery of the reaction tube; the upper distribution cylinder is also uniformly provided with a plurality of flow holes for uniformly distributing the shell-side medium flowing to the shell-side outlet.

13. The tubular fixed-bed reactor according to claim 12, characterized in that, Both the upper distribution cylinder and the lower distribution cylinder have connecting ends; The connecting end of the lower distribution cylinder is located on the lower tube sheet. The lower distribution cylinder and the shell-side cylinder form a lower distribution cavity that communicates with the shell-side inlet. The plurality of flow holes on the lower distribution cylinder are all connected to the lower distribution cavity. The upper distribution cylinder is connected to the upper tube sheet. The upper distribution cylinder and the shell-side cylinder form an upper distribution cavity that communicates with the shell-side outlet. The plurality of flow holes on the upper distribution cylinder are all connected to the upper distribution cavity.

14. The tubular fixed-bed reactor according to claim 13, characterized in that, The upper distribution cylinder and the lower distribution cylinder each have an extended end opposite to their respective connecting ends; The shell-side inlet is directly opposite the side peripheral wall of the lower distribution cylinder, and the distance between the outer end face of the extended end of the lower distribution cylinder and the center of the shell-side inlet is the inner diameter of the shell-side inlet; and / or, The shell-side outlet is directly opposite the side wall of the upper distribution cylinder, and the distance between the outer end face of the outer extension end of the upper distribution cylinder and the center of the shell-side outlet is the inner diameter of the shell-side outlet.

15. The tubular fixed-bed reactor according to claim 13, characterized in that, The upper distribution cylinder and the lower distribution cylinder each have multiple drainage notches formed at the circumferential edges of their respective connecting ends.

16. The tubular fixed-bed reactor according to claim 12, characterized in that, The inner circumferential walls of both the upper and lower distribution cylinders abut against the outermost reaction tube.

17. The tubular fixed-bed reactor according to any one of claims 12-16, characterized in that, The plurality of flow holes on the upper distribution cylinder are arranged in at least one row along the circumference of the upper distribution cylinder, and the plurality of flow holes on the lower distribution cylinder are arranged in at least one row along the circumference of the lower distribution cylinder; the flow holes in each row are arranged at equal intervals, and / or the positions of adjacent rows of flow holes are staggered.

18. The tubular fixed-bed reactor according to claim 17, characterized in that, The number of flow-through holes in each row on the lower distribution cylinder is not less than four times the number of shell-side inlets; and / or, the number of flow-through holes in each row on the upper distribution cylinder is not less than four times the number of shell-side outlets; and / or, The sum of the flow areas of the plurality of flow holes on the lower distribution cylinder is not less than twice the sum of the flow areas of the shell-side inlet; and / or, the sum of the flow areas of the plurality of flow holes on the upper distribution cylinder is not less than twice the sum of the flow areas of the shell-side outlet; and / or, The nominal diameters of both the shell-side inlet and the shell-side outlet are 350 mm; and / or, The number of shell-side inlets and shell-side outlets are both 2-4.

19. The tubular fixed-bed reactor according to any one of claims 13-15, characterized in that, The tubular fixed-bed reactor further includes a lower baffle plate, which is disposed between the lower distribution cylinder and the shell-side cylinder to enclose and form the lower distribution cavity; and / or The tubular fixed-bed reactor also includes an upper baffle plate, which is disposed between the upper distribution cylinder and the shell-side cylinder to enclose and form the upper distribution cavity.

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