Catalyst fixing mechanism and tubular and tubular fixed bed reactors using same

Abstract

The utility model discloses a catalyst fixing mechanism and tubular and tubular fixed bed reactors using the same, and relates to the technical field of fixed bed reactors, the catalyst fixing mechanism comprises double-helix main fixing frames, a plurality of supports used for fixing catalysts are connected between the two main fixing frames, and the supports are connected with the fixed bed reactors. The main fixing frame is provided with a plurality of diversion branch strips, the catalyst fixing mechanism can stably and uniformly fix a catalyst, and a tubular fixed bed reactor and a tubular fixed bed reactor using the fixing mechanism are provided, so that the problem of non-uniform catalyst distribution of the fixed bed reactor needing to be filled with the catalyst in the prior art can be solved, and the catalytic efficiency is obviously improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fixed bed reactors, in particular to a catalyst fixing mechanism and a tubular fixed bed reactor using the same. Background Art

[0002] In the chemical industry, tubular fixed-bed reactors, also known as packed-bed reactors, are often used. These reactors are loaded with solid catalysts or solid reactants to carry out multiphase reactions. The solids are typically granular, with a diameter of approximately 2 to 15 mm, and are deposited into a bed of a certain height (or thickness). The bed remains stationary, while the fluid passes through it to carry out the reaction. This differs from fluidized and moving-bed reactors in that the solid particles remain stationary. Fixed-bed reactors are primarily used for gas-solid catalytic reactions, such as ammonia synthesis towers, sulfur dioxide contact oxidizers, and hydrocarbon steam reformers. For non-catalytic gas-solid or liquid-solid reactions, the bed is filled with solid reactants. Trickle-bed reactors can also be classified as fixed-bed reactors, where gas and liquid phases flow concurrently downward through the bed, forming gas-liquid-solid contact. For example, patent application number "201210371631.5," published on January 9, 2013, proposes a tubular fixed-bed reactor.

[0003] However, existing fixed-bed reactors, particularly when loaded with catalyst, often suffer from uneven catalyst distribution and suboptimal reaction efficiency. This is particularly true in industrial production where catalyst raw material costs are high. Low catalyst utilization or excessive catalyst losses can increase production costs, complicate subsequent processing, and impact product quality stability.

[0004] Therefore, technical personnel in this industry are still constantly exploring and considering making improvements in the equipment used in production and product process optimization in order to improve production efficiency and reduce production costs. Utility Model Content

[0005] The utility model aims to solve the problems of uneven catalyst distribution and low catalytic efficiency in fixed-bed reactors that need to be filled with catalysts in the prior art, and proposes a catalyst fixing mechanism and a tubular and tube-type fixed-bed reactor using the fixing mechanism.

[0006] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present utility model is as follows:

[0007] The catalyst fixing mechanism comprises a main fixing frame in a double helical shape, a plurality of brackets for fixing the catalyst are connected between the two main fixing frames, and a plurality of guide bars are arranged on the main fixing frames.

[0008] Furthermore, the distal end of the guide branch faces outward.

[0009] Furthermore, the guide branches are evenly distributed.

[0010] Furthermore, adjacent guide branches are arranged in a staggered manner, and the guide branches are welded to the main fixing frame, or the guide branches are connected to the main fixing frame through a threaded structure.

[0011] Furthermore, the support is a mesh or oblique strip structure; the distance between adjacent guide strips is 2 to 8 mm.

[0012] A tubular fixed bed reactor using the above-mentioned catalyst fixing mechanism comprises a shell and a plurality of reaction tubes. The shell is provided with a feed port at the top and a discharge port at the bottom. The upper and lower ends of the reaction tubes are fixed in the shell via an upper tube plate and a lower tube plate, respectively. A chamber for passing the medium is formed between the shell and the reaction tubes, the upper tube plate and the lower tube plate. An inlet communicating with the chamber is provided at the bottom of the shell; an outlet communicating with the chamber is provided at the top of the shell. The catalyst fixing mechanism is built into the reaction tubes.

[0013] Furthermore, the inner diameter of the reaction tube is set to 30-50 mm, and the guide bar is in contact with the inner wall of the reaction tube.

[0014] Furthermore, a pressure sensor I and a temperature sensor I are provided on the shell near the feed port; a pressure sensor II, a temperature sensor II and a liquid level sensor are provided on the shell near the discharge port.

[0015] A tubular fixed-bed reactor using the aforementioned catalyst fixing mechanism comprises a tubular main body, wherein a plurality of reaction tubes are connected in series via pipelines in the tubular main body, the reaction tubes are equipped with a catalyst fixing mechanism, the first reaction tube is connected to the feed port I of the tubular main body, and the tail end of the last reaction tube is connected to the discharge port I of the tubular main body.

[0016] Furthermore, a plurality of temperature sensors III are provided on the tubular body; the temperature sensors III are distributed in the first section, the middle section and the tail section of the tubular body.

[0017] Beneficial effects of the utility model:

[0018] 1. In the present invention, a novel catalyst fixing mechanism is proposed, including a main fixing frame in a double helical shape, a number of brackets for fixing the catalyst are connected between the two main fixing frames, and a number of guide branches are provided on the main fixing frames. The catalyst fixing mechanism can be applied to a shell-and-tube fixed bed reactor and a tubular fixed bed reactor. In particular, for reactions in which the raw material is gas phase and the product is liquid phase, the reaction efficiency can be greatly improved. The main reason is that: the catalyst is fixed on the catalyst fixing mechanism in a double helical shape. When the raw gas passes through the catalyst fixing mechanism fixed with the catalyst, the raw gas can form a turbulent flow, which makes the contact with the catalyst more sufficient. At the same time, the liquid phase product flows in the expected direction along the guide branches connected to the main fixing frame, avoiding the liquid phase product covering the catalyst for a long time and causing the catalytic efficiency to decrease. At the same time, the guide branches transfer the main product in time, which can avoid the main product participating in other reactions and producing other by-products.

[0019] Second, in the present invention, the distal ends of the diversion branches face outward, facilitating timely transfer of product liquid. Preferably, the diversion branches are evenly distributed. Adjacent diversion branches are staggered for optimal diversion. The diversion branches can be welded to the main mounting frame or connected to the main mounting frame via a threaded structure.

[0020] In this utility model, the bracket serves as a catalyst holder and can be designed as a mesh or diagonal strip structure, facilitating catalyst retention while leaving ample space for the feed gas to flow smoothly. Preferably, the bracket can be designed as a removable small module fixed to the main bracket to facilitate catalyst loading. A single main bracket can accommodate a varying number of small modules as needed. Adjacent guide strips should ideally be spaced 2-8 mm apart.

[0021] 4. In the present invention, a preferred shell-and-tube fixed-bed reactor and a tubular fixed-bed reactor are also proposed. The catalyst fixing mechanism with a specific structure mentioned above is installed in the reaction tube of the reactor. The catalyst fixing mechanism has a double-helical main fixing frame, which can enhance the mixing mass transfer and heat transfer of materials in the reactor, make the material mixing more uniform, make the raw materials fully contact with the catalyst, improve the conversion rate, reduce local thermal effects, and significantly improve the selectivity of the reaction. The catalyst fixing mechanism is placed in the reaction tube for easy replacement.

[0022] Fifth, in this utility model, the upper and lower ends of the reaction tubes in the tubular fixed-bed reactor are fixed within the shell via upper and lower tube sheets, respectively. A chamber for medium flow is formed between the shell, the reaction tubes, and the upper and lower tube sheets. The reaction temperature within the reactor can be controlled by introducing thermal oil into the chamber, providing stable reaction temperature conditions. The entire structure is also easy to disassemble and assemble. During operation, the catalyst can be first secured to a bracket (or the aforementioned "small module"), and then the entire catalyst securing mechanism can be directly placed into the reaction tubes. This significantly improves catalyst replacement efficiency and reduces risks during production.

[0023] 6. In the present invention, the inner diameter of the reaction tube in the tubular fixed bed reactor is preferably set to 30-50 mm. When designing the catalyst fixing mechanism, its maximum diameter is the same as the inner diameter of the reaction tube (so that the guide branch just contacts the inner wall of the reaction tube). The catalyst fixing mechanism is in the form of a long strip and is placed vertically downward into the interior of the reaction tube. Preferably, only one matching catalyst fixing mechanism is placed in each reaction tube.

[0024] 7. In the present invention, a pressure sensor I and a temperature sensor I are provided on the shell of the tubular fixed bed reactor near the feed port side, which are used to monitor the pressure and temperature of the upper part of the reactor; a pressure sensor II and a temperature sensor II are provided on the shell near the discharge port side, which are used to monitor the pressure and temperature of the bottom of the reactor; a liquid level sensor is provided on the reactor to assist in controlling the discharge rate.

[0025] 8. The present invention innovatively proposes a tubular fixed-bed reactor, in which a plurality of reaction tubes are connected in series through pipelines in the tubular body, which can significantly prolong the residence time of the reactants in the tubular body and improve the reaction efficiency.

[0026] 9. In the present invention, temperature sensors III are distributed in the first section, middle section and tail section of the tubular body to monitor the temperature of each point in the reactor to ensure that the reaction proceeds normally and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the catalyst fixing mechanism.

[0028] Figure 2 It is a structural schematic diagram of a shell-and-tube fixed bed reactor.

[0029] Figure 3 It is a structural schematic diagram of another embodiment of a shell and tube fixed bed reactor.

[0030] Figure 4 It is a structural schematic diagram of a tubular fixed bed reactor.

[0031] Figure 5 It is a structural schematic diagram of another embodiment of a tubular fixed bed reactor.

[0032] Among them, 1. Main fixing frame; 2. Bracket; 3. Guide branch; 4. Shell; 5. Reaction tube; 6. Feed port; 7. Discharge port; 8. Upper tube plate; 9. Lower tube plate; 10. Chamber; 11. Inlet; 12. Outlet; 13. Pressure sensor I; 14. Temperature sensor I; 15. Pressure sensor II; 16. Temperature sensor II; 17. Liquid level sensor; 18. Tubular body; 19. Feed port I; 20. Discharge port I; 21. Temperature sensor III; 100. Catalyst fixing mechanism. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto.

[0034] Example 1

[0035] This embodiment is the most basic implementation method, the catalyst fixing mechanism, refer to Figure 1 , including a main fixing frame 1 in a double helical shape, a plurality of brackets 2 for fixing the catalyst are connected between the two main fixing frames 1, and a plurality of guide branches 3 are arranged on the main fixing frames 1.

[0036] Preferably, the distal end of the guide branch 3 faces outward.

[0037] Preferably, the guide branches 3 are evenly distributed.

[0038] Example 2

[0039] This embodiment is a further optimization of embodiment 1, the difference being that:

[0040] Adjacent guide branches 3 are arranged in a staggered manner. The guide branches 3 are welded to the main fixing frame 1 , or the guide branches 3 are connected to the main fixing frame 1 through a threaded structure.

[0041] Example 3

[0042] This embodiment is a further optimization of embodiment 1, the difference being that:

[0043] The support 2 is a mesh or oblique strip structure. Figure 1 , Figure 1 The bracket 2 is an oblique strip structure; the adjacent guide strips 3 are 2~8mm apart.

[0044] Example 4

[0045] A tubular fixed bed reactor, which relates to the technical field of fixed bed reactors, comprises a shell 4 and a plurality of reaction tubes 5. Figure 2The shell 4 is provided with a feed port 6 at the top and a discharge port 7 at the bottom. The upper and lower ends of the reaction tube 5 are fixed in the shell 4 through an upper tube plate 8 and a lower tube plate 9 respectively. A chamber 10 for passing the medium is formed between the shell 4 and the reaction tube 5, the upper tube plate 8 and the lower tube plate 9. The lower part of the shell 4 is provided with an inlet 11 connected to the chamber 10; the upper part of the shell 4 is provided with an outlet 12 connected to the chamber 10. The reaction tube 5 has a built-in catalyst fixing mechanism 100.

[0046] In this embodiment, the catalyst fixing mechanism 100 includes a main fixing frame 1 in a double helical shape. Figure 1 A number of brackets 2 for fixing the catalyst are connected between the two main fixing frames 1, and a number of guide bars 3 are provided on the main fixing frames 1.

[0047] In this embodiment, the distal ends of the guide branches 3 face outwards, and the guide branches 3 are evenly distributed.

[0048] Example 5

[0049] The difference between this embodiment and embodiment 4 is that:

[0050] The inner diameter of the reaction tube 5 is preferably set to 30-50 mm. When designing the catalyst fixing mechanism 100, its maximum diameter is preferably the same as the inner diameter of the reaction tube 5, even if the guide branch 3 contacts the inner wall of the reaction tube 5. The catalyst fixing mechanism 100 is in the form of a long strip and is vertically placed downwardly into the interior of the reaction tube 5. Figure 1 or Figure 2 .

[0051] Example 6

[0052] Compared with Examples 4-5, this embodiment differs in that:

[0053] refer to Figure 3 The shell 4 of the tubular fixed-bed reactor is equipped with a pressure sensor I 13 and a temperature sensor I 14 near the feed port 6. A pressure sensor II 15, a temperature sensor II 16, and a liquid level sensor 17 are also installed near the discharge port 7. Pressure sensor I 13 and temperature sensor I 14 are used to monitor the pressure and temperature at the top of the reactor, respectively. Pressure sensor II 15 and temperature sensor II 16 are used to monitor the pressure and temperature at the bottom of the reactor. The liquid level sensor 17 provided on the reactor is used to assist in controlling the discharge rate.

[0054] Example 7

[0055] A tubular fixed bed reactor, relating to the technical field of fixed bed reactors, comprises a tubular body 18, wherein a plurality of reaction tubes 5 are connected in series via a pipeline in the tubular body 18, wherein the reaction tube 5 is provided with a catalyst fixing mechanism 100, Figure 4 , Figure 4The diagram shows a structure in which two reaction tubes 5 are connected in series within tubular body 18. The first reaction tube 5 is connected to feed port I 19 of tubular body 18, and the tail end of the second reaction tube 5 is connected to discharge port I 20 of tubular body 18. The serial connection of multiple reaction tubes 5 within tubular body 18 significantly prolongs the residence time of reactants within tubular body 18 and improves reaction efficiency.

[0056] In this embodiment, the catalyst fixing mechanism 100 includes a main fixing frame 1 in a double helical shape. Figure 1 A plurality of brackets 2 for fixing the catalyst are connected between the two main fixing frames 1, and a plurality of guide branches 3 are provided on the main fixing frames 1. The distal ends of the guide branches 3 face outwards, and the guide branches 3 are evenly distributed.

[0057] Example 8

[0058] The difference between this embodiment and embodiment 7 is that:

[0059] The tubular body 18 is provided with a plurality of temperature sensors III 21. Preferably, the temperature sensors III 21 are distributed in the first section, the middle section and the tail section of the tubular body 18. Figure 5 .

[0060] Example 9

[0061] Compared with Examples 7-8, this embodiment differs in that:

[0062] The inner diameter of the reaction tube 5 in the tubular fixed bed reactor is preferably set to 30-50 mm, and the guide branch 3 is in contact with the inner wall of the reaction tube 5 .

Claims

1. Catalyst fixing mechanism, characterized by: It comprises a main fixing frame (1) in a double helical shape, a plurality of supports (2) for fixing the catalyst are connected between the two main fixing frames (1), and a plurality of guide bars (3) are arranged on the main fixing frames (1).

2. The catalyst fixing mechanism according to claim 1, characterized in that: The distal end of the guide branch (3) faces outward.

3. The catalyst fixing mechanism according to claim 1, characterized in that: The guide branches (3) are evenly distributed.

4. The catalyst fixing mechanism according to claim 1, characterized in that: Adjacent guide branches (3) are arranged in a staggered manner, and the guide branches (3) are welded to the main fixing frame (1), or the guide branches (3) are connected to the main fixing frame (1) via a threaded structure.

5. The catalyst fixing mechanism according to claim 1, characterized in that: The support (2) is a mesh or oblique strip structure; adjacent diversion strips (3) are 2 to 8 mm apart.

6. A tubular fixed bed reactor using the catalyst fixing mechanism according to claim 1, characterized in that: The invention comprises a shell (4) and a plurality of reaction tubes (5). The shell (4) is provided with a feed port (6) at the top and a discharge port (7) at the bottom. The upper and lower ends of the reaction tubes (5) are fixed in the shell (4) via an upper tube plate (8) and a lower tube plate (9), respectively. A chamber (10) for passing a medium is formed between the shell (4), the reaction tubes (5), the upper tube plate (8), and the lower tube plate (9). The lower portion of the shell (4) is provided with an inlet (11) communicating with the chamber (10); the upper portion of the shell (4) is provided with an outlet (12) communicating with the chamber (10). The reaction tubes (5) are provided with a built-in catalyst fixing mechanism (100).

7. The tubular fixed bed reactor according to claim 6, characterized in that: The inner diameter of the reaction tube (5) is set to 30-50 mm, and the guide strip (3) is in contact with the inner wall of the reaction tube (5).

8. The tubular fixed bed reactor according to claim 6, characterized in that: A pressure sensor I (13) and a temperature sensor I (14) are provided on the housing (4) near the feed port (6); a pressure sensor II (15), a temperature sensor II (16) and a liquid level sensor (17) are provided on the housing (4) near the discharge port (7).

9. A tubular fixed-bed reactor using the catalyst fixing mechanism according to claim 1, characterized in that: The invention comprises a tubular body (18), wherein a plurality of reaction tubes (5) are connected in series via a pipeline in the tubular body (18), the reaction tubes (5) are provided with a catalyst fixing mechanism (100), the first reaction tube (5) is connected to a feed port I (19) of the tubular body (18), and the tail of the last reaction tube (5) is connected to a discharge port I (20) of the tubular body (18).

10. The tubular fixed-bed reactor according to claim 9, characterized in that: A plurality of temperature sensors III (21) are provided on the tubular body (18); the temperature sensors III (21) are distributed in the first section, the middle section and the tail section of the tubular body (18).

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