An inlet structure for a liquid metal catalytic cracking natural gas to hydrogen production unit

Abstract

This invention discloses an inlet structure for a liquid metal catalytic cracking natural gas hydrogen production device, comprising an inlet pipe and a gas distribution structure. The gas distribution structure includes a first gas chamber, several first gas channels, a second gas chamber, and several second gas channels. The outlet end of the inlet pipe is connected to the bottom of the first gas chamber. Several first gas channels are evenly distributed in the gas distribution structure, and their bottoms are connected to the tops of the first gas chambers. The bottoms of the second gas chambers are connected to the tops of the several first gas channels. Several second gas channels are evenly distributed in the gas distribution structure, and their bottoms are connected to the tops of the second gas chambers, with the tops extending to the upper surface of the gas distribution structure to form exhaust ports. This invention's inlet structure, through the two-stage porous structure and gas channels, enables the natural gas to be sufficiently and evenly distributed before entering the liquid metal, effectively avoiding the problem of uneven gas dispersion and improving the uniformity, stability, and efficiency of the reaction.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen production equipment technology, and in particular to an air inlet structure for a liquid metal catalytic cracking natural gas hydrogen production device. Background Technology

[0002] Molten metal cracking of methane, a newly emerging hydrogen production technology in recent years, operates on the core principle of catalytic cracking of methane in high-temperature liquid metal to directly generate hydrogen and solid carbon without producing carbon dioxide. This technology is considered a green alternative to traditional methane steam reforming for hydrogen production and has attracted significant attention in the context of carbon neutrality. It effectively solves the problems of high energy consumption, low conversion rate, and catalyst deactivation associated with traditional methane thermal or catalytic cracking, avoiding the high carbon emissions of methane steam reforming for hydrogen production. Furthermore, it produces value-added carbon products simultaneously with hydrogen production, thus garnering widespread attention.

[0003] This technology introduces natural gas into a molten medium, where it comes into contact with a catalyst at high temperatures, achieving a highly efficient pyrolysis reaction. The molten medium possesses good thermal stability and conductivity, providing a uniform reaction environment and extending the catalyst's lifespan.

[0004] However, existing molten medium catalytic cracking devices have shortcomings in their gas inlet design, resulting in insufficient gas flow, uneven gas distribution, and localized overheating, affecting the stability and efficiency of the reaction. To address this, a patent titled "A Liquid Metal High-Temperature Cracking Methane Hydrogen Production System" (patent number ZL202110242946.9) incorporates a conical distributor with uniformly distributed vents, allowing methane gas to enter the tank and diffuse during its ascent, ensuring sufficient contact with liquid tin. However, because the entire distributor, except for the inlet pipe which is connected to the tank exterior, is submerged within the liquid metal of the tank, it is prone to short service life and uneven gas dispersion. Therefore, improvements are necessary. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an air intake structure for a liquid metal catalytic cracking natural gas to hydrogen production device, so as to optimize the air intake structure, improve the uniformity of gas entering the molten medium, and extend the service life.

[0006] The technical solution adopted by this utility model to solve its technical problem is: to provide an air intake structure for a liquid metal catalytic cracking natural gas to hydrogen production device, which includes an air intake pipe and a gas distribution structure;

[0007] The air distribution structure is provided with a first air chamber, several first air channels, a second air chamber, and several second air channels.

[0008] The air outlet of the air inlet pipe is connected to the bottom of the first air chamber;

[0009] Several first air passages are evenly distributed in the air distribution structure, and their bottoms are connected to the top of the first air chamber.

[0010] The bottom of the second air chamber is connected to the top of several of the first air passages;

[0011] Several second air passages are evenly distributed in the air distribution structure, with their bottoms connected to the tops of the second air chambers, and their tops extending to the upper surface of the air distribution structure to form exhaust ports.

[0012] Furthermore, a first porous structure is provided in the first air chamber, and the upper surface of the first porous structure covers the bottom of several first air passages.

[0013] The second air chamber is provided with a second porous structure, and the lower surface of the first porous structure covers the top of several first air passages, and the upper surface covers the bottom of several second air passages.

[0014] Furthermore, the gas distribution structure is divided into a first gas distribution structure and a second gas distribution structure;

[0015] The first air chamber is located at the bottom of the first air distribution structure, and a plurality of the first air channels are evenly distributed in the first air distribution structure.

[0016] The second air chamber is formed by joining the top of the first air distribution structure and the bottom of the second air distribution structure together, and several second air channels are evenly distributed in the second air distribution structure.

[0017] Furthermore, a radial limiting structure is formed between the top of the first air distribution structure and the bottom of the second air distribution structure through a concave-convex structure.

[0018] Furthermore, the joint between the top of the first air distribution structure and the bottom of the second air distribution structure is filled with a high-temperature resistant sealing material.

[0019] Furthermore, the first air distribution structure is a frustum-shaped structure, the first air passage is a slit structure, and a number of the first slits are evenly distributed around the central axis of the first air distribution structure and are distributed in a spoke-like pattern on the radial cross-section.

[0020] Furthermore, the first slit has a rectangular structure with a length of 35 mm and a width of 1.5 mm in the radial cross-section.

[0021] Furthermore, the second air distribution structure is a frustum-shaped structure, and the second air passage includes two types of air passages: a circular hole structure and a slit structure, namely a straight through hole and a second slit; a plurality of the straight through holes are arranged on at least two concentric rings distributed around the central axis of the first air distribution structure, and the straight through holes located on the same concentric ring are distributed in a equidistant manner; a plurality of the second slits are arranged around the straight through holes, and the plurality of the second slits are evenly distributed around the central axis of the second air distribution structure and are distributed in a spoke-like manner on the radial cross-section.

[0022] Furthermore, the number of concentric rings is four, the spacing between adjacent concentric rings is 4mm, and the diameter of the through hole is 0.4mm; the second slit has a rectangular structure with a length of 25mm and a width of 0.4mm in the radial cross-section.

[0023] Furthermore, the porosity of the first porous structure and the second porous structure is 75%.

[0024] The beneficial effects of this utility model are as follows:

[0025] The gas inlet structure of this invention, through the arrangement of a two-stage porous structure and gas channels, enables natural gas to be fully and evenly distributed before entering the liquid metal, effectively avoiding the problem of uneven gas dispersion and improving the uniformity, stability and efficiency of the reaction. At the same time, since the gas inlet structure of this invention is top-outlet, it can be installed outside the bottom of the pyrolysis furnace body during installation, avoiding prolonged contact with the liquid metal inside the pyrolysis furnace body, and extending the service life of the gas distribution structure. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the air intake structure provided by this utility model;

[0027] Figure 2 Is Figure 1 The structural diagram after concealing the first and second porous structures on the basis;

[0028] Figure 3 yes Figure 1 Top view of the first gas distribution structure in the middle;

[0029] Figure 4 yes Figure 1 Top view of the second gas distribution structure in the middle;

[0030] Figure 5 This is a dimensional structural diagram of the first or second slit in the radial section of this utility model;

[0031] Figure 6This is a dimensional structural diagram of the first or second porous structure in the present invention on the axial cross section.

[0032] Figure 7 This is a diagram illustrating the application of the air intake structure provided by this utility model. Detailed Implementation

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

[0034] See Figures 1 to 4 This utility model provides an air intake structure for a liquid metal catalytic cracking natural gas to hydrogen production device, including an air intake pipe 100 and an air distribution structure 200.

[0035] See Figure 1 and Figure 2 The intake pipe 100 is used to introduce natural gas into the entire gas distribution structure 200. The gas distribution structure 200 is the core component of the entire intake structure. Its interior, arranged sequentially along the airflow direction, includes a first gas chamber 2a, several first gas passages, a second gas chamber 2b, and several second gas passages. (See [reference]). Figure 2 The air outlet of the air inlet pipe 100 is connected to the bottom of the first air chamber 2a inside the air distribution structure 200.

[0036] See Figure 1 and Figure 2 A first porous structure 2c is provided inside the first gas chamber 2a, and the upper surface of the first porous structure 2c covers the bottom of several first gas channels. The first porous structure 2c plays a role in initially distributing the natural gas evenly. Several first gas channels are evenly distributed in the gas distribution structure 200, and their bottoms are connected to the top of the first gas chamber 2a, so that the natural gas coming out of the first porous structure 2c can enter each of the first gas channels evenly.

[0037] See Figure 1 and Figure 2 A second porous structure 2d is provided within the second gas chamber 2b, with its lower surface covering the tops of several first gas channels and its upper surface covering the bottoms of several second gas channels. The several second gas channels are evenly distributed within the gas distribution structure 200, with their bottoms connected to the tops of the second gas chamber 2b and their tops extending to the upper surface of the gas distribution structure 200 to form exhaust ports. During operation, the natural gas exiting the second porous structure 2d can evenly enter each of the second gas channels.

[0038] The first porous structure 2c and the second porous structure 2d have a porosity of 75%. Through the filtering and dispersing effect of the porous structure, the natural gas can be more evenly distributed when flowing through the gas chamber and gas passage, reducing the possibility of excessive local airflow. The first porous structure 2c and the second porous structure 2d can be made of the same material as the permeable brick. Permeable brick is an important refractory material with good refractory performance and air permeability. It is mainly made of tabular corundum (mainly composed of alumina), spinel, chromium oxide and other materials through molding and firing. It has the characteristics of high strength, corrosion resistance and good air permeability, which can meet the above requirement of a porosity of 75%, so that the natural gas can be evenly distributed and dispersed when it passes through.

[0039] In a preferred embodiment, such as Figure 1 and Figure 2 As shown, for ease of manufacturing, the gas distribution structure 200 is divided into a first gas distribution structure 210 and a second gas distribution structure 220. The first gas distribution structure 210 has a frustum-shaped structure, with a first air chamber 2a located at the bottom of the first gas distribution structure 210, and several first air channels evenly distributed within the first gas distribution structure 210. The second gas distribution structure 220 also has a frustum-shaped structure, with several second air channels evenly distributed within the second gas distribution structure 220. The second air chamber 2b is formed by joining the top of the first gas distribution structure 210 and the bottom of the second gas distribution structure 220. To ensure the stability of the joining, a coaxial concave-convex structure forms a radial constraint between the top of the first gas distribution structure 210 and the bottom of the second gas distribution structure 220, and the joint is filled with a high-temperature resistant sealing material to prevent gas leakage.

[0040] During the manufacturing process, the first air distribution structure 210 and the second air distribution structure 220 are processed separately, and then the two are joined together by a concave-convex structure (filled with high-temperature resistant sealing material during the joining process) to form a complete air distribution structure 200.

[0041] The first gas distribution structure 210 and the second gas distribution structure 220 are mainly made of alumina. The high-temperature resistant sealing material can be a high-temperature resistant coating, such as the high-temperature resistant coating XZ-T001 produced by Hefei Xiangzheng Chemical Technology Co., Ltd. This coating can also be used as a high-temperature resistant adhesive to connect the joint of the first gas distribution structure 210 and the second gas distribution structure 220, and can withstand temperatures of 1200℃ or even higher.

[0042] In a preferred embodiment, see Figure 3 The first air passage has a slit structure, which is the first slit 2e. Several first slits 2e are evenly distributed around the central axis of the first air distribution structure 210 and are distributed in a spoke-like pattern on the radial cross section.

[0043] Preferably, the first slit 2e has a rectangular structure with a length of 35 mm and a width of 1.5 mm in the radial cross-section, i.e., see [reference needed]. Figure 5 In the figure, L = 35mm and W = 1.5mm.

[0044] In a preferred embodiment, see Figure 4 The second gas channel includes two types of channels: a circular hole structure and a slit structure, namely a straight through-hole 2f and a second slit 2g. A plurality of straight through-holes 2f are arranged on at least two concentric rings distributed around the central axis of the first gas distribution structure 210, with the straight through-holes 2f on the same concentric ring distributed at equal intervals. A plurality of second slits 2g are arranged around the periphery of the straight through-holes 2f, uniformly distributed around the central axis of the second gas distribution structure 220 and arranged in a spoke-like pattern in the radial cross-section. This design aims to further optimize the distribution of natural gas, ensuring better dispersion uniformity when it enters the liquid metal reaction zone.

[0045] Preferred, such as Figure 4 As shown, there are four concentric rings, with a spacing of 4 mm between adjacent rings, and the diameter of the through hole 2f is 0.4 mm. The second slit 2g has a rectangular structure with a length of 25 mm and a width of 0.4 mm in the radial cross-section, as shown in the figure. Figure 5 In the figure, L = 25 mm and W = 0.4 mm.

[0046] In a preferred embodiment, see Figure 6 The dimensions of the first porous structure 2c and the second porous structure 2d are: diameter D4 = 110 mm and height H = 20 mm.

[0047] See Figure 3 The distance D3 between the outermost edges of the two relatively distributed first slits 2e is 90 mm. (See also...) Figure 4 The distance between the outermost edges of the two relatively distributed second slits 2g is D1 = 90 mm.

[0048] Of course, the second gas channel is not limited to the above structure. The second gas channel can also be set as a uniformly distributed circular hole structure without the slit structure. This can also achieve the purpose of improving the uniformity of natural gas dispersion. However, such a structure is much more difficult to process. Therefore, it is preferable to use the above two gas channel structures with a circular hole structure in the inner layer and a slit structure in the outer layer. This can reduce the processing difficulty while ensuring the dispersion effect of natural gas.

[0049] During installation, please refer to Figure 7 As shown, the gas distribution structure 200 of this utility model is installed below the pyrolysis furnace body 300. The gas inlet end of the gas inlet pipe 100 is connected to the natural gas cylinder 400. A valve 510, a pressure gauge 520 and a flow meter 520 are arranged sequentially on the gas inlet pipe 100 along the airflow direction.

[0050] The working principle of the air intake structure of this utility model is as follows:

[0051] Intake phase:

[0052] When valve 510 is opened, the natural gas in gas cylinder 400 is introduced into gas distribution structure 200 through gas inlet pipe 100; among them, pressure gauge 520 and flow meter 520 are used to monitor natural gas pressure and flow rate, respectively.

[0053] Initial gas distribution stage:

[0054] After natural gas enters the first gas chamber 2a, the first porous structure 2c in the first gas chamber 2a plays a role in initially distributing the natural gas evenly, so that the natural gas can be evenly distributed before entering the subsequent first slit 2e; when the natural gas flows through the first slit 2e, it can be more evenly dispersed, avoiding excessive local airflow.

[0055] Secondary gas distribution stage:

[0056] After the natural gas flows out from the first slit 2e, it enters the second gas chamber 2b. The second porous structure 2d in the second gas chamber 2b further distributes the natural gas, making it more uniform before entering the second gas passage. Then, the natural gas enters the subsequent straight hole 2f and the second slit 2g. The straight hole 2f and the second slit 2g enhance the uniformity of natural gas dispersion, allowing the outflowing natural gas bubbles 700 to enter the liquid metal 600 in the pyrolysis furnace body 300 evenly and fully contact and react with the liquid metal 600.

[0057] The gas inlet structure of this invention, through its two-stage porous structure and gas channels, ensures that natural gas is evenly distributed before entering the liquid metal, effectively avoiding uneven gas dispersion and improving reaction stability and efficiency. Furthermore, because the gas inlet structure is top-exit, it can be installed outside the bottom of the pyrolysis furnace body 300, avoiding prolonged contact with the liquid metal inside the furnace and extending the service life of the gas distribution structure.

[0058] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant, characterized by, Includes an intake pipe (100) and an air distribution structure (200); The air distribution structure (200) is provided with a first air chamber (2a), a plurality of first air channels, a second air chamber (2b), and a plurality of second air channels; The air outlet of the air inlet pipe (100) is connected to the bottom of the first air chamber (2a); Several first air passages are evenly distributed in the air distribution structure (200), and their bottoms are connected to the top of the first air chamber (2a); The bottom of the second air chamber (2b) is connected to the top of several of the first air passages; Several second air passages are evenly distributed in the air distribution structure (200), and the bottom of the second air passage is connected to the top of the second air chamber (2b), and the top extends to the upper surface of the air distribution structure (200) to form an exhaust port.

2. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen device according to claim 1, characterized in that, The first air chamber (2a) is provided with a first porous structure (2c), and the upper surface of the first porous structure (2c) covers the bottom of several first air passages; The second air chamber (2b) is provided with a second porous structure (2d), and the lower surface of the first porous structure (2c) covers the top of a plurality of first air passages, and the upper surface covers the bottom of a plurality of second air passages.

3. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen device according to claim 2, characterized in that, The gas distribution structure (200) is divided into a first gas distribution structure (210) and a second gas distribution structure (220). The first air chamber (2a) is located at the bottom of the first air distribution structure (210), and a plurality of the first air channels are evenly distributed in the first air distribution structure (210); The second air chamber (2b) is formed by joining the top of the first air distribution structure (210) and the bottom of the second air distribution structure (220), and a number of second air channels are evenly distributed in the second air distribution structure (220).

4. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen device according to claim 3, characterized in that, A radial constraint is formed between the top of the first air distribution structure (210) and the bottom of the second air distribution structure (220) by means of a concave-convex structure.

5. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 3, wherein, The joint between the top of the first air distribution structure (210) and the bottom of the second air distribution structure (220) is filled with a high-temperature resistant sealing material.

6. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 3, wherein, The first air distribution structure (210) is a frustum-shaped structure, and the first air passage is a slit structure, which is the first slit (2e); a plurality of the first slits (2e) are evenly distributed around the central axis of the first air distribution structure (210) and the plurality of the first slits (2e) are distributed in a spoke-like manner on the radial cross section.

7. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 6, wherein, The first slit (2e) has a rectangular structure with a length of 35 mm and a width of 1.5 mm in the radial cross section.

8. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 3, wherein, The second air distribution structure (220) is a frustum-shaped structure. The second air passage includes two types of air passages: a circular hole structure and a slit structure, namely a through hole (2f) and a slit (2g). A plurality of the through holes (2f) are arranged on at least two concentric rings distributed around the central axis of the first air distribution structure (210), and the through holes (2f) located on the same concentric ring are distributed in an equally spaced manner. A plurality of the second slits (2g) are arranged around the through holes (2f), and the plurality of the second slits (2g) are evenly distributed around the central axis of the second air distribution structure (220), and the plurality of the second slits (2g) are distributed in a spoke-like manner on the radial cross section.

9. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 8, wherein, The number of concentric rings is four, the spacing between adjacent concentric rings is 4mm, and the diameter of the through hole (2f) is 0.4mm; the second slit (2g) has a rectangular structure with a length of 25mm and a width of 0.4mm in the radial cross section.

10. The gas inlet structure for a liquid metal catalytic cracking natural gas to hydrogen plant of claim 2, wherein, The porosity of the first porous structure (2c) and the second porous structure (2d) is 75%.

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