Compact type inflammable explosive raw material gas mixing device

Abstract

The utility model provides a compact type inflammable explosive raw material gas mixing device, and belongs to the technical field of chemical reaction equipment. The device comprises a mixing pipeline, an upstream rectification barrier and a gas distribution pipeline, the upstream rectification barrier and the gas distribution pipeline are vertically arranged in the mixing pipeline in sequence; the upstream rectification barrier is of a circular latticed structure and is formed by combining a plurality of groups of vertical barriers, baffling barriers and horizontal barriers; the gas distribution pipeline can specifically adopt a two-layer and three-ring type distribution structure form; through the upstream rectification barrier and the gas distribution pipeline, the raw material gas can be rapidly and fully mixed in the short mixing pipeline, and the problems that an existing gas-gas mixing device is large in occupied area and difficult to arrange are solved. Meanwhile, the safety and the production rate of the equipment are improved, and safe and efficient operation of the fixed bed reactor equipment is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of chemical reaction equipment technology, and in particular to a compact flammable and explosive raw material gas mixing device. Background Technology

[0002] Fixed-bed reactors are one of the core pieces of equipment in chemical production, widely used in industries such as petrochemicals, organic synthesis, food and pharmaceuticals, and metallurgy. Their core characteristic is that catalysts or solid reactants are packed in a static bed within the reactor, and gaseous or liquid reactants undergo chemical reactions as they pass through this bed. In actual industrial production, gaseous reactants typically consist of multiple different gases, requiring a gas-to-gas mixing unit operation before they enter the fixed-bed reactor. Examples include the mixing of natural gas and air in ammonia synthesis, the mixing of ethylene and oxygen in ethylene oxide synthesis, and the mixing of n-butane and air in maleic anhydride synthesis.

[0003] In gas-gas mixing processes, a significant number of procedures use combustible gases and oxygen-containing gases (air or a mixture of oxygen and inert gases) as feedstock. During this process, the resulting combustible mixture may inevitably reach its explosive concentration limits (the range of flammable and explosive concentrations) due to uneven or insufficient mixing. If ignition conditions are met (such as reaching the flash point), the mixture will rapidly explode, potentially causing equipment shutdown or damage, or even a serious safety accident. Therefore, in the aforementioned gas-gas mixing unit operations, specially designed gas mixing devices must be used to minimize the time and spatial domain of the combustible mixture, achieving thorough mixing in a shorter time and smaller space, thereby ensuring the safe and efficient operation of the fixed-bed reactor.

[0004] Currently, several solutions exist for gas-gas mixers that mix flammable and explosive raw materials with oxygen. For example, patents CN103521137A and CN203540496U disclose gas mixers that are of the "finger-shaped branch pipe type." This type of gas mixing distributor consists of a main manifold, finger-shaped distribution branches, and a mixing pipe. Several raw material gas holes on the distribution pipes allow butane flowing out of the distribution pipes to mix with air flowing in the mixing pipe. Its drawbacks are that all distribution branches are on the same cross-section of the mixing pipe, occupying the original space of the mixing pipe at that cross-section. Especially when the branch pipe diameter is large, this causes significant local pressure drops and local high-velocity zones within the mixing pipe, which is detrimental to thorough gas mixing and energy saving in the mixing device. Both US3702619A and CN118718786A disclose gas mixers of the "annular coaxial type." This type of gas mixer distributor consists of a main manifold, annular distribution branches, and a mixing pipe. Through several raw material gas holes on the distribution branches, the gas B flowing out of the distribution branches is uniformly mixed with the gas A flowing inside the mixing pipe. Compared to the aforementioned scheme 1, the annular distribution branches used in this scheme reduce mutual interference of airflows. Furthermore, by arranging two or three layers of concentric annular distribution branches of different diameters along the axial direction of the mixing pipe, this scheme prevents significant local pressure drops and localized high-velocity zones within the mixing pipe.

[0005] Both Scheme 1 and Scheme 2 suffer from the drawback of a large pipeline mixing device length, leading to increased equipment footprint or installation difficulties. The reasons are twofold: Firstly, to control the uniform gas outflow from the distribution branch pipe and ensure thorough gas mixing, the distribution branch pipe should be located in the stable flow region within the mixing pipeline section (e.g., US3702619A specifies that the preferred stable flow region is 3 to 11 times the pipe diameter downstream of the bend). Secondly, when the mainstream gas velocity in the mixing pipeline is high (corresponding to high-flow production conditions) or the velocity difference between the two raw material gases is small, the mixed gas cannot quickly achieve a fully mixed state through free diffusion after passing through the gas mixing distributor. Therefore, a straight pipe section needs to be maintained downstream (8 to 10 times the pipe diameter in claim CN118718786A, resulting in a large device size) or a static mixer needs to be added (to enhance turbulent diffusion, but this causes additional pressure drop and energy consumption) to ensure thorough gas mixing. Utility Model Content

[0006] To address the problems of existing gas-gas mixing devices having large footprints and being difficult to install, this utility model provides a compact flammable and explosive raw material gas mixing device. It can achieve rapid and thorough mixing of raw material gases within a shorter mixing pipeline, reducing the space occupied by the equipment, while also improving the economic efficiency and safety of the equipment.

[0007] This utility model provides a compact flammable and explosive raw material gas mixing device, which adopts the following technical solution:

[0008] A compact flammable and explosive raw material gas mixing device is provided. The mixing device can be directly connected to a curved gas inlet pipe and includes a horizontally oriented mixing pipe, an upstream rectifier grid, and a gas distribution pipe. The upstream rectifier grid and the gas distribution pipe are arranged vertically inside the mixing pipe. The upstream rectifier grid is located in the upstream region of the mixing pipe.

[0009] The upstream rectifier grid has a circular mesh structure, including multiple sets of vertically arranged vertical grids, multiple sets of horizontally arranged baffle grids and horizontal grids; the baffle grids are located away from the bend of the curved intake pipe, and the horizontal grids are located near the bend of the curved intake pipe; the edge of the upstream rectifier grid is fixedly connected to the inner wall of the mixing pipe.

[0010] The gas distribution pipeline includes a main manifold located outside the mixing pipeline, an annular branch pipe located inside the mixing pipeline, and distribution branch pipes; the main manifold is connected to the annular branch pipe through the distribution branch pipes; the annular branch pipe is provided with multiple gas outlets.

[0011] Preferably, the distribution branch pipe includes a first distribution branch pipe, a second distribution branch pipe and a third distribution branch pipe with successively decreasing pipe diameters, and the annular branch pipe includes a first annular branch pipe, a second annular branch pipe and a third annular branch pipe with successively decreasing pipe cross-sections.

[0012] Preferably, one end of the first distribution branch pipe penetrates the wall of the mixing pipe and is connected to one end of the main manifold, and the other end of the first distribution branch pipe is connected to the first annular branch pipe; one end of the second distribution branch pipe penetrates the wall of the mixing pipe and is connected to the other end of the main manifold, and the other end of the second distribution branch pipe is connected to the second annular branch pipe; one end of the third distribution branch pipe is connected to the end of the first distribution branch pipe or the second distribution branch pipe, and the other end of the third distribution branch pipe is connected to the third annular branch pipe.

[0013] Preferably, the diameter of the main manifold is set to be 4 to 5 times the diameter of each distribution branch pipe; the cross-sectional area of ​​the first distribution branch pipe is 4 to 5 times that of the third distribution branch pipe, and the cross-sectional area of ​​the second distribution branch pipe is 2 to 3 times that of the third distribution branch pipe; the cross-sectional area of ​​the first annular branch pipe is 4 to 5 times that of the third annular branch pipe, and the cross-sectional area of ​​the second annular branch pipe is 2 to 3 times that of the third annular branch pipe.

[0014] More preferably, the cross-sectional area ratio of the first distribution branch pipe, the second distribution branch pipe and the third distribution branch pipe is 4.59:2.46:1; the cross-sectional area ratio of the first annular branch pipe, the second annular branch pipe and the third annular branch pipe is 4:2.56:1.

[0015] More preferably, the diameter of the annular branch pipe is set according to the diameter of the mixing pipe, and the diameter ratio of the mixing pipe to the three annular branch pipes is set to 80:2:1.6:1.

[0016] Preferably, each annular branch pipe is provided with multiple rings of air outlets, and each ring of air outlets is evenly distributed along the circumference of the annular branch pipe; the diameter of the air outlets is set according to the diameter of the mixing pipe, and the diameter of the air outlets is set to 1 / 250 of the diameter of the mixing pipe.

[0017] Preferably, the annular branch pipe is provided with two rings of air outlets, namely an inner ring air outlet and an outer ring air outlet. At the same cross-section of the annular branch pipe, the included angle between the inner ring air outlet and the outer ring air outlet is 90°.

[0018] Preferably, the gas distribution pipe is positioned in the mixing pipe such that the distance between the gas distribution pipe and the upstream rectifier 3 is 0.25 to 0.75 times the diameter of the mixing pipe; and the distance between the gas distribution pipe and the outlet of the mixing pipe is 2 to 2.5 times the diameter of the mixing pipe.

[0019] Preferably, the vertical grid and the baffle grid, and the horizontal grid are spaced apart by 0.09 to 0.11 times the diameter of the mixing pipe; the vertical grid and the horizontal grid are strip plates; and the baffle grid is a baffle plate with an inclined angle.

[0020] Preferably, the mixing device further includes a downstream swirl rectifier, which includes a bladed gas swirler and a downstream rectifier grid, both of which are arranged vertically in sequence in the downstream region of the mixing pipe; the edges of the downstream rectifier grid and the bladed gas swirler are fixedly connected to the inner wall of the mixing pipe.

[0021] A bladed gas cyclone separator comprises multiple swirling blades, each blade having an angle.

[0022] The downstream rectifier grid has a circular mesh structure, including multiple sets of vertically arranged downstream vertical grids and multiple sets of horizontally arranged downstream horizontal grids.

[0023] Preferably, the downstream swirl rectifier is specifically positioned in the mixing pipe such that the distance between the gas distribution pipe and the downstream swirl rectifier is 0.75 to 1.25 times the diameter of the mixing pipe; and the distance between the downstream swirl rectifier and the outlet of the mixing pipe is 0.75 to 1.25 times the diameter of the mixing pipe.

[0024] Preferably, the bladed gas cyclone separator can use 12 to 16 cyclone blades with an inclination angle of 30° to 60°; the width of the cyclone blades is set according to the diameter of the mixing pipe, and the width of the cyclone blades is set to 0.15 times the diameter of the mixing pipe 1.

[0025] In summary, this utility model has the following beneficial effects:

[0026] 1) This device uses a 2-layer 3-ring gas distribution pipeline to ensure that the raw gas is fully mixed in the radial direction of the pipeline while reducing the length of the raw gas distribution branch pipe assembly in the axial direction of the mixing pipeline. Compared with the 3-layer 3-ring gas distributor of US3702619A, the axial length of the distribution branch pipe assembly can be reduced by 50%, which is comparable to the 2-layer 2-ring gas distributor.

[0027] 2) This device, by installing a flow-rectifying grid upstream of the mixing pipeline, allows direct connection to the pipeline bend. The uneven outflow at the bend is rectified by the grid, improving flow uniformity. At this point, a distribution branch assembly can be directly arranged downstream of the grid, achieving thorough and uniform gas mixing. Therefore, it eliminates the need to be located in the downstream flow stability zone (3 to 11 times the pipe diameter) specified in US3702619A, reducing the overall axial length of the gas mixing device and saving installation space. Furthermore, because this device achieves uniform mixing without the need for a traditional static mixer, energy consumption is significantly reduced, improving the equipment's economic efficiency.

[0028] 3) In addition, this application can also achieve better gas mixing by adding a swirl rectifier downstream of the mixing pipeline. The mixed gas first swirls through the swirl blades to further mix the gas; then it is rectified by the grid to change the direction of the mixed gas flow to axial flow, and finally obtains a well mixed raw material gas.

[0029] In summary, this device can achieve rapid and thorough mixing of raw gas within a relatively short mixing pipeline, solving the problem of large footprint caused by the large length of existing gas-gas mixing devices, while also improving the economic efficiency of the equipment. Furthermore, by shortening the mixing pipeline length, the gas mixing rate is accelerated, and the time and spatial domains of the combustible gas mixture are shortened, improving the safety and production rate of the equipment and ensuring the safe and efficient operation of the fixed-bed reactor. Attached Figure Description

[0030] Figure 1 This is a perspective view of the overall structure of a compact flammable and explosive raw material gas mixing device according to an embodiment of the present invention;

[0031] Figure 2 This is a three-dimensional schematic diagram of the upstream rectifier grid of a compact flammable and explosive raw material gas mixing device according to an embodiment of the present invention;

[0032] Figure 3 This is a three-dimensional schematic diagram of the gas distribution pipeline of a compact flammable and explosive raw material gas mixing device according to an embodiment of the present utility model;

[0033] Figure 4This is a side view of the gas distribution pipeline of a compact flammable and explosive raw material gas mixing device according to an embodiment of the present invention;

[0034] Figure 5 A perspective view of a blade-type gas cyclone in a compact flammable and explosive raw material gas mixing device according to an embodiment of this utility model;

[0035] Figure 6 This is a perspective view of a downstream rectifier grid of a compact flammable and explosive raw material gas mixing device according to an embodiment of the present invention;

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Mixing duct; 2. Gas distribution duct; 3. Upstream rectifier grid; 4. Downstream swirl rectifier; 5. Bent intake duct;

[0038] 21. Main manifold; 22. First distribution branch pipe; 23. Second distribution branch pipe; 24. Third distribution branch pipe; 25. First annular branch pipe; 26. Second annular branch pipe; 27. Third annular branch pipe; 28. Vent outlet;

[0039] 31. Vertical grid; 32. Flow deflector grid; 33. Horizontal grid;

[0040] 41. Blade-type gas cyclone separator; 42. Downstream rectifier grid; 411. Swirl blades; 421. Downstream vertical grid; 422. Downstream horizontal grid. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, the various features in each embodiment can be combined with each other. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0042] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] Example 1

[0045] Combination Figures 1-6 As shown, this embodiment provides a compact flammable and explosive raw material gas mixing device. This mixing device can be directly connected to a curved air inlet pipe 5 with a bend angle of 90°. It includes a horizontally oriented mixing pipe 1, an upstream rectifier grid 3, and a gas distribution pipe 2. According to the flow direction of the gas inside the mixing pipe, the upstream rectifier grid and the gas distribution pipe are arranged vertically inside the mixing pipe in sequence. The upstream rectifier grid is located in the upstream region of the mixing pipe near the curved air inlet pipe.

[0046] Upstream refers to the beginning or front part of the gas flow direction inside the mixing pipe; downstream refers to the end or rear part of the gas flow direction inside the mixing pipe.

[0047] The upstream rectifier grid has a circular mesh structure. The edge of the upstream rectifier grid is fixedly connected to the inner wall of the mixing pipe. The upstream rectifier grid 3 consists of multiple sets of vertical grids 31, deflector grids 32, and horizontal grids 33. The vertical grids are arranged at equal intervals along the vertical direction, and the horizontal grids and deflector grids are arranged at equal intervals along the horizontal direction. The deflector grids are located away from the bend of the curved intake pipe, and the horizontal grids are located near the bend of the curved intake pipe. The three are orthogonal to each other, forming the circular mesh structure of the upstream rectifier grid. In one specific implementation, the multiple sets of vertical grids 31, deflector grids 32, and horizontal grids 33 are first welded and fixed to form the circular mesh structure of the upstream rectifier grid 3. Then, the edge of the upstream rectifier grid 3 is welded and fixed to the inner wall of a cylindrical plate. The cylindrical plate is embedded into the inner wall of the mixing pipe 1 at a suitable position and welded in place.

[0048] The gas distribution pipeline 2 includes a main manifold 21 located outside the mixing pipeline, a distribution branch pipe, and an annular branch pipe located inside the mixing pipeline; the main manifold is connected to the annular branch pipe through the distribution branch pipe; and the annular branch pipe is provided with multiple gas outlets 28.

[0049] The distribution branch pipe 2 includes a first distribution branch pipe 22, a second distribution branch pipe 23, and a third distribution branch pipe 24 with successively decreasing pipe diameters. The annular branch pipe includes a first annular branch pipe 25, a second annular branch pipe 26, and a third annular branch pipe 27 with successively decreasing pipe cross-sections. One end of the first distribution branch pipe penetrates the wall of the mixing pipe and connects to one end of the main conduit, while the other end of the first distribution branch pipe connects to the first annular branch pipe. One end of the second distribution branch pipe penetrates the wall of the mixing pipe and connects to the other end of the main conduit, while the other end of the second distribution branch pipe connects to the second annular branch pipe. One end of the third distribution branch pipe is connected to the end of the first distribution branch pipe, while the other end of the third distribution branch pipe connects to the third annular branch pipe.

[0050] Suppose the target mixture consists of gas A, which has a larger volume fraction, and gas B, which has a smaller volume fraction. The mixing device of this invention is used to mix the two gases. The mixing pipe of the device is directly connected to an upstream curved inlet pipe with a 90° bend. Gas A is introduced into the curved inlet pipe, and gas B is introduced into the gas distribution pipe. Gas A enters the mixing pipe through the curved inlet pipe and flows through an upstream rectifier grid located in the upstream region of the mixing pipe. The upstream rectifier grid rectifies the uneven velocity distribution of gas A after the 90° bend, resulting in a relatively uniform output velocity. Gas B is then processed through a two-layer, three-ring gas distribution pipe, ensuring that gas B is evenly distributed in the mixing pipe. The evenly distributed gas B and the evenly flowing gas B can be thoroughly and uniformly mixed. The resulting fully mixed gas can be used as feed gas and directly transported to a fixed-bed reactor for further processing.

[0051] This invention, by adding a flow-rectifying grid upstream of the mixing pipeline, allows the device to be directly connected to the pipeline bend. The uneven outflow at the bend is rectified by the grid, improving the flow uniformity. Therefore, the distribution branch pipe assembly can be directly arranged downstream of the grid, achieving thorough and uniform gas mixing. It eliminates the need for the downstream flow stability zone of 3 to 11 times the pipe diameter specified in US3702619A, reducing the overall axial length of the gas mixing device. Simultaneously, by using a two-layer, three-ring gas distribution pipe, it ensures thorough mixing of the raw gas in the radial direction of the pipeline while reducing the axial length of the raw gas distribution branch pipe assembly in the mixing pipeline. Therefore, this device, through the introduction of the upstream flow-rectifying grid and gas distribution pipe, can achieve rapid and thorough mixing of the raw gas within a shorter mixing pipeline, solving the problem of existing gas-gas mixing devices being too long and thus occupying a large area.

[0052] In some preferred embodiments, the gas distribution pipe 2 is specifically positioned in the mixing pipe such that the distance between the gas distribution pipe 2 and the upstream rectifier grid 3 is 0.25 to 0.75 times the diameter of the mixing pipe 1; and the distance between the gas distribution pipe 2 and the outlet of the mixing pipe 1 is 2 to 2.5 times the diameter of the mixing pipe 1.

[0053] In some preferred embodiments, the arrangement interval between the vertical grid and the baffle grid and the horizontal grid is 0.09 to 0.11 times the diameter of the mixing pipe 1; wherein, the vertical grid and the horizontal grid are strip plates; the baffle grid is a baffle plate with an inclined angle, which can be set as a baffle plate with an inclined angle of 30°.

[0054] In some preferred embodiments, the diameter of the main manifold 21 is at least 4 to 5 times the diameter of each distribution branch pipe to ensure pressure stability within the main manifold 21. The cross-sectional area ratios of the first, second, and third distribution branches decrease sequentially; for example, the cross-sectional area of ​​the first distribution branch pipe can be 4 to 5 times that of the third distribution branch pipe, and the cross-sectional area of ​​the second distribution branch pipe can be 2 to 3 times that of the third distribution branch pipe. Similarly, the cross-sectional area ratios of the first, second, and third annular branches decrease sequentially; for example, the cross-sectional area ratio of the first, second, and third distribution branches can be 4.59:2.46:1; and the cross-sectional area ratio of the first, second, and third annular branches can be 4:2.56:1.

[0055] In some other preferred embodiments, the diameter of the annular branch pipe can be set according to the diameter of the mixed pipe. The cross-sectional area ratio of the mixed pipe 1 and the 3 annular branch pipes can be set to 6400:4:2.56:1, and the converted diameter ratio can be 80:2:1.6:1.

[0056] In some preferred embodiments, multiple vent holes are provided on each annular branch pipe, and each vent hole is evenly distributed along the circumference of the annular branch pipe.

[0057] In a further preferred embodiment, the diameter of the vent hole can be set according to the diameter of the mixing pipe, and the vent hole diameter can be set to 1 / 250 of the diameter of the mixing pipe; two rings of vent holes are provided on the annular branch pipe, namely the inner ring vent hole and the outer ring vent hole, and the included angle between the inner ring vent hole and the outer ring vent hole at the same cross section of the annular branch pipe is 90°; the number of vent holes in the first annular branch pipe, the second annular branch pipe and the third annular branch pipe decreases sequentially, and the ratio of the number of vent holes can be set to 3.22:2.44:1.

[0058] Example 2

[0059] This embodiment is based on Embodiment 1, and the difference between it and Embodiment 1 is as follows:

[0060] Combination Figures 1-6 As shown, the mixing device can also be equipped with a downstream swirl rectifier 4 in the downstream region of the mixing pipe. The downstream swirl rectifier 4 includes a bladed gas swirler 41 and a downstream rectifier grid 42, which are arranged vertically in sequence in the downstream region of the mixing pipe according to the flow direction of the gas inside the mixing pipe. The edges of the downstream rectifier grid and the bladed gas swirler are fixedly connected to the inner wall of the mixing pipe. The bladed gas swirler 41 includes multiple swirl blades 411, each of which has an inclination angle; the bladed gas swirler can further enhance the mixing effect of the two gases. As a specific implementation, each swirl blade 411 is first welded and fixed at a certain swirl angle, with its head and tail respectively, to the inner and outer cylindrical plates. Then, the outer cylindrical plate is embedded into the inner wall surface of the mixing pipe at a suitable position and welded and fixed.

[0061] The downstream rectifier grid 42 has a circular mesh structure and is composed of multiple sets of downstream vertical grids 421 and downstream horizontal grids 422. The multiple sets of downstream vertical grids are arranged at equal intervals in the vertical direction, and the multiple sets of downstream horizontal grids are arranged at equal intervals in the horizontal direction. The two are orthogonal to each other to form the circular mesh structure of the downstream rectifier grid. The downstream rectifier grid can further rectify the mixed gas, changing its flow direction to axial.

[0062] When the mixed gas flows through the downstream region of the mixing pipe, it first passes through a bladed gas cyclone separator. The mixed gas interacts with the cyclone blades to generate swirling flow, thereby achieving further and thorough mixing of the gas. Then, the fully mixed gas flows through the downstream rectifier grid. Through the rectification effect of the grid, the flow direction of the mixed gas is changed to axial. Finally, a well-mixed axially oriented mixed gas is obtained, which can be used as feed gas and directly transported to the fixed-bed reactor for the next step of the operation.

[0063] In some preferred embodiments, the downstream swirl rectifier is specifically positioned in the mixing pipe such that the distance between the gas distribution pipe 2 and the downstream swirl rectifier 4 is 0.75 to 1.25 times the diameter of the mixing pipe 1; and the distance between the downstream swirl rectifier 4 and the outlet of the mixing pipe 1 is 0.75 to 1.25 times the diameter of the mixing pipe 1.

[0064] In a further preferred embodiment, the bladed gas cyclone separator may employ 12 to 16 cyclone blades, with the blade inclination angle being 30° to 60°; the width of the cyclone blades may be set according to the diameter of the mixing pipe, and the width of the cyclone blades may be set to 0.15 times the diameter of the mixing pipe 1.

[0065] In a further preferred embodiment, the arrangement interval between the downstream vertical grid and the downstream horizontal grid is 0.09 to 0.11 times the diameter of the mixing pipe.

[0066] Example 3

[0067] In this embodiment, taking the synthesis of maleic anhydride from n-butane and air as an example, a gas-to-gas mixing device is equipped upstream of the fixed-bed reactor to mix the n-butane feed gas with air. Gas mixing experiments were conducted using the gas-to-gas mixing devices of Embodiments 1 and 2 of this invention (with the addition of a downstream cyclone rectifier) ​​and the gas mixer disclosed in patent CN103521137A. Performance parameters of each gas-to-gas mixing device were collected and compared. The gas mixing uniformity evaluation standard was based on the reference "Gas Mixing and Hazard Analysis in Oxygen Mixer in Ethylene Oxide Process_Zhang Xiaofeng", which specifically provides a statistical method for gas mixing uniformity. The specific comparison results are shown below:

[0068]

[0069] Based on the above comparative data, it can be seen that this utility model shortens the pipe length by about 73% compared with the traditional long straight pipe solution, and the mixing device is more compact.

[0070] Meanwhile, without adding a downstream cyclone rectifier, the total pressure drop of the mixing unit decreased by about 37%, which is beneficial to energy saving. The uniformity of the mixed gas at the unit outlet increased by about 7.6%, which can improve the efficiency of subsequent chemical reactions. The uniformity of the flow rate of the mixed gas at the unit outlet did not change much.

[0071] To achieve better mixing, a downstream swirl rectifier can be added. In this case, the uniformity of the mixed gas is improved by 9.2% compared to the traditional long straight pipeline scheme, but the total pressure drop of the device is also increased by 8.5%.

[0072] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A compact flammable and explosive raw material gas mixing device, which can be directly connected to a curved gas inlet pipe, characterized in that: The upstream rectifying baffle and the gas distribution pipeline are vertically arranged in the interior of the mixing pipeline in sequence; the upstream rectifying baffle is located in the upstream region of the mixing pipeline; The upstream rectifying baffle is in a circular grid structure and comprises a plurality of groups of vertically arranged vertical baffles, a plurality of groups of transversely arranged baffle baffles and horizontal baffles; the baffle baffles are arranged away from the center of curvature of the curved gas inlet pipeline, and the horizontal baffles are arranged close to the center of curvature of the curved gas inlet pipeline; the edge of the upstream rectifying baffle is fixedly connected with the inner wall of the mixing pipeline; The gas distribution pipeline comprises a collecting header located outside the mixing pipeline, an annular branch pipe located inside the mixing pipeline and a distribution branch pipe; the collecting header is connected with the annular branch pipe through the distribution branch pipe; a plurality of gas outlet holes are arranged on the annular branch pipe.

2. A compact, flammable and explosive material gas mixing device according to claim 1, characterized in that: The distribution branch pipe comprises a first distribution branch pipe, a second distribution branch pipe and a third distribution branch pipe with diameters decreasing in sequence, and the annular branch pipe comprises a first annular branch pipe, a second annular branch pipe and a third annular branch pipe with cross sections decreasing in sequence.

3. A compact, flammable and explosive gas mixture device according to claim 2, characterized in that: One end of the first distribution branch pipe penetrates the pipe wall of the mixing pipeline and is connected with one end of the collecting header, and the other end of the first distribution branch pipe is connected with the first annular branch pipe; one end of the second distribution branch pipe penetrates the pipe wall of the mixing pipeline and is connected with the other end of the collecting header, and the other end of the second distribution branch pipe is connected with the second annular branch pipe; one end of the third distribution branch pipe is connected to the end of the first distribution branch pipe or the second distribution branch pipe, and the other end of the third distribution branch pipe is connected with the third annular branch pipe.

4. A compact, flammable and explosive gas mixture device according to claim 3, characterized in that: The diameter of the collecting header is set to be 4-5 times the diameter of each distribution branch pipe; the cross-sectional area of the first distribution branch pipe is 4-5 times the cross-sectional area of the third distribution branch pipe, and the cross-sectional area of the second distribution branch pipe is 2-3 times the cross-sectional area of the third distribution branch pipe; the cross-sectional area of the first annular branch pipe is 4-5 times the cross-sectional area of the third annular branch pipe, and the cross-sectional area of the second annular branch pipe is 2-3 times the cross-sectional area of the third annular branch pipe.

5. A compact, flammable and explosive material gas mixing device according to claim 2, characterized in that: A plurality of rings of the gas outlet holes are arranged on each annular branch pipe, and each ring of the gas outlet holes is uniformly distributed along the circumference of the annular branch pipe; the diameter of the gas outlet hole is set according to the diameter of the mixing pipeline, and the diameter of the gas outlet hole is set to be 1 / 250 of the diameter of the mixing pipeline.

6. A compact, flammable and explosive material gas mixing device according to claim 5, characterized in that: Two rings of the gas outlet holes are arranged on the annular branch pipe, which are the inner ring of gas outlet holes and the outer ring of gas outlet holes; at the same cross section of the annular branch pipe, the included angle between the inner ring of gas outlet holes and the outer ring of gas outlet holes is 90°.

7. The compact, flammable and explosive material gas mixing device according to claim 1, characterized in that: The specific arrangement position of the gas distribution pipeline in the mixing pipeline is that the distance between the gas distribution pipeline and the upstream rectifying baffle is 0.25-0.75 times the diameter of the mixing pipeline, and the distance between the gas distribution pipeline and the outlet of the mixing pipeline is 2-2.5 times the diameter of the mixing pipeline.

8. The compact, flammable and explosive material gas mixing device according to claim 1, characterized in that: The arrangement interval of the vertical baffle, the baffle baffle and the horizontal baffle is 0.09-0.11 times of the diameter of the mixing pipeline; the vertical baffle and the horizontal baffle are strip-shaped plates; and the baffle baffle is a baffle plate with an inclined angle.

9. The compact, flammable and explosive material gas mixing device according to claim 1, characterized in that: Further comprising a downstream cyclone rectifier, the downstream cyclone rectifier comprising a vane-type gas cyclone and a downstream rectification baffle, both of which are vertically arranged in sequence in the downstream area of the mixing pipeline; the edge of the downstream rectification baffle and the vane-type gas cyclone are fixedly connected with the inner wall of the mixing pipeline; The gas cyclone comprises a plurality of cyclone vanes, and each cyclone vane is provided with an inclination angle; The downstream rectification baffle is in a circular grid structure, comprising a plurality of groups of downstream vertical baffles arranged vertically and a plurality of groups of downstream horizontal baffles arranged transversely.

10. The compact, flammable and explosive fuel gas mixing device according to claim 9, characterized in that: The specific arrangement position of the downstream cyclone rectifier in the mixing pipeline is that the interval between the gas distribution pipeline and the downstream cyclone rectifier is 0.75-1.25 times of the diameter of the mixing pipeline; and the interval between the downstream cyclone rectifier and the outlet of the mixing pipeline is 0.75-1.25 times of the diameter of the mixing pipeline.

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