Feed seal for a microchannel reactor

Abstract

The present application relates to the technical field of sealing, and discloses a kind of feed sealing device of microchannel reactor, microchannel reactor, detachably installed with feed distributor;Sealing shell is equipped with positive pressure chamber, the sealing shell is installed on the microchannel reactor and covers the feed distributor in the positive pressure chamber;Multiple feed pipes, the inner end of the feed pipe is located in the positive pressure chamber and is connected with the feed distributor, the outer end of the feed pipe extends out of the sealing shell and is sealed with the sealing shell connection;Protective gas feed piece is arranged on the sealing shell and is used to introduce protective gas into the positive pressure chamber.The present application has the advantages of simple structure, easy processing, easy to disassemble, good sealing and guaranteeing the safety of reaction process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing, in particular to a feed sealing device of a micro-channel reactor. BACKGROUND

[0002] The micro-channel reactor mainly refers to a three-dimensional structure element for chemical reactions manufactured by micro-processing technology or a highly integrated micro-reaction system including heat exchange, mixing, separation, analysis and control and the like, and generally contains fluid flow channels with an equivalent diameter of several microns to several millimeters, and chemical reactions are carried out in the micron-level channels. Compared with the traditional fixed bed reactor, the micro-channel reactor is used in the reaction field requiring mass transfer and heat transfer intensification to improve the reaction efficiency, reduce the energy consumption, reduce the reaction volume and realize the integration.

[0003] The micro-channel reactor applied to industrial production needs to be combined into one micro-reactor by "number amplification" to meet the production scale requirements. For most gas-solid heterogeneous catalytic reactions, the raw gas has been pre-mixed before entering the reactor, and only one sampling port is needed to meet the feed requirements. For gas-liquid-solid three-phase catalytic reactions, it is difficult to ensure the uniformity of raw material composition and the same proportion of raw materials entering each micro-channel. For some special gas-solid heterogeneous catalytic reactions, the raw gas can only be mixed in the micro-channel, such as the catalytic partial oxidation of CH4. The pre-mixed raw gas CH4 and air will form an explosive mixture, and only mixing in the micron-level channel can ensure the safety of the reaction system. For the above-mentioned cases where raw materials cannot be pre-mixed, two or more raw materials must be separately distributed into each channel through a micro-channel distributor.

[0004] At present, the micro-channel reactor mostly adopts the feed mode of a single feed port after pre-mixing, and how to realize the sealing of the inlet of the micro-channel reactor under the condition of two or more feeds is one of the important problems to be solved for widening the industrial application of the micro-channel reactor. SUMMARY

[0005] The purpose of the present application is to overcome the safety problems caused by raw material pre-mixing in the prior art, and provide a feed sealing device of a micro-channel reactor, which has the advantages of simple structure, easy processing, convenient disassembly and reassembly, good sealing performance and safety guarantee for the reaction process.

[0006] In order to achieve the above purpose, the present application discloses a feed sealing device of a micro-channel reactor, which comprises:

[0007] The micro-channel reactor is detachably installed with a feed distributor;

[0008] A sealing shell, which is provided with a positive pressure cavity, is mounted on the micro-channel reactor and covers the feed distributor in the positive pressure cavity;

[0009] A plurality of feed pipes, the inner ends of which are located in the positive pressure cavity and connected to the feed distributor, the outer ends of which extend out of the sealing shell and are sealingly connected to the sealing shell;

[0010] A protective gas feeding member is provided on the sealing shell and used for feeding protective gas into the positive pressure cavity.

[0011] In some embodiments of the present application, the feed distributor is fixedly connected to each of the feed pipes, and the feed distributor is connected to the micro-channel reactor by bolts.

[0012] In some embodiments of the present application, the sealing shell comprises a flange sealingly and fixedly provided on the outer wall of the micro-channel reactor and a flange cover sealingly connected to the flange, and the flange and the flange cover jointly form the positive pressure cavity covering the feed distributor.

[0013] In some embodiments of the present application, a through hole for passing each feed pipe is formed in the flange cover, and the through hole is provided as a stepped hole, and the small hole of the stepped hole is located above the large hole.

[0014] The feed pipe has a thick pipe section, which cooperates with the large hole of the stepped hole to form a sealing structure, and a gasket is arranged between the thick pipe section and the large hole of the stepped hole.

[0015] In some embodiments of the present application, the gasket is selected from a graphite gasket or a metal gasket.

[0016] In some embodiments of the present application, a pipe joint is threadedly connected to the extending end of the feed pipe, the pipe joint is used for mounting a raw material conveying pipe connected to a raw material storage tank, and a pressing block is threadedly connected to the feed pipe between the pipe joint and the flange cover, and the flange cover and the thick pipe section are pressed to enhance the sealing by rotating the pressing block.

[0017] In some embodiments of the present application, a clamping position is provided on the pipe joint to facilitate the force exerted by a tool.

[0018] In some embodiments of the present application, the tool is a wrench, and the clamping position is a plane oppositely provided on the outer peripheral wall of the pipe joint.

[0019] In some embodiments of the present application, the large hole of the stepped hole is provided as a square hole, and the outer side wall surface of the thick pipe section has a plane cooperating with the side wall surface of the square hole to prevent relative rotation between the feed pipe and the stepped hole.

[0020] In some embodiments of the present application, the feed pipe located inside the sealed housing has a coil section spiraled in the height direction.

[0021] By the above technical solution, the present application realizes the sealing problem at the inlet of the reactor when two or more raw materials are fed separately, has the advantages of simple structure, easy processing, convenient disassembly and assembly, good sealing performance and safety guarantee for the reaction process. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic view of the feed sealing device of the micro-channel reactor of the specific embodiment;

[0023] Figure 2 is Figure 1 is a longitudinal sectional view of the flange cover;

[0024] Figure 3 is Figure 2 is a bottom view of the stepped hole;

[0025] Figure 4 is a bottom view of the cooperation of the stepped hole and the thick pipe section.

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] 2 flange; 3 feed distributor; 4 feed pipe; 5 coil section; 7 thick pipe section; 8 flange cover; 9 pressing block; 11 plane, 13 pipe joint; 14 large hole; 15 small hole; 16 sealing surface; 17 protective gas feeding piece; 18 split nut. DETAILED DESCRIPTION

[0028] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0029] In the present application, the orientation words such as "up, down, left, right" used without the opposite description generally refer to the up, down, left, right shown in the drawings; "inner, outer" refers to the inner, outer relative to the contour of each component itself.

[0030] In the prior art, the reactor is large, and the safety problem caused by the premixing of raw materials can be prevented by separate feeding. The micro-channel reactor is used in the reaction field requiring mass transfer and heat transfer intensification to improve the reaction efficiency, reduce the energy consumption, reduce the reaction volume and realize the high integration of the reaction. The existing micro-channel distributor is connected with the micro-channel main body through bolts, and there is a leakage problem at the connection under the pressurized reaction condition. Therefore, the micro-channel distributor and the reactor need to be arranged in a sealed cavity, and how to realize the connection of the two or more feed pipes through the cavity sealing and the micro-channel distributor is not disclosed by the related technology at present.

[0031] To solve the above problems, such as Figure 1 As shown, this invention discloses a feed sealing device for a microchannel reactor. The microchannel reactor is connected to the inner ends of at least two feed pipes 4 via a feed distributor 3. The feed distributor 3 can divide the material from each feed pipe 3 into multiple streams and feed them into the microchannel reactor. The feed distributor 3 is detachably connected to the microchannel reactor. The feed sealing device includes a sealing shell that is sealed on the microchannel reactor. The sealing shell surrounds and defines a positive pressure chamber that covers the feed distributor 3. The outer end of the feed pipe 4 extends out of the sealing shell and is sealed to the sealing shell. A protective gas feed element 17 connected to a protective gas source is provided on the sealing shell. The protective gas feed element 17 can be configured as a protective gas inlet or a protective gas feed pipe. The sealing shell seals and encloses the feed distributor 3 and the feed pipes 4, and introduces protective gas into the interior of the sealing shell through the protective gas inlet to form a positive pressure protection, preventing leakage between the feed distributor 3 and the microchannel reactor, ensuring that the reaction raw materials are not premixed, and guaranteeing the safety of the reaction process.

[0032] In some embodiments of the present invention, the protective gas may be selected from nitrogen or argon.

[0033] In some embodiments of the present invention, the feed distributor 3 is fixedly connected to each feed pipe 4, for example by welding, and the feed distributor 3 is bolted to the microchannel reactor. In this way, when adding or replacing the catalyst to the microchannel reactor, the feed distributor 3 and the feed pipe 4 can be installed and removed as a whole, thereby improving the replacement efficiency.

[0034] To facilitate the assembly and disassembly of the feed sealing device, in some embodiments of the present invention, the sealing housing includes a flange 2 that is sealed and fixedly disposed on the outer wall of the microchannel reactor and a flange cover 8 that is sealed to the flange 2. The flange 2 and the flange cover 8 together form the positive pressure chamber of the cover feed distributor 3. It should be noted that the flange 2 and the flange cover 8 are connected by bolts and sealed using a sealing method in the prior art, such as the sealing method in HG / T20592 to HG / T20635-2009.

[0035] In some embodiments of the present invention, such as Figures 2-3 As shown, the flange cover 8 has a protective gas inlet 17 and a through hole for each feed pipe to pass through. The through hole is a stepped hole, with the smaller hole 15 of the stepped hole located above the larger hole 14. The feed pipe 4 has a thicker section 7, which cooperates with the larger hole 14 of the stepped hole to form a sealing structure. Figure 3As shown, the stepped surface between the large hole 14 and the small hole 15 is formed as a sealing surface 16 in contact with the protruding surface of the radial direction of the rough pipe segment 7, wherein a gasket is arranged between the rough pipe segment 7 and the large hole 14 of the stepped hole to strengthen the sealing, wherein the smoothness of the sealing surface 16 needs to meet the sealing requirements, for example, the arithmetic mean deviation Ra value of the sealing surface profile is not greater than 0.4 μm according to GB / T1031-2009.

[0036] In some embodiments of the present application, the gasket can be selected as a graphite gasket or a metal gasket (for example, a copper gasket) according to the actual working condition and the type of protective gas to achieve the purpose of strengthening the sealing.

[0037] In some embodiments of the present application, the protruding end of the feed pipe 4 is threadedly connected with a pipe joint 13, the pipe joint 13 is used to install and connect the raw material conveying pipe of the raw material storage tank, and the compression block 9 is threadedly connected on the feed pipe 4 between the pipe joint 13 and the flange cover 8, the compression block 9 can be selected as a compression nut, and the flange cover 8 and the rough pipe segment 7 are compressed by rotating the compression block 9 to strengthen the sealing.

[0038] In some embodiments of the present application, the pipe joint 13 is provided with a clamping position for facilitating the force of the tool. Specifically, for example, the tool is a wrench, and the clamping position can be correspondingly provided with a plane 11 on the outer peripheral wall of the pipe joint 13, and the plane 11 can be a cutting plane. In some embodiments of the present application, as shown in Figure 1 The pipe joint 13 is connected with a matched split nut 18 (for example, SS-4-VCR-4-SN split nut) at one end and is connected (for example, welded) with a threaded connection segment at the other end to form, wherein the threaded connection segment is provided with threaded segments at both ends, the middle segment of the threaded connection segment is not provided with threads, and the outer peripheral wall of the middle segment is provided with a plane 11 in opposite directions, and the threaded connection segment is tightened to prevent the compression block 9 from loosening.

[0039] As shown in Figures 3-4 To avoid the rotation of the feed pipe when the compression block 9 is rotated, resulting in the inability to compress, in some embodiments of the present application, the large hole 14 of the stepped hole is provided as a square hole, and the outer side wall surface of the rough pipe segment 7 has a plane matched with the side wall surface of the square hole to limit the relative rotation between the feed pipe 4 and the stepped hole.

[0040] When the compression block 9, the flange cover 8 and the rough pipe segment 7 are compressed, the feed pipe 4 may be subjected to a compression force which can cause displacement and deformation of the feed pipe 4, therefore, as shown in Figure 1 The feed pipe 4 located in the positive pressure cavity has a coil segment 5 rotated in the height direction to buffer and avoid damage caused by deformation.

[0041] The advantages of the present application will be illustrated by the following embodiments, but the present application is not limited thereto.

[0042] The following examples employ a feed seal for a microchannel reactor as shown in Figures 1-4 The feed seal for a microchannel reactor as shown in FIG. 1, wherein the microchannel reactor is connected to a feed distributor 3, a flange 2 is welded on the microchannel reactor and surrounds the feed distributor 3, the flange 2 is bolted and sealed with a flange cover 8, two feed tubes 4 are respectively connected to the feed distributor 3 through the flange cover 8, wherein the feed tubes 4 between the flange cover 8 and the feed distributor 3 are provided with a thick tube segment 7, the flange cover 8 is provided with a protective gas feed 17 and a stepped hole, the large hole 14 of the stepped hole is matched with the thick tube segment 7 and a gasket is arranged between the two, the feed tube 4 above the thick tube segment 7 extends out of the flange cover 8 and the extended feed tube is provided with, from bottom to top, a compression nut, a threaded connection segment, a standard pipe joint and a split nut, and two cutting planes 11 are oppositely arranged on the outer side wall surface of the threaded connection segment; wherein the small hole 15 of the stepped hole is a round hole, the large hole 14 is a square hole, and the outer wall surface of the thick tube segment 7 has a flat surface matched with the wall surface of the large hole 14, and the rotation is limited by the matching of the thick tube segment 7 and the wall surface of the large hole 14.

[0043] Example 1

[0044] In the methane catalytic partial oxidation reaction system, methane and air are easy to form an explosive mixture at high temperature, so the two raw materials cannot be premixed. The feed distributor 3 is fastened to the microchannel reactor by bolts, a copper gasket is installed between the thick tube segment 7 of the feed tube 4 and the large hole 14, the two feed tubes 4 pass through the flange cover 8 from the stepped hole, and the feed tube 4 between the flange cover 8 and the feed distributor 3 is provided with a coil segment 5. The compression nut and the pipe joint 13 are installed above the feed tube 4, the pipe joint 13 adopts a standard pipe joint with product number 6LV-4-HVCR-3-1.31SR, one end of which is connected to a matching split nut SS-4-VCR-4-SN, and the other end is welded with a threaded connection segment, wherein the two ends of the threaded connection segment are provided with threads, the middle segment of the threaded connection segment is not provided with threads, and the outer peripheral wall of the middle segment is oppositely provided with planes 11, the compression nut is tightened to realize the sealing of the sealing surface. The protective gas feed 17 is connected to the nitrogen gas charging interface. The raw material gas CH4 and O2 enter the feed distributor 3 through two feed tubes 4 respectively. The cavity inside the flange is flushed with protective nitrogen gas through the nitrogen gas charging interface to prevent leakage of raw material gas between the microchannel reactor and the feed distributor 3. The pressure change in the cavity of the microchannel reactor flange is monitored through the pressure gauge of the nitrogen gas charging pipeline, and whether there is leakage at all sealing interface positions is monitored through the olfactory sensitive instrument, and the air tightness test results are listed in Table 1.

[0045] Example 2

[0046] Hydrogen and oxygen can form explosive mixtures over a wide range of concentrations (5-96 vol% H2) and are involved in a number of side reactions. The use of microreactor technology and separate feed of the raw materials can suppress the progress of the explosion and thus reduce the safety risks of the direct synthesis of hydrogen peroxide from hydrogen and oxygen. The use of the present application Figures 1-4 As shown in Figure 1, the device structure is the same as in Example 1, and the raw material gases H2and O2are fed into the feed distributor 3 through two feed pipes 4. The cavity inside the flange is filled with protective nitrogen gas through the nitrogen gas charging port to prevent leakage of the raw material gases between the microchannel reactor and the feed distributor. The pressure change in the cavity inside the flange of the microchannel reactor is monitored through the pressure gauge of the nitrogen gas charging pipeline, and whether there is leakage at all sealed interface positions is monitored through the olfactory sensitive instrument. The results of the air tightness test are shown in Table 1.

[0047] Comparative Example 1

[0048] Unlike Example 1, the threaded connection section of the pipe joint 13 is provided with continuous threads, and the flat surface 11 is not provided. The large hole 14 of the stepped hole is provided with a round hole matching the size of the thick pipe section 7, instead of a square hole with a limiting function. The cavity inside the flange is filled with protective nitrogen gas through the nitrogen gas charging port, the pressure change in the cavity inside the flange of the microchannel reactor is monitored through the pressure gauge of the nitrogen gas charging pipeline, and whether there is leakage at all sealed interface positions is monitored through the olfactory sensitive instrument. The results of the air tightness test are shown in Table 1.

[0049] Comparative Example 2

[0050] Unlike Example 2, the feed pipe 4 is not provided with the coil section 5, but is a straight pipe. The same sealing structure installation steps as in Example 2 are adopted, and the cavity inside the flange is filled with protective nitrogen gas through the nitrogen gas charging port, the pressure change in the cavity inside the flange of the microchannel reactor is monitored through the pressure gauge of the nitrogen gas charging pipeline, and whether there is leakage at all sealed interface positions is monitored through the olfactory sensitive instrument. The results of the air tightness test are shown in Table 1.

[0051] Table 1 Air tightness test results at room temperature

[0052] 30 min ΔP 5 h ΔP Leak monitoring Ease of tightening Example 1 0 0 No leak Easy Example 2 0 0 No leak Easy Comparative Example 1 200 \ Leak Feed tube whipping, difficult to tighten Comparative Example 2 50 \ Leak Straight tube in cavity, no deformation, difficult to tighten

[0053] Note: ΔP is the pressure drop value, kPa; the initial pressure is 1000 kPa.

[0054] The present application adopts the method of opening holes in the flange cover and forming compression sealing surface at the holes to realize the sealing when two or more raw material pipelines are connected to the micro-channel reactor, and to achieve the requirement of the reaction system for no premixing of raw materials. In the method, two or more feeding pipes are directly connected to the connecting ports of the feeding distributor, and the feeding pipes are taken out together with the feeding distributor when the catalyst is loaded. The flange cover is provided with a protective gas feeding port, and the reaction condition is protected by nitrogen to prevent the internal gas of the reactor from leaking. The present application has the advantages of simple structure, easy processing, easy disassembly and assembly, and good sealing, and solves the sealing problem of the micro-channel reactor when multiple feeding pipes pass through the flange cover to meet the requirement of no premixing of raw materials, and ensures the safety of the reaction process.

[0055] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. However, these simple modifications and combinations should also be regarded as the disclosed content of the present application, and belong to the protection scope of the present application.

Claims

1. A feed sealing device for a microchannel reactor, characterized in that, The feed sealing device includes: Microchannel reactor, with a feed distributor detachably installed (3); A sealed housing with a positive pressure chamber inside is installed on the microchannel reactor and covers the feed distributor (3) inside the positive pressure chamber; Multiple feed pipes (4), the inner end of the feed pipe (4) is located in the positive pressure chamber and connected to the feed distributor (3), and the outer end of the feed pipe (4) extends out of the sealing housing and is sealed to the sealing housing; A protective gas inlet (17) is provided on the sealing housing and is used to introduce protective gas into the positive pressure chamber; The sealed housing includes a flange (2) that is sealed and fixedly disposed on the outer wall of the microchannel reactor and a flange cover (8) that is sealed to the flange (2). The flange (2) and the flange cover (8) together form a positive pressure chamber covering the feed distributor (3). The flange cover (8) has a through hole for each feed pipe to pass through. The through hole is a stepped hole, and the small hole (15) of the stepped hole is located above the large hole (14). The feed pipe (4) has a thick pipe section (7). The thick pipe section (7) cooperates with the large hole (14) of the stepped hole to form a sealing structure. The thick pipe section (7) and the stepped hole form a sealing structure. A gasket is provided between the large holes (14). The protruding end of the feed pipe (4) is threaded with a pipe fitting (13). The pipe fitting (13) is used to install the raw material conveying pipe connecting the raw material storage tank. A clamping block (9) is threaded on the feed pipe (4) between the pipe fitting (13) and the flange cover (8). The flange cover (8) and the thick pipe section (7) are clamped by rotating the clamping block (9) to strengthen the seal. The large hole (14) of the stepped hole is set as a square hole. The outer wall surface of the thick pipe section (7) has a plane that matches the side wall surface of the square hole to prevent relative rotation between the feed pipe (4) and the stepped hole.

2. The feed sealing device for the microchannel reactor according to claim 1, characterized in that, The feed distributor (3) is fixedly connected to each of the feed pipes (4), and the feed distributor (3) is connected to the microchannel reactor by bolts.

3. The feed sealing device for the microchannel reactor according to claim 1, characterized in that, The gasket is selected from graphite gaskets or metal gaskets.

4. The feed sealing device for the microchannel reactor according to claim 1, characterized in that, The pipe joint (13) is provided with a locking position to facilitate the application of force by loading and unloading tools.

5. The feed sealing device for the microchannel reactor according to claim 4, characterized in that, The loading and unloading tool is a wrench, and the locking position is a plane (11) that is relatively set on the outer peripheral wall of the pipe joint (13).

6. The feed sealing device for the microchannel reactor according to claim 1, characterized in that, The feed pipe (4) located in the positive pressure chamber has a coil section (5) that is coiled in the height direction.

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