Gas-liquid distributor and upflowing reactor

Abstract

The gas-liquid distributor and upflow reactor, the gas-liquid distributor comprises feeding distribution structure, mixing main pipe (7), transition section (8) and outlet (10) which are communicated in sequence from bottom to top; the feeding distribution structure is composed of bubble cap (3), flow baffle (2) and liquid inlet pipe (4) from bottom to top, the bottom of the liquid inlet pipe is opened below the flow baffle, the top is opened in the mixing main pipe, the annular space between the sidewall of the bubble cap and the main pipe is liquid inlet (1); the wall of the mixing main pipe is provided with air inlet (6), and the transition section is internally provided with distribution component (9). The gas-liquid distributor provided by the application can form jet flow to shear at high speed, so that the gas phase is dispersed in the liquid phase in the form of small bubbles, the gas-liquid mass transfer efficiency can be significantly improved, and the reaction efficiency is promoted, and the gas-liquid distributor is especially suitable for hydrocarbon oil liquid phase hydrogenation process device.

Description

Technical Field

[0001] This invention relates to reactor internals and reactors, and more specifically, to a gas-liquid distributor and an upward-flowing reactor. Background Technology

[0002] Upward-flow reactors are a widely used technology in the petrochemical industry, including upward-flow fixed-bed residue hydrotreating reactors, fluidized-bed hydrotreating reactors, and suspended-bed hydrotreating reactors. Compared with traditional downflow fixed-bed reactors, upward-flow reactors have advantages such as better adaptability to high-metal and low-quality feedstocks, higher reactor space utilization, and lower pressure drop. However, they also have drawbacks, such as uneven micro-expansion of the catalyst bed, which can easily lead to material flow deviation, causing temperature fluctuations in the catalyst bed, increased radial temperature difference, and a tendency for hot spots to appear.

[0003] In an upward-flowing reactor, both the gaseous and liquid phases of the reaction stream flow upwards. The liquid phase at the reactor outlet is continuous, while hydrogen is dispersed. Since hydrogen is supplied as dissolved hydrogen, to ensure stable hydrogen partial pressure and dissolution rate, the dissolved hydrogen in the liquid phase is always saturated, and a small amount of hydrogen exists in gaseous form. For gas-liquid two-phase mass transfer processes, especially liquid-phase hydrogenation processes where the reaction rate is much greater than the mass transfer rate, the mass transfer rate is crucial in determining the macroscopic reaction rate and thus becomes the controlling step. Increasing the mass transfer surface area can significantly improve the mass transfer rate; however, existing technologies have limited increases in mass transfer surface area due to the large bubble diameter, thus limiting the hydrogen dissolution rate and mass transfer efficiency.

[0004] CN205095759U discloses an upward-flowing gas-liquid distributor, which includes a guide pipe and mixing elements. Mixing elements are spaced apart above the upper opening of the guide pipe. The mixed fluid flowing through the guide pipe exits from the upper opening and reaches the mixing elements. This device only enhances the mixing between the gas and liquid phases through the mixing elements; technical parameters such as bubble size and distribution uniformity, as well as the corresponding technical effects, are not described.

[0005] CN203737216U discloses an upward-flowing gas-liquid distributor for a multiphase flow reactor. The distributor comprises a rain cap, a distribution plate, a gas-liquid riser pipe, an inlet pipe, a connector, and baffles. This distributor effectively suppresses the generation of large bubbles, thereby improving the efficiency of gas-liquid mass transfer within the reactor. However, this distributor suffers from limitations such as limited operational flexibility.

[0006] CN211754819U discloses an upward-flowing gas-liquid distributor with packing material, comprising a proprietary upward-flowing gas-liquid distributor consisting of a coaxial and fixedly connected lower straight pipe section, a hyperbolic pipe, and an upper straight pipe section. The upper straight pipe section is filled with wire mesh corrugated packing material; the lower straight pipe section has a through hole, with the bottom opening of the lower straight pipe section serving as the inlet and the top opening of the upper straight pipe section serving as the outlet. However, this invention is not applicable to hydrogenation processes such as those involving residual oil. A drawback of this invention is the lack of radial gas diffusion functionality. Summary of the Invention

[0007] To address the problems of uneven gas-phase dispersion and limited radial dispersion effect in existing technologies, this invention provides a gas-liquid distributor and an upward reactor. The gas-liquid distributor can be used for gas-liquid two-phase dispersion in an upward reactor, and is particularly suitable for hydrogenation reactors for gasoline, diesel, residual oil, wax oil, and lubricating oil.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a gas-liquid distributor, comprising a feed distribution structure, a mixing main pipe 7, a transition section 8, and an outlet 10 connected sequentially from bottom to top; the feed distribution structure is composed of a bubble cap 3, a baffle plate 2, and a liquid inlet pipe 4, the baffle plate having an open structure, the bottom opening of the liquid inlet pipe being located below the baffle plate, and the top opening being located inside the mixing main pipe, the annular gap between the side wall of the bubble cap and the mixing main pipe serving as the liquid inlet 1; the mixing main pipe wall having an air inlet 6, and the transition section having an internal distribution component 9.

[0009] Secondly, the upward reactor provided by the present invention has multiple distribution plates 11 inside the reactor shell, each distribution plate having a catalyst bed. The distribution plates have openings, and the gas-liquid distributors mentioned above are provided corresponding to the openings. The reactor shell has a bottom raw material inlet, a top outlet, and a gas inlet, with the gas inlet located below the bottom distribution plate.

[0010] The application method of the gas-liquid distributor provided by the present invention is as follows: the liquid phase entering the upward reactor enters the gas-liquid distributor through the lower inlet, the liquid flow passes through the baffle plate and enters the bubble cap, and enters the inlet pipe through the bottom liquid phase inlet. The distribution is enhanced by the baffle structure, and after forming a high-speed jet, it enters the mixing main pipe. In the mixing main pipe, the gas phase enters through the gas inlet and is sheared into multiple micro bubbles by the high-speed liquid phase jet. Then, the gas and liquid phases are further dispersed and radially diffused by the distribution components in the transition section, and finally overflow through the top outlet to form a uniform bubbling flow.

[0011] The beneficial effects of the gas-liquid distributor and upward reactor provided by this invention are as follows:

[0012] The gas-liquid distributor provided by this invention can efficiently mix gas and liquid and generate microbubbles through a feeding and distributing structure, a mixing main pipe, and an upper transition section to enhance gas-liquid mass transfer efficiency. Compared with the prior art, the gas-liquid distributor provided by this invention increases the gas holdup by more than 56% and has better distribution performance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of one embodiment of a gas-liquid distributor.

[0014] Figure 2 This is a schematic diagram of the second embodiment of the gas-liquid distributor.

[0015] Figure 3 A schematic diagram of one embodiment of the distribution component.

[0016] Figure 4 A schematic diagram of the structure for the second embodiment of the distribution component.

[0017] Figure 5 This is a schematic diagram of an upward-flowing reactor.

[0018] Figure 6 This is a schematic diagram of the gas-liquid distributor in Comparative Example 1.

[0019] in:

[0020] 1-Inlet 2-Baffle 3-Bubble

[0021] 4-Liquid inlet pipe; 5-Liquid phase outlet; 6-Gas inlet.

[0022] 7-Mixed main pipe 8-Transition section 9-Distribution component

[0023] 10-Exports 11-Distribution Panel 12-Raw Material Imports

[0024] 13-Product Export

[0025] 14-Inlet 15-Liquid riser pipe 16-Through hole

[0026] 17-Export Detailed Implementation

[0027] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0028] In this application, the terms "upper part," "lower part," and "bottom" are all based on the relative positional relationship of the container or component. Specifically, "bottom" refers to the position of the container from bottom to top of 0-10%, and "top" refers to the position of the container from bottom to top of 90-100%.

[0029] In a first aspect, the present invention provides a gas-liquid distributor, comprising, from bottom to top, a feeding distribution structure, a mixing main pipe 7, a transition section 8, and an outlet 10 connected in sequence; the feeding distribution structure is composed of a bubble cap 3, a baffle plate 2, and a liquid inlet pipe 4, the baffle plate having an open structure, the bottom opening of the liquid inlet pipe being below the baffle plate, and the top opening being inside the mixing main pipe, the annular gap between the side wall of the bubble cap and the mixing main pipe being the liquid inlet 1; the mixing main pipe wall having an air inlet 6, and the transition section having a distribution component 9.

[0030] Optionally, the inner diameter ratio of the inlet pipe to the mixing main pipe is 1:2 to 20, preferably 1:3 to 10, more preferably 1:6 to 10; the inner diameter ratio of the mixing main pipe to the blister is 1:1.2 to 20, preferably 1:1.2 to 2; the inner diameter ratio of the mixing main pipe to the outlet is 1:3 to 10, preferably 1:4 to 7; and the height ratio of the blister, the mixing main pipe, and the transition section is 1 to 5:10 to 30:5 to 30.

[0031] Optionally, the distance between the baffle and the bottom of the bubble cap is 30% to 90% of the bubble cap height; the bottom of the mixing main pipe is at least 10 mm away from the baffle; the inlet pipe extends into the mixing main pipe by 5 to 100 mm; and the outlet height is 30 to 200 mm.

[0032] Optionally, the inner diameter of the blister pack is 30-80 mm, preferably 30-60 mm; the inner diameter of the liquid inlet pipe is 2-20 mm, preferably 5-10 mm.

[0033] Preferably, the inlet pipe is conical or trapezoidal, with the ratio of the inner diameter of the top to the bottom being 1:2 to 10.

[0034] Optionally, the baffle plate has an open structure with an open area ratio of 2% to 30%, and the distance between the baffle plate and the bottom of the bubble cap is 30% to 90% of the bubble cap height.

[0035] Optionally, the ratio of the inner diameter of the inlet pipe to the mixing main pipe is 1:2 to 20, preferably 1:3 to 10, and the ratio of the height of the inlet pipe to the mixing main pipe is 1:2 to 20, preferably 1:3 to 5.

[0036] Optionally, in the mixing main pipe, the diameter of the air inlet is 1-10 mm, preferably 2-5 mm; preferably, the air inlet is located in the mixing main pipe at a height range of 30%-80% from bottom to top; preferably, 2-24 air inlets are evenly distributed in the circumference of the mixing main pipe, more preferably 4-12 air inlets.

[0037] Optionally, when the outlet inner diameter is larger than the mixing main pipe inner diameter, the transition section is an inverted conical structure with a distribution component inside. When the outlet inner diameter is the same as the mixing main pipe inner diameter, the transition section is a straight cylinder with a distribution component inside. In the transition section, the distribution component is at least one layer of sieve plate or sieve mesh structure with a porosity of 2%-50%; or the distribution component has a porosity of 30%-50% and a specific surface area of ​​200-2000 m². ～1 The packing material. The distribution component can be structured packing or random packing; optionally, the packing material is wire mesh packing or corrugated packing.

[0038] Optionally, the blister pack, inlet pipe, mixing main pipe, and transition section are coaxially arranged.

[0039] Optionally, the blister pack and the inlet pipe are movably connected, and the mixing main pipe and the transition section are movably connected. Preferably, a threaded connection is used.

[0040] Secondly, the present invention provides an upward reactor, wherein multiple distribution disks 11 are provided inside the reactor shell, each distribution disk is provided with a catalyst bed, the distribution disks are perforated, and any of the above-mentioned gas-liquid distributors are provided corresponding to the perforations, the reactor shell is provided with a bottom raw material inlet, a top outlet and a gas inlet, the gas inlet being located below the bottommost distribution disk.

[0041] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0042] The structure and effects of the gas-liquid distributor provided by the present invention will be described below with reference to the accompanying drawings.

[0043] Appendix Figure 1 This is a schematic diagram of one embodiment of a gas-liquid distributor. (See attached diagram.) Figure 1 As shown, the gas-liquid distributor includes a feed distribution structure, a mixing main pipe 7, a transition section 8, and an outlet 10 connected sequentially from bottom to top. The feed distribution structure consists of a bubble cap 3, a baffle plate 2, and a liquid inlet pipe 4. The bottom opening of the liquid inlet pipe is located below the baffle plate, and the top liquid phase outlet 5 opens into the mixing main pipe. The annular gap between the side wall of the bubble cap and the mixing main pipe is the liquid inlet 1. The mixing main pipe has an air inlet 6 on its wall. The transition section has an inverted conical structure and is equipped with a distribution component 9 inside.

[0044] Appendix Figure 2 This is a schematic diagram of a second embodiment of the gas-liquid distributor. (See attached diagram.) Figure 1The difference is that the inner diameter of the inlet pipe 4 is the same as that of the mixing main pipe, and the transition section is a straight cylindrical structure.

[0045] Appendix Figure 3 A schematic diagram of one embodiment of the distribution component within the transition section is shown in the attached figure. Figure 3 As shown, the distribution component is a plate-type structured packing, which can be made of carbon steel, stainless steel, etc., with an opening ratio of 2% to 30%.

[0046] Appendix Figure 4 A structural schematic diagram of the second embodiment of the distribution component within the transition section is shown in the attached diagram. Figure 4 As shown, the distribution component is a structured packing material with small holes, which can be made of carbon steel, stainless steel, etc., with an opening rate of 2% to 30%.

[0047] Appendix Figure 5 This is a schematic diagram of an upward-flowing reactor. (See attached diagram) Figure 5 As shown, a distribution plate 11 is provided at the lower part of the shell of the upward hydrogenation reactor. The distribution plate has openings, and a gas-liquid distributor of any of the above-mentioned types is provided corresponding to the openings. A raw material inlet 12 is provided at the bottom of the shell of the upward hydrogenation reactor. The raw material inlet is located below the bottom distribution plate 11, and the gas inlet is also located below the bottom distribution plate 11. The reactor shell is provided with a top outlet 13.

[0048] The following examples further illustrate the structure and effects of the gas-liquid distributor and the upward reactor provided by the present invention, but the present invention is not limited thereto.

[0049] Comparative Example 1

[0050] The structure of the gas-liquid distributor using existing technology is shown in the attached diagram. Figure 6 The structure of the gas-liquid distributor includes a gas-liquid phase inlet 14, a riser pipe 15, a central opening 16, and an outlet 17. The gas-liquid distributor pipe has an inner diameter of 50 mm and a length of 100 mm. There are two vent holes with a diameter of 5 mm in the middle of the pipe. The top structure of the riser pipe is a perforated plate structure with 20 holes, each with a diameter of 3 mm.

[0051] Gas-liquid distribution method:

[0052] The liquid phase enters the riser pipe directly from the lower port of the gas-liquid distributor, while the gas phase enters from the side of the pipe. After mixing, the two phases move upward and form bubbles at the opening in the middle, which overflow directly from the top into the upward reactor.

[0053] (1) In the process of measuring gas holdup, the initial liquid level height and the liquid level height after bubbling are measured by the volume expansion method, and the gas holdup E in the liquid phase is calculated. a The calculation formula is as follows:

[0054]

[0055] Among them, H i H represents the initial liquid level height. n The liquid level height after bubbling; gas holdup E a The results are shown in Table 1.

[0056] (2) Bubble diameter measurement process

[0057] The diameter of bubbles in the cross-section of the liquid is measured, and the average bubble diameter is used to represent the mixing effect between the gas and liquid phases. During the measurement, it is assumed that all bubbles are spherical, and the equivalent diameter d of the bubble can be represented by the Sauter chord length. 32 The calculation formula is as follows:

[0058]

[0059] Where: n i For a diameter of d i The number of bubbles is denoted as N; N is the total number of bubbles counted. The results are shown in Table 2.

[0060] Example 1

[0061] A distribution plate is installed at the lower part of the upward-flowing reactor. The distribution plate has openings, and gas-liquid distributors are installed corresponding to these openings. The raw material inlet 12 is located at the bottom of the reactor, and the gas inlet is located below the lowest distribution plate. The structure of the gas-liquid distributor is shown in the attached figure. Figure 1 As shown, the liquid inlet 1 and the baffle 2 form a bubble cover 3, which, together with the liquid inlet pipe 4, forms a lower jet generation structure.

[0062] The following specifications are provided: inlet pipe inner diameter 5mm, mixing main pipe inner diameter 50mm, bubble cap inner diameter 60mm, outlet inner diameter 200mm, bubble cap height 20mm, mixing main pipe height 200mm, transition section height 100mm, baffle plate distance from bubble cap bottom 10mm; mixing main pipe bottom distance from baffle plate 20mm; inlet pipe extends 20mm into mixing main pipe; outlet height 50mm. The baffle plate has holes with an opening rate of 5%. Six air inlets with a diameter of 2mm are evenly distributed along the circumference at 50% of the mixing main pipe height. Five layers of perforated plates are installed in the transition section with an opening rate of 30%.

[0063] Gas-liquid distribution method:

[0064] The liquid enters the bubble cap through the baffle plate from the gas-liquid distributor inlet and then forms a jet from the liquid inlet pipe into the mixing main pipe. The gas enters through the gas inlet. After the gas and liquid phases are mixed in the mixing main pipe, they enter the transition section to enhance the dispersion effect. After reaching the top, they overflow through the multi-stage perforated plate into the upward reactor.

[0065] Example 2

[0066] As attached Figure 5 As shown, the upward-flowing reactor has two layers of distribution plates. Each distribution plate has openings, and gas-liquid distributors are installed corresponding to these openings. The raw material inlet is located at the bottom of the reactor, and the gas inlet is located below the lowest distribution plate. The method described in the attached diagram... Figure 2 The gas-liquid distributor structure shown has an inlet 1 and a baffle 2 forming a bubble cap structure 3, which together with the inlet pipe 4 forms a lower jet generation structure.

[0067] The inlet pipe has an inner diameter of 5mm, the mixing main pipe has an inner diameter of 30mm, the bubble cap has an inner diameter of 50mm, the outlet has an inner diameter of 200mm, the bubble cap height is 30mm, the mixing main pipe height is 300mm, the transition section height is 150mm, and the distance between the baffle and the bottom of the bubble cap is 10mm; the distance between the bottom of the mixing main pipe and the baffle is 20mm; the inlet pipe extends 20mm into the mixing main pipe; and the outlet height is 100mm. The baffle has holes with an opening ratio of 25%.

[0068] The mixing main pipe has six 3mm diameter air inlets at 60% of its height from bottom to top, evenly distributed along the circumference. The transition section is filled with wire mesh packing with a porosity of 10%.

[0069] Gas-liquid distribution method:

[0070] The liquid enters the bubble cap through the baffle plate from the gas-liquid distributor inlet and then forms a jet from the liquid inlet pipe into the mixing main pipe. The gas enters through the gas inlet. The gas and liquid phases are mixed in the mixing main pipe and then reach the transition section. The liquid is further dispersed by the wire mesh packing in the transition section and overflows into the upward reactor.

[0071] The measurement and calculation methods for each parameter are the same as in Comparative Example 1. The calculation results are shown in Table 1.

[0072] Table 1

[0073] Comparative Example 1 4.149 Example 1 7.246 Example 2 6.411

[0074] Table 2

[0075] Comparative Example 1 7.43 Example 1 4.15 Example 2 3.82

[0076] Generally, a higher gas holdup indicates better fluid distribution performance. As shown in Table 1, compared to Comparative Example 1, the multi-stage dispersion structure of the gas-liquid distributor provided by this invention can provide a greater mass transfer driving force, thereby increasing the mass transfer rate. Compared to Comparative Example 1, the gas holdup of Examples 1-2 of the gas-liquid distributor provided by this invention is also higher. Therefore, compared with the prior art, the gas-liquid distributor of this invention has a larger gas holdup and thus better distribution performance.

[0077] As shown in Table 2, the average bubble diameter of the gas-liquid distributor in Comparative Example 1 is 7.43 mm, while the bubble diameter of the gas-liquid distributors in Examples 1-2 is approximately 3-4 mm. This indicates that the gas-liquid distributor provided by the present invention has a slightly better mixing effect than the gas-liquid distributor in Comparative Example 1, generating smaller bubble diameters. Compared with the prior art, the gas-liquid distributor of the present invention has smaller bubble diameters, thus exhibiting better dispersion performance.

[0078] In upward-flowing gas-liquid two-phase reactions, smaller bubble diameters generally increase the gas-liquid mass transfer surface area and prolong the bubble residence time, both of which enhance mass transfer. For hydrogenation reactions, this translates to increased contact time between the hydrogen and oil components, further improving mass transfer and reaction rates between the gas and liquid phases. Therefore, minimizing bubble size is advantageous for both upward-flowing and all-liquid-phase hydrogenation processes from any perspective.

Claims

1. A gas-liquid distributor, characterized in that, The system includes a feed distribution structure, a mixing main pipe (7), a transition section (8), and an outlet (10) connected sequentially from bottom to top. The feed distribution structure consists of a bubble cap (3), a baffle plate (2), and an inlet pipe (4). The baffle plate has an open structure. The bottom of the inlet pipe opens below the baffle plate, and the top opens inside the mixing main pipe. The bottom of the mixing main pipe is at least 10 mm away from the baffle plate. The annular gap between the side wall of the bubble cap and the mixing main pipe is the inlet (1). The mixing main pipe has an air inlet (6) on its wall. The transition section is provided with a distribution component (9). The distribution component is at least one layer of sieve plate or sieve mesh with an opening rate of 2%-50%. Alternatively, the distribution component has a porosity of 30%-50% and a specific surface area of ​​200-2000 m². -1 The packing material; the inner diameter ratio of the mixing main pipe to the outlet is 1:(3~10); the inner diameter ratio of the inlet pipe to the mixing main pipe is 1:(2~20); the inlet pipe extends into the mixing main pipe by 5~100mm.

2. The gas-liquid distributor according to claim 1, characterized in that, The inner diameter ratio of the mixing main pipe to the blister is 1:(1.2~20); the height ratio of the blister, the mixing main pipe and the transition section is (1~5):(10~30):(5~30).

3. The gas-liquid distributor according to claim 2, characterized in that, The ratio of the inner diameter of the inlet pipe to the mixing main pipe is 1:(6-10); the ratio of the inner diameter of the mixing main pipe to the bubble cap is 1:(1.2-2); and the ratio of the inner diameter of the mixing main pipe to the outlet is 1:(4-7).

4. The gas-liquid distributor according to claim 1, 2, or 3, characterized in that, The distance between the baffle and the bottom of the bubble cap is 30% to 90% of the bubble cap height; the outlet height is 30 to 200 mm.

5. The gas-liquid distributor according to claim 1, 2, or 3, characterized in that, The inner diameter of the blister pack is 30-80 mm, and the inner diameter of the liquid inlet pipe is 2-20 mm.

6. The gas-liquid distributor according to claim 5, characterized in that, The inner diameter of the blister pack is 30-60 mm, and the inner diameter of the liquid inlet pipe is 5-10 mm.

7. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The baffle plate has an opening ratio of 2%-30%.

8. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The diameter of the air inlet is 1 to 10 mm.

9. The gas-liquid distributor according to claim 8, characterized in that, The diameter of the air inlet is 2-5 mm.

10. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The air inlet is located within a height range of 30%-80% from bottom to top of the mixing main pipe.

11. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The mixing tube has 2 to 24 air inlets evenly distributed around its circumference.

12. The gas-liquid distributor according to claim 11, characterized in that, The mixing tube has 4 to 12 air inlets evenly distributed around its circumference.

13. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The blister pack, inlet pipe, mixing main pipe, and transition section are coaxially arranged.

14. The gas-liquid distributor according to claim 1, 2 or 3, characterized in that, The blister pack and the inlet pipe are connected movably, as are the mixing main pipe and the transition section.

15. An upward-flowing reactor, characterized in that, The reactor shell is provided with multiple distribution plates (11), each distribution plate is provided with a catalyst bed, the distribution plates are provided with openings, and gas-liquid distributors according to any one of claims 1-14 are provided corresponding to the openings. The reactor shell is provided with a bottom raw material inlet, a top outlet and a gas inlet, the gas inlet being located below the bottom distribution plate.

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