Gas-liquid distributor and upstream reactor

Abstract

The gas-liquid distributor comprises a feeding distribution structure, a mixing main pipe (7), a transition section (8) and an outlet (10) which are communicated in sequence from bottom to top; the feed distribution structure is composed of a bubble cap (3), a flow baffle (2) and a liquid inlet pipe (4) from bottom to top, an opening in the bottom of the liquid inlet pipe is formed below the flow baffle, an opening in the top of the liquid inlet pipe is formed in the mixing main pipe, and an annular space between the side wall of the bubble cap and the main pipe is a liquid inlet (1); an air inlet (6) is formed in the pipe wall of the mixing main pipe, and a distribution component (9) is arranged in the transition section. According to the gas-liquid distributor provided by the invention, the gas phase is efficiently dispersed in the liquid phase in the form of tiny bubbles by forming jet flow and shearing at a high speed, the gas-liquid mass transfer efficiency can be remarkably improved, the reaction efficiency is further promoted, and the gas-liquid distributor is particularly suitable for a hydrocarbon oil liquid phase hydrogenation process device.

Description

Technical Field

[0001] The present invention relates to a reactor internal component and a reactor, and more particularly to a gas-liquid distributor and an upward reactor. Background Art

[0002] The upward reactor is a widely used technology in the field of petrochemicals, such as the upward fixed-bed residue oil hydrogenation reactor, the fluidized bed hydrogenation reactor and the suspended bed hydrogenation reactor. Compared with the traditional downward fixed-bed reactor, the upward reactor has the advantages of good adaptability to high-metal and low-quality raw materials, high reactor space utilization, and low pressure drop. However, it also has the advantages of uneven micro-expansion of the catalyst bed, which can easily lead to material deviation and cause catalyst bed temperature fluctuations, increase radial temperature differences, and easily cause hot spots.

[0003] In an upward reactor, both the gas phase and the liquid phase of the reactant flow flow in the reactor in a bottom-up direction, the liquid phase of the reactor outlet section is a continuous phase, and the hydrogen is a dispersed phase. Since the hydrogen is provided in the form of dissolved hydrogen, in order to ensure a stable hydrogen partial pressure and hydrogen dissolution rate, the dissolved hydrogen in the liquid phase is always in a saturated state and a small amount of hydrogen exists in the form of gas. 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 the key to determining the macroscopic reaction rate and therefore becomes a controlling step. The mass transfer rate can be significantly increased by increasing the mass transfer specific surface area, but the prior art has a limited increase in the mass transfer specific surface area due to the large bubble diameter, which limits the hydrogen dissolution rate and mass transfer effect.

[0004] CN205095759U discloses an upward gas-liquid distributor, which includes a flow guide tube and a flow mixing piece. The flow mixing piece is arranged above the upper pipe opening of the flow guide tube at intervals, and the mixed fluid passing through the flow guide tube flows out from the upper pipe opening of the flow guide tube and reaches the flow mixing piece. The device only strengthens the mixing between the gas and liquid phases through the flow mixing piece, and the technical parameters such as the bubble size and distribution uniformity and the corresponding technical effects are not described.

[0005] CN203737216U discloses an upward gas-liquid distributor for a multiphase flow reactor, which is composed of a rain cap, a distribution plate, a gas-liquid riser, an air inlet pipe, a connector and a baffle. The distributor has an inhibitory effect on the amount of large bubbles generated, and can improve the efficiency of gas-liquid mass transfer in the reactor, but the distributor has problems such as low operational flexibility.

[0006] CN211754819U discloses an upward gas-liquid distributor with fillers, including a proprietary upward gas-liquid distributor consisting of a coaxial and fixedly connected lower straight pipe section, a hyperbolic pipe and an upper straight pipe section, wherein the upper straight pipe section is filled with a wire mesh corrugated filler; a through hole is provided on the lower straight pipe section, the bottom opening of the lower straight pipe section is an inlet, and the top opening of the upper straight pipe section is an outlet. However, the invention cannot be applied to hydrogenation processes such as residual oil. The disadvantage of the invention is that it does not have the function of radial diffusion of gas. Summary of the invention

[0007] In view of the problems of uneven gas phase dispersion and limited radial dispersion effect in the prior art, the present invention provides a gas-liquid distributor and an ascending reactor. The gas-liquid distributor can be used for gas-liquid two-phase dispersion in an ascending reactor, and is particularly suitable for hydrogenation reactors such as gasoline, diesel, residual oil, wax oil and lubricating oil.

[0008] To achieve the above-mentioned purpose, 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 which are sequentially connected 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 is an open-hole structure, the bottom opening of the liquid inlet pipe is located below the baffle plate, and the top opening is in the mixing main pipe, and the annular gap between the side wall of the bubble cap and the mixing main pipe is the liquid inlet 1; the wall of the mixing main pipe is provided with an air inlet 6, and the transition section is provided with a distribution component 9 inside.

[0009] In the second aspect, the upward reactor provided by the present invention has a multi-layer distribution plate 11 arranged in the reactor shell, each layer of the distribution plate is provided with a catalyst bed, the distribution plate has holes, and the above-mentioned gas-liquid distributor is arranged corresponding to the holes, and the reactor shell is provided with a bottom raw material inlet, a top outlet and a gas inlet, and the gas inlet is 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 liquid inlet, the liquid flow passes through the baffle plate into the bubble cap, enters the liquid inlet pipe through the liquid phase inlet at the bottom, is distributed and strengthened by the baffle structure, and then enters the mixing main pipe after forming a high-speed jet. In the mixing main pipe, the gas phase enters through the gas inlet and is sheared into a plurality of tiny bubbles by the high-speed liquid phase jet. Thereafter, the gas-liquid two phases are further dispersed and radially diffused by the distribution component in the transition section, and finally overflow through the top outlet to form a uniform bubbling flow.

[0011] The gas-liquid distributor and the upward reactor provided by the present invention have the following beneficial effects:

[0012] The gas-liquid distributor provided by the present invention can efficiently mix gas and liquid and generate tiny bubbles to enhance the gas-liquid mass transfer efficiency through the feed distribution structure, the mixing main pipe and the upper transition section. Compared with the prior art, the gas-liquid distributor provided by the present invention has a gas holdup rate increased by more than 56% and has better distribution performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The figure is a schematic structural diagram of an implementation scheme of a gas-liquid distributor.

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

[0015] Figure 3 A schematic structural diagram of an implementation scheme of a distribution component.

[0016] Figure 4 It is a schematic structural diagram of a second embodiment of a distribution component.

[0017] Figure 5 Schematic diagram of the structure of the upward reactor.

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

[0019] in:

[0020] 1-Liquid inlet 2-Baffle 3-Blister

[0021] 4-Liquid inlet pipe 5-Liquid outlet 6-Air inlet

[0022] 7-mixing main pipe 8-transition section 9-distribution component

[0023] 10- outlet 11- distribution plate 12- raw material inlet

[0024] 13-Product export

[0025] 14- inlet 15- liquid lifting pipe 16- through hole

[0026] 17-Exit DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

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

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

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

[0031] Optionally, the distance between the baffle and the bottom of the bubble is 30% to 90% of the bubble height; the bottom of the mixing main pipe is not less than 10 mm away from the baffle; the liquid 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 bubble cap is 30 to 80 mm, preferably 30 to 60 mm; the inner diameter of the liquid inlet tube is 2 to 20 mm, preferably 5 to 10 mm.

[0033] Preferably, the liquid inlet pipe is conical or terraced, and the ratio of the inner diameters of the top and the bottom is 1:2-10.

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

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

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

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

[0038] Optionally, the bubble cap, liquid inlet pipe, main mixing pipe and transition section are coaxially arranged.

[0039] Optionally, the bubble cap and the liquid inlet pipe are movably connected, and the main mixing pipe and the transition section are movably connected, preferably through threaded connection.

[0040] In a second aspect, the present invention provides an upward reactor, wherein a plurality of distribution plates 11 are arranged in the reactor shell, each distribution plate is provided with a catalyst bed, the distribution plate is provided with holes, and any one of the above-mentioned gas-liquid distributors is arranged corresponding to the holes, the reactor shell is provided with a bottom raw material inlet, a top outlet and a gas inlet, and the gas inlet is located below the lowest distribution plate.

[0041] The above content describes in detail the preferred embodiments of the present invention. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

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

[0043] Attached Figure 1 FIG. 1 is a schematic diagram of a gas-liquid distributor according to an embodiment of the present invention. 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 which are connected in sequence 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 bottom opening of the liquid inlet pipe is located below the baffle plate, the liquid phase outlet 5 at the top opens in the mixing main pipe, and the annular gap between the side wall of the bubble cap and the mixing main pipe is the liquid inlet 1; the wall of the mixing main pipe is provided with an air inlet 6, the transition section is an inverted cone structure, and a distribution component 9 is provided inside.

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

[0045] Attached Figure 3 A schematic diagram of a distribution component in a transition section is shown in FIG. Figure 3 As shown, the distribution component is a plate-type structured packing, which can be made of carbon steel, stainless steel, etc., and has an opening rate of 2% to 30%.

[0046] Attached Figure 4 FIG. 1 is a schematic diagram of a second embodiment of a distribution component in a transition section, as shown in FIG. Figure 4 As shown, the distribution component is a structured filler with small holes, and the material can be carbon steel, stainless steel, etc., and the opening rate is 2% to 30%.

[0047] Attached Figure 5 Schematic diagram of the structure of the upward reactor. Figure 5 As shown, a distribution plate 11 is arranged at the lower part of the shell of the ascending hydrogenation reactor, and a hole is opened on the distribution plate. Any of the above-mentioned gas-liquid distributors is arranged corresponding to the hole. A raw material inlet 12 is arranged at the bottom of the shell of the ascending hydrogenation reactor, and the raw material inlet is located below the lowest distribution plate 11. The gas inlet is also located below the lowest distribution plate 11. The reactor shell is provided with a top outlet 13.

[0048] The structure and effect of the gas-liquid distributor and the ascending reactor provided by the present invention are further illustrated by examples below, but the present invention is not limited thereto.

[0049] Comparative Example 1

[0050] The gas-liquid distributor in the prior art is used, and the structure is shown in the attached Figure 6 The structure of the gas-liquid distributor includes a gas-liquid phase inlet 14, a riser 15, a middle opening 16 and an outlet 17. The gas-liquid distributor tube has an inner diameter of 50 mm and a length of 100 mm. Two vents with a diameter of 5 mm are opened in the middle of the tube. The top structure of the riser is a porous plate structure with 20 holes and a diameter of 3 mm.

[0051] Gas-liquid distribution method:

[0052] The liquid phase directly enters the riser from the lower port of the gas-liquid distributor, and the gas phase enters from the side of the tube. After the two are mixed, they move upward, forming bubbles at the middle opening and overflowing directly from the top into the upward reactor.

[0053] (1) Gas holdup measurement process: The volume expansion method is used to measure the initial liquid level and the liquid level after bubbling, and the gas holdup E in the liquid phase is calculated. a , the calculation formula is as follows:

[0054]

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

[0056] (2) Bubble diameter measurement process

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

[0058]

[0059] Where: n i The diameter is d i The number of bubbles is shown in Table 2.

[0060] Example 1

[0061] A distribution plate is arranged at the lower part of the upward reactor, and a hole is opened on the distribution plate. A gas-liquid distributor is arranged corresponding to the hole. 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 plate 2 form a bubble cap 3, and the liquid inlet pipe 4 form a lower jet generating structure.

[0062] Among them: the inner diameter of the liquid inlet pipe is 5mm, the inner diameter of the mixing main pipe is 50mm, the inner diameter of the bubble cap is 60mm, the inner diameter of the outlet is 200mm, the bubble cap height is 20mm, the height of the mixing main pipe is 200mm, the height of the transition section is 100mm, the distance between the baffle plate and the bottom of the bubble cap is 10mm; the distance between the bottom of the mixing main pipe and the baffle plate is 20mm; the liquid inlet pipe extends into the mixing main pipe by 20mm; the outlet height is 50mm. The baffle plate is provided with holes, and the opening rate is 5%. There are 6 air inlets evenly distributed along the circumference at the position of 50% of the height of the mixing main pipe, with an aperture of 2mm. Five layers of porous plates are set in the transition section, and the opening rate of the porous plates is 30%.

[0063] Gas-liquid distribution method:

[0064] The liquid enters the bubble cap from the inlet of the gas-liquid distributor through the baffle plate 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 enter the transition section to enhance the dispersion effect. After reaching the top, they overflow through the multi-stage porous plate into the upward reactor.

[0065] Example 2

[0066] As attached Figure 5 As shown, two layers of distribution plates are arranged in the upward reactor, and holes are opened on the distribution plates. Gas-liquid distributors are arranged corresponding to the holes. The raw material inlet is located at the bottom of the reactor, and the gas inlet is located below the lowest distribution plate. Figure 2 In the gas-liquid distributor structure shown, the liquid inlet 1 and the baffle plate 2 form a bubble structure 3, and the liquid inlet pipe 4 form a lower jet generating structure.

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

[0068] Six air inlets with a diameter of 3 mm are arranged at 60% of the height from bottom to top of the mixing main pipe, and the air inlets are evenly distributed along the circumference. The transition section is filled with a wire mesh filler with an opening rate of 10%.

[0069] Gas-liquid distribution method:

[0070] The liquid enters the bubble cap from the inlet of the gas-liquid distributor through the baffle plate 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 are mixed in the mixing main pipe and then reach the transition section. They are further dispersed through the wire mesh filler in the transition section and overflow into the upward reactor.

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

[0072] Table 1

[0073] Examples <![CDATA[Gas holdup E a , %]]> Comparative Example 1 4.149 Example 1 7.246 Example 2 6.411

[0074] Table 2

[0075] Examples Average bubble diameter d / mm Comparative Example 1 7.43 Example 1 4.15 Example 2 3.82

[0076] Generally speaking, the greater the gas holdup, the better the fluid distribution performance. As can be seen from Table 1, compared with Comparative Example 1, the multi-stage dispersion structure of the gas-liquid distributor provided by the present invention can provide a greater mass transfer driving force, thereby increasing the mass transfer rate. Compared with Comparative Example 1, the gas holdups of Examples 1-2 of the gas-liquid distributor provided by the present invention are all higher. It can be seen that compared with the prior art, the gas-liquid distributor of the present invention has a larger gas holdup and therefore has better distribution performance.

[0077] As can be seen from 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 distributor in Examples 1-2 is about 3-4 mm. This indicates that the mixing effect of the gas-liquid distributor provided by the present invention is slightly better than that of the gas-liquid distributor in Comparative Example 1, and the generated bubble diameter is smaller. Compared with the prior art, the gas-liquid distributor of the present invention has a smaller bubble diameter and therefore has better dispersion performance.

[0078] In the upward flow and reaction process of gas-liquid two-phase co-flow, generally speaking, a smaller bubble diameter is conducive to increasing the gas-liquid mass transfer surface area and extending the bubble residence time, both of which are conducive to enhancing the mass transfer effect. For hydrogenation reactions, it is equivalent to increasing the contact time between hydrogen and oil materials, achieving the effect of further improving the mass transfer and reaction rate between the gas and liquid phases. Therefore, no matter from which aspect, minimizing the bubble size is beneficial for the upward or all-liquid phase hydrogenation reaction process.

Claims

1. A gas-liquid distributor, characterized in that: The invention comprises a feed distribution structure, a mixing main pipe (7), a transition section (8) and an outlet (10) which are connected in sequence 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 is an open-hole structure; the bottom of the liquid inlet pipe opens below the baffle plate and the top opens in the mixing main pipe; the annular gap between the side wall of the bubble cap and the main pipe is a liquid inlet (1); the wall of the mixing main pipe is provided with an air inlet (6); and a distribution component (9) is provided in the transition section.

2. The gas-liquid distributor according to claim 1, characterized in that: The inner diameter ratio of the liquid inlet pipe to the mixing pipe is 1:2-20; the inner diameter ratio of the mixing pipe to the bubble cap is 1:1.2-20; the inner diameter ratio of the mixing pipe to the outlet is 1:3-10; the height ratio of the bubble cap, the mixing pipe and the transition section is 1-5:10-30:5-30; Preferably, the inner diameter ratio of the liquid inlet pipe to the mixing main pipe is 1:6-10; the inner diameter ratio of the mixing main pipe to the bubble cap is 1:1.2-2; and the inner diameter ratio of the mixing main pipe to the outlet is 1:4-7.

3. The gas-liquid distributor according to claim 1 or 2, characterized in that: The distance between the baffle and the bottom of the bubble is 30% to 90% of the bubble height; the distance between the bottom of the mixing main pipe and the baffle is not less than 10 mm; the liquid inlet pipe extends into the mixing main pipe by 5 to 100 mm; and the outlet height is 30 to 200 mm.

4. The gas-liquid distributor according to claim 2, characterized in that: The inner diameter of the bubble cap is 30-80 mm, preferably 30-60 mm; the inner diameter of the liquid inlet tube is 2-20 mm, preferably 5-10 mm.

5. The gas-liquid distributor according to claim 1, characterized in that: The opening rate of the baffle plate is 2%-30%.

6. The gas-liquid distributor according to claim 1, characterized in that: From bottom to top, the diameter of the air inlet is 1 to 10 mm, preferably 2 to 5 mm; Preferably, the air inlet is arranged within a height range of 30%-80% from bottom to top of the mixing main pipe; Preferably, 2 to 24 air inlets are evenly distributed in the circumferential direction of the mixing main pipe, and more preferably 4 to 12 air inlets are evenly distributed.

7. The gas-liquid distributor according to claim 1, characterized in that: The distribution member is at least one layer of sieve plate or sieve mesh, and the opening rate is 2%-50%; Alternatively, the distribution component has an opening rate of 30% to 50%.

8. The gas-liquid distributor according to claim 1, characterized in that: The bubble cap, liquid inlet pipe, mixing main pipe and transition section are coaxially arranged.

9. The gas-liquid distributor according to claim 1, characterized in that: The bubble cap is movably connected to the liquid inlet pipe, and the main pipe is movably connected to the transition section.

10. An upward reactor, characterized in that: A plurality of distribution plates (11) are arranged in the reactor shell, each of which is provided with a catalyst bed. The distribution plates are provided with holes, and the gas-liquid distributors described in any one of claims 1 to 9 are arranged corresponding to the holes. The reactor shell is provided with a bottom raw material inlet, a top outlet and a gas inlet, and the gas inlet is located below the lowest distribution plate.

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