Fixed bed reactor for three-phase reaction and multi-stage fixed bed reactor system

Abstract

The utility model provides a fixed bed reactor and multistage fixed bed reactor system for three-phase reaction, the fixed bed reactor comprises a shell, a gas-liquid distributor and a catalyst bed layer, the gas-liquid distributor and the catalyst bed layer are sequentially arranged from top to bottom along the axial direction of the shell, particularly, the gas-liquid distributor comprises a gas-liquid distribution disc, a plurality of overflow pipes are distributed on the gas-liquid distribution disc, and the catalyst bed layer is arranged on the gas-liquid distribution disc. The overflow pipe penetrates through the gas-liquid distribution disc, a liquid overflow opening is formed in the side face of the overflow pipe, the overflow pipe is a conical pipe, and one or more sets of centripetal thorns inclining downwards can be arranged on the inner wall of the overflow pipe. The fixed bed reactor is favorable for improving the problems of insufficient mixing of gas and liquid materials, non-uniform feeding distribution, low catalytic reaction efficiency, poor product quality and lower yield in the prior art, and is favorable for industrial production.

Description

TECHNICAL FIELD

[0001] The utility model relates to a chemical industry technical field, concretely relates to a kind of fixed bed reactor and multistage fixed bed reactor system for gas-liquid-solid three-phase reaction. BACKGROUND

[0002] Fixed bed reactor is also called packed bed reactor, which can be filled with solid catalyst for chemical production, and is commonly used to realize gas-liquid-solid three-phase reaction (for example, hydrogenation reaction). In the fixed bed reactor, a reaction system of gas-liquid-solid three-phase coexistence is formed, and the reaction efficiency depends on the interphase mass transfer rate of gas-liquid-solid three-phase. Since the gas phase needs to be dissolved into the liquid phase to occur adsorption reaction with the solid phase (catalyst), the gas distribution mode has an important influence on the mass transfer efficiency of the reactor and the use efficiency of reactants (such as hydrogen).

[0003] Patent document CN101279229A discloses a trickle bed reactor, which comprises a gas-liquid distributor. The gas phase enters the reactor from the top of the liquid phase passage pipe of the gas-liquid distributor through the small holes laterally, and the liquid phase flows out from the small holes of the liquid passage pipe of the gas-liquid distributor, forming annular distribution with different diameters to improve the gas-liquid distribution inside the reactor.

[0004] Patent CN202860503U discloses a trickle bed liquid distributor, which comprises a plate-shaped body with a plurality of liquid drop holes. A plurality of liquid drop heads with cylindrical through holes are fixed to the bottom surface of the plate-shaped body, and the cylindrical through holes of the liquid drop heads are aligned with the liquid drop holes.

[0005] However, the gas-liquid distributor in the prior art can improve the initial uniformity of the gas-liquid two-phase on the upper part of the catalyst bed in the reactor, but as the scale of the device is expanded, the diameter and height of the reactor are continuously increased, and the overall gas-liquid distribution uniformity is still not ideal. The liquid phase material is prone to form wall flow on the reactor wall, which reduces the reaction efficiency. UTILITY MODEL CONTENT

[0006] To overcome the shortcomings of the prior art, the utility model provides a fixed bed reactor and a multistage fixed bed reactor system for three-phase reaction (for example, hydrogenation reaction), which can realize higher uniformity of gas-liquid reaction raw materials and is beneficial to improve the reaction efficiency.

[0007] In the first aspect of the utility model, a fixed bed reactor for three-phase reaction is provided, which comprises a shell, a gas-liquid distributor and a catalyst bed arranged in the shell in sequence from top to bottom along the axial direction.

[0008] Specifically, the gas-liquid distributor comprises a gas-liquid distribution disc, a plurality of overflow pipes are distributed on the gas-liquid distribution disc, the overflow pipes pass through the gas-liquid distribution disc, a liquid overflow port (one or more) is formed on the side surface, and the heights of all overflow ports are consistent.

[0009] Specifically, the overflow pipes on the gas-liquid distribution plate are uniformly distributed.

[0010] Specifically, the top of the overflow pipe can be open or not.

[0011] Specifically, the overflow pipe is a tapered pipe, and the longitudinal section thereof is an inverted trapezoid (the inner diameter of the overflow pipe continuously decreases as it approaches the gas-liquid distribution plate, the gas flow rate suddenly increases after the gas phase material passes through the minimum inner diameter section, which can atomize the liquid phase material, strengthen the dispersion of the liquid phase material, form an atomized uniform distribution, and be beneficial to the uniform dispersion of the gas-liquid phase material).

[0012] Specifically, the inner wall of the overflow pipe is provided with one or more groups of downwardly inclined thorn-like structures (centripetal thorns), and the positions of the thorn-like structures on the inner wall are lower than the overflow port.

[0013] In some embodiments, the inner wall of the overflow pipe is provided with one group of downwardly inclined thorn-like structures (centripetal thorns), and each group contains a plurality of thorn-like structures (such as 3, 4, 5, etc.), which are located at the same axial height level of the overflow pipe and are uniformly distributed along the circumferential direction of the inner wall of the overflow pipe, and the tips of the thorn-like structures converge at the central position of the overflow pipe, which can effectively avoid the formation of wall flow of the liquid phase material.

[0014] In some embodiments, the inner wall of the overflow pipe is provided with a plurality of groups (for example, 2 groups) of downwardly inclined thorn-like structures (centripetal thorns), and each group contains a plurality of thorn-like structures (such as 3, 4, 5, etc.), which are located at the same axial height level of the overflow pipe and are uniformly distributed along the circumferential direction of the inner wall of the overflow pipe, and the tips of the thorn-like structures converge at the central position of the overflow pipe; each group of thorn-like structures is located at a different axial height of the overflow pipe. Preferably, each group of thorn-like structures is uniformly distributed along the axial direction of the overflow pipe (i.e., the distance between each group is equal).

[0015] Specifically, the upper end of the shell is provided with a material inlet (including a gas material inlet and a liquid material inlet), and a material feeding pipeline communicating with the liquid material inlet is arranged in the shell, and the material feeding pipeline extends along the shell to the gas-liquid distribution plate. The liquid layer is formed on the gas-liquid distribution plate, and the gas phase material fills the space composed of the gas-liquid distribution plate and the shell under pressure. When the liquid layer is higher than the height of the overflow port, the liquid material enters the overflow pipe through the overflow port, flows along the thorn-like structures to the center of the overflow pipe, and then flows downward. The gas material enters the overflow pipe through the opening at the top of the overflow pipe and / or the overflow port, flows rapidly downward along the pipeline, and is atomized when passing through the minimum inner diameter section due to the sudden increase in the gas flow rate, which can strengthen the dispersion of the liquid material and form an atomized uniform distribution. The uniformly distributed gas-liquid two-phase material enters the catalyst bed from top to bottom.

[0016] Specifically, the shell is further provided with a material outlet, which is located in the lower half of the shell, for example, the bottom.

[0017] Specifically, the catalyst bed comprises a plurality of columns filled with solid catalyst, wherein each column is in communication with an overflow pipe, and the gas-liquid two-phase material uniformly distributed through the overflow pipe enters the column and reacts under the action of the solid catalyst (hundreds of columns can be arranged in parallel in the fixed bed reactor, and the reaction process of each column needs to be consistent, the gas-liquid ratio, gas-liquid flow rate and pressure are consistent, if there is deviation, the reaction effect will be unsatisfactory, the yield will be low, and the quality will be poor. The gas-liquid distributor of the present application can ensure the uniformity of each reaction column, and the reaction consistency is the core part of the fixed bed reactor). The product obtained by reaction is discharged from the material outlet of the reactor.

[0018] Specifically, the fixed bed reactor can also be provided with a sampling device to monitor the consumption of reaction material and product yield and other parameters in real time.

[0019] Specifically, the fixed bed reactor can also comprise a temperature control and monitoring device to monitor and control the reaction temperature therein.

[0020] Specifically, the fixed bed reactor can also comprise a pressure control and monitoring device to monitor and control the pressure of the gas-liquid two-phase material mixture and the pressure in the reactor.

[0021] Specifically, the fixed bed reactor can also comprise a liquid level control and monitoring device to monitor the liquid layer height on the gas-liquid distribution disc.

[0022] In the second aspect of the present application, a multi-stage fixed bed reactor system for three-phase reaction is provided, which comprises two or more (for example, two or three) fixed bed reactors as described in the first aspect, and the fixed bed reactors are connected in series.

[0023] The present application provides a fixed bed reactor and a multi-stage fixed bed reactor system for three-phase reaction (such as hydrogenation reaction), which is beneficial to improve the problems of insufficient mixing of gas-liquid material, uneven distribution of feed, low catalytic reaction efficiency, poor quality of obtained product, and low yield in the prior art, and is beneficial to industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The fixed bed reactor of the present application is shown in the schematic diagram; wherein, Figure 1 A is a partial sectional view of the reactor, Figure 1 B is a sectional view of the overflow pipe.

[0025] Figure 2 The sectional view of the overflow pipe with centripetal spurs is shown.

[0026] Figure 3 The top view of the overflow pipe with centripetal spurs is shown.

[0027] Wherein: 1 - shell, 2 - gas-liquid distributor, 3 - catalyst bed, 4 - liquid material inlet, 5 - gas material inlet, 6 - feed line, 7 - overflow pipe, 8 - gas-liquid distribution disc, 9 - catalyst bed column, 10 - overflow port, 11 - centripetal spur. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0029] Embodiment 1

[0030] As shown in Figure 1 A, a fixed bed reactor for three-phase reaction comprises a shell 1, a gas-liquid distributor 2, and a catalyst bed 3 arranged in sequence along the axial direction of the shell from top to bottom.

[0031] The gas-liquid distributor 2 comprises a gas-liquid distribution disc 8, on which a plurality of overflow pipes 7 are distributed, the overflow pipes 7 penetrating through the gas-liquid distribution disc 8, and the heights of all the overflow pipes are consistent. As shown in Figure 1 B, the overflow pipes 7 are conical pipes, the longitudinal section of which is an inverted trapezoid, and the inner diameter of the overflow pipes 7 is constantly decreasing in the direction from the pipe opening to the gas-liquid distribution disc 8, which is conducive to the uniform dispersion of gas-liquid phase materials. The top of the overflow pipes 7 is open, and a liquid overflow port 10 (multiple, as shown in Figure 1 B, or one, not shown) is formed on the side surface, and the heights of all the overflow ports are consistent.

[0032] The upper end of the shell 1 is provided with a liquid material inlet 4 and a gas material inlet 5, and the shell 1 is provided with a material feed line 6 communicating with the liquid material inlet 4, the line 6 extending along the shell 1 to the gas-liquid distribution disc 8. After the liquid material enters the shell 1 through the liquid material inlet 4 and the feed line 6, a liquid layer is formed on the gas-liquid distribution disc 8, and the gas phase material enters the shell 1 through the gas material inlet 5, and fills the space composed of the gas-liquid distribution disc 8 and the shell 1 under pressure. When the liquid layer is higher than the height of the overflow port 10, the liquid enters the overflow pipe 7 through the overflow port 10. The gas material enters the overflow pipe through the top opening of the overflow pipe 7 and the overflow port 10, and the flow rate of the gas suddenly increases after passing through the minimum inner diameter section of the overflow pipe, so that the liquid is atomized, the dispersion of the liquid material is strengthened, and uniform distribution is formed. The uniformly distributed gas-liquid two-phase materials enter the catalyst bed 3 from top to bottom.

[0033] The catalyst bed 3 comprises a plurality of columns 9 filled with solid catalyst, and the overflow pipes 7 are communicated with the columns 9 one by one respectively, and the uniformly distributed gas-liquid two-phase material enters the columns 9 through the overflow pipes 7 and is reacted under the action of the solid catalyst. The reaction products are discharged from the reactor through a material outlet (not shown).

[0034] Example 2

[0035] A fixed bed reactor for three-phase reaction is shown in Figure 1 A. As shown in Figure 2 , a group of downwardly inclined thorns (centripetal thorns) 11 are arranged on the inner wall of the overflow pipe 7, each group comprising 3 thorns, which are located at the same axial height level of the overflow pipe 7 and are uniformly distributed along the inner wall of the overflow pipe 7 (as shown in Figure 3 , the tips of the thorns 11 converge at the center position of the overflow pipe, which can effectively prevent the formation of wall flow of liquid material, and is beneficial to the uniform dispersion of gas-liquid material and reaction efficiency.

[0036] After the liquid material enters the shell 1 through the liquid material inlet 4 and the feed pipe 6, a liquid layer is formed on the gas-liquid distribution disc 8, and the gas phase material enters the shell 1 through the gas material inlet 5, and fills the space composed of the gas-liquid distribution disc 8 and the shell 1 under pressure. When the liquid layer is higher than the height of the overflow port 10, it enters the overflow pipe 7 through the overflow port 10, flows along the thorns 11 to the center of the overflow pipe 7 and flows downward. The gas material enters the overflow pipe through the top opening of the overflow pipe 7 and the overflow port 10, flows rapidly downward along the pipe, and is atomized when passing through the minimum inner diameter section, so that the liquid material is dispersed and uniformly distributed. The uniformly distributed gas-liquid two-phase material enters the catalyst bed 3 from top to bottom.

[0037] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A fixed bed reactor for a three-phase reaction, characterized by, The fixed bed reactor comprises a shell, a gas-liquid distributor arranged in sequence along the axial direction of the shell from top to bottom, and a catalyst bed layer; The gas-liquid distributor comprises a gas-liquid distribution disc on which a plurality of overflow pipes are distributed, the overflow pipes penetrating through the gas-liquid distribution disc and having liquid overflow openings opened on the side surface, and the heights of all overflow openings are consistent; the overflow pipes are conical pipes, and the longitudinal section thereof is an inverted trapezoid; The shell is provided with a liquid material inlet and a gas material inlet at the upper end, and a material feeding pipeline is arranged in the shell and connected to the liquid material inlet, the material feeding pipeline extending along the shell to the gas-liquid distribution disc; the shell is further provided with a material outlet.

2. The fixed bed reactor of claim 1, wherein, The overflow pipes on the gas-liquid distribution disc are uniformly distributed.

3. The fixed bed reactor of claim 1, wherein, A group of downwardly inclined thorn-like structures are arranged on the inner wall of the overflow pipe, each group comprising a plurality of thorn-like structures, the thorn-like structures in each group being located at the same height level in the axial direction of the overflow pipe and being uniformly distributed along the circumferential direction of the inner wall of the overflow pipe, and the tips of the thorn-like structures converging at the central position of the overflow pipe.

4. The fixed bed reactor of claim 1, wherein, A plurality of groups of downwardly inclined thorn-like structures are arranged on the inner wall of the overflow pipe, each group comprising a plurality of thorn-like structures, the thorn-like structures in each group being located at the same height level in the axial direction of the overflow pipe and being uniformly distributed along the circumferential direction of the inner wall of the overflow pipe, and the tips of the thorn-like structures converging at the central position of the overflow pipe; the thorn-like structures in different groups are located at different height levels in the axial direction of the overflow pipe.

5. The fixed bed reactor according to claim 3 or 4, characterized in that Each group comprises three thorn-like structures and is uniformly distributed along the circumferential direction of the inner wall of the overflow pipe.

6. The fixed bed reactor of any one of claims 1-4, wherein, The catalyst bed layer comprises a plurality of column tubes filled with solid catalysts, and the overflow pipes are in one-to-one correspondence with the column tubes.

7. The fixed bed reactor of claim 1, wherein, The fixed bed reactor further comprises a liquid level control and monitoring device.

8. The fixed bed reactor of claim 1, wherein, The fixed bed reactor further comprises a temperature control and monitoring device.

9. The fixed bed reactor of claim 1, wherein, The fixed bed reactor further comprises a pressure control and monitoring device.

10. A multi-stage fixed bed reactor system for a three-phase reaction, characterized in that, The multi-stage fixed bed reactor system comprises two or more fixed bed reactors as claimed in any one of claims 1-9, and the fixed bed reactors are connected in series.

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