Powerful premixing type anti-bias fixed bed reactor

Abstract

The invention aims to provide a powerful premixing type anti-bias fixed bed reactor, which belongs to the technical field of chemical equipment reaction devices, and comprises a shell, an inlet pipeline and an outlet pipeline are respectively arranged at the top end and the bottom of the shell, an anti-bias diffuser and a catalytic reaction zone are arranged in the shell from top to bottom, and the anti-bias diffuser is communicated with the catalytic reaction zone. By using the reactor, gas entering the reactor is buffered and rectified, so that the problem of serious gas bias flow is effectively solved, and the phenomenon of non-uniform distribution of sections in the reactor is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment reaction devices, and in particular relates to a strong premixing anti-bias flow fixed bed reactor. Background Art

[0002] In the modern chemical industry, fixed bed reactors play a vital role. The basic principle is to allow the reactants to pass through a fixed bed filled with catalyst at a certain flow rate, where chemical reactions occur under the action of the catalyst to generate the target product. However, traditional fixed bed reactors face many technical challenges in practical applications, which seriously affect the further improvement of their performance and efficiency.

[0003] In many reactions, different gas raw materials need to be fully mixed before entering the reaction bed to ensure efficient reaction. However, traditional reactors often lack effective gas mixing devices, resulting in poor gas mixing effect. If the mixing is uneven, it will not only reduce the synthesis efficiency of the gas, but also cause local overheating of the reaction, affect the service life of the catalyst, and even cause safety accidents. This is because uneven gas mixing will cause the reaction rate in the local area of ​​the bed to be too fast, and the heat accumulation cannot be dissipated in time. Bias flow refers to the fact that the reaction materials are not evenly distributed when passing through the fixed bed, but the flow rate in the local area is too fast or too slow. This problem is mainly caused by unreasonable internal structural design of the reactor and uneven gas distribution. Bias flow will cause a series of adverse consequences, such as some catalysts are not fully utilized, reducing the overall utilization rate of the catalyst; at the same time, the residence time of the reaction materials in the bed is inconsistent, resulting in incomplete reaction and unstable product quality. In some processes with high requirements for product purity, such as fine chemical synthesis, bias flow problems may cause the impurity content in the product to exceed the standard, seriously affecting product quality.

[0004] In order to overcome these defects of traditional fixed bed reactors, it is urgent to develop a new type of fixed bed reactor that can effectively solve the problems of gas mixing, bias flow, pressure control and material diffusion, improve the performance, stability and reliability of the reactor, so as to meet the growing production needs and strict requirements on product quality of the modern chemical industry. The powerful premixed anti-bias flow fixed bed reactor of the present invention is an innovative solution designed to solve these problems.

[0005] A Chinese patent with application number CN115738915 A discloses an anti-bias flow fixed bed reactor. The patent sets an anti-bias flow diffuser on the top of the reactor shell, which is an overflow weir of a truncated cone-shaped cylinder with an arc surface, which improves the problem of oil and gas bias flow and avoids the uneven distribution of the internal cross-section of the reactor. However, the overflow weir designed in this system is not highly anti-overflow, resulting in the problem of gas bias flow; and the baffle plate at the upper end of the overflow weir is too simple and cannot provide good dispersion and impact protection. In addition, the overflow weir lacks the ability to disperse gas, and its ability is relatively single, which makes its overall operating efficiency low. Summary of the invention

[0006] The present invention aims at the problem of uneven gas-liquid distribution caused by bias flow and other problems in existing fixed bed reactors, and provides a strong premixed anti-bias flow fixed bed reactor. By using the reactor of the present invention, the fixed bed feed port and the inlet diffuser at the top of the reactor are modified, so that the incoming gas is buffered and rectified, which effectively improves the serious problem of gas bias flow and avoids the uneven distribution of the internal cross section of the reactor. It can effectively solve the problems of gas mixing, bias flow, pressure control and material diffusion, and improve the performance, stability and reliability of the reactor.

[0007] To achieve the above object, the present invention adopts the following technical solution: A strong premixed anti-bias flow fixed bed reactor comprises a shell, wherein the top and bottom of the shell are respectively provided with an inlet pipeline and an outlet pipeline, wherein an anti-bias flow diffuser and a catalytic reaction zone are arranged in the shell from top to bottom, wherein a pressure valve gas micro-mixing device is arranged in the inlet pipeline, wherein the pressure valve gas micro-mixing device comprises a pressure valve body along the flow direction of the inlet pipeline and two spirally twisted baffle buffer plates arranged at the inner corners of the inlet pipeline, wherein the free ends of the baffle buffer plates face the flow direction of the inlet pipeline, wherein the pressure valve body comprises a connecting plate, wherein the surface of the connecting plate is provided with two circles of through holes, wherein the end surface of the connecting plate is provided with a spring, wherein one end of the spring is connected with a baffle plate, wherein a gas distribution plate 1 is provided at the inlet of the pressure valve body, wherein the gas distribution plate 1 is provided with a plurality of through holes, wherein the spring is located between the gas distribution plate 1 and the connecting plate, and wherein a dust screen is provided at the inlet of the pressure valve body.

[0008] Furthermore, one end of the two baffle plates is connected to the inner wall of the inlet pipeline, and is gradually twisted and extended along the axis of the inlet pipeline, and is staggered up and down. The baffle plate near the entrance of the inlet pipeline is located at the upper end of the inlet pipeline, and its height is 2 / 5 of the diameter of the inlet pipeline. The baffle plate far from the entrance of the inlet pipeline is located at the lower end of the inlet pipeline, and its height is 4 / 5 of the diameter of the inlet pipeline. The spacing between the connecting ends of the two baffle plates and the inlet pipeline is 70-150mm.

[0009] Furthermore, there is a gap between the free ends of the two baffle buffer plates, and a gas phase overflow area is formed between the two baffle buffer plates.

[0010] Furthermore, the inlet pipe diameter of the pressure valve body is 2 / 3 of the inlet pipeline diameter.

[0011] Furthermore, the number of through holes in two circles on the end surface of the connection plate are 20 and 24 respectively, and the hole diameter is 30 mm.

[0012] Furthermore, the anti-bias flow diffuser includes a cylinder body, an overflow weir is arranged inside the cylinder body, an inwardly concave truncated cone-shaped baffle is arranged in the gas inlet direction of the overflow weir, the gas inlet end of the overflow weir is a gas distribution plate 2, and air holes are evenly distributed on the gas distribution plate 2, and two layers of outer circular upwardly bent baffles with different diameters and two layers of inner circular corrugated baffles with different diameters are arranged below the gas distribution plate 2, the outer circular upwardly bent baffles and the inner circular corrugated baffles are alternately arranged, and a support plate is provided at the bottom of the overflow weir, and a plurality of through holes are provided on the support plate, and the through holes are connected to a plurality of uniform diffusion devices through pipes.

[0013] Furthermore, both end edges of the truncated cone baffle are bent upward to form a circular ring shape, and the diameter of the circular arc shape is 1 / 10 of the diameter of the lower end of the truncated cone baffle.

[0014] Furthermore, the uniform diffusion device includes a plurality of curved feed pipes, each having a diameter of 30 mm, a fixed box connected to the end of the curved feed pipe, the fixed box being connected to a plurality of downwardly curved air outlet pipes, the aperture of the air outlet pipes being 5 mm, and a corrugated baffle being provided at the upper end of the curved feed pipe.

[0015] Furthermore, a catalyst with a length of 1.8 m is provided in the catalytic reaction zone, and a SiC pellet layer is provided at the bottom of the catalytic reaction zone, and the length of the SiC pellet layer is 0.3 m.

[0016] Furthermore, the outer layer of the catalytic reaction zone is connected to a heat melting furnace device, a thermocouple is arranged on the heat melting furnace device, and a pressure gauge, a safety valve, a motor and a thermometer are arranged on the shell.

[0017] The beneficial effects of the present invention are as follows: 1. Efficient gas-liquid premixing. For the role of the pressure valve gas micro-mixing device: The design of the two baffle plates in the pressure valve gas micro-mixing device enables the gas and liquid to form a complex flow path when entering the reactor, promoting full contact and mixing between the two. When the gas and liquid mixture hits the baffle plate, it changes the flow direction and generates turbulence, thereby enhancing the mass transfer effect between the phases and making the gas-liquid mixing more uniform. The dense through holes at the bottom of the fixed box and the dust-proof net at the entrance of the pressure valve can prevent impurities from entering and affecting the reaction while ensuring the normal circulation of gas, and also help maintain the stability of the pressure in the system, which is indirectly conducive to the stable progress of the gas-liquid mixing process.

[0018] 2. For the anti-bias diffuser auxiliary premixing, the overflow weir in the anti-bias diffuser is truncated and has an arc surface. It is equipped with two layers of inner circular corrugated baffles and two layers of outer circular baffles that are bent upward. There is a channel between the baffles and the overflow weir. After the gas enters through the pores at the gas inlet end of the overflow weir, it will continuously change its flow direction in these structures, further enhancing the gas-liquid mixing effect. The gas will be dispersed and redistributed when passing through the baffles, and the contact with the liquid will be more sufficient, which improves the premixing efficiency.

[0019] 3. Effectively prevent deviation. Regarding the structural design of the anti-deviation diffuser: the overflow weir baffle of the anti-deviation diffuser is an arc-shaped inward concave type, and its edge is larger than the diameter end of the inlet aperture at the upper end of the overflow weir, which can effectively prevent part of the gas from flowing back into the inlet pipe, ensuring that the material flows in the predetermined direction in the reactor, and preventing local flow rate abnormalities and deviation caused by gas reflux. The spacing of 200 mm between the baffle and the small diameter end of the overflow weir is reasonably designed, so that the material can enter the subsequent uniform diffusion device more evenly after being blocked and guided by the baffle, avoiding the accumulation or rapid passage of materials in local areas, thereby preventing the occurrence of deviation. The overall structure works synergistically, from the pressure valve gas micro-mixing device to the anti-deviation diffuser to the filler catalytic system inside the reactor, the structural design of the entire reactor cooperates with each other. After the pressure valve gas micro-mixing device has carried out preliminary homogenization treatment on the material, the anti-bias flow diffuser further optimizes the material distribution to ensure that the material flow rate and concentration entering the catalytic reaction zone are uniform. In this way, in the catalytic reaction zone, the material can be evenly contacted and reacted with the spiral structure catalyst, avoiding the excessive use or underutilization of some catalysts due to bias flow, and ensuring the efficient and stable progress of the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a structural schematic diagram of a pressure valve gas micro-mixing device; Figure 3It is a structural schematic diagram of the anti-bias flow diffuser; Among them: 1-shell; 101-inlet pipeline; 102-outlet pipeline; 103-hot melting furnace; 104-thermocouple; 105-pressure gauge; 106-safety valve; 107-motor; 108-thermometer; 109-rotating opening; 110-corner; 2-pressure valve body; 201-gas distribution plate 1; 202-baffle plate; 203-spring; 204-connecting plate; 3-baffle buffer plate; 301-gap; 302-gas phase overflow area; 4-truncated cone baffle Plate; 5-overflow weir; 501-gas distribution plate 2; 502-vent; 503-a baffle plate 1 with an outer circular upward bend; 504-a baffle plate 1 with an inner circular corrugated baffle; 505-a baffle plate 2 with an outer circular upward bend; 506-a baffle plate 2 with an inner circular corrugated baffle; 6-uniform diffusion device; 601-support plate; 602-perforation; 603-curved feed pipe; 604-gas outlet pipe; 605-corrugated baffle plate; 606-fixed box; 7-SiC pellet layer. DETAILED DESCRIPTION

[0021] The present invention will be further described with reference to the accompanying drawings.

[0022] As shown in the figure, a strong premixed anti-bias flow fixed bed reactor includes a shell 1, and the top and bottom of the shell 1 are respectively provided with an inlet pipeline 101 and an outlet pipeline 102. The inlet pipeline 101 is used to introduce the reaction gas therein, and the outlet collector 102 intercepts a small amount of catalyst or dust, and at the same time, the reacted gas is gathered and discharged through the exhaust pipeline. The outside of the outlet collector 102 is wrapped with a metal wire mesh.

[0023] An anti-bias diffuser and a catalytic reaction zone are arranged from top to bottom in the shell 1, a pressure valve gas micro-mixing device is arranged in the inlet pipeline 101, the pressure valve gas micro-mixing device comprises a pressure valve body 2 along the flow direction of the inlet pipeline 101 and two spirally twisted baffle plates 3 arranged at the corners of the inlet pipeline 101, the free ends of the baffle plates 3 face the flow direction of the inlet pipeline 101, the pressure valve body 2 comprises a connecting plate 204, the surface of the connecting plate 204 is provided with two circles of through holes, the end face of the connecting plate 204 is provided with a spring 203, one end of the spring 203 is connected to a baffle plate 202, a gas distribution plate 201 is arranged at the inlet of the pressure valve body 2, a plurality of through holes are arranged on the gas distribution plate 201, the spring 203 is located between the gas distribution plate 201 and the connecting plate 204, and a dust net is arranged at the inlet of the pressure valve body 2.

[0024] The gas in the inlet pipeline 101 enters the shell 1 through the pressure valve gas micro-mixing device, which mainly diffuses the mixed bubble flow quickly to the cross-section of the entire reactor to avoid the formation of a central flow and a back-mixing flow, thereby playing a role in initial distribution. When the gas flows through the baffle 202, it will impact and compress the baffle 202, and the spring 203 will be compressed. When the gas refluxes or the pressure of the device is too high, the baffle 202 will be pushed, causing the spring 203 to stretch, blocking the inlet and preventing the gas from flowing back.

[0025] Furthermore, one end of the two baffle plates 3 is connected to the inner wall of the inlet pipeline 101, and is gradually twisted and extended along the axis of the inlet pipeline 101, and is staggered up and down. The baffle plate 3 near the entrance of the inlet pipeline 101 is located at the upper end of the inlet pipeline 101, and its height is 2 / 5 of the diameter of the inlet pipeline 101. The baffle plate 3 away from the entrance of the inlet pipeline 101 is located at the lower end of the inlet pipeline 101, and its height is 4 / 5 of the diameter of the inlet pipeline 101. The spacing between the connecting ends of the two baffle plates 3 and the inlet pipeline 101 is 70-150mm.

[0026] Furthermore, there is a gap 301 between the free ends of the two baffle buffer plates 3 , and a gas phase overflow area 302 is formed between the two baffle buffer plates 3 .

[0027] Furthermore, the inlet diameter of the pressure valve body 2 is 2 / 3 of the diameter of the inlet pipeline 101 .

[0028] Furthermore, the number of through holes in two circles on the end surface of the connecting plate 204 is 20 and 24 respectively, and the hole diameter is 30 mm.

[0029] Furthermore, the anti-bias diffuser includes a cylinder body, an overflow weir 5 is provided inside the cylinder body, an inwardly recessed truncated cone-shaped baffle plate 4 is provided in the gas inlet direction of the overflow weir 5, the gas inlet end of the overflow weir 5 is a gas distribution plate 501, and the gas distribution plate 501 is evenly distributed with vents 502, and two layers of outer circular upwardly bent baffle plates with different diameters and two layers of inner circular corrugated baffle plates with different diameters are provided below the gas distribution plate 501, the outer circular upwardly bent baffle plates and the inner circular corrugated baffle plates are alternately arranged, and a support plate 601 is provided at the bottom of the overflow weir 5, and a plurality of through holes 602 are provided on the support plate 601, and the through holes 602 are connected to a plurality of uniform diffusion devices 6 through pipelines.

[0030] Furthermore, both end edges of the truncated cone baffle plate 4 are bent upward to form a circular ring shape, and the diameter of the circular arc shape is 1 / 10 of the diameter of the lower end of the truncated cone baffle plate 4 .

[0031] Furthermore, the uniform diffusion device 6 includes a plurality of curved feed pipes 603, each having a diameter of 30 mm, and the end of the curved feed pipe 603 is connected to a fixed box 606, and the fixed box is connected to a plurality of downwardly curved air outlet pipes 604, each having an aperture of 5 mm, and a corrugated baffle 605 is provided at the upper end of the curved feed pipe 603.

[0032] Furthermore, a catalyst with a length of 1.8 m is provided in the catalytic reaction zone, and a SiC pellet layer 7 is provided at the bottom of the catalytic reaction zone, and the length of the SiC pellet layer 7 is 0.3 m.

[0033] Furthermore, the outer layer of the catalytic reaction zone is connected to a heat melting furnace device, a thermocouple 104 is provided on the heat melting furnace device, and a pressure gauge 105, a safety valve 106, a motor 107, and a thermometer 108 are provided on the shell 1.

[0034] The working principle of the present invention is as follows: the present invention achieves gas mixing in advance by arranging a pressure valve gas micro-mixing device in the inlet pipeline. Before the liquid phase enters the reactor, it will pass through two layers of baffle buffer plates at the inlet pipeline for buffering. This is because if the gas phase with a high flow rate directly enters the reactor, a deviation phenomenon will occur due to centrifugal force, and these two layers of baffle buffer plates can effectively avoid the deviation phenomenon. At the same time, a specific meteorological layer can be formed between the two layers of baffle buffer plates, thereby preventing the generation of microbubbles and then stably entering the interior of the reactor. The buffered liquid phase will bypass the first baffle buffer plate and collide with the second baffle buffer plate at the position of the inlet pipe close to the reactor, and the second baffle buffer plate mainly bears the role of liquid overflow. The pressure valve device is in a downward compression state under normal conditions. When the gas flows back and the gas pressure is too high, the spring will be stretched, and the baffle will block the pipe mouth to prevent the gas from flowing back.

[0035] Inlet anti-deviation diffuser, after the gas enters from the inlet pipeline, it first contacts the baffle. After the flow-guiding effect of the baffle, the gas then enters the overflow area, where the liquid phase begins to accumulate. In view of the fact that when the oil in the pipeline enters the reactor, it will inevitably deviate due to various factors, that is, more oil tends to flow to the side away from the flow direction of the inlet pipeline. In order to effectively prevent the uneven overflow of the fluid entering the overflow weir due to the deviation of the inlet pipeline, symmetrical and uniform air outlet holes are set on the surface of the overflow weir. Among them, the inner and outer circle baffles with different internal diameters fully and evenly block the overflow of accumulated liquid. After the overflowing fluid hits the baffle and is deflected, it will flow downward from the center of the cylinder. The gas flowing down from the center of the cylinder will then hit the support plate located below the cylinder, thereby prompting the fluid to be fully diffused in the uniform diffusion device within the reactor shell. The gas accumulates on the corrugated baffle plate, and flows from the uniform gas port on the corrugated baffle plate to the small diameter gas outlet pipe, so that the gas is evenly mixed and fully reacts with the catalyst when it reaches the reaction zone.

Claims

1. A strong premixed anti-bias flow fixed bed reactor, characterized in that: The invention comprises a shell (1), wherein the top and bottom of the shell (1) are respectively provided with an inlet pipeline (101) and an outlet pipeline (102), wherein an anti-bias flow diffuser and a catalytic reaction zone are provided in the shell (1) from top to bottom, wherein a pressure valve gas micro-mixing device is provided in the inlet pipeline (101), wherein the pressure valve gas micro-mixing device comprises a pressure valve body (2) arranged along the flow direction of the inlet pipeline (101) and two helically twisted baffle plates (3) arranged at the inner corners of the inlet pipeline (101), wherein the free ends of the baffle plates (3) face the inlet pipeline (101) and the outlet pipeline (102) is provided with ... 1), the pressure valve body (2) comprises a connecting plate (204), the surface of the connecting plate (204) is provided with two circles of through holes, the end surface of the connecting plate (204) is provided with a spring (203), one end of the spring (203) is connected to a baffle plate (202), a gas distribution plate (201) is provided at the inlet of the pressure valve body (2), a plurality of through holes are provided on the gas distribution plate (201), the spring (203) is located between the gas distribution plate (201) and the connecting plate (204), and a dust screen is provided at the inlet of the pressure valve body (2).

2. The strong premixed anti-bias flow fixed bed reactor according to claim 1, characterized in that: One end of the two baffle buffer plates (3) is connected to the inner wall of the inlet pipeline (101), and they are gradually twisted and extended along the axis of the inlet pipeline (101), and are arranged in a staggered manner up and down. The baffle buffer plate (3) close to the entrance of the inlet pipeline (101) is located at the upper end of the inlet pipeline (101) and has a height of 2 / 5 of the diameter of the inlet pipeline (101). The baffle buffer plate (3) far from the entrance of the inlet pipeline (101) is located at the lower end of the inlet pipeline (101) and has a height of 4 / 5 of the diameter of the inlet pipeline (101). The spacing between the connection ends of the two baffle buffer plates (3) and the inlet pipeline (101) is 70-150 mm.

3. The strong premixed anti-bias flow fixed bed reactor according to claim 2, characterized in that: There is a gap (301) between the free ends of the two baffle buffer plates (3), and a gas phase overflow area (302) is formed between the two baffle buffer plates (3).

4. The strong premixed anti-bias flow fixed bed reactor according to claim 3, characterized in that: The inlet pipe diameter of the pressure valve body (2) is 2 / 3 of the pipe diameter of the inlet pipeline (101).

5. The strong premixed anti-bias flow fixed bed reactor according to claim 4, characterized in that: The number of through holes in two circles on the end surface of the connection plate (204) are 20 and 24 respectively, and the hole diameter is 30 mm.

6. The strong premixed anti-bias flow fixed bed reactor according to claim 1, characterized in that: The anti-deviation diffuser comprises a cylinder, an overflow weir (5) is arranged inside the cylinder, a truncated cone-shaped baffle plate (4) recessed inwardly is arranged in the gas inlet direction of the overflow weir (5), the gas inlet end of the overflow weir (5) is a gas distribution plate 2 (501), the gas distribution plate 2 (501) is evenly distributed with vent holes (502), two layers of outer circular upwardly bent baffle plates with different diameters and two layers of inner circular corrugated baffle plates with different diameters are arranged below the gas distribution plate 2 (501), the outer circular upwardly bent baffle plates and the inner circular corrugated baffle plates are arranged alternately, a support plate (601) is arranged at the bottom of the overflow weir (5), a plurality of through holes (602) are arranged on the support plate (601), and the through holes (602) are connected to a plurality of uniform diffusion devices (6) through pipelines.

7. The strong premixed anti-bias flow fixed bed reactor according to claim 6, characterized in that: The edges of both ends of the truncated cone baffle (4) are bent upward to form a circular ring shape, and the diameter of the circular arc shape is 1 / 10 of the diameter of the lower end of the truncated cone baffle (4).

8. The strong premixing anti-bias flow fixed bed reactor according to claim 6, characterized in that: The uniform diffusion device (6) comprises a plurality of curved feed pipes (603), each having a diameter of 30 mm, a fixing box (606) connected to the end of the curved feed pipe (603), the fixing box being connected to a plurality of downwardly curved air outlet pipes (604), each having a hole diameter of 5 mm, and a corrugated baffle (605) being provided at the upper end of the curved feed pipe (603).

9. The strong premixed anti-bias flow fixed bed reactor according to claim 1, characterized in that: A catalyst with a length of 1.8 m is provided in the catalytic reaction zone, and a SiC pellet layer (7) is provided at the bottom of the catalytic reaction zone. The length of the SiC pellet layer (7) is 0.3 m.

10. The strong premixing anti-bias flow fixed bed reactor according to claim 1, characterized in that: The outer layer of the catalytic reaction zone is connected to a heat melting furnace device, on which a thermocouple (104) is provided, and the shell (1) is provided with a pressure gauge (105), a safety valve (106), a motor (107), and a thermometer (108).

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