A high-efficiency premixed fixed-bed reactor with anti-deviation flow

Abstract

The purpose of this invention is to provide a high-efficiency premixed anti-deviation fixed-bed reactor, belonging to the technical field of chemical equipment reaction devices. It includes a shell, with an inlet pipeline at the top and an outlet pipeline at the bottom. An anti-deviation diffuser and a catalytic reaction zone are arranged inside the shell from top to bottom. A pressure valve gas micro-mixing device is installed in the inlet pipeline. By using this invention, the gas entering the reactor is buffered and rectified, effectively improving the problem of severe gas deviation and avoiding uneven cross-sectional distribution inside the reactor.

Description

Technical Field

[0001] This invention belongs to the technical field of chemical equipment and reaction devices, specifically relating to a high-efficiency premixed anti-deviation fixed-bed reactor. Background Technology

[0002] In modern chemical industry, fixed-bed reactors play a crucial role. Their basic principle is to allow reactants to flow at a controlled rate through a fixed bed filled with catalyst, where a chemical reaction occurs under the catalyst's influence, thereby generating the target product. However, traditional fixed-bed reactors face numerous technical challenges in practical applications, severely hindering further improvements in their performance and efficiency.

[0003] In many reactions, different gaseous feedstocks need to be thoroughly mixed before entering the reaction bed to ensure efficient reaction. However, traditional reactors often lack effective gas mixing devices, resulting in poor gas mixing. Inhomogeneous mixing not only reduces gas synthesis efficiency but can also lead to localized overheating, affecting catalyst lifespan and even causing safety accidents. This is because uneven gas mixing causes excessively rapid reaction rates in localized areas within the bed, leading to heat accumulation that cannot dissipate quickly enough. Flow deviation refers to the reaction materials failing to distribute evenly as they pass through a fixed bed, resulting in excessively fast or slow flow rates in localized areas. This problem mainly stems from unreasonable reactor internal structure design and uneven gas distribution. Flow deviation causes a series of adverse consequences, such as some catalyst not being fully utilized, reducing the overall catalyst utilization rate; simultaneously, inconsistent residence times of reactants within the bed lead to incomplete reactions and unstable product quality. In processes with high purity requirements, such as fine chemical synthesis, flow deviation can cause impurity levels in the product to exceed standards, severely impacting product quality.

[0004] To overcome these shortcomings of traditional fixed-bed reactors, there is an urgent need to develop a novel fixed-bed reactor that can effectively solve problems such as gas mixing, flow deviation, pressure control, and material diffusion, thereby improving the reactor's performance, stability, and reliability. This will meet the growing production demands and stringent quality requirements of modern chemical industry. The high-efficiency premixed anti-flow deviation fixed-bed reactor of this invention is an innovative solution designed to address these problems.

[0005] Chinese patent application CN115738915 A discloses a fixed-bed reactor with anti-flow deviation. This patent uses an anti-flow deviation diffuser at the top of the reactor shell, which is an overflow weir with a frustum-shaped cylindrical body with an arc-shaped surface, to improve the problem of oil and gas flow deviation and avoid uneven cross-sectional distribution inside the reactor. However, the overflow weir in this system does not provide a high degree of overflow prevention, resulting in gas flow deviation. Furthermore, the baffle plate at the top of the overflow weir is too simple and does not provide good dispersion or shock absorption capabilities. In addition, the overflow weir lacks the ability to disperse gas, making its function relatively limited and resulting in low overall operating efficiency. Summary of the Invention

[0006] This invention addresses the problem of uneven gas-liquid distribution caused by flow deviation in existing fixed-bed reactors. It provides a highly efficient premixed, anti-flow deviation fixed-bed reactor. By modifying the fixed-bed feed inlet and the inlet diffuser at the top of the reactor, the incoming gas is buffered and rectified, effectively improving the severe gas flow deviation problem and preventing uneven cross-sectional distribution within the reactor. This effectively solves problems related to gas mixing, flow deviation, pressure control, and material diffusion, improving the reactor's performance, stability, and reliability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-efficiency premixed anti-deviation fixed-bed reactor includes a shell, with an inlet pipeline at the top and an outlet pipeline at the bottom. An anti-deviation diffuser and a catalytic reaction zone are arranged inside the shell from top to bottom. A pressure valve gas micro-mixing device is installed inside the inlet pipeline. The pressure valve gas micro-mixing device includes a pressure valve body along the flow direction of the inlet pipeline and two spirally twisted baffle plates located at the corners of the inlet pipeline. The free ends of the baffle plates face the flow direction of the inlet pipeline. The pressure valve body includes a connecting plate with two rings of through holes on its surface. A spring is provided on the end face of the connecting plate, and one end of the spring is connected to a baffle plate. A gas distribution disk with several through holes is provided at the inlet of the pressure valve body. The spring is located between the gas distribution disk and the connecting plate. A dustproof screen is provided at the inlet of the pressure valve body.

[0009] Furthermore, one end of each of the two baffle plates is connected to the inner wall of the inlet pipe, and they gradually twist and extend along the axis of the inlet pipe, and are staggered in height. The baffle plate near the inlet pipe is located at the upper end of the inlet pipe, with a height of 2 / 5 of the pipe diameter of the inlet pipe, and the baffle plate away from the inlet pipe is located at the lower end of the inlet pipe, with a height of 4 / 5 of the pipe diameter of the inlet pipe. The distance between the connection ends of the two baffle plates and the inlet pipe is 70-150mm.

[0010] Furthermore, there is a gap between the free ends of the two baffle plates, forming a gas phase overflow zone between the two baffle plates.

[0011] Furthermore, the inlet pipe diameter of the pressure valve body is 2 / 3 of the inlet pipeline diameter.

[0012] Furthermore, the number of through holes in the two rings on the end face of the connecting plate is 20 and 24 respectively, and the hole diameter is 30mm.

[0013] Furthermore, the anti-deflection diffuser includes a cylindrical body, inside which is an overflow weir. A concave frustum-shaped baffle is provided at the gas inlet direction of the overflow weir. The gas inlet end of the overflow weir is a second gas distribution disk. Ventilation holes are evenly distributed on the second gas distribution disk. Below the second gas distribution disk are two layers of upward-bent outer ring baffles and two layers of corrugated inner ring baffles of different diameters. The upward-bent outer ring baffles and corrugated inner ring baffles are arranged alternately. A support plate is provided at the bottom of the overflow weir. Several perforations are provided on the support plate, and these perforations are connected to several uniform diffusion devices via pipes.

[0014] Furthermore, the two ends of the frustum-shaped baffle are bent upward to form an annular shape, and the diameter of the annular shape is 1 / 10 of the diameter of the lower end of the frustum-shaped baffle.

[0015] Furthermore, the uniform diffusion device includes several curved feed pipes with a diameter of 30 mm. A fixing box is connected to the end of the curved feed pipe, and several downwardly curved air outlet pipes are connected to the fixing box. The air outlet pipes have an aperture of 5 mm, and a corrugated baffle is provided at the upper end of the curved feed pipe.

[0016] Furthermore, the catalytic reaction zone contains a catalyst with a length of 1.8m, and the bottom of the catalytic reaction zone contains a SiC pellet layer with a length of 0.3m.

[0017] Furthermore, the outer layer of the catalytic reaction zone is connected to a hot melt furnace device, which is equipped with a thermocouple, and the shell is equipped with a pressure gauge, a safety valve, a motor, and a thermometer.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. Highly efficient gas-liquid premixing. The function of the pressure valve gas micro-mixing device: The design of the two baffle plates in the pressure valve gas micro-mixing device allows the gas and liquid to form complex flow paths when entering the reactor, promoting full contact and mixing between them. When the gas and liquid mixture impacts the baffle plates, it changes the flow direction and generates turbulence, thereby enhancing the interphase mass transfer effect and making the gas-liquid mixing more uniform. The densely perforated bottom of the fixed box and the dustproof screen at the pressure valve inlet ensure normal gas flow while preventing impurities from entering and affecting the reaction. It also helps maintain stable pressure within the system, indirectly contributing to the stable operation of the gas-liquid mixing process.

[0020] 2. For the anti-deviation diffuser-assisted premixing, the overflow weir in the anti-deviation diffuser is frustum-shaped with an arc-shaped surface. It contains two layers of inner-ring corrugated baffles and two layers of outer-ring upward-bent baffles. There are channels between the baffles and the overflow weir. After the gas enters through the vents at the gas inlet end of the overflow weir, its flow direction continuously changes within these structures, further enhancing the gas-liquid mixing effect. As the gas passes through the baffles, it is dispersed and redistributed, resulting in more thorough contact with the liquid and improved premixing efficiency.

[0021] 3. Effectively prevents flow deviation. The anti-flow deviation diffuser design features an inwardly concave, arc-shaped overflow weir baffle. Its edge is larger than the diameter of the upper inlet orifice of the overflow weir, effectively preventing some gas from flowing back into the inlet pipe. This ensures the material flows in the predetermined direction within the reactor, preventing localized flow velocity anomalies and flow deviation caused by gas backflow. The 200 mm distance between the baffle and the small-diameter end of the overflow weir is strategically designed, allowing the material to enter the subsequent uniform diffusion device relatively evenly after being blocked and guided by the baffle. This avoids material accumulation or rapid passage in localized areas, thus preventing flow deviation. The overall structure works synergistically; from the pressure valve gas micro-mixing device to the anti-flow deviation diffuser and the packing catalytic system inside the reactor, the entire reactor's structural design works in concert. After the pressure valve gas micro-mixing device performs preliminary homogenization of the material, the anti-deviation diffuser further optimizes the material distribution, ensuring that the material flow rate and concentration entering the catalytic reaction zone are uniform. In this way, the material can uniformly contact and react with the spiral structure catalyst in the catalytic reaction zone, avoiding the overuse or underutilization of some catalyst due to deviation, and ensuring the efficient and stable reaction. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a schematic diagram of a pressure valve gas micro-mixing device;

[0024] Figure 3 A schematic diagram of the structure of the anti-diffuser;

[0025] Wherein: 1-Shell; 101-Inlet pipe; 102-Outlet pipe; 103-Heat 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 one; 202-Baffle plate; 203-Spring; 204-Connecting plate; 3-Baffle buffer plate; 301-Gap; 302-Gas phase overflow area; 4-Frustoconical baffle. 5-Overflow weir; 501-Gas distribution plate II; 502-Ventilation hole; 503-Outer ring circular baffle I bent upwards; 504-Inner ring circular corrugated baffle I; 505-Outer ring circular baffle II bent upwards; 506-Inner ring circular corrugated baffle II; 6-Uniform diffusion device; 601-Support plate; 602-Perforation; 603-Curved feed pipe; 604-Outlet pipe; 605-Wave baffle; 606-Fixing box; 7-SiC pellet layer. Detailed Implementation

[0026] The invention will be further described with reference to the accompanying drawings.

[0027] As shown in the figure, a high-efficiency premixed anti-deviation fixed bed reactor includes a shell 1. 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 reaction gas into it. The outlet collector 102 intercepts a small amount of catalyst or dust, and at the same time, it gathers the gas after the reaction and discharges it through the discharge pipeline. The outlet collector 102 is wrapped with a metal wire mesh.

[0028] The housing 1 is equipped with an anti-deviation diffuser and a catalytic reaction zone from top to bottom. The inlet pipeline 101 is equipped with a pressure valve gas micro-mixing device. The pressure valve gas micro-mixing device includes a pressure valve body 2 along the inlet pipeline 101 flow direction and two spirally twisted baffle plates 3 set at the corners of the inlet pipeline 101. The free ends of the baffle plates 3 face the inlet pipeline 101 flow direction. The pressure valve body 2 includes a connecting plate 204. The surface of the connecting plate 204 is provided with two rings 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 disk 201 is provided at the inlet of the pressure valve body 2. The gas distribution disk 201 is provided with several through holes. The spring 203 is located between the gas distribution disk 201 and the connecting plate 204. A dustproof net is provided at the inlet of the pressure valve body 2.

[0029] The gas in the inlet pipeline 101 enters the shell 1 through the pressure valve gas micro-mixing device. Its main function is to quickly diffuse the mixed gas bubble flow across the entire cross-section of the reactor, avoiding the formation of central flow and back-mixing flow, and playing an initial distribution role. When the gas flows through the baffle plate 202, it will impact and compress the baffle plate 202, and the spring 203 will be compressed. When the gas flows back or the device pressure is too high, it will push the baffle plate 202, causing the spring 203 to stretch, blocking the inlet and preventing gas backflow.

[0030] Furthermore, one end of each of the two baffle plates 3 is connected to the inner wall of the inlet pipe 101, and they gradually twist and extend along the axis of the inlet pipe 101, and are staggered in height. The baffle plate 3 near the inlet of the inlet pipe 101 is located at the upper end of the inlet pipe 101, with a height of 2 / 5 of the diameter of the inlet pipe 101. The baffle plate 3 away from the inlet of the inlet pipe 101 is located at the lower end of the inlet pipe 101, with a height of 4 / 5 of the diameter of the inlet pipe 101. The distance between the connection ends of the two baffle plates 3 and the inlet pipe 101 is 70-150mm.

[0031] Furthermore, there is a gap 301 between the free ends of the two baffle plates 3, and a gas phase overflow zone 302 is formed between the two baffle plates 3.

[0032] Furthermore, the inlet pipe diameter of the pressure valve body 2 is 2 / 3 of the diameter of the inlet pipe 101.

[0033] Furthermore, the number of through holes on the two rings of the end face of the connecting plate 204 are 20 and 24 respectively, and the hole diameter is 30mm.

[0034] Furthermore, the anti-deflection diffuser includes a cylindrical body, inside which is provided an overflow weir 5. A concave frustum-shaped baffle 4 is provided at the gas inlet direction of the overflow weir 5. The gas inlet end of the overflow weir 5 is a second gas distribution disk 501. Ventilation holes 502 are evenly distributed on the second gas distribution disk 501. Below the second gas distribution disk 501 are two layers of upward-bent outer ring baffles and two layers of corrugated inner ring baffles of different diameters. The upward-bent outer ring baffles and corrugated inner ring baffles are arranged alternately. A support plate 601 is provided at the bottom of the overflow weir 5. Several perforations 602 are provided on the support plate 601, and several uniform diffusion devices 6 are connected to the perforations 602 via pipes.

[0035] Furthermore, the two ends of the frustum-shaped baffle 4 are bent upward to form an annular shape, and the diameter of the annular shape is 1 / 10 of the diameter of the lower end of the frustum-shaped baffle 4.

[0036] Furthermore, the uniform diffusion device 6 includes several curved feed pipes 603, the diameter of the curved feed pipes 603 is 30mm, the end of the curved feed pipes 603 is connected to a fixing box 606, the fixing box is connected to several downwardly curved air outlet pipes 604, the diameter of the air outlet pipes 604 is 5mm, and the upper end of the curved feed pipes 603 is provided with a corrugated baffle 605.

[0037] Furthermore, the catalytic reaction zone is provided with a catalyst with a length of 1.8m, and the bottom of the catalytic reaction zone is provided with a SiC pellet layer 7, the SiC pellet layer 7 having a length of 0.3m.

[0038] Furthermore, the outer layer of the catalytic reaction zone is connected to a hot melt furnace device, which is equipped with a thermocouple 104, and the housing 1 is equipped with a pressure gauge 105, a safety valve 106, a motor 107, and a thermometer 108.

[0039] The working principle of this invention is as follows: This invention achieves gas mixing beforehand by installing a pressure valve gas micro-mixing device in the inlet pipeline. Before the liquid phase enters the reactor, it passes through two layers of baffle plates at the inlet pipeline for buffering. This is because if the high-velocity gas phase directly enters the reactor, centrifugal force will cause flow deviation, which these two layers of baffle plates effectively prevent. Simultaneously, a specific gas atmosphere is formed between the two layers of baffle plates, thereby preventing the generation of microbubbles and ensuring stable entry into the reactor. After buffering, the liquid phase bypasses the first baffle plate and collides with the second baffle plate near the reactor at the inlet pipe. The second baffle plate mainly serves to prevent overflow of accumulated liquid. Under normal conditions, the pressure valve device is in a downward compression state. When gas backflow occurs or the gas pressure is too high, the spring stretches, and the baffle plate blocks the pipe opening, preventing gas backflow.

[0040] The inlet anti-deviation diffuser allows gas entering from the inlet pipeline to first contact the baffle plate. Guided by the baffle plate, the gas then enters the overflow area, where liquid phase begins to accumulate. Given that oil entering the reactor from the pipeline often inevitably experiences deviation due to various factors—meaning more oil tends to flow away from the direction of the inlet pipeline's flow—symmetrical and uniform vent holes are installed on the overflow weir surface to effectively prevent uneven overflow caused by inlet pipeline deviation. The inner and outer circumference baffle plates, with different internal diameters, effectively and uniformly block and prevent liquid overflow. The overflowing fluid, after impacting and being deflected by the baffle plates, flows downwards from the center of the cylinder. The gas flowing down from the center of the cylinder then impacts the support plate located below the cylinder, thereby promoting the full diffusion of the fluid within the reactor shell in the uniform diffusion device. The gas-liquid corrugated baffle plate, from the uniform gas port on the corrugated baffle plate to the small-diameter gas outlet pipe, ensures that the gas is mixed evenly and reacts fully with the catalyst when it reaches the reaction zone.

Claims

1. A high-efficiency premixed anti-deviation fixed-bed reactor, characterized in that: The device includes a housing (1), with an inlet pipe (101) at the top and an outlet pipe (102) at the bottom. An anti-deviation diffuser and a catalytic reaction zone are arranged inside the housing (1) from top to bottom. A pressure valve gas micro-mixing device is installed inside the inlet pipe (101). The pressure valve gas micro-mixing device includes a pressure valve body (2) along the flow direction of the inlet pipe (101) and two spirally twisted baffle plates (3) located at the corner inside the inlet pipe (101). The free ends of the baffle plates (3) face the inlet pipe (102). 1) In the direction of incoming flow, the pressure valve body (2) includes a connecting plate (204), the surface of the connecting plate (204) is provided with two rings 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), the inlet of the pressure valve body (2) is provided with a gas distribution plate (201), the gas distribution plate (201) is provided with several through holes, the spring (203) is located between the gas distribution plate (201) and the connecting plate (204), and the inlet of the pressure valve body (2) is provided with a dustproof net; The anti-deviation diffuser includes a cylinder, and an overflow weir (5) is provided inside the cylinder. A concave frustum-shaped baffle (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 disk II (501). Ventilation holes (502) are evenly distributed on the gas distribution disk II (501). Two layers of outer ring circular baffles with different diameters bent upwards and two layers of inner ring circular corrugated baffles with different diameters are provided below the gas distribution disk II (501). The outer ring circular baffles bent upwards and the inner ring circular corrugated baffles are located inside the overflow weir (5). The outer ring circular baffles bent upwards and the inner ring circular corrugated baffles are arranged alternately. A support plate (601) is provided at the bottom of the overflow weir (5). Several perforations (602) are provided on the support plate (601). Several uniform diffusion devices (6) are connected to the perforations (602) through pipes.

2. The high-efficiency premixed anti-deviation fixed-bed reactor according to claim 1, characterized in that: One end of each of the two baffle plates (3) is connected to the inner wall of the inlet pipe (101), and they gradually twist and extend along the axis of the inlet pipe (101) and are staggered in the upper and lower parts. The baffle plate (3) near the inlet of the inlet pipe (101) is located at the upper end of the inlet pipe (101) and its height is 2 / 5 of the pipe diameter of the inlet pipe (101). The baffle plate (3) away from the inlet of the inlet pipe (101) is located at the lower end of the inlet pipe (101) and its height is 4 / 5 of the pipe diameter of the inlet pipe (101). The distance between the connection ends of the two baffle plates (3) and the inlet pipe (101) is 70-150mm.

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

4. The high-efficiency premixed anti-deviation 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 inlet pipe diameter (101).

5. A high-efficiency premixed anti-deviation fixed-bed reactor according to claim 4, characterized in that: The connecting plate (204) has 20 and 24 through holes on the end face, respectively, with a hole diameter of 30mm.

6. The high-efficiency premixed anti-deviation fixed-bed reactor according to claim 1, characterized in that: The two ends of the frustum-shaped baffle (4) are bent upward to form an arc shape, and the diameter of the arc shape is 1 / 10 of the diameter of the lower end of the frustum-shaped baffle (4).

7. A high-efficiency premixed anti-deviation fixed-bed reactor according to claim 1, characterized in that: The uniform diffusion device (6) includes several curved feed pipes (603), the diameter of the curved feed pipes (603) is 30mm, the end of the curved feed pipes (603) is connected to a fixed box (606), the fixed box is connected to several downwardly curved air outlet pipes (604), the diameter of the air outlet pipes (604) is 5mm, and the upper end of the curved feed pipes (603) is provided with a corrugated baffle plate (605).

8. A high-efficiency premixed anti-deviation fixed-bed reactor according to claim 1, characterized in that: The catalytic reaction zone contains a catalyst with a length of 1.8m, and the bottom of the catalytic reaction zone contains a SiC pellet layer (7) with a length of 0.3m.

9. A high-efficiency premixed anti-deviation fixed-bed reactor according to claim 1, characterized in that: The outer layer of the catalytic reaction zone is connected to a hot melt furnace device, which is equipped with a thermocouple (104) and a pressure gauge (105), a safety valve (106), a motor (107), and a thermometer (108) on the shell (1).

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