Spiral plate type fixed bed reactor for synthetic exothermic reaction

Abstract

The invention relates to the technical field of fixed bed reactors, in particular to a spiral plate type fixed bed reactor for synthetic exothermic reaction, which comprises a shell and two spiral plates arranged in the shell in parallel, and the two spiral plates form a heat exchange channel and a reaction channel; an inclined plate and a through hole are arranged in the heat exchange channel; the inclined plate is obliquely arranged in the heat exchange channel, the bottom of the inclined plate is fixedly connected with the heat exchange channel, and a gap exists between the upper portion of the inclined plate and the upper portion of the heat exchange channel. The through holes are horizontally formed in the inclined plate in a penetrating mode, and the multiple through holes are formed in the extending direction of the inclined plate. A stable temperature environment is provided for the whole reaction process, so that the overall reaction efficiency and the product purity are improved.

Description

Technical Field

[0001] This invention relates to the field of fixed-bed reactor technology, and more specifically to a spiral plate fixed-bed reactor for synthesizing exothermic reactions. Background Technology

[0002] Existing fixed-bed reactors are mostly cylindrical in shape, but traditional tubular fixed-bed reactors have drawbacks such as low heat transfer coefficient and low catalyst bed space utilization.

[0003] Chinese Patent Publication No. CN108114672B discloses a homogenized spiral plate fixed-bed reactor for gas-solid phase contact catalytic reaction, comprising an inlet and outlet for the gas phase and a heat exchange medium, and one or more spiral plate fixed-bed reaction sections within the reactor. The structure of the spiral plate fixed-bed reaction section is similar to that of a spiral plate heat exchanger, consisting of two parallel metal plates rolled into two spiral channels. One channel is closed at both ends, serving as a heat exchange medium channel. The heat exchange medium flows through the spiral channel and undergoes heat exchange through the plate walls, reaching the central tube at the center of the reactor, and then exiting through the heat exchange medium outlet connected to the central tube. The other channel is not sealed at either end, and after being filled with catalyst, it forms a fixed bed. The uppermost end of the bed is connected to the gas inlet, and the lowermost end is connected to the gas outlet. Gas enters the reactor through the inlet, reacts axially through the catalyst fixed bed, and then exits through the gas outlet.

[0004] Compared to traditional fixed-bed reactors, the above-mentioned scheme has better thermal uniformity. However, when used for the synthesis of exothermic reactions, temperature differences still exist. Specifically, during the reaction, gas or liquid is introduced from the top of the fixed-bed reactor. When it passes through the catalyst, it accelerates the reaction and releases heat. Due to the spiral structure, the heat inside the fixed-bed reactor is greater than the heat outside. In addition, as the exothermic reaction proceeds, the heat gradually decreases. That is, the temperature in the upper half of the spiral plate fixed-bed reactor is higher than that in the lower half. The heat exchange medium set in the existing spiral flow channel cannot solve the above two temperature unevenness phenomena, which can easily lead to a decrease in the overall reaction rate and product purity. Excessive temperature can also accelerate catalyst deactivation and shorten the catalyst's lifespan. Summary of the Invention

[0005] To address the aforementioned issues, a spiral plate fixed-bed reactor for synthesizing exothermic reactions is provided. By incorporating perforated inclined plates within the heat exchange channel, the lower-temperature heat exchange medium flows upwards and mixes with the upper-temperature medium, while ensuring smooth flow of the heat exchange medium and effectively balancing the axial temperature difference within the reactor. This design allows the heat exchange medium to flow alternately and undulating in the vertical direction, improving heat exchange uniformity and preventing an imbalance where the upper half of the reaction channel is high-temperature and the lower half is low-temperature.

[0006] To address the problems of existing technologies, this invention provides a spiral plate fixed-bed reactor for synthesizing exothermic reactions, comprising a shell and two spiral plates arranged in parallel inside the shell, the two spiral plates forming a heat exchange channel and a reaction channel;

[0007] Inclined plates and through holes are provided inside the heat exchange channel;

[0008] The inclined plate is set at an angle inside the heat exchange channel. The bottom of the inclined plate is fixedly connected to the heat exchange channel, and there is a gap between the upper part of the inclined plate and the upper part of the heat exchange channel.

[0009] Through holes are horizontally formed on the inclined plate, and multiple through holes are provided in the extending direction of the inclined plate.

[0010] Preferably, multiple heat dissipation fins are fixedly installed on the outer sidewall of the heat exchange channel.

[0011] Preferably, the number of heat dissipation fins on the sidewall of the heat exchange channel gradually increases from the outside to the inside.

[0012] Preferably, a return pipe communicating with the heat exchange channel is provided at the center of the heat exchange channel, and the upper part of the return pipe vertically passes through the upper part of the shell and extends out.

[0013] Preferably, a surrounding sleeve is provided at the upper part of the shell. The surrounding sleeve has an annular structure and surrounds the return pipe. The surrounding sleeve and the outer wall of the return pipe form an annular cavity, which is connected to the shell. Multiple inlets for liquid or gas to enter are provided on the side wall of the surrounding sleeve.

[0014] Preferably, multiple liquid inlet pipes are vertically arranged at the end of the heat exchange channel located on the outer ring.

[0015] Preferably, a main pipeline is vertically arranged on one side of the shell, and the liquid inlet pipe passes through the side wall of the shell and is connected to the main pipeline.

[0016] Preferably, a baffle plate is provided at the upper part of the liquid inlet pipe. The baffle plate has a ring structure and is fixedly installed on the inner wall of the shell.

[0017] Preferably, a first guide slope is provided on the upper part of the baffle plate. The first guide slope is a ring structure, and the height of the inner ring of the first guide slope is lower than the height of the outer ring.

[0018] Preferably, a second guide slope is provided at the upper part of the heat exchange channel. The second guide slope has a spiral structure and the upper part of the second guide slope has a pointed structure.

[0019] The advantages of this invention compared to the prior art are:

[0020] 1. This invention utilizes an inclined plate with through holes within the heat exchange channel to guide the lower-temperature heat exchange medium to flow upwards and mix with the upper-temperature medium, while ensuring smooth flow of the heat exchange medium and effectively balancing the axial temperature difference in the reactor. This design allows the heat exchange medium to flow alternately and undulatingly in the vertical direction, improving heat exchange uniformity and avoiding the imbalance of high temperature in the upper half and low temperature in the lower half of the reaction channel. This provides a stable temperature environment throughout the reaction process, thereby improving overall reaction efficiency and product purity.

[0021] 2. By arranging heat dissipation fins on the outer wall of the heat exchange channel in a manner that gradually increases in number from the outside to the inside, the heat dissipation area of ​​the heat exchange channel is significantly expanded, and radial differential heat dissipation is achieved. The core area near the center of the shell has stronger heat dissipation capacity, precisely solving the problem of heat being difficult to dissipate inside the spiral structure, effectively reducing the radial temperature difference, avoiding accelerated deactivation of the catalyst in the core area due to high temperature, extending the service life of the catalyst, and reducing replacement costs and downtime maintenance time in production.

[0022] 3. By optimizing the layout of the inlet pipe, installing baffles and guide slopes, and rationally arranging the return pipe and surrounding sleeve, the uniform flow and stable supply of the heat exchange medium are ensured, while avoiding direct impact of reactants on the internal components of the equipment. These designs not only improve the stability and durability of the equipment operation but also further optimize the hydrodynamic environment of the reaction system, allowing the reactants to fully contact the catalyst. Combined with a highly efficient heat exchange structure, this multi-dimensional approach ensures the smooth and efficient conduct of the exothermic reaction. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of a spiral plate fixed bed reactor for synthesizing exothermic reactions according to the present invention.

[0024] Figure 2 This is a top view of a spiral plate fixed-bed reactor for synthesizing exothermic reactions according to the present invention.

[0025] Figure 3 This invention relates to a spiral plate fixed-bed reactor for synthesizing exothermic reactions. Figure 2 Schematic diagram of cross-section at point AA.

[0026] Figure 4 This is a cross-sectional three-dimensional schematic diagram of a spiral plate fixed bed reactor for synthesizing exothermic reactions according to the present invention.

[0027] Figure 5 This is a schematic internal plan view of the heat exchange channel of a spiral plate fixed bed reactor for synthesizing exothermic reactions according to the present invention.

[0028] Figure 6This is a schematic diagram of the outer heat dissipation fins distribution plan after the heat exchange channel of a spiral plate fixed bed reactor for synthesizing exothermic reactions is unfolded according to the present invention.

[0029] The following are the labels in the diagram: 1. Shell; 2. Spiral plate; 21. Heat exchange channel; 211. Inclined plate; 212. Through hole; 213. Heat dissipation fins; 214. Liquid inlet pipe; 215. Main pipeline; 216. Second guide slope; 22. Reaction channel; 23. Return pipe; 24. Baffle plate; 241. First guide slope; 3. Enclosure sleeve; 31. Inlet. Detailed Implementation

[0030] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figures 1-5 A spiral plate fixed bed reactor for synthesizing exothermic reactions includes a shell 1 and two spiral plates 2 arranged in parallel inside the shell 1, the two spiral plates 2 forming a heat exchange channel 21 and a reaction channel 22.

[0032] An inclined plate 211 and a through hole 212 are provided in the heat exchange channel 21;

[0033] The inclined plate 211 is inclinedly disposed in the heat exchange channel 21. The bottom of the inclined plate 211 is fixedly connected to the heat exchange channel 21, and there is a gap between the upper part of the inclined plate 211 and the upper part of the heat exchange channel 21.

[0034] Through holes 212 are horizontally opened through the inclined plate 211, and multiple through holes 212 are provided in the extending direction of the inclined plate 211.

[0035] A catalyst is placed inside reaction channel 22, and a heat exchange medium, which is a fluid, is placed inside heat exchange channel 21. When the spiral plate type fixed bed reactor is used for the synthesis of exothermic reactions, the gas or liquid is introduced from the top of the reactor and comes into full contact with the catalyst in reaction channel 22. This process rapidly activates the reaction and releases a large amount of heat. The stronger the catalytic activity of the catalyst, the faster the reaction rate, and the more concentrated the heat generated per unit time.

[0036] Because fixed-bed reactors employ a spiral structure design, their internal flow channels are relatively closed and the paths are tortuous, resulting in a much smaller heat exchange area with the external environment compared to the reactor exterior. In contrast, the reactor exterior can dissipate heat directly through the environment or simple heat exchange structures, while internal heat can only diffuse outwards via conduction through limited flow channels. This leads to a continuous accumulation of heat inside, creating a radial temperature difference where the internal temperature is higher than the external temperature.

[0037] Meanwhile, as the exothermic reaction progresses downwards along the spiral channel, the concentration of the reaction substrate gradually decreases, the reaction intensity weakens accordingly, and the released heat gradually diminishes. This results in the upper half of the reactor maintaining a high temperature due to the vigorous reaction and concentrated heat production, while the lower half experiences a lower temperature due to the slower reaction and reduced heat production, further creating a significant axial temperature difference.

[0038] The heat exchange medium configured in the existing spiral flow channel has a flow path and heat exchange efficiency that cannot accurately match the aforementioned dual temperature difference requirements in the radial and axial directions. In the radial direction, the heat exchange medium, influenced by the heat exchange channel 21, is distributed in a planar spiral shape within the shell 1, making it unable to quickly remove the heat accumulated in the core area. In the axial direction, the temperature regulation of the heat exchange medium lacks specificity, making it difficult to balance the temperature differences between the upper and lower sections. This temperature unevenness not only leads to local reaction rate imbalances in the reaction system, resulting in an overall decrease in product formation efficiency, but also reduces product purity due to local reaction conditions deviating from the optimal range. More seriously, excessively high local temperatures can damage the crystal structure and active components of the catalyst, accelerating catalyst deactivation, significantly shortening its service life, increasing catalyst replacement costs and downtime maintenance during production, and causing significant economic losses to industrial production.

[0039] To avoid the aforementioned issues, the existing spiral plate type 2 fixed bed reactor was optimized. This design allows the heat exchange medium in the spiral plate type 2 fixed bed reactor of this invention to achieve alternating undulating flow in the vertical direction when flowing through the heat exchange channel 21. This mixes the heat exchange medium in the vertical direction, reduces the temperature difference of the heat exchange medium in the vertical direction, and improves the heat exchange efficiency. The specific structure and working process of this invention are as follows:

[0040] When the spiral plate type fixed bed reactor is used for an exothermic synthesis reaction, the gas or liquid used for the reaction is introduced from the upper part of the shell 1. The gas or liquid passes vertically through the reaction channel 22, and the catalyst in the reaction channel 22 accelerates the gas or liquid reaction and releases heat. At this time, the heat exchange medium in the heat exchange channel 21 is in a continuous flow state. Since the heat exchange channel 21 is provided with an inclined plate 211, and the bottom of the inclined plate 211 is fixedly connected to the bottom of the heat exchange channel 21, while the upper part of the inclined plate 211 is separated from the upper part of the heat exchange channel 21, when the heat exchange medium flows in the heat exchange channel 21, the inclined plate 211 guides the heat exchange medium. That is, the heat exchange medium in the lower layer flows upward under the guidance of the inclined plate 211. The temperature of the lower heat exchange medium is lower, and the temperature of the upper heat exchange medium is higher. Under the guidance of the inclined plate 211, the upper and lower heat exchange media mix, which reduces the temperature of the upper heat exchange medium and improves the heat absorption effect. To ensure the fluidity of the heat exchange medium, through holes 212 are provided on the inclined plate 211. When the heat exchange medium passes through the inclined plate 211, some of the heat exchange medium passes through the through holes 212, while some of the heat exchange medium moves upward under the guidance of the inclined plate 211. This allows the upper and lower heat exchange media to mix while ensuring the smooth flow of the heat exchange medium.

[0041] Reference Figure 6 Multiple heat dissipation fins 213 are fixedly installed on the outer side wall of the heat exchange channel 21.

[0042] By setting heat dissipation fins 213 on the outer wall of the heat exchange channel 21, that is, the heat dissipation fins 213 are fixedly set on the side wall of the spiral plate 2, the outer surface area of ​​the heat exchange channel 21 is increased, the heat dissipation effect of the heat exchange channel 21 is improved, the activity of the catalyst set in the reaction channel 22 is extended, and the replacement cycle of the catalyst is extended.

[0043] Reference Figure 6 The number of heat dissipation fins 213 gradually increases from the outside to the inside on the side wall of the heat exchange channel 21.

[0044] By adjusting the number of heat dissipation fins 213, differentiated heat dissipation is achieved at different locations within the heat exchange channel 21. The closer to the center of the heat exchange channel 21, the more heat dissipation fins 213 are present. Since the heat dissipation fins 213 are vertically fixed on the outer wall of the heat exchange channel 21 and are relatively thin, they are not subjected to significant impact when gas or liquid passes through the reaction channel 22. Increasing the number of heat dissipation fins 213 results in a larger heat dissipation area and better heat dissipation effect in the radial direction of the shell 1, closer to the center of the shell 1. This reduces the internal radial temperature difference in the spiral plate 2-type fixed-bed reactor used for exothermic synthesis reactions, preventing rapid deactivation of the catalyst near the center of the shell 1 due to high temperatures.

[0045] Reference Figure 3 and Figure 4 A return pipe 23 is provided in the center of the heat exchange channel 21 and communicates with the heat exchange channel 21. The upper part of the return pipe 23 passes vertically through the upper part of the shell 1 and extends out.

[0046] By vertically setting the return pipe 23 inside the housing 1, it is ensured that the gas or liquid entering the housing 1 will not impact the return pipe 23 when it descends, thus avoiding corrosion damage to the return pipe 23 after long-term use.

[0047] Reference Figure 3 and Figure 4 A surrounding sleeve 3 is provided on the upper part of the housing 1. The surrounding sleeve 3 is an annular structure and surrounds the return pipe 23. The surrounding sleeve 3 and the outer wall of the return pipe 23 form an annular cavity, which is connected to the housing 1. Multiple inlets 31 for liquid or gas to enter are provided on the side wall of the surrounding sleeve 3.

[0048] Since the return pipe 23 is vertically arranged, the traditional method of directly discharging gas or liquid from the top of the housing 1 is not feasible. By setting up a surrounding sleeve 3, an annular cavity is formed between the surrounding sleeve 3 and the outer wall of the return pipe 23, and multiple inlets 31 are provided on the side wall of the surrounding sleeve 3, thereby completing the introduction of gas or liquid.

[0049] Reference Figure 1 and Figure 4 Multiple liquid inlet pipes 214 are vertically installed at the end of the outer ring of the heat exchange channel 21.

[0050] By vertically installing multiple inlet pipes 214 at the ends of the heat exchange channel 21, the flowability of the heat exchange medium in the heat exchange channel 21 is improved compared to the traditional method of installing only one inlet pipe 214. If only one inlet pipe 214 is installed, and if the inlet pipe 214 is located in the upper layer of the heat exchange channel 21, the flow velocity of the heat exchange medium in the upper layer of the heat exchange channel 21 will be greater than that in the lower layer.

[0051] Reference Figure 1 and Figure 4 A main pipeline 215 is vertically installed on one side of the housing 1, and an inlet pipe 214 passes through the side wall of the housing 1 and is connected to the main pipeline 215.

[0052] The main pipe 215 is located on the outside of the housing 1, which avoids the impact of gas or liquid inside the housing 1 on the main pipe 215 and extends the service life of the main pipe 215.

[0053] Reference Figure 3 and Figure 4 A baffle plate 24 is provided at the upper part of the liquid inlet pipe 214. The baffle plate 24 has an annular structure and is fixedly installed on the inner wall of the housing 1.

[0054] By setting up the baffle plate 24, the direct impact of gas or liquid on the liquid inlet pipe 214 after entering the housing 1 can be avoided.

[0055] Reference Figure 3 and Figure 4 A first guide slope 241 is provided on the upper part of the baffle plate 24. The first guide slope 241 is a ring structure, and the height of the inner ring of the first guide slope 241 is lower than the height of the outer ring.

[0056] The first guide slope 241 reduces the impact on the shielding plate 24 when it shields the gas or liquid.

[0057] Reference Figure 4 A second guide slope 216 is provided at the upper part of the heat exchange channel 21. The second guide slope 216 has a spiral structure and the upper part of the second guide slope 216 has a pointed structure.

[0058] By providing a second guide slope 216 at the upper part of the heat exchange channel 21, the impact damage to the heat exchange channel 21 when gas or liquid enters the shell 1 is reduced.

[0059] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A spiral plate fixed bed reactor for synthesizing exothermic reactions, comprising a shell (1) and two spiral plates (2) arranged in parallel inside the shell (1), the two spiral plates (2) forming a heat exchange channel (21) and a reaction channel (22). Its features are, An inclined plate (211) and a through hole (212) are provided in the heat exchange channel (21). The inclined plate (211) is inclinedly installed in the heat exchange channel (21). The bottom of the inclined plate (211) is fixedly connected to the heat exchange channel (21), and there is a gap between the upper part of the inclined plate (211) and the upper part of the heat exchange channel (21). Through holes (212) are horizontally opened on the inclined plate (211), and multiple through holes (212) are provided in the extending direction of the inclined plate (211).

2. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 1, characterized in that, Multiple heat dissipation fins (213) are fixedly installed on the outer side wall of the heat exchange channel (21).

3. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 2, characterized in that, The number of heat dissipation fins (213) gradually increases from the outside to the inside on the side wall of the heat exchange channel (21).

4. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 1, characterized in that, A return pipe (23) connected to the heat exchange channel (21) is provided in the center of the heat exchange channel (21). The upper part of the return pipe (23) passes vertically through the upper part of the shell (1) and extends out.

5. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 4, characterized in that, A surrounding sleeve (3) is provided on the upper part of the shell (1). The surrounding sleeve (3) is an annular structure and surrounds the return pipe (23). The surrounding sleeve (3) and the outer wall of the return pipe (23) form an annular cavity. The annular cavity is connected to the shell (1). Multiple inlets (31) for liquid or gas to enter are provided on the side wall of the surrounding sleeve (3).

6. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 1, characterized in that, Multiple liquid inlet pipes (214) are vertically arranged at the end of the outer ring of the heat exchange channel (21).

7. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 6, characterized in that, A main pipeline (215) is vertically arranged on one side of the shell (1), and an inlet pipe (214) passes through the side wall of the shell (1) and connects to the main pipeline (215).

8. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 6, characterized in that, A baffle plate (24) is provided at the upper part of the liquid inlet pipe (214). The baffle plate (24) is a ring structure and is fixedly installed on the inner wall of the shell (1).

9. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 8, characterized in that, A first guide slope (241) is provided on the upper part of the shield (24). The first guide slope (241) is a ring structure, and the height of the inner ring of the first guide slope (241) is lower than the height of the outer ring.

10. A spiral plate fixed-bed reactor for synthesizing exothermic reactions according to claim 1, characterized in that, A second guide slope (216) is provided at the upper part of the heat exchange channel (21). The second guide slope (216) has a spiral structure and the upper part of the second guide slope (216) has a pointed structure.

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