A particle packed fixed bed reactor

Abstract

This invention discloses a particle-packed fixed-bed reactor, comprising a central gas supply and heating device, an outlet mesh limiter, a shroud, a reactor shell, and catalyst particles. A central gas supply and heating device is incorporated into the particle-packed fixed-bed reactor. This device is coaxial with the reactor shell and consists of a mesh limiter, a gas supply pipe, and a pipe wall heater. The device is fixed to the reactor shell inlet by the mesh limiter at one end. The gas supply pipe and the pipe wall heater are inserted axially into the reactor shell. The gas supply pipe is a hollow tubular structure, and the pipe wall heater is spirally wound on the wall surface of the gas supply pipe, which can increase the average temperature while introducing reactants into the middle and rear parts of the reactor. This invention effectively solves the problem of limited reaction rate caused by radial temperature inhomogeneity and low reactant concentration in traditional particle-packed fixed-bed reactors. Furthermore, it has a compact structure, high space utilization, and can significantly improve the production efficiency of particle-packed fixed-bed reactors.

Description

Technical Field

[0001] This invention relates to a chemical reactor, and more particularly to a particle-packed fixed-bed reactor. It can be used for the production of various chemical raw materials and for endothermic chemical reactions. Background Technology

[0002] Particle-packed fixed-bed reactors are common in nuclear energy, petrochemicals, energy storage, renewable energy, and dust removal and purification fields, such as ammonia synthesis towers, sulfur dioxide contact oxidizers, solar collectors, and gas purifiers. Particle-packed fixed-bed reactors offer advantages such as compact structure, large internal specific surface area, strong flow turbulence, simple design and manufacturing, and stable operation. They are mainly used for gas (liquid)-solid phase reactions and gas purification. In modern industrial production, particle-packed fixed-bed reactors are mostly multi-circular tube arrays with small tube diameters and particle size ratios. Due to the large number of catalyst particles made of low thermal conductivity materials inside, the heat exchange performance within the particle-packed fixed-bed reactor is poor. This results in a low average temperature and uneven temperature distribution inside the fixed-bed reactor. According to the principles of chemical reaction, a low average temperature limits the efficiency of the reaction, and an uneven temperature distribution reduces the reactor's lifespan. Furthermore, the tube bank length of a particle packed fixed bed reactor can typically reach more than ten meters. As the axial distance of the tube bank increases, the reaction fluid is continuously consumed, and the concentration of the reaction fluid in the middle and rear sections of the tube bank is usually low. According to the principle of chemical reaction, a low concentration of reaction fluid limits the efficiency of the reaction and easily leads to uneven temperature distribution in the axial direction of the tube bank, thereby affecting the service life of the reactor.

[0003] Therefore, for particle-packed fixed-bed reactors, there is an urgent need for a simple and easy-to-implement structure that can improve heat transfer and the concentration of the reaction fluid in the middle and rear sections, in order to solve the technical shortcomings of particle-packed fixed-bed reactors. Summary of the Invention

[0004] To address the limitations and shortcomings of the aforementioned research, this invention proposes a particle-packed fixed-bed reactor, which features a simple manufacturing process, compact structure, strong heat exchange capacity, high reaction efficiency, and reduced wall effects.

[0005] The technical solution of this invention is implemented as follows:

[0006] The present invention discloses a specific structure of a particle-packed fixed-bed reactor, comprising: a central gas supply and heating device, an outlet mesh limiter, a rectifier, a reactor shell, and catalyst particles; the reactor shell is a tubular structure with inlets and outlets; the central gas supply and heating device is coaxial with the reactor shell and is fixed to the inlet of the reactor shell by the mesh limiter at one end; a gas supply pipe and a pipe wall heater are inserted axially into the reactor shell; the outlet mesh limiter is located at the outlet of the reactor shell; two rectifiers are respectively located outside the mesh limiter of the central gas supply and heating device and outside the mesh limiter of the outlet; the catalyst particles are randomly arranged inside the reactor shell and within the space between the gas supply pipe of the central gas supply and heating device and the mesh limiter of the central gas supply and heating device; the particle-packed fixed-bed reactors are connected in parallel to form multiple sets of particle-packed fixed-bed reactors.

[0007] The central gas supply heating device includes a mesh limiter, a gas supply pipe, and pipe wall heaters. Its features include: the mesh limiter has a mesh structure with an axial through-hole at its radial center; the gas supply pipe is a hollow tube structure connected and fixed to the central through-hole on the mesh limiter, with a length 0.5-0.8 times the length of the reactor shell and a diameter 0.1-0.3 times the diameter of the reactor shell; the pipe wall heaters have a rope-like structure, wound axially along the outer wall of the gas supply pipe in a spiral pattern, with a pitch 0.1-0.5 times the length of the gas supply pipe; there are at least two pipe wall heaters, with their ends arranged in an equiangular array on the outer wall of the gas supply pipe; the outer shell of the pipe wall heaters is made of a high-temperature resistant inert metal, protecting the pipe wall heaters while not participating in the chemical reactions within the particle-stabilized bed reactor.

[0008] The catalyst particles can be spherical, petal-shaped, near-spherical, cylindrical, etc., with a particle diameter of 0.14-0.5 times the diameter of the reactor shell. The catalyst must not enter the gas supply pipe of the central gas supply and heating device. The catalyst particles are randomly arranged within the fixed bed shell, which can be disordered, ordered, composite, or a random combination of the above arrangements.

[0009] Compared with the prior art, the present invention has the following advantages

[0010] 1. The central gas supply heating device is coaxial with the reactor shell. The rope-shaped tube wall heater is wound around the outer wall of the gas supply pipe along the axial direction of the gas supply pipe. It has a heating function and can provide a central heat source to increase the average temperature of the particle-stabilized bed, thus improving the reaction efficiency within the particle-stabilized bed. One end of the gas supply pipe is connected to the central through hole of the mesh limiter at the inlet of the reactor shell, allowing the inlet fluid to flow directly into the gas supply pipe. The other end is inserted into the reactor shell, which can transport the inlet reaction fluid to a distance of 0.5-0.8 axial length of the particle-stabilized bed reactor to replenish the consumed reaction fluid, increase the reaction fluid concentration, and thus improve the overall reaction efficiency within the particle-stabilized bed.

[0011] 2. The spirally arranged rope-shaped tube wall heaters in the central gas supply heating device not only serve as flow guides and reduce internal flow losses, but also make the heating effect more obvious, improve temperature uniformity, extend the service life of catalyst particles and reactors, reduce the influence of wall effects in fixed beds, and enhance the safety of the reactor.

[0012] 3. The particle packed fixed bed reactor has a simple manufacturing process, compact structure, and high space utilization. It can improve the chemical reaction rate without adding an additional active gas delivery device to the original particle packed fixed bed reactor. The particle packed fixed bed reactor can be conveniently and quickly upgraded on the original fixed bed reactor to achieve efficient production. Attached Figure Description

[0013] Figure 1(a) is a schematic diagram of the particle-packed fixed bed reactor-1 of the present invention.

[0014] Figure 1(b) is a left view of the particle-packed fixed-bed reactor-1 of the present invention.

[0015] Figure 1(c) is a cross-sectional view of the particle packed fixed bed reactor-1 shown in Figure 1(b), AA section.

[0016] Figure 2(a) is a schematic diagram of the central heating device with gas pipeline-a and pipe wall heater-a according to the present invention.

[0017] Figure 2(b) is a left view of the central heating device with gas pipeline-a and pipe wall heater-a according to the present invention.

[0018] Figure 2(c) is a cross-sectional view of the central heating device AA shown in Figure 2(b), which has a gas pipeline-a and a pipe wall heater-a.

[0019] Figure 3(a) is a schematic diagram of the gas transmission pipe-a according to the present invention;

[0020] Figure 3(b) is a left view of the gas transmission pipe-a described in this invention;

[0021] Figure 3(c) is a schematic diagram of the gas transmission pipe-b according to the present invention;

[0022] Figure 3(d) is a left view of the gas transmission pipe-b described in this invention;

[0023] Figure 4(a) is a left view of the particle-packed fixed bed reactor-2 of the present invention.

[0024] Figure 4(b) is a cross-sectional view of the particle packed fixed bed reactor-2 shown in Figure 4(a) along section AA.

[0025] Figure 5 This is a schematic diagram of the fairing described in this invention.

[0026] Figure 6 This is a schematic diagram of the outlet mesh limiter described in this invention.

[0027] In the diagram: 1 is the shroud; 2 is the mesh limiter; 3 is the reactor shell; 4 is the catalyst particles; 5 is the gas supply pipe-a; 6 is the pipe wall heater-a; 7 is the gas supply pipe-b; 8 is the pipe wall heater-b; 9 is the outlet mesh limiter. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] As shown in Figures 1(a) to (c), the particle-packed fixed-bed reactor-1 of the present invention comprises: a shroud 1, a mesh retainer 2, a reactor shell 3, catalyst particles 4, a gas supply pipe-a5, a pipe wall heater-a6, and an outlet mesh retainer 9. The central gas supply heating device is coaxial with the reactor shell 3 and is fixed to the inlet of the reactor shell 3 by the mesh retainer at one end. The gas supply pipe-a5 and the pipe wall heater-a6 are inserted axially into the reactor shell 3. The outlet mesh retainer 9 is located at the outlet of the reactor shell 3. The two shrouds 1 are located outside the mesh retainer 2 and outside the outlet mesh retainer 9, respectively. The catalyst particles 4 are randomly arranged inside the reactor shell 3, outside the gas supply pipe-a5, and within the space between the outlet mesh retainer 9 and the mesh retainer 2.

[0030] As shown in Figures 2(a) to (c), the central gas supply heating device consists of a mesh limiter 2, a gas supply pipe-a5, and a pipe wall heater-a6. The mesh limiter 2 has a mesh structure with an axial through hole at its radial center. The gas supply pipe-a5 is a hollow tube structure connected and fixed to the central through hole on the mesh limiter via a tapered section. As shown in Figures 3(a) and 3(b), the length of the gas supply pipe-a5 is 0.67 times the length of the reactor shell. The pipe wall heater-a6 has a rope-like structure, which is wound around the outer wall of the gas supply pipe-a5 along the axial direction of the gas supply pipe in a spiral pattern. The pitch of the spiral is 0.1 times the length of the gas supply pipe-a5. There are four pipe wall heaters-a6, and their ends are distributed in an equiangular array on the outer wall of the gas supply pipe-a5.

[0031] When the reactor of this invention is in operation, as the reaction fluid flows from the pipe to the inlet of the reactor shell 3 through the rectifier 1, a portion of the reaction fluid directly enters the reactor shell 3 through the mesh limiter 2 and reacts with the catalyst particles 4; another portion of the reaction fluid enters the gas supply pipe-a5 through the central through-hole on the mesh limiter 2. This portion of fluid does not participate in the reaction initially and is heated by the pipe wall heater-a6 before flowing directly into a position 0.67 times the axial distance of the particle-packed fixed bed reactor. When the portion of the reaction fluid that directly enters the reactor shell 3 reacts with the catalyst particles 4, it can obtain heat both through the reactor shell 3 and through the pipe wall heater-a6 located on the gas supply pipe-a5. Therefore, the average temperature inside the particle-packed fixed bed reactor is increased, and the reaction rate is enhanced. At the same time, the pipe wall heater-a6 has a spiral structure, which also plays a certain role in guiding the fluid and reducing internal flow losses. When the part of the reaction fluid flows to a position 0.5 times the axial distance of the particle-packed fixed bed reactor, the concentration of the reaction fluid decreases due to continuous reaction consumption. According to the principle of chemical reaction, the reaction rate decreases. At this time, another part of the reaction fluid is transported through the gas supply pipe -a5 without being reacted. This part of the reaction fluid is also heated by the pipe wall heater -a6, carrying more heat. Therefore, the concentration of the reaction fluid in the rear part of the particle-packed fixed bed reactor increases rapidly, and more heat is obtained for the reaction. According to the principle of chemical reaction, the chemical reaction rate is increased, and the overall production rate of the particle-packed fixed bed reactor is improved.

[0032] Figures 4(a) and 4(b) show the particle-packed fixed-bed reactor-2 of the present invention. Its structure and composition are basically the same as those of the particle-packed fixed-bed reactor-1, but the differences are that the particle-packed fixed-bed reactor-2 has a gas supply pipe-b7 and a tube wall heater-b8, and the packing method of the catalyst particles 4 inside the particle-packed fixed-bed reactor-2 is also different from that in the particle-packed fixed-bed reactor-1. As shown in Figures 3(c) and 3(d), the length of the gas supply pipe-b7 in the particle-packed fixed-bed reactor-2 is 0.5 times the length of the reactor shell 3. The tube wall heater-b8 is wound in a spiral along the axial direction of the gas supply pipe-b7 on the outer wall, and the pitch of the spiral is 0.2 times the length of the gas supply pipe-b7. There are six tube wall heaters-b8, and their ends are distributed in an equiangular array on the outer wall of the gas supply pipe-b6.

[0033] The particle-packed fixed-bed reactor of this invention features structural innovation based on chemical reaction principles, increasing the average temperature within the reactor and the concentration of the reaction fluid in the middle and rear sections, thereby improving the reaction rate and production efficiency. Furthermore, this particle-packed fixed-bed reactor eliminates the need for additional active gas delivery devices outside the existing reactor, resulting in a simple manufacturing process, compact structure, and high space utilization. It can be rapidly modified from existing particle-packed fixed-bed reactors, demonstrating promising engineering application prospects.

Claims

1. A granular packing fixed bed reactor comprising: Central gas supply and heating device, outlet mesh limiter, rectifier, reactor shell, catalyst particles; The reactor shell is a tubular structure with inlets and outlets. This particle-packed fixed-bed reactor is characterized by a central gas supply heating device fixed to the reactor shell inlet via a mesh limiter at one end; a gas supply pipe and a pipe wall heater are axially inserted into the reactor shell; an outlet mesh limiter is located at the reactor shell outlet; two rectifiers are located outside the mesh limiter of the central gas supply heating device and outside the mesh limiter of the outlet, respectively; catalyst particles are randomly arranged inside the reactor shell, outside the gas supply pipe of the central gas supply heating device, and within the space between the outlet mesh limiter and the mesh limiter of the central gas supply heating device. The central gas supply heating device includes a mesh limiter, a gas supply pipe, and a pipe wall heater. The device is coaxial with the reactor shell; the mesh limiter has a mesh structure with an axial through hole at its radial center; the gas supply pipe is a hollow tube structure connected and fixed to the central through hole on the mesh limiter, the length of the gas supply pipe is 0.5-0.8 times the length of the reactor shell, and its diameter is 0.1-0.3 times the diameter of the reactor shell; the ends of multiple tube wall heaters are distributed in an equiangular array on the outer wall of the gas supply pipe; they are wound along the outer wall of the gas supply pipe in a spiral line along the axial direction, the pitch of which is 0.1-0.5 times the length of the gas supply pipe; the shell of the tube wall heater is made of high-temperature resistant inert metal, which protects the tube wall heater and does not participate in the chemical reaction in the particle packed bed fixed bed reactor.

2. A granular packing fixed bed reactor according to claim 1, characterized in that: The tube wall heater has a rope-like structure, and there are at least two tube wall heaters.

3. A granular packing fixed bed reactor according to claim 1, characterized in that: The outlet mesh limiter has a mesh structure and is used to limit the position of catalyst particles inside the reactor shell.

4. A granular packing fixed bed reactor according to claim 1, characterized in that: The fairing is used to connect the reactor to the piping.

5. A granular packing fixed bed reactor as claimed in claim 1, characterized in that: The catalyst particles are spherical, petal-shaped, near-spherical, or cylindrical, with a particle diameter of 0.14-0.5 times the diameter of the reactor shell. The catalyst must not enter the gas supply pipe of the central gas supply and heating device.

6. A granular packing fixed bed reactor according to claim 1, characterized in that: The catalyst particles are randomly arranged inside the fixed bed shell, which can be disordered, ordered, composite, or a random combination of the above arrangements.

7. A granular packing fixed bed reactor according to claim 1, characterized in that: This particle-packed fixed-bed reactor can be connected in parallel to form multiple sets of particle-packed fixed-bed reactors.

8. A granular packing fixed bed reactor according to claim 1, characterized in that: This particle-packed fixed-bed reactor is suitable for endothermic chemical reactions.

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