A heat pipe type ammonia synthesis reactor

Abstract

The present invention relates to a heat pipe-type ammonia synthesis reactor, comprising a cylinder and heat pipes. The cylinder is horizontally arranged with an elliptical longitudinal cross-section and internally provided with a partition, which divides the interior of the cylinder into a heat exchange chamber and a reaction chamber. The heat exchange chamber is located above the reaction chamber. End caps are provided at both ends of the heat exchange chamber and the reaction chamber, respectively. The end caps are provided with a reaction gas inlet, a reaction gas outlet, a heat exchange gas inlet, and a heat exchange gas outlet. The reaction chamber is provided with multiple catalyst layers, which are arranged vertically and spaced apart from each other. Multiple heat pipes are vertically and sealedly inserted through the partition, with their lower portions positioned within the catalyst layers, and their upper and lower ends respectively abutting against the top and bottom surfaces of the cylinder. The present invention can accurately and uniformly control the temperature of the catalyst layers, improve the reaction efficiency of the reactor, and fully meet production needs.

Description

Technical Field

[0001] The present invention relates to a chemical plant, in particular to a synthetic ammonia reactor, specifically a heat pipe type synthetic ammonia reactor. Background Art

[0002] Ammonia is an indispensable raw material in many chemical production fields. The synthetic ammonia industry, centered around ammonia synthesis, plays a crucial role in the national economy. As a pillar of the chemical industry, synthetic ammonia boasts high production output and high energy consumption. Its operating principle involves subjecting an ammonia synthesis reactor to high pressure and temperature, where nitrogen and hydrogen react over a catalyst to produce ammonia.

[0003] The ammonia synthesis reactor must meet the following process requirements: first, the ammonia synthesis reaction should be carried out as close to the optimal temperature as possible to obtain large production capacity and high ammonia synthesis yield; second, the pressure drop of the ammonia synthesis reactor should be reduced to reduce the power consumption of the circulating gas; finally, the structure of the ammonia synthesis reactor should be simple and reliable, and meet the requirements of high temperature and high pressure.

[0004] Currently, the most widely used ammonia synthesis reactors are vertically mounted cylinders, typically housing multiple horizontal catalyst layers. The reactant gases flow downward through the different catalyst layers, allowing the reactants of varying concentrations to react at the appropriate catalyst layer temperatures.

[0005] To keep the catalyst layer operating at the appropriate temperature, a heat exchange structure must be arranged within the catalyst layer. Currently, the main method involves installing multiple heat exchange tubes within the catalyst layer, which lower its temperature by passing a heat exchange gas through the tubes to exchange heat with the catalyst layer. However, this heat exchange structure suffers from a cold tube effect, which reduces reactor efficiency. Furthermore, it can easily lead to uneven temperature distribution in the catalyst layer and inaccurate temperature control, resulting in low reaction efficiency of the reactant gas in the catalyst layer.

[0006] Therefore, improvements are needed to better meet production needs. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies of the prior art and provide a heat pipe type ammonia synthesis reactor that can accurately and evenly control the temperature of the catalyst layer, improve the reaction efficiency of the reactor, and fully meet production needs.

[0008] The technical solution of the present invention is:

[0009] A heat pipe type ammonia synthesis reactor comprises a cylinder and a heat pipe. The cylinder is horizontally arranged and has an elliptical longitudinal cross-section. A partition is provided inside the cylinder. The partition is arranged along the axial direction of the cylinder to separate the interior of the cylinder into a heat exchange chamber and a reaction chamber, which are isolated from each other. The heat exchange chamber is located above the reaction chamber.

[0010] The heat exchange chamber and the reaction chamber are provided with sealing heads at both ends, so that the heat exchange chamber and the reaction chamber form closed cavities respectively; the sealing heads are provided with a reaction gas inlet, a reaction gas outlet, a heat exchange gas inlet and a heat exchange gas outlet respectively;

[0011] The reaction chamber is provided with a plurality of catalyst layers; the catalyst layers are vertically arranged with spacing from each other;

[0012] There are multiple heat pipes, which are vertically sealed and penetrate the partition, with their lower parts placed in the catalyst layer and their upper and lower ends respectively resting on the top and bottom surfaces of the cylinder; the heat pipes have the same volume and are evenly distributed.

[0013] Furthermore, the longitudinal section of the partition is an arc shape with an opening facing downward.

[0014] Furthermore, the head is in the shape of a hemispherical shell; the reaction gas inlet and the reaction gas outlet are respectively located at the left and right ends of the reaction chamber; the heat exchange gas inlet and the heat exchange gas outlet are respectively located at the right and left ends of the heat exchange chamber.

[0015] Furthermore, the catalyst layer includes a first catalyst layer, a second catalyst layer and a third catalyst layer arranged in sequence from left to right; the height of the first catalyst layer is 10-20% of the total catalyst filling height; the height of the second catalyst layer is 20-40% of the total catalyst filling height; the height of the third catalyst layer is 40-70% of the total catalyst filling height.

[0016] Furthermore, it also includes a distribution plate; the distribution plate is in the shape of a circular plate and is provided with a plurality of evenly distributed distribution holes; the distribution plate is respectively arranged in the head at the left end of the reaction chamber and the head at the right end of the heat exchange chamber.

[0017] Furthermore, the ratio of the opening area to the non-opening area of ​​the distribution plate is 1:1-1:3.

[0018] Furthermore, the reaction gas inlet and the heat exchange gas inlet are respectively centrally arranged on the head; and the distribution plate is directly opposite to the reaction gas inlet or the heat exchange gas inlet.

[0019] Furthermore, the distribution plate is connected to the inner wall of the head through a connecting rod.

[0020] Furthermore, the heat pipes are staggered; the distance between adjacent heat pipes is 50-200 mm.

[0021] Beneficial effects of the present invention:

[0022] 1. By separating the reaction gas from the heat exchange gas, the reactor structure is greatly simplified.

[0023] 2. The extremely high thermal conductivity of the heat pipe is utilized to improve the temperature uniformity of each catalyst layer in the reactor and the accuracy of temperature control.

[0024] 3. The staggered arrangement of the heat pipes increases the disturbance of the reaction gas, strengthens the heat exchange between the reaction gas and the heat pipes, and the chemical reaction between the reaction gas and the catalyst layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention.

[0026] Figure 2 yes Figure 1 AA direction schematic diagram in.

[0027] Figure 3 yes Figure 1 BB direction schematic diagram in.

[0028] Figure 4 yes Figure 1 The CC direction diagram in .

[0029] Among them, 1-heat exchange gas inlet; 2-reaction gas outlet; 3-head; 4-cylinder; 5-third catalyst layer; 6-insulation layer; 7-second catalyst layer; 8-first catalyst layer; 9-connecting rod; 10-reaction gas inlet; 11-distribution plate; 12-heat exchange gas outlet; 13-partition; 14-heat pipe; 15-distribution hole; 16-heat exchange chamber; 17-reaction chamber. Implementation Method

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments. The terms "left" and "right" mentioned herein are for the purpose of describing the technical solution and are not intended to limit the technical solution.

[0031] like Figures 1 to 4 shown.

[0032] A heat pipe type ammonia synthesis reactor comprises a cylinder 4 and a heat pipe 14.

[0033] The cylinder 4 is horizontally arranged and has an elliptical longitudinal cross-section. A partition 13 is provided inside the cylinder. The partition 13 is a straight plate disposed along the axial direction of the cylinder, dividing the interior of the cylinder 4 into a heat exchange chamber 16 and a reaction chamber 17, which are isolated from each other. The heat exchange chamber 16 is located above the reaction chamber 17.

[0034] The longitudinal section of the partition 13 is in the shape of an arc with an opening facing downward, so that the cross section of the reaction chamber 17 is circular or approximately circular, so as to improve its pressure resistance.

[0035] The heat exchange chamber 16 and the reaction chamber 17 are each provided with a sealing head 3 at both ends, so that the heat exchange chamber 16 and the reaction chamber 17 form a closed cavity. The sealing head 3 is in the shape of a hemispherical shell, which facilitates the convergence of gas.

[0036] The head 3 is provided with a reaction gas inlet 10, a reaction gas outlet 2, a heat exchange gas inlet 1, and a heat exchange gas outlet 12. The reaction gas inlet 10 and reaction gas outlet 2 are located at the left and right ends of the reaction chamber 17, respectively. The heat exchange gas inlet 1 and heat exchange gas outlet 12 are located at the right and left ends of the heat exchange chamber 16, respectively. Preferably, the reaction gas inlet, reaction gas outlet, heat exchange gas inlet, and heat exchange gas outlet are all located in the center of the corresponding head to facilitate uniform gas flow.

[0037] The reaction chamber 17 is provided with three vertically arranged catalyst layers, which are, from left to right, the first catalyst layer 8, the second catalyst layer 7 and the third catalyst layer 5. The structures of the first catalyst layer 8, the second catalyst layer 7 and the third catalyst layer 5 are basically the same, and are all horizontally placed cylindrical shapes, with their left and right end faces being wire mesh end plates. The end plates are disc-shaped, and their peripheries are connected to the inner wall of the reaction chamber, and catalysts are filled between the end plates to form each catalyst layer. The three catalyst layers are parallel to each other, and an insulating layer 6 with a width of 50-200mm is provided between adjacent catalyst layers to reduce temperature interference between different catalyst layers. Preferably, the height of the first catalyst layer 8 is 10-20% of the total catalyst filling height; the height of the second catalyst layer 7 is 20-40% of the total catalyst filling height; and the height of the third catalyst layer 5 is 40-70% of the total catalyst filling height, so that the temperature of each catalyst layer can be controlled by controlling the number of heat pipes.

[0038] The heat pipes 14 are multiple and vertically penetrate the partition 13. The penetration points are sealed to ensure the sealing between the heat exchange chamber 16 and the reaction chamber 17. The lower portion of the heat pipe 14 is placed in the catalyst layer, and its upper and lower ends respectively abut against the top and bottom surfaces of the cylinder 4, maximizing its heat exchange efficiency to exchange heat with the catalyst layer. The lengths of the heat pipes 14 vary, and their cross-sectional sizes are adapted to their lengths, so that the volumes of the heat pipes are the same, thereby generating the same heat exchange capacity. The medium filled in the heat pipes 14 is liquid ammonia.

[0039] The heat pipes 14 are evenly distributed along the central cross section of the cylinder 4 and are staggered to ensure uniform heat exchange. Preferably, the distance between adjacent heat pipes is 50-200 mm.

[0040] Furthermore, a distribution plate 11 is also included. The distribution plate 11 consists of two pieces, which are respectively arranged in the head at the left end of the reaction chamber 17 and the head at the right end of the heat exchange chamber 16. The distribution plate 11 is in the shape of a circular plate, on which a plurality of evenly distributed distribution holes 15 are provided, and is connected to the inner wall of the head 3 through a connecting rod 9. The distribution holes 15 are through-holes of the same size. When the reaction gas or the heat exchange gas flows in, a part of the gas can flow directly through the distribution holes 15 on the distribution plate 11 under the obstruction of the distribution plate 11, and the other part of the gas will collide with the unperforated area on the distribution plate 11, forming gas collision, rebound and diffusion, thereby realizing uniform flow of the reaction gas. Preferably, the distribution plate 11 is directly opposite the reaction gas inlet 10 or the heat exchange gas inlet 1. At the same time, the outer diameter of the distribution plate 11 is 1 / 5-4 / 5 of the inner diameter of the end face of the head, its thickness is 5-15 mm, and the ratio of its opening area to the non-opening area is 1:1-1:3, thereby improving the flow balancing effect.

[0041] The operation process of the present invention is:

[0042] The reaction gas enters the reaction chamber through the reaction gas inlet, flows evenly through the distribution plate, and then flows rightward through the first, second, and third catalyst layers. Under suitable temperature and pressure conditions, efficient reactions occur in each layer. The reacted gas is discharged through the reaction gas outlet.

[0043] The chemical reaction between the reactant gas and the catalyst layer releases heat, evaporating the liquid ammonia in the heat pipe into vaporized ammonia. This vaporized ammonia flows upward, transferring heat from the reaction chamber to the heat exchange chamber. Simultaneously, the heat exchange gas enters the heat exchange chamber through the heat exchange gas inlet, passes through the distribution plate, and then flows leftward, exchanging heat with the heat pipe, cooling it. Finally, the heated heat exchange gas is discharged through the heat exchange gas outlet.

[0044] After cooling, the heat pipe inside the heat exchange chamber transforms from gaseous ammonia to liquid ammonia, which flows under gravity to the bottom of the heat pipe in the catalyst layer, where it exchanges heat with the catalyst layer again. This cycle cools the catalyst layer, preventing excessive temperatures from affecting catalyst activity.

[0045] Furthermore, the heat exchange capacity of the heat pipe can be precisely controlled by controlling the flow rate and flow rate of the heat exchange gas, and the temperature of the catalyst layer can be precisely adjusted to the following target temperature: the reaction temperature of the first catalyst layer is 460-470°C; the reaction temperature of the second catalyst layer is 440-450°C; the reaction temperature of the third catalyst layer is 420-430°C.

[0046] The present invention has the following characteristics:

[0047] 1. By separating the reaction gas from the heat exchange gas, the reactor structure is greatly simplified.

[0048] 2. The extremely high thermal conductivity of the heat pipe is utilized to improve the temperature uniformity of each catalyst layer in the reactor and the accuracy of temperature control.

[0049] 3. The staggered arrangement of the heat pipes increases the disturbance of the reaction gas, strengthens the heat exchange between the reaction gas and the heat pipes, and the chemical reaction between the reaction gas and the catalyst layer.

[0050] The parts not involved in the present invention are the same as the existing technology or can be implemented by using the existing technology.

Claims

1. A heat pipe type ammonia synthesis reactor, comprising a cylinder and a heat pipe, characterized in that: The cylinder is horizontally placed, has an elliptical longitudinal section, and is provided with a partition plate inside. The partition plate is arranged along the axial direction of the cylinder to separate the interior of the cylinder into a heat exchange chamber and a reaction chamber that are isolated from each other. The heat exchange chamber is located above the reaction chamber. The heat exchange chamber and the reaction chamber are provided with sealing heads at both ends, so that the heat exchange chamber and the reaction chamber form closed cavities respectively; the sealing heads are provided with a reaction gas inlet, a reaction gas outlet, a heat exchange gas inlet and a heat exchange gas outlet respectively; The reaction chamber is provided with a plurality of catalyst layers; the catalyst layers are vertically arranged with spacing from each other; The heat pipes are multiple and vertically sealed and penetrate the partition, with their lower parts placed in the catalyst layer and their upper and lower ends respectively resting against the top and bottom surfaces of the cylinder; the heat pipes have the same volume and are evenly distributed; The catalyst layer includes a first catalyst layer, a second catalyst layer and a third catalyst layer arranged in sequence from left to right; the height of the first catalyst layer is 10-20% of the total catalyst filling height; the height of the second catalyst layer is 20-40% of the total catalyst filling height; the height of the third catalyst layer is 40-70% of the total catalyst filling height; It also includes a distribution plate; the distribution plate is in the shape of a circular plate and is provided with a plurality of evenly distributed distribution holes; the distribution plate is respectively arranged in the head at the left end of the reaction chamber and the head at the right end of the heat exchange chamber; The ratio of the opening area to the non-opening area of ​​the distribution plate is 1:1-1:3; The distribution plate is connected to the inner wall of the head through a connecting rod.

2. The heat pipe type ammonia synthesis reactor according to claim 1, characterized in that: The longitudinal section of the partition is in the shape of an arc with an opening facing downward.

3. The heat pipe type ammonia synthesis reactor according to claim 1, characterized in that: The head is in the shape of a hemispherical shell; the reaction gas inlet and the reaction gas outlet are respectively located at the left end and the right end of the reaction chamber; the heat exchange gas inlet and the heat exchange gas outlet are respectively located at the right end and the left end of the heat exchange chamber.

4. The heat pipe type ammonia synthesis reactor according to claim 1, characterized in that: The reaction gas inlet and the heat exchange gas inlet are respectively centrally arranged on the head; the distribution plate is directly opposite to the reaction gas inlet or the heat exchange gas inlet.

5. The heat pipe type ammonia synthesis reactor according to claim 1, characterized in that: The heat pipes are staggered; the distance between adjacent heat pipes is 50-200 mm.

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