Temperature control type reactor suitable for methylamine synthesis

Abstract

The utility model discloses a temperature control type reactor suitable for methylamine synthesis, which comprises a shell and a reaction inner container arranged in the shell, the top of the shell is provided with a raw material gas inlet pipe I through which raw material gas I passes, a gap between the reaction inner container and the shell forms a channel of raw material gas II, the reaction inner container comprises an inner container shell, a group of U-shaped tube bundles are arranged in the inner container shell, a distribution cylinder structure for uniformly distributing raw material gas is arranged at the top of the inner container shell, a cold air distribution section is arranged at the upper part of the inner container shell, a group of cold air inlet holes for raw material gas II to enter are formed in the cold air distribution section, and the top end of the distribution cylinder structure is connected with a raw material gas inlet pipe I; the bottom of the U-shaped tube bundle is connected with an inlet of the U-shaped tube bundle, heat generated in the reaction process is continuously removed by raw material gas in the U-shaped tube bundle, efficient heat removal is carried out on a catalyst bed layer, it is ensured that the catalyst bed layer fluctuates in the optimal temperature interval, and the reaction efficiency of a catalyst is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of methylamine synthesis, and particularly relates to a temperature control reactor suitable for methylamine synthesis. Background Technique

[0002] At present, fixed-bed adiabatic reactors are mostly used in the field of methylamine production. The raw material gas enters from the top of the reactor, passes through the catalyst bed layer, and leaves from the bottom. It mainly has the following disadvantages: 1. It is difficult to control the reaction temperature during the whole process after the raw material gas enters the reactor, so the reaction is difficult to proceed at the optimal reaction temperature (390°C - 410°C); 2. In a conventional adiabatic reactor, the gas phase is difficult to be evenly distributed, and local hot spots are likely to occur, which reduces the reaction conversion rate and affects the catalyst life at the same time; 3. Since the reaction temperature of methylamine is relatively high, it will rise to 500°C at the highest, so the conventional adiabatic reactor puts extremely high requirements on the material of the equipment shell. Usually, SS321 is used, and the equipment wall thickness is relatively high, increasing the equipment investment.

[0003] Therefore, the utility model provides a temperature control reactor suitable for methylamine synthesis, which can effectively control the temperature in the methylamine reaction. Content of the Utility Model

[0004] In view of the problems existing in the prior art, the purpose of the utility model is to provide a temperature control reactor suitable for methylamine synthesis, which solves the problems of uneven gas phase distribution in the reactor and too high temperature of the catalyst bed layer.

[0005] To achieve the above purpose, the technical solution of the utility model is as follows:

[0006] A temperature control reactor suitable for methylamine synthesis, including an outer shell and a reaction inner tank arranged inside the outer shell. The top of the outer shell is provided with a raw material gas inlet pipe one for the passage of raw material gas one. The gap between the reaction inner tank and the outer shell forms a passage for raw material gas two. The reaction inner tank includes an inner tank outer shell. A catalyst bed layer is arranged inside the inner tank outer shell. The bottom of the inner tank outer shell is provided with a reaction gas discharge pipe. A group of U-shaped tube bundles are arranged inside the inner tank outer shell. The top of the inner tank outer shell is provided with a distribution cylinder structure for evenly distributing the raw material gas. The upper part of the inner tank outer shell is provided with a cold air distribution section. A group of cold air inlet holes for the entry of raw material gas two are arranged on the cold air distribution section. The top end of the cold air distribution section is detachably connected to the distribution cylinder structure. The top end of the distribution cylinder structure is connected to the raw material gas inlet pipe one, and its bottom is connected to the inlet of the U-shaped tube bundle.

[0007] Further, the distribution cylinder structure includes a primary distribution cylinder and a secondary distribution cylinder. The secondary distribution cylinder is bolted to the cold air section in segments. The secondary distribution cylinder is located below the primary distribution cylinder. The two distribution cylinders are connected by a connecting pipe. A set of raw gas vent holes I are provided on the bottom surface of the primary distribution cylinder, and a set of raw gas vent holes II are provided on the bottom surface of the secondary distribution cylinder. The raw gas vent holes II are connected to the inlet of the U-shaped tube bundle.

[0008] Further, the raw gas vent holes I are evenly distributed in a rice shape, and the aperture of each raw gas vent hole I is 50 - 250 mm; the primary distribution cylinder is a circular cylinder section with a diameter of 500 - 2000 mm.

[0009] Further, the aperture of the raw gas vent holes II is 19 - 38 mm, and the center distance between adjacent two raw gas vent holes II is 50 - 150 mm.

[0010] Further, the cold air inlet holes are opened on the circumferential surface of the cold air distribution section. The diameter of the cold air inlet holes is 5 - 25 mm, and the distance between adjacent two cold air inlet holes is 50 - 200 mm.

[0011] Further, a support plate is provided in the inner container housing. The U-shaped tube bundle is supported by the support plate. A leakage prevention mechanism for preventing catalyst leakage is provided at the air outlet of each U-shaped tube bundle.

[0012] Further, the leakage prevention mechanism includes a U-shaped tube head and lightweight balls filled inside the U-shaped tube head.

[0013] Further, the U-shaped tube head has a flared structure, and a cross-shaped baffle for preventing the lightweight balls from being blown out is provided at the top of the U-shaped tube head.

[0014] Further, a raw gas feed pipe II for the second raw gas to enter is provided on the side of the housing. The raw gas feed pipe II is a circular ring pipe, and a set of second raw gas distribution holes are opened on its upper surface. The second raw gas distribution holes are evenly distributed along the ring, and their aperture is 25 - 250 mm.

[0015] Further, an air outlet screen is provided at the reaction gas discharge pipe. A catalyst discharge port is provided at the bottom of the inner container housing, and the catalyst discharge port is located beside the reaction gas discharge pipe; a catalyst feed port is provided at the upper end of the side of the inner container housing.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] 1) By adopting the technical solution of the present utility model, a set of U-shaped tube bundles are provided inside the inner tank housing, and the heat generated during the reaction process is continuously removed by the raw material gas in the U-shaped tube bundles, efficiently removing heat from the catalyst bed layer, ensuring that the catalyst bed layer fluctuates within the optimal temperature range, and improving the reaction efficiency of the catalyst;

[0018] 2) With the two-stage distributor and the supporting U-shaped tube bundles provided in the present utility model, the reaction gas can be evenly distributed, ensuring efficient reaction;

[0019] 3) The present utility model has an independent internal and external structure, and the raw material gas is used for cooling and heat insulation in the middle, greatly reducing the temperature of the external housing, reducing the material requirements for the housing, and reducing the equipment cost;

[0020] 4) The present utility model separately sets two raw material inlet ports, and by controlling the ratio between the two, ensures that the reaction gas enters the catalyst bed layer at the optimal reaction temperature for reaction;

[0021] 5) The present utility model is provided with a leakage prevention mechanism at the air outlet of the U-shaped tube bundle to prevent catalyst leakage. When the raw material gas rises, it is pushed up, and the raw material gas enters the top of the reaction inner tank. When there is no gas passing through, the sphere falls back to block the channel, preventing the catalyst from entering. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of the reactor of the present utility model;

[0023] Figure 2 is a bottom view of the first-stage distribution cylinder of the present utility model;

[0024] Figure 3 is a schematic diagram of the distribution of cold air inlet holes on the cold air distribution section of the present utility model;

[0025] Figure 4 is a bottom view of the second-stage distribution cylinder of the present utility model;

[0026] Figure 5 is a schematic diagram of the structure of the U-shaped tube head of the present utility model;

[0027] Figure 6 is a schematic diagram of the structure of the second raw material gas inlet pipe of the present utility model.

[0028] In the figure: 1. Outer shell; 2. Reaction inner tank; 3. Air outlet screen; 4. Cold air distribution section; 5. Inner tank shell; 6. Primary distribution cylinder; 601. First raw gas vent hole; 7. U-shaped tube head; 8. Secondary distribution cylinder; 801. Second raw gas vent hole; 9. U-shaped tube bundle; 10. Connecting pipe; 11. First raw gas inlet pipe; 12. Second raw gas feed pipe; 13. Reaction gas discharge pipe; 14. Catalyst discharge port; 15. Catalyst feed port; 16. Support plate; 17. Catalyst bed; 18. Fastener; 19. Cold air inlet hole; 20. Lightweight ball; 21. Cross baffle; 22. Second raw gas distribution hole. Detailed implementation mode

[0029] The present invention will be further described below in conjunction with the drawings and embodiments, but the scope protected by the present invention is not limited to the described scope.

[0030] Refer to Figure 1 , a temperature-controlled reactor suitable for methylamine synthesis, comprising an outer shell 1 and a reaction inner tank 2 arranged inside the outer shell 1. The reaction inner tank 2 is connected to the outer shell 1 through a fastener 18. The fastener 18 is specifically a bolt, which is convenient for maintenance. In this embodiment, the material of the outer shell 1 is carbon steel, and the material of the reaction inner tank 2 is 304L.

[0031] Compared with the traditional adiabatic reactor shell material SS321, the wall thickness of the outer shell 1 of the present invention is thin, the material is cheap, and the equipment investment cost is small.

[0032] The top of the outer shell 1 is provided with a first raw gas inlet pipe 11 for the passage of the first raw gas. The gap between the reaction inner tank 2 and the outer shell 1 forms a passage for the second raw gas, and the gap between the two is 20 - 200 mm. The raw gas is used for cooling and heat insulation to reduce the temperature of the external shell.

[0033] The present invention separately sets a first raw gas inlet and a second raw gas inlet. By controlling the ratio between the two at 1:1 - 10:1, it is ensured that the reaction gas enters the catalyst bed for reaction at the optimal reaction temperature.

[0034] The reaction inner tank 2 includes an inner tank shell 5. A catalyst bed 17 is arranged inside the inner tank shell 5. The bottom of the inner tank shell 5 is provided with a reaction gas discharge pipe 13, and an air outlet screen 3 is arranged at the reaction gas discharge pipe 13.

[0035] A group of U-shaped tube bundles 9 are arranged inside the inner tank shell 5. The U-shaped tube bundles 9 pass through the catalyst bed 17 and return to the top of the reaction inner tank 2 to transfer the heat of the catalytic reaction. At the same time, the temperature of the raw gas itself rises. The present invention uses the U-shaped tube bundles 9 to efficiently transfer the heat of the catalyst bed 17, ensuring that the catalyst bed 17 fluctuates within the optimal temperature range and improving the reaction efficiency of the catalyst.

[0036] At the top of the inner tank shell 5, there is a distribution cylinder structure for making the raw material gas distribute evenly. At the upper part of the inner tank shell 5, there is a cold air distribution section 4. On the cold air distribution section 4, there is a group of cold air inlet holes 19 for the second raw material gas to enter. The top end of the cold air distribution section 4 is detachably connected to the distribution cylinder structure. The top end of the distribution cylinder structure is connected to the first raw material gas inlet pipe 11, and its bottom end is connected to the inlet of the U-shaped tube bundle 9.

[0037] Please refer to Figure 2 and 4 , the distribution cylinder structure includes a primary distribution cylinder 6 and a secondary distribution cylinder 8. The secondary distribution cylinder 8 is detachably connected to the cold air distribution section 4, specifically by bolt connection, which is convenient for maintenance.

[0038] The secondary distribution cylinder 8 is located below the primary distribution cylinder 6. The two distribution cylinders are connected by a connecting pipe 10. On the bottom surface of the primary distribution cylinder 6, there is a group of first raw material gas ventilation holes 601. On the bottom surface of the secondary distribution cylinder 8, there is a group of second raw material gas ventilation holes 801. The second raw material gas ventilation holes 801 are connected to the inlet of the U-shaped tube bundle 9.

[0039] Please refer to Figure 2 , the first raw material gas ventilation holes 601 are evenly distributed in a cross shape. The aperture of each first raw material gas ventilation hole 601 is 50 - 250 mm. The primary distribution cylinder 6 is a circular cylinder section with a length of 500 - 2000 mm. According to the requirements of the treatment process, the primary distribution cylinder is provided with 2 - 4 rows of ventilation holes in a cross shape.

[0040] Please refer to Figure 4 , the aperture of the second raw material gas ventilation holes 801 is 19 - 38 mm. The center distance between adjacent two second raw material gas ventilation holes 801 is 50 - 150 mm, and they are evenly distributed in the form of 60°, 30° or 45°.

[0041] The raw material gas passes through the primary distributor 5, the connecting pipe 7, and the secondary distributor 6 and enters the U-shaped tube bundle 9. The U-shaped tube bundle 9 passes through the catalyst bed 17 and returns to the top of the reaction inner tank 2 to remove the heat of the catalytic reaction, and at the same time, the temperature of the raw material gas itself rises.

[0042] Please refer to Figure 3 , the cold air inlet holes 19 are opened on the circumferential surface of the cold air distribution section 4. The diameter of the cold air inlet holes 19 is 5 - 25 mm, and the distance between adjacent two cold air inlet holes 19 is 50 - 200 mm. As the cold air inlet holes 19, it ensures that the external raw material gas enters the inner tank evenly and mixes evenly with the heated raw material gas.

[0043] Please refer to Figure 1 and Figure 5, To prevent catalyst leakage, a leakage prevention mechanism is provided at the air outlet of each U-shaped tube bundle 9. The leakage prevention mechanism includes a U-shaped tube head 7 and lightweight balls 20 filled inside the U-shaped tube head 7. The lightweight balls 20 are lightweight refractory porcelain balls. When the raw material gas rises, it is pushed up, and the raw material gas enters the top of the reaction inner tank. When there is no gas passing through, the spheres fall back to block the channel, preventing the catalyst from entering.

[0044] To prevent the lightweight balls from being blown out, a cross-shaped baffle 21 is provided at the top of the U-shaped tube head 7. The U-shaped tube head 7 has a flared structure, which facilitates the escape of the raw material gas.

[0045] Please refer to Figure 6 As shown, a second raw material gas inlet pipe 12 for the second raw material gas is provided on the side of the outer shell 1. The second raw material gas inlet pipe 12 is a circular ring pipe, and a group of second raw material gas distribution holes 22 are opened on its upper surface. The second raw material gas distribution holes 22 are evenly distributed along the ring, and their aperture is 25 - 250 mm. Example 1

[0046] Control Figure 1 , Taking the reaction of trimethylamine as an example.

[0047] The raw material gas (250°C - 270°C) is divided into two streams and enters the first raw material gas inlet pipe 11 and the second raw material gas inlet pipe 12 respectively.

[0048] Part of the raw material gas enters the annulus between the housing 1 and the reaction inner tank 2 through the second raw material gas distribution holes 22 of the second raw material gas inlet pipe 12. After reaching the top of the reactor, it evenly enters the reaction inner tank 2 through the cold air inlet holes 19;

[0049] Another part of the raw material gas enters the reaction inner tank 2 directly through the first raw material gas inlet pipe 11, undergoes primary distribution through the first distribution cylinder 6, then passes through the connecting pipe 10, enters the second distribution cylinder 8 for secondary distribution. After the raw material gas is evenly distributed twice, it enters the U-shaped tube bundle 9, first passes downward through the catalyst bed 17 to remove part of the heat generated by the reaction. After passing through the U-shaped elbow at the bottom, it continues to move upward to remove the reaction heat, and at the same time, the temperature of the raw material gas itself rises. Finally, it passes through the U-shaped tube head 7 and enters the top of the reaction inner tank to be fully mixed with the second raw material gas to reach the optimal temperature (360°C - 390°C) for the catalyst reaction. Then it passes downward through the catalyst bed 17 for reaction. During the process, the heat generated by the reaction is continuously removed by the raw material gas in the U-shaped tube bundle 9. The reacted gas passes through the outlet screen and enters the reaction gas discharge pipe 13, and finally enters the downstream section; the overall reaction temperature fluctuation is controlled between (390 - 420)°C. At the same time, the temperature of the outer shell 1 is controlled below 300°C.

Claims

1. A temperature-controlled reactor suitable for methylamine synthesis, comprising a housing (1) and a reaction inner tank (2) disposed within the housing (1). The top of the housing (1) is provided with a raw material gas inlet pipe one (11) for the passage of raw material gas one. The space between the reaction inner tank (2) and the housing (1) forms a passage for raw material gas two. The reaction inner tank (2) includes an inner tank housing (5). A catalyst bed layer (17) is provided within the inner tank housing (5). The bottom of the inner tank housing (5) is provided with a reaction gas discharge pipe (13), characterized in that Inside the inner container housing (5), a group of U-shaped tube bundles (9) are provided. At the top of the inner container housing (5), a distribution cylinder structure for evenly distributing the raw material gas is provided. At the upper part of the inner container housing (5), a cold air distribution section (4) is provided. On the cold air distribution section (4), a group of cold air inlet holes (19) for the entry of the second raw material gas are provided. The top end of the cold air distribution section (4) is detachably connected to the distribution cylinder structure. The top end of the distribution cylinder structure is connected to the first raw material gas inlet pipe (11), and its bottom is connected to the inlet of the U-shaped tube bundle (9).

2. The temperature-controlled reactor applicable to methylamine synthesis according to claim 1, characterized in that The distribution cylinder structure includes a primary distribution cylinder (6) and a secondary distribution cylinder (8). The secondary distribution cylinder (8) is connected to the cold air section (4) by bolts. The secondary distribution cylinder (8) is located below the primary distribution cylinder (6). The two distribution cylinders are connected by a connecting pipe (10). A group of first raw material gas ventilation holes (601) are provided on the bottom surface of the primary distribution cylinder (6). A group of second raw material gas ventilation holes (801) are provided on the bottom surface of the secondary distribution cylinder (8). The second raw material gas ventilation holes (801) are connected to the inlet of the U-shaped tube bundle (9).

3. The temperature-controlled reactor applicable to methylamine synthesis according to claim 2, characterized in that The first raw material gas ventilation holes (601) are evenly distributed in a cross shape, and the aperture of each first raw material gas ventilation hole (601) is 50 - 250 mm; the primary distribution cylinder (6) is a circular cylinder section with a length of 500 - 2000 mm.

4. The temperature-controlled reactor applicable to methylamine synthesis according to claim 2, characterized in that The aperture of the second raw material gas ventilation holes (801) is 19 - 38 mm, and the center distance between adjacent second raw material gas ventilation holes (801) is 50 - 150 mm.

5. The temperature-controlled reactor applicable to methylamine synthesis according to claim 2, characterized in that The cold air inlet holes (19) are provided on the circumferential surface of the cold air distribution section (4). The diameter of the cold air inlet holes (19) is 5 - 25 mm, and the distance between adjacent cold air inlet holes (19) is 50 - 200 mm.

6. The temperature-controlled reactor applicable to methylamine synthesis according to claim 1, wherein In the inner container housing (5), a support plate (16) is provided. The U-shaped tube bundle (9) is supported by the support plate (16). At the air outlet of each U-shaped tube bundle (9), a leakage prevention mechanism for preventing the catalyst from leaking is provided.

7. The temperature control type reactor applicable to methylamine synthesis according to claim 6, characterized in that The leakage prevention mechanism includes a U-shaped tube head (7) and lightweight balls (20) filled inside the U-shaped tube head (7).

8. A temperature-controlled reactor suitable for methylamine synthesis according to claim 7, characterized in that The U-shaped tube head (7) has a trumpet-shaped structure. At the top of the U-shaped tube head (7), a cross-shaped baffle (21) for preventing the lightweight balls from being blown out is provided.

9. The temperature-controlled reactor applicable to methylamine synthesis according to claim 7, characterized in that On the side of the housing (1), a second raw material gas inlet pipe (12) for the entry of the second raw material gas is provided. The second raw material gas inlet pipe (12) is a circular ring pipe, and a group of second raw material gas distribution holes (22) are provided on its upper surface. The second raw material gas distribution holes (22) are evenly distributed along the ring, and their aperture is 25 - 250 mm.

10. The temperature-controlled reactor applicable to methylamine synthesis according to claim 1, characterized in that At the reaction gas outlet pipe (13), an outlet screen (3) is provided. At the bottom of the inner container housing (5), a catalyst discharge port (14) is provided. The catalyst discharge port (14) is located beside the reaction gas outlet pipe (13); at the upper end of the side of the inner container housing (5), a catalyst inlet port (15) is provided.

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