Two-stage reaction system for urotropine production

Abstract

The utility model belongs to the technical field of heterocyclic compound production, and particularly relates to a two-stage reaction system for urotropine production, which comprises a falling film absorption tower, a first absorption module, a second absorption module and a third absorption module are sequentially arranged in the falling film absorption tower from top to bottom, and a mixing cavity is arranged at the bottom of the falling film absorption tower. The first absorption module, the second absorption module and the third absorption module are communicated with one another, liquid sprayers, double filler layers and gas dispersers are arranged in the first absorption module, the second absorption module and the third absorption module at intervals, the liquid sprayers are connected with liquid inlet pipelines, and the gas dispersers are connected with gas inlet pipelines; a plurality of liquid distributors are arranged in the middle of the packed tower at intervals, and a vacuum pump is connected to the top of the packed tower. According to the utility model, the production efficiency of urotropine is improved, the energy consumption is reduced, the use of equipment is reduced, and high efficiency, economical efficiency and environmental friendliness are realized.

Description

Technical Field

[0001] This invention belongs to the field of heterocyclic compound production technology, specifically relating to a two-stage reaction system for the production of hexamethylenetetramine. Background Technology

[0002] Urotropine is an important raw material in chemical production. Traditional urotropine production equipment suffers from the following problems: low single-stage reaction efficiency, insufficient reaction temperature control leading to numerous side reactions, and a yield of only about 70%; high absorption load, low mass transfer efficiency of traditional packed towers, requiring multi-layer towers or large-volume equipment, resulting in high energy consumption; waste of thermal energy, with the exothermic reaction not being effectively utilized, requiring additional cooling systems; and the mainstream liquid-phase method requires evaporation and concentration followed by multi-effect evaporation and crystallization, resulting in high steam consumption. Falling film absorption towers can solve these problems to some extent.

[0003] The falling film absorber contains several falling film structures with regularly arranged packing to enhance mass transfer. However, due to the limited height of the falling film absorber, it is impossible to simultaneously increase the throughput and efficiency, thus affecting the absorption efficiency. Utility Model Content

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a two-stage reaction system for the production of hexamethylenetetramine, which increases the gas-liquid mixing efficiency and thus improves the reaction production efficiency.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] The two-stage reaction system for the production of urotropine described in this utility model includes a falling film absorption tower. Inside the falling film absorption tower, from top to bottom, are arranged a first absorption module, a second absorption module, and a third absorption module. A mixing chamber is located at the bottom of the falling film absorption tower. The first, second, and third absorption modules are interconnected. Each of the first, second, and third absorption modules is equipped with a liquid sprayer, a double packing layer, and a gas disperser at intervals. The liquid sprayer is connected to a liquid inlet pipe, and the gas disperser is connected to an air inlet pipe. The falling film absorption tower is connected to a packed tower, and several liquid distributors are spaced apart in the middle of the packed tower. A vacuum pump is connected to the top of the packed tower.

[0007] in:

[0008] The dual-packing layer includes an outer coarse packing layer and an inner fine packing layer, with the outer coarse packing layer surrounding the outer side of the inner fine packing layer.

[0009] The top of the falling film absorption tower is connected to the lower part of the packed tower, and the lower part of the falling film absorption tower is connected to the upper part of the packed tower.

[0010] A heat exchange jacket is installed on the outside of the falling film absorption tower.

[0011] The liquid sprayer is located above the double packing layer, and the gas disperser is located below the double packing layer.

[0012] A microchannel device is provided at the bottom of the mixing chamber, and the microchannel device is connected to the air intake pipe.

[0013] The bottom of the first absorption module is provided with a connecting channel one, and the bottom of the second absorption module is provided with a connecting channel two. The bottom of the first absorption module is connected to the liquid sprayer in the second absorption module through the connecting channel one, and the bottom of the second absorption module is connected to the liquid sprayer in the third absorption module through the connecting channel two.

[0014] Both the first and second connecting channels are arranged in a funnel shape.

[0015] The top of the packed tower is connected to a liquid storage tank, and a vacuum pump is installed between the packed tower and the liquid storage tank.

[0016] The liquid distributor has several through holes at the top and several nozzles at the bottom; the packed tower is filled with several Pall ring packing rings.

[0017] The beneficial effects of this utility model are:

[0018] This invention utilizes a falling film absorption tower and a packed tower in synergy to increase reaction efficiency to over 90%. During absorption, the load on the packed tower is reduced, significantly decreasing energy consumption and equipment size. The falling film absorption tower is internally divided into three absorption modules, improving the utilization rate of its internal space. The feeding process allows gas to be processed step-by-step within the tower. Each layer is equipped with an independent liquid sprayer and a double packing layer, resulting in an exponential increase in gas-liquid contact area and improved gas-liquid mixing efficiency. The double packing layer significantly extends the gas-liquid mixing time, ensuring sufficient gas-liquid contact. The packed tower, through its packing configuration, increases the processing efficiency of the reaction liquid by approximately five times, and the high mass transfer efficiency reduces the tower volume by 80%. This invention achieves improved hexamethylenetetramine production efficiency, reduced energy consumption, and combines high efficiency, economy, and environmental friendliness. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the double-filler layer structure of this utility model;

[0021] In the diagram: 1. Falling film absorption tower; 2. Packed tower; 3. First absorption module; 4. Second absorption module; 5. Third absorption module; 6. Mixing chamber; 7. Double packing layer; 8. Liquid sprayer; 9. Gas disperser; 10. Liquid distributor; 11. Vacuum pump; 12. Liquid storage tank; 13. Liquid inlet pipe; 14. Gas inlet pipe; 15. Microchannel device; 101. Heat exchange jacket; 301. Connecting channel one; 401. Connecting channel two; 701. Outer coarse packing; 702. Inner fine packing. Detailed Implementation

[0022] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0023] Example 1

[0024] like Figure 1-2 As shown, the two-stage reaction system for the production of hexamethylenetetramine according to this utility model includes a falling film absorption tower 1. Inside the falling film absorption tower 1, from top to bottom, are arranged a first absorption module 3, a second absorption module 4, and a third absorption module 5. A mixing chamber 6 is provided at the bottom of the falling film absorption tower 1. The first absorption module 3, the second absorption module 4, and the third absorption module 5 are interconnected. Inside each of the first absorption module 3, the second absorption module 4, and the third absorption module 5, there are spaced liquid sprayers 8, double packing layers 7, and gas dispersers 9. The liquid sprayers 8 are connected to a liquid inlet pipe 13, and the gas dispersers 9 are connected to a gas inlet pipe 14. The falling film absorption tower 1 is connected to a packed tower 2. Several liquid distributors 10 are spaced apart in the middle of the packed tower 2, and a vacuum pump 11 is connected to the top of the packed tower 2.

[0025] The double packing layer 7 includes an outer coarse packing layer 701 and an inner fine packing layer 702, with the outer coarse packing layer 701 arranged around the outer side of the inner fine packing layer 702.

[0026] The top of the falling film absorption tower 1 is connected to the bottom of the packed tower 2, and the bottom of the falling film absorption tower 1 is connected to the top of the packed tower 2.

[0027] A heat exchange jacket 101 is installed on the outside of the falling film absorption tower 1.

[0028] The liquid sprayer 8 is located above the double packing layer 7, and the gas disperser 9 is located below the double packing layer 7.

[0029] A microchannel device 15 is provided at the bottom of the mixing chamber 6, and the microchannel device 15 is connected to the air intake pipe 14.

[0030] The bottom of the first absorption module 3 is provided with a connecting channel 301, and the bottom of the second absorption module 4 is provided with a connecting channel 401. The bottom of the first absorption module 3 is connected to the liquid sprayer 8 in the second absorption module 4 through the connecting channel 301, and the bottom of the second absorption module 4 is connected to the liquid sprayer 8 in the third absorption module 5 through the connecting channel 401.

[0031] Both connecting channel 1 (301) and connecting channel 2 (401) are arranged in a funnel shape.

[0032] A liquid storage tank 12 is connected to the top of the packed tower 2, and a vacuum pump 11 is installed between the packed tower 2 and the liquid storage tank 12.

[0033] The liquid distributor 10 has several through holes at the top and several nozzles at the bottom; the packed tower 2 is filled with several Pall ring packing rings.

[0034] Working principle and process:

[0035] Formaldehyde is transported through the inlet pipe 14 to the gas disperser 9 within the first absorption module 3, the second absorption module 4, and the third absorption module 5. Ammonia-containing mother liquor is transported through the liquid inlet pipe 13 to the liquid sprayer 8 within the first absorption module 3, the second absorption module 4, and the third absorption module 5. Subsequently, the gas and liquid phases are uniformly dispersed within the first absorption module 3, the second absorption module 4, and the third absorption module 5 for thorough contact. Due to the structure of the double-filler layer 7, the gas and liquid phases, upon entering the inner fine filler 702, are retained due to the uneven internal channels, achieving thorough mixing of the gas and liquid phases within the inner fine filler 702. As the mixture diffuses outward, it passes through the outer coarse packing 701, which further promotes the mixing process. The mixture from the first absorption module 3 enters the second absorption module 4 and the third absorption module 5, and flows downward in sequence, increasing the mixing time. After the mixture flows to the mixing chamber 6, the microchannel device 15 at the bottom of the mixing chamber 6 blows formaldehyde into the mixture to form tiny bubbles. Then the mixture enters the liquid distributor 10 at the top of the packed tower 2. The gas enters the bottom of the packed tower 2 from the top of the falling film absorption tower 1, and then reacts again in a countercurrent manner. The vacuum pump 11 at the top of the packed tower 2 can create a negative pressure environment inside the packed tower 2, so that the gas and liquid are fully mixed.

Claims

1. A two-stage reaction system for the production of hexamethylenetetramine, comprising a falling film absorber (1), characterized in that, The falling film absorption tower (1) is provided with a first absorption module (3), a second absorption module (4) and a third absorption module (5) arranged from top to bottom. A mixing chamber (6) is provided at the bottom of the falling film absorption tower (1). The first absorption module (3), the second absorption module (4) and the third absorption module (5) are interconnected. The first absorption module (3), the second absorption module (4) and the third absorption module (5) are all provided with a liquid sprayer (8), a double packing layer (7) and a gas disperser (9) at intervals. The liquid sprayer (8) is connected to the liquid inlet pipe (13). The gas disperser (9) is connected to the gas inlet pipe (14). The falling film absorption tower (1) is connected to the packed tower (2). Several liquid distributors (10) are arranged at intervals in the middle of the packed tower (2). A vacuum pump (11) is connected to the top of the packed tower (2).

2. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, The double packing layer (7) includes an outer coarse packing layer (701) and an inner fine packing layer (702), with the outer coarse packing layer (701) surrounding the outer side of the inner fine packing layer (702).

3. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, The top of the falling film absorption tower (1) is connected to the bottom of the packed tower (2), and the bottom of the falling film absorption tower (1) is connected to the top of the packed tower (2).

4. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, A heat exchange jacket (101) is installed on the outside of the falling film absorption tower (1).

5. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, The liquid sprayer (8) is located above the double packing layer (7), and the gas disperser (9) is located below the double packing layer (7).

6. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, A microchannel device (15) is provided at the bottom of the mixing chamber (6), and the microchannel device (15) is connected to the air intake pipe (14).

7. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, The bottom of the first absorption module (3) is provided with a connecting channel one (301), and the bottom of the second absorption module (4) is provided with a connecting channel two (401). The bottom of the first absorption module (3) is connected to the liquid sprayer (8) in the second absorption module (4) through the connecting channel one (301), and the bottom of the second absorption module (4) is connected to the liquid sprayer (8) in the third absorption module (5) through the connecting channel two (401).

8. The two-stage reaction system for the production of hexamethylenetetramine according to claim 7, characterized in that, Both connecting channel one (301) and connecting channel two (401) are arranged in a funnel shape.

9. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, A liquid storage tank (12) is connected to the top of the packed tower (2), and a vacuum pump (11) is installed between the packed tower (2) and the liquid storage tank (12).

10. The two-stage reaction system for the production of hexamethylenetetramine according to claim 1, characterized in that, The liquid distributor (10) has several through holes at the top and several nozzles at the bottom; the packed tower (2) is filled with several Pall ring packing rings.

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