Spraying device for efficiently recovering caprolactam in neutralization and crystallization reactor

Abstract

The utility model discloses a spraying device for efficiently recovering caprolactam in a neutralization crystallization reactor, which relates to the technical field of chemical equipment, and comprises a neutralization crystallizer body, a demisting net and two spraying disc external support structures, the spraying disc external supporting structures are fixedly connected to the inner wall of the neutralization crystallizer body, the tops of the two spraying disc external supporting structures are provided with an upper spraying disc and a lower spraying disc respectively, the upper spraying disc is arranged above the demisting net, and the lower spraying disc is arranged below the demisting net. By arranging the upper spraying disc and the lower spraying disc and combining with the arrangement of the demisting net, multilayer interception and efficient absorption of gas-phase caprolactam are realized, process water is introduced through the spraying water feeding pipeline, and then the water is uniformly distributed to the spraying ring pipes of the upper spraying disc and the lower spraying disc through the spraying ring pipe communicating pipe; and fine and dense water mist sprayed from the spraying holes covers the whole crystallizer space.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically a spray device for efficient recovery of caprolactam in a neutralization crystallization reactor. Background Technology

[0002] The caprolactam industry is a product of many high-tech fields in the chemical industry, and its production process is complex and lengthy. In the production of the byproduct ammonium sulfate, domestic caprolactam manufacturers generally use DTB-type neutralization crystallization reactors. High-quality liquid ammonia reacts with sulfuric acid from the rearrangement liquid from the preceding ammonia oxime unit under a high vacuum environment in the neutralization crystallizer. Excess water evaporates to form a saturated ammonium sulfate mother liquor, generating ammonium sulfate slurry. Crude caprolactam oil is simultaneously separated in the crystallizer based on solubility differences. The ammonium sulfate slurry undergoes subsequent thickening, centrifugation, and drying processes to form the final ammonium sulfate product. The crude caprolactam oil is further separated and purified before being sent to the caprolactam refining unit.

[0003] The existing shower head spray has a small coverage area and the spray volume is difficult to control. If the spray is not in place, the demister screen will not be thoroughly cleaned, which will affect the vacuum pressure in the crystallizer and the evaporation condensate index will easily exceed the standard. More importantly, it will lead to a low recovery rate of caprolactam carried by evaporation, resulting in a large loss. However, if the spray is too frequent, it will cause too much water phase in the system, affecting the separation and yield of caprolactam and ammonium sulfate mother liquor, and affecting the load and production capacity. Utility Model Content

[0004] The purpose of this invention is to provide a spray device for efficient recovery of caprolactam in a neutralization crystallization reactor, so as to solve the problems in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A spray device for efficient recovery of caprolactam within a neutralization crystallization reactor, comprising:

[0007] Neutralize the crystallizer body;

[0008] A demisting screen is disposed inside the neutralizing crystallizer body;

[0009] It also includes two external support structures for the spray discs, which are fixedly connected to the inner wall of the neutralizing crystallizer body. An upper spray disc and a lower spray disc are respectively installed on the top of the two external support structures for the spray discs. The upper spray disc is located above the demister screen, and the lower spray disc is located below the demister screen.

[0010] Based on the above technical solutions, this utility model also provides the following optional technical solutions:

[0011] In one alternative: both the upper and lower spray plates are provided with spray ring pipes, and a spray ring pipe connecting pipe is also provided on one side of the upper and lower spray plates, wherein the spray ring pipes are connected to the spray ring pipe connecting pipe.

[0012] In one alternative: the spray ring pipe is provided with a plurality of spray holes.

[0013] In one alternative: spray water inlet pipelines are also provided on the upper spray plate and the lower spray plate.

[0014] In one alternative: the spray water inlet pipeline is connected to the spray ring pipe.

[0015] In one alternative: the diameter of the lower spray plate is larger than the diameter of the upper spray plate.

[0016] In one alternative: both the upper and lower spray discs are provided with an internal support structure between them and the spray ring pipe.

[0017] In one alternative: the diameter of the spray holes is Φ1mm, the spacing between the spray holes is 2cm, and the spray holes are symmetrically arranged along the vertical axis of the spray ring pipe.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] This invention achieves multi-layered interception and efficient absorption of gaseous caprolactam by setting up upper and lower spray plates and combining them with the arrangement of the demister net. Process water is introduced through the spray water inlet pipeline, and then the water is evenly distributed to the spray ring pipes of the upper and lower spray plates through the spray ring pipe connecting pipe. Fine water mist is sprayed from the spray holes to cover the entire crystallizer space. This effectively controls the amount of rinsing water while allowing the spray water to fully cover the upper and lower parts of the demister net through the small holes on the spray ring pipe. The spray water has a large coverage area and can efficiently absorb caprolactam entrained in the evaporated water vapor. At the same time, the effective control of the spray water volume ensures the recovery efficiency without causing excessive water phase in the system, which will not affect the separation and yield of caprolactam and ammonium sulfate mother liquor, and reduces the loss of caprolactam. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Figure 2 This is a top view schematic diagram of the upper spray plate of this utility model.

[0022] Figure 3 This is a schematic diagram of the cross-sectional structure of the defogging mesh of this utility model.

[0023] Figure 4 This is a top view of the lower spray plate structure of this utility model.

[0024] Among them: 100, neutralizing crystallizer body; 200, demister screen; 301, external support structure of spray plate; 302, upper spray plate; 303, lower spray plate; 401, internal support structure of spray plate; 402, spray ring pipe; 403, spray ring pipe connecting pipe; 501, spray hole; 502, spray water inlet pipeline. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] In one embodiment, such as Figures 1-4 As shown, a spray device for efficient recovery of caprolactam in a neutralization crystallization reactor includes: a neutralization crystallizer body 100, a demister 200, and two external support structures 301 for the spray discs. The demister 200 is disposed inside the neutralization crystallizer body 100, and the external support structures 301 for the spray discs are fixedly connected to the inner wall of the neutralization crystallizer body 100. An upper spray disc 302 and a lower spray disc 303 are respectively installed on the top of the two external support structures 301 for the spray discs. The upper spray disc 302 is disposed above the demister 200, and the lower spray disc 303 is disposed below the demister 200. The external support structures 301 facilitate the fixation of the upper spray disc 302 and the lower spray disc 303.

[0027] In one embodiment, such as Figure 2 and Figure 4 As shown, both the upper spray plate 302 and the lower spray plate 303 are equipped with spray ring pipes 402. A spray ring pipe connecting pipe 403 is also provided on one side of the upper spray plate 302 and the lower spray plate 303. The spray ring pipe 402 is connected to the spray ring pipe connecting pipe 403. The spray ring pipe connecting pipe 403 connects the spray ring pipes of the upper spray plate 302 and the lower spray plate 303 to form a unified water supply network.

[0028] In one embodiment, such as Figure 2 and Figure 4 As shown, the spray ring pipe 402 is provided with a plurality of spray holes 501; water is sprayed out evenly through the spray holes 501.

[0029] In one embodiment, such as Figure 2 and Figure 4 As shown, spray water inlet pipelines 502 are also provided on the upper spray plate 302 and the lower spray plate 303; external process water is introduced into the interior of the neutralizing crystallizer body 100 through the spray water inlet pipelines 502.

[0030] In one embodiment, such as Figure 2 and Figure 4 As shown, the spray water inlet pipeline 502 is connected to the spray ring pipe 402, which facilitates the delivery of process water into the spray ring pipe 402.

[0031] In one embodiment, such as Figure 2 and Figure 4 As shown, the diameter of the lower spray plate 303 is larger than that of the upper spray plate 302. The larger diameter of the lower spray plate 303 is to cover the lower part of the crystallizer and capture caprolactam that has not been fully absorbed by the upper spray plate due to gas phase diffusion. The smaller diameter of the spray plate 302 is focused on covering the area at the top of the crystallizer where the gas phase is concentrated, which conforms to the gas phase distribution law, thereby maximizing the recovery of resources.

[0032] In one embodiment, such as Figure 2 and Figure 4 As shown, the upper spray plate 302 and the lower spray plate 303 are each provided with an internal support structure 401 between them and the spray ring pipe 402. The internal support structure 401 reinforces the connection point of the spray ring pipe 402, ensuring that the water flow can be evenly distributed under high pressure, while preventing the spray ring pipe from deforming due to mechanical stress.

[0033] In one embodiment, such as Figure 2 and Figure 4 As shown, the diameter of the spray holes 501 is Φ1mm, the spacing of the spray holes 501 is 2cm, and the spray holes 501 are symmetrically opened along the vertical axis of the spray ring pipe 402; so that the water flow can form a uniform and fine water mist, covering the entire reactor space, increasing the contact area between caprolactam and water mist, thereby improving the absorption efficiency.

[0034] The above embodiment discloses a spray device for efficient recovery of caprolactam in a neutralization crystallization reactor. In operation, the upper spray plate 302 and lower spray plate 303, located inside the neutralization crystallizer body 100, combined with the arrangement of the demister 200, achieve multi-layer interception and efficient absorption of gaseous caprolactam. Process water is then introduced into the device through the spray water inlet pipeline 502. The water is evenly distributed into the spray ring pipes 402 of the upper and lower spray plates through the spray ring pipe connecting pipe 403, and finally sprayed out through the spray holes 501, forming a fine water mist covering the entire crystallizer space. The process water flow rate is approximately 3 t / h, the pressure is approximately 0.9 MPa, and the temperature is approximately 50°C. Caprolactam is easily soluble in water. By using the spray device to turn the spray water into a water mist state, filling the upper and lower parts of the demister, the gaseous phase containing some caprolactam distilled from the crystallizer can be effectively intercepted. The caprolactam can be efficiently absorbed back into the system, reducing caprolactam loss.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A spray device for efficiently recovering caprolactam in a neutralization crystallization reactor, comprising: a neutralization crystallizer body (100); a demisting screen (200) arranged inside the neutralization crystallizer body (100); characterized in that it further comprises two spray disc external support structures (301) fixedly connected to the inner wall of the neutralization crystallizer body (100), the top of each of the two spray disc external support structures (301) is respectively provided with an upper spray disc (302) and a lower spray disc (303), the upper spray disc (302) is arranged above the demisting screen (200), and the lower spray disc (303) is arranged below the demisting screen (200).

2. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 1, characterized in that, The upper spray disc (302) and the lower spray disc (303) are both provided with a spray ring pipe (402), and one side of the upper spray disc (302) and the lower spray disc (303) is further provided with a spray ring pipe communication pipe (403), the spray ring pipe (402) communicates with the spray ring pipe communication pipe (403).

3. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 2, characterized in that, The spray ring pipe (402) is provided with a plurality of spray holes (501).

4. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 1, characterized in that, The upper spray disc (302) and the lower spray disc (303) are further provided with a spray water feeding pipeline (502).

5. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 4, characterized in that, The spray water feeding pipeline (502) communicates with the spray ring pipe (402).

6. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 1, characterized in that, The diameter of the lower spray disc (303) is greater than that of the upper spray disc (302).

7. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 2, characterized in that, The upper spray disc (302) and the lower spray disc (303) are both provided with a spray disc internal support structure (401) between the upper spray disc (302) and the lower spray disc (303) and the spray ring pipe (402).

8. The spray device for efficiently recovering caprolactam in a neutralization crystallization reactor according to claim 3, characterized in that, The diameter of the spray hole (501) is Φ1 mm, the interval of the spray hole (501) is 2 cm, and the spray hole (501) is symmetrically arranged along the vertical axis of the spray ring pipe (402).

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