Efficient caprolactam deacidification system

Abstract

The utility model provides an efficient caprolactam deacidification system which comprises a weak base washing tower and a water washing tower, a caprolactam aqueous solution inlet pipe is arranged on the side face of the weak base washing tower, a sodium hydroxide inlet pipe is arranged on the upper portion of the weak base washing tower, and the caprolactam aqueous solution inlet pipe is provided with a plurality of branch pipes connected with different positions of the weak base washing tower. The utility model has the beneficial effect that the innovative scheme of multiple strands of branch pipes is adopted. By means of the design, the feeding positions are dispersed and are not limited to a single inlet any more. And through the dispersion mode, each layer of tower plate can fully exert the extraction capability of the tower plate. In chemical production, a tower plate is a key assembly in the extraction process and directly affects the extraction efficiency and the product quality. By optimizing feeding distribution, each layer of tower plate can work efficiently, so that the excellent extraction effect of the alkaline washing tower can be better played, and the effect of the whole extraction process reaches the optimal state.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, in particular to an efficient caprolactam deacidification system. Background Art

[0002] Caprolactam is an important chemical raw material. High-quality caprolactam raw materials can be made into high-end textiles, while low-purity caprolactam can be made into engineering plastics. As a result, the value of the products produced in the early stage was greatly reduced due to purity issues, and the company's benefits were seriously affected.

[0003] In recent years, the scale of enterprises mainly producing caprolactam has grown by leaps and bounds, but the quality is uneven. In the final analysis, there is still no deep understanding of the characteristics of caprolactam, especially the downstream processes of caprolactam. The acidic substances in the caprolactam solution can seriously affect the subsequent product performance. In the caprolactam evaporation and purification process, the acidic residue will also seriously increase the operating load, thereby affecting the purity of the product.

[0004] In the prior art, caprolactam directly enters the three-effect process for distillation and purification after the extraction process. The acidic substances carried by caprolactam cannot be removed in these unit operations, resulting in a decrease in product quality. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the problem that the acidic substances in the caprolactam solution seriously affect the performance of its subsequent products is solved.

[0006] The utility model provides an efficient caprolactam deacidification system, comprising a weak alkali washing tower and a water washing tower, wherein a caprolactam aqueous solution inlet pipe is arranged on the side of the weak alkali washing tower, a sodium hydroxide inlet pipe is arranged on the top, and the caprolactam aqueous solution inlet pipe is provided with multiple branch pipes connected to different positions of the weak alkali washing tower.

[0007] Furthermore, a buffer tank is provided between the weak alkali washing tower and the water washing tower to prevent excessive pressure in the weak alkali washing tower.

[0008] Furthermore, a single call valve is arranged on the top of the buffer tank to connect to the flare system, so that the waste gas is discharged into the flare system.

[0009] Furthermore, the sodium hydroxide inlet pipe is provided with a sodium hydroxide storage tank, the sodium hydroxide storage tank is provided with a desalted water inlet pipe to introduce desalted water to dilute the sodium hydroxide, and the sodium hydroxide storage tank is also provided with a pH online measuring instrument to ensure that the pH value of the alkali solution introduced into the alkali washing tower is stable at 7.8 to 8.2.

[0010] Furthermore, the weak alkali washing tower is provided with a bottom heat exchanger for temperature control so that the temperature of the weak alkali washing tower is maintained at 42°C to 48°C.

[0011] As a preferred solution, the pipeline from the bottom heat exchanger to the weak alkali washing tower is provided with multiple branch pipes to improve the reaction efficiency.

[0012] As a preferred solution, nitrogen is introduced into the top of the buffer tank to form a nitrogen seal to prevent caprolactam from being oxidized.

[0013] As a preferred solution, the sodium hydroxide liquid inlet pipe is provided with a heating device to prevent the pipe from being blocked.

[0014] As a preferred embodiment, the water washing tower is a plate-type water washing tower for washing impurities in the deacidified caprolactam aqueous solution.

[0015] The beneficial effects of the utility model are:

[0016] 1. The utility model adopts an innovative solution of multiple branch pipes in the design of the inlet pipe of the caprolactam aqueous solution. This design allows the feed position to be dispersed and is no longer limited to a single inlet. This dispersed approach ensures that each layer of the tower plate can fully exert its extraction capacity. In chemical production, the tower plate is a key component in the extraction process, which directly affects the extraction efficiency and product quality. By optimizing the feed distribution, we ensure that each layer of the tower plate can work efficiently, thereby better exerting the excellent extraction effect of the alkali washing tower and achieving the optimal effect of the entire extraction process.

[0017] 2. The utility model uses a process combining alkali washing and water washing to treat caprolactam. Alkaline washing is a process of removing impurities in caprolactam by chemically reacting an alkaline solution with them. Water washing further removes residual impurities and reaction products through the difference in mutual solubility between water and caprolactam. The combined use of these two methods not only greatly improves the purity of caprolactam, but also significantly improves its chromaticity. In the chemical market, the purity and chromaticity of a product are important indicators of its quality. By improving these two indicators of caprolactam, we have successfully enhanced its competitiveness in the market and increased the unit price of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the utility model easier to understand, the utility model is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0019] Figure 1 A schematic structural diagram of the utility model.

[0020] The reference numerals in the accompanying drawings are:

[0021] 1. Weak alkaline washing tower; 2. Water washing tower; 3. Multiple branch pipes; 4. Buffer tank; 41. Single call valve; 5. Sodium hydroxide storage tank; 6. Tower bottom heat exchanger. DETAILED DESCRIPTION

[0022] To illustrate the features of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0023] Example:

[0024] See also Figure 1 This embodiment aims at the deficiencies of the prior art and solves the problem of inconvenient frequent transportation of small materials in an environment with limited working space. An efficient caprolactam deacidification system is provided, including a weak alkali washing tower 1 and a water washing tower 2. A caprolactam aqueous solution inlet pipe is arranged on the side of the weak alkali washing tower 1, and a sodium hydroxide inlet pipe is arranged on the upper part. The caprolactam aqueous solution inlet pipe is provided with multiple branch pipes 3 connected to different positions of the weak alkali washing tower 1. In this embodiment, the multiple branch pipes 3 are divided into three branches, which are respectively connected to the upper, middle and lower parts of the weak alkali washing tower 1.

[0025] In order to prevent the weak alkali tower from having too high pressure, a gas phase connecting pipe is set between the buffer tank 4 and the weak alkali washing tower 1 in this embodiment, that is, a buffer tank 4 is set between the weak alkali washing tower 1 and the water washing tower 2 to prevent the pressure in the weak alkali washing tower 1 from being too high. In addition, a single call valve 41 is set on the top of the buffer tank 4 to connect with the flare system to discharge the exhaust gas into the flare system, and nitrogen is introduced into the top of the buffer tank 4 to form a nitrogen seal to prevent the oxidation of caprolactam.

[0026] The sodium hydroxide inlet pipe is provided with a sodium hydroxide storage tank 5, and the sodium hydroxide storage tank 5 is provided with a desalted water inlet pipe to pass desalted water to dilute the sodium hydroxide, and gradually dilute and adjust the original sodium hydroxide. The sodium hydroxide storage tank 5 is also provided with a pH online measuring instrument to ensure that the pH value of the alkali solution passed into the alkali washing tower is stable at 7.8 to 8.2. In order to prevent the alkalinity from exceeding the standard, regulating valves are provided on the sodium hydroxide pipeline and the desalted water pipeline and proportional regulation control is performed therewith.

[0027] In this embodiment, the weak alkali washing tower 1 is provided with a bottom heat exchanger 6 for temperature control, so that the temperature of the weak alkali washing tower 1 is maintained at 42° C. to 48° C., and multiple branch pipes 3 are provided in the pipeline from the bottom heat exchanger 6 to the weak alkali washing tower 1 to improve the reaction efficiency.

[0028] This embodiment also makes adaptive adjustments to specific usage scenarios. The sodium hydroxide inlet pipe is provided with a heating device to prevent pipe blockage, and the water washing tower 2 is configured as a plate-type water washing tower to wash impurities in the deacidified caprolactam aqueous solution.

[0029] The above embodiments and drawings are only used to illustrate the technical solution of the utility model, and are not intended to limit the utility model. The utility model is described in detail with reference to the preferred embodiments. It should be understood by ordinary technicians in this field that the changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the utility model do not deviate from the purpose of the utility model and should also fall within the scope of protection of the claims of the utility model. Other related technical structures not fully disclosed in the utility model are prior art in the field.

Claims

1. An efficient caprolactam deacidification system, comprising a weak base washing tower (1) and a water washing tower (2), characterized in that: A caprolactam aqueous solution inlet pipe is arranged on the side of the weak alkali washing tower (1), and a sodium hydroxide inlet pipe is arranged on the top. The caprolactam aqueous solution inlet pipe is provided with multiple branch pipes (3) connected to different positions of the weak alkali washing tower (1).

2. The efficient caprolactam deacidification system according to claim 1, characterized in that: A buffer tank (4) is provided between the weak alkali washing tower (1) and the water washing tower (2) to prevent excessive pressure in the weak alkali washing tower (1).

3. The efficient caprolactam deacidification system according to claim 2, characterized in that: A single call valve (41) is arranged on the top of the buffer tank (4) to communicate with the flare system, so that the waste gas is discharged into the flare system.

4. The efficient caprolactam deacidification system according to claim 1, characterized in that: The sodium hydroxide inlet pipe is provided with a sodium hydroxide storage tank (5), and the sodium hydroxide storage tank (5) is provided with a desalted water inlet pipe for introducing desalted water to dilute the sodium hydroxide. The sodium hydroxide storage tank (5) is also provided with a pH online measuring instrument to ensure that the pH value of the alkali solution introduced into the alkali washing tower is stable at 7.8 to 8.

2.

5. The efficient caprolactam deacidification system according to claim 1, characterized in that: The weak alkali washing tower (1) is provided with a bottom heat exchanger (6) for temperature control, so that the temperature of the weak alkali washing tower (1) is maintained at 42° C. to 48° C.

6. The efficient caprolactam deacidification system according to claim 5, characterized in that: The pipeline from the tower bottom heat exchanger (6) back to the weak alkali washing tower (1) is provided with multiple branch pipes (3) to improve the reaction efficiency.

7. The efficient caprolactam deacidification system according to claim 2, characterized in that: Nitrogen is introduced into the top of the buffer tank (4) to form a nitrogen seal to prevent caprolactam from being oxidized.

8. The efficient caprolactam deacidification system according to claim 1, characterized in that: The sodium hydroxide liquid inlet pipe is provided with a heating device to prevent the pipe from being blocked.

9. The efficient caprolactam deacidification system according to claim 1, characterized in that: The water washing tower (2) is a plate-type water washing tower for washing impurities in the caprolactam aqueous solution after deacidification.

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