A light-removing column for nmp

Abstract

A kind of light component removal tower for NMP, including vertical cylinder and bottom plate arranged in the bottom of cylinder, the center of cylinder top end head is provided with gas phase outlet, the bottom head of cylinder is fixed with liquid phase outlet elbow pipe, multiple groups of interval arrangement distributor are arranged in cylinder from top to bottom, one group of grid is respectively fixed in cylinder below each group of distributor, the cylinder between each group of grid and distributor is respectively filled with packing, the cylinder above the bottommost distributor is fixed with material inlet pipe in communication with outside, the cylinder above the topmost distributor is fixed with reflux pipe in communication with outside.The utility model effectively removes light component impurity in NMP, and the purity of NMP is significantly improved;Light component is separated from NMP, and light component can be further treated and recycled, resource utilization is improved, and production cost is reduced;The stable operation of light component removal cylinder helps to ensure the continuity and stability of the whole production process, and provides high-quality raw materials for subsequent production process.

Description

Technical Field

[0001] This utility model relates to a light-weight removal tower, specifically a light-weight removal tower for NMP. Background Technology

[0002] The NMP light component removal tower is a key piece of equipment used in the purification and separation process of N-methylpyrrolidone (NMP). The light component removal tower separates residual low-boiling-point light components (such as monomethylamine and water) from the NMP production process through distillation, ensuring the purity of the main product meets standards. For example, after the condensation reaction of γ-butyrolactone and monomethylamine, the light component removal tower removes unreacted excess monomethylamine under vacuum conditions, preventing its contamination of the finished product. Through multi-stage light component removal processes (such as single-stage dehydration and double-stage dehydration), the impurity content (such as water and low-boiling-point substances) in NMP is significantly reduced. The separated light components (such as monomethylamine) can be recycled in upstream reaction processes, reducing raw material loss. Some light components (such as tetrahydrofuran) can also be sold as by-products, improving resource utilization.

[0003] However, existing NMP light removal towers have the following shortcomings:

[0004] Insufficient NMP purity: An unreasonable light component removal structure design, lacking the necessary shunting distribution structure, may result in residual light component impurities in the NMP, failing to meet the purity requirements of high-end industries. For example, in lithium battery production, low-purity NMP may cause decreased electrolyte stability and increased risk of internal short circuits, directly affecting battery performance and safety.

[0005] Resource waste and rising costs: The lack of a reflux structure and incomplete separation of light components may lead to impurities being mixed into the recycling system, increasing the difficulty of subsequent treatment. If unrecovered light components are discharged directly, it will not only waste raw materials, but may also generate additional pollution control costs due to failure to meet environmental protection standards.

[0006] Unstable production process: If the design of the light-light removal tower (or light-light removal section) is unreasonable or its operation is unstable, it may become a bottleneck in production. For example, low mass transfer efficiency, easy blockage or frequent failures in the tower can lead to production interruption, increased energy consumption, and even affect the stability of raw material supply to downstream processes. Utility Model Content

[0007] To address the aforementioned problems, the purpose of this invention is to provide a light-weight removal tower for NMP.

[0008] To achieve the above objectives, the technical solution of this utility model is as follows: a light-weight removal tower for NMP, comprising a vertical cylindrical body and a bottom plate at the bottom of the cylindrical body, a gas phase outlet at the center of the top end cap of the cylindrical body, a liquid phase outlet bend fixed to the bottom end cap of the cylindrical body, multiple sets of spaced distributors arranged from top to bottom inside the cylindrical body, a set of grid plates fixed in the cylindrical body below each set of distributors, and packing material filling the cylindrical body between each set of grid plates and distributors, a material inlet pipe connected to the outside fixed above the bottom distributor, and a reflux pipe connected to the outside fixed above the top distributor.

[0009] Furthermore, the opening of the bottom end cap of the cylinder, which connects to the liquid phase outlet bend, is covered with an anti-vortex baffle. The main body of the anti-vortex baffle is a vertically intersecting cross-shaped plate, with the intersection located at the center of the bottom end cap opening. A horizontal circular plate is fixedly covered above the cross-shaped plate.

[0010] Furthermore, the distributor consists of a horizontal support circular plate and multiple vertical distribution pipes penetrating the support circular plate, and the outer periphery of the support circular plate is fixedly connected to the inner wall of the cylinder.

[0011] Furthermore, a reboiler return pipe that communicates with the outside is fixed to the side wall of the cylinder below the bottom grid plate.

[0012] Furthermore, a skirt support tube is fixed at the bottom of the cylinder, the upper end of the skirt support tube is covered by the lower end cap of the cylinder, and exhaust pipes communicating with the inside of the skirt support tube are respectively provided on both sides of the top of the skirt support tube, while an inspection hole communicating with the inside of the skirt support tube is provided on one side of the bottom of the skirt support tube.

[0013] Furthermore, manholes are provided on the side wall of the cylinder at each distributor and on the bottom side wall of the cylinder.

[0014] Furthermore, the side wall of the cylinder is also provided with multiple pressure gauge mounting ports, level gauge mounting ports, and thermometer mounting ports arranged at intervals.

[0015] With the above settings, this utility model has the following advantages:

[0016] 1. Improve NMP purity: This invention features a multi-component flow distribution structure and a filler structure, which effectively removes light component impurities from NMP, significantly improving the purity of NMP and meeting the quality requirements of different industries. For example, in lithium battery production, high-purity NMP is crucial for ensuring battery performance and safety.

[0017] 2. Recovery of light components: A reflux structure is provided, that is, a reflux pipe connected to the outside is fixed on the cylinder above the top distributor. The reflux structure works in conjunction with the distributor structure to separate light components from NMP, which can be further processed and recycled, improving resource utilization and reducing production costs.

[0018] 3. Optimize the production process: As a key link in the NMP production process, this utility model has a multi-stage purification structure and is strongly supported and fixed by structures such as grid plates. The stable operation of the light removal cylinder helps to ensure the continuity and stability of the entire production process and provides high-quality raw materials for subsequent production processes. Attached Figure Description

[0019] The present invention will now be further described with reference to the accompanying drawings.

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

[0021] Figure 2 This is a schematic diagram of the upper part of the present invention;

[0022] Figure 3 This is a schematic diagram of the main structure of the anti-vortex baffle part of this utility model;

[0023] Figure 4 This is a bottom view of the anti-vortex baffle section of this utility model.

[0024] Figure 5 This is a physical reference drawing of the present invention. Detailed Implementation

[0025] like Figure 1-4 As shown, a light-weight removal tower for NMP includes a vertical cylindrical body 1 and a bottom plate 2 at the bottom of the cylindrical body 1. A gas phase outlet 3 is provided at the center of the top end cap of the cylindrical body 1, and a liquid phase outlet bend 4 is fixed to the bottom end cap of the cylindrical body 1. Multiple sets of spaced distributors 5 are arranged from top to bottom inside the cylindrical body 1. A set of grid plates 6 is fixed inside the cylindrical body 1 below each set of distributors 5. The cylindrical body 1 between each set of grid plates 6 and distributors 5 is filled with packing material 7. A material inlet pipe 9 communicating with the outside is fixed above the bottom distributor 5 of the cylindrical body 1, and a reflux pipe 10 communicating with the outside is fixed above the top distributor 5 of the cylindrical body 1.

[0026] The opening of the bottom end cap of the cylinder 1, which connects to the liquid phase outlet bend 4, is covered with an anti-vortex baffle 11. The main body of the anti-vortex baffle 11 is a vertically intersecting cross-shaped plate 1101, with the intersection located at the center of the bottom end cap opening. A horizontal circular plate 1102 is fixedly covered above the cross-shaped plate. The distributor 5 consists of a horizontal supporting circular plate 501 and multiple vertically penetrating distribution pipes 502, and the outer periphery of the supporting circular plate 501 is fixedly connected to the inner wall of the cylinder 1.

[0027] In addition, a reboiler return pipe 12 communicating with the outside is fixed to the side wall of the cylinder 1 below the bottom grid plate 6. A skirt support cylinder 13 is fixed to the bottom of the cylinder 1. The upper end of the skirt support cylinder 13 is covered by the lower end cap of the cylinder 1. Exhaust pipes 14 communicating with the inside of the skirt support cylinder 13 are respectively provided on both sides of the top of the skirt support cylinder 13. An inspection hole 15 communicating with the inside of the skirt support cylinder 13 is provided on one side of the bottom of the skirt support cylinder 13. Manholes 8 are respectively provided on the side wall of the cylinder 1 at each group of distributors 5 and on the bottom side wall of the cylinder 1. Multiple pressure gauge mounting ports, level gauge mounting ports and thermometer mounting ports are also provided on the side wall of the cylinder 1 at intervals.

[0028] The specific working principle is as follows:

[0029] Distillation principle: Utilizing the difference in boiling points between NMP and light components (such as water, low-boiling-point organic impurities, etc.), the mixture is heated to a certain temperature in the light component removal column (i.e., cylinder 1). Because of their lower boiling points, the light components are more likely to vaporize and rise as steam, while NMP is relatively difficult to vaporize and remains in the column as a liquid, thus achieving the initial separation of NMP and light components.

[0030] Gas-liquid mass transfer principle: The column is equipped with packing material 7 or trays. The rising vapor and the falling liquid have sufficient gas-liquid contact mass transfer on the surface of the packing material or trays. Some of the NMP in the vapor will condense into the liquid, while some of the light components in the liquid will vaporize into the vapor. After multiple such mass transfer processes, the light components are continuously enriched at the top of the column, and NMP is enriched at the bottom of the column, achieving a more efficient separation effect.

[0031] Structural features of this utility model

[0032] The cylinder 1 is generally a cylindrical vertical structure made of materials such as carbon steel and stainless steel to ensure stability and corrosion resistance under high temperature and corrosive conditions.

[0033] The material inlet pipe 9 is located in the middle or lower part of the cylinder 1. It is used to introduce a mixture containing NMP and light components into the cylinder 1. The light components and some NMP vapor in the rising steam at the top of the cylinder 1 are condensed into liquid. Part of the condensate is returned to the cylinder 1 as the top reflux liquid to maintain the gas-liquid balance and stable separation effect in the cylinder 1. The other part is taken out as the light component product.

[0034] The skirt holder 13 is connected to the bottom of the cylinder 1, providing heat for the distillation process inside the cylinder 1, causing the liquid at the bottom of the cylinder 1 to vaporize and generate rising steam, which drives the distillation process.

[0035] The packing or cylinder plate 1 is the mass transfer component of the light removal cylinder 1. The packing is usually structured packing or bulk packing, which has a large specific surface area and good mass transfer performance, enabling full contact between gas and liquid. The cylinder plate 1 can take various forms such as sieve plate and float valve cylinder plate 1. Mass transfer and separation are achieved through gas-liquid flow and contact on the cylinder plate 1.

[0036] The discharge ports include the light component gas phase outlet 3 at the top of the cylinder 1 and the NMP discharge port (i.e., the liquid phase outlet bend 4) at the bottom of the cylinder 1. The discharge port at the top of the cylinder 1 discharges the separated light component product or tail gas; the discharge port at the bottom of the cylinder 1 discharges the NMP product with relatively high purity after light component removal treatment, which can be sent to subsequent processes for further processing or directly used as the finished product.

[0037] The above description is merely an illustrative embodiment of this utility model and is not intended to limit the scope of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model should fall within the protection scope of this utility model.

Claims

1. A light-weight removal tower for NMP, comprising a vertical cylindrical body (1) and a bottom plate (2) disposed at the bottom of the cylindrical body (1), wherein a gas phase outlet (3) is disposed at the center of the top end cap of the cylindrical body (1), characterized in that: The bottom end cap of the cylinder (1) is fixed with a liquid phase outlet bend (4). Multiple sets of distributors (5) are arranged from top to bottom inside the cylinder (1). A set of grid plates (6) is fixed in the cylinder (1) below each set of distributors (5). The cylinder (1) between each set of grid plates (6) and distributors (5) is filled with packing material (7). The cylinder (1) above the bottommost distributor (5) is fixed with a material inlet pipe (9) that communicates with the outside. The cylinder (1) above the topmost distributor (5) is fixed with a return pipe (10) that communicates with the outside.

2. The light-weight removal tower for NMP as described in claim 1, characterized in that: The bottom end cap of the cylinder (1) is covered with an anti-vortex baffle (11) at the opening of the liquid phase outlet bend (4). The main body of the anti-vortex baffle (11) is a vertical cross-shaped plate (1101), and the cross part is located at the center of the bottom end cap opening. A horizontal circular plate (1102) is fixed on top of the cross-shaped plate.

3. A light-weight removal tower for NMP as described in claim 1, characterized in that: The distributor (5) consists of a horizontal support circular plate (501) and multiple distribution pipes (502) that penetrate the support circular plate (501) vertically, and the outer periphery of the support circular plate (501) is fixedly connected to the inner wall of the cylinder (1).

4. A light-weight removal tower for NMP as described in claim 1, characterized in that: The bottommost grid plate (6) has a reboiler return pipe (12) fixed on the side wall of the cylinder (1) below it, which is connected to the outside.

5. A light-weight removal tower for NMP as described in claim 1, characterized in that: A skirt support tube (13) is fixed at the bottom of the cylinder (1). The upper end of the skirt support tube (13) is covered by the lower end cap of the cylinder (1). Exhaust pipes (14) communicating with the inside of the skirt support tube (13) are respectively provided on the top two sides of the skirt support tube (13). An inspection hole (15) communicating with the inside of the skirt support tube (13) is provided on the bottom side of the skirt support tube (13).

6. A light-weight removal tower for NMP as described in claim 1, characterized in that: Manholes (8) are provided on the side wall of the cylinder (1) at each distributor (5) and on the bottom side wall of the cylinder (1).

7. A light-weight removal tower for NMP as described in claim 1, characterized in that: The side wall of the cylinder (1) is also provided with multiple pressure gauge installation ports, level gauge installation ports and thermometer installation ports arranged at intervals.

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