System for cooling high-temperature EG (ethylene glycol) at bottom of process tower in polyester production

Abstract

The utility model discloses a high-temperature EG (ethylene glycol) cooling system at the bottom of a process tower in polyester production, which comprises a slurry tank, an esterification reaction kettle I, an esterification reaction kettle II, the process tower and a slurry preparation ethylene glycol tank, the esterification reaction kettle I is communicated with the esterification reaction kettle II through a pipeline, and the esterification reaction kettle II is communicated with the process tower through a pipeline; the bottom of the process tower is communicated with a circulating pump a through an ethylene glycol pipeline I, the circulating pump a is communicated with an esterification reaction kettle I through a pipeline, a slurry preparation ethylene glycol tank is communicated with a circulating pump b through a pipeline, and the circulating pump b is communicated with a slurry tank through an ethylene glycol pipeline III; a temperature sensor and a regulating valve are arranged on the pipeline between the heat exchanger and the slurry-preparing ethylene glycol tank, a jacketed pipe is arranged on the pipeline between the process tower and the slurry-preparing ethylene glycol tank for cooling, and the device is mainly applied to the aspect of chemical production.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of chemical production, especially relates to a system for cooling high-temperature EG at the bottom of a process column in polyester production. BACKGROUND

[0002] The process column is a necessary device in polyester production, which mainly functions to maintain and regulate the temperature and pressure required for esterification reaction, ensure normal reaction, reduce the use of waste water and steam, lower production cost, and reduce environmental pollution. The most important function is to separate and purify unreacted ethylene glycol. Esterification reaction produces a large amount of water. The process column is connected to the esterification reactor through a gas phase pipeline. Ethylene glycol steam containing water enters the process column through the gas phase pipeline. Through the design of the tray and the filler, ethylene glycol can be effectively separated, and the quality of the product can be improved. The ethylene glycol extracted from the column is pumped back to the esterification system to supplement the reaction, and part of it is used for slurry preparation.

[0003] Slurry temperature is an important factor affecting the density of polyester. When the slurry temperature increases, the density of polyester decreases, and vice versa. This is because when the slurry temperature rises, the molecular chain activity of polyester increases, the freedom of molecular chain increases, which leads to the stretching of molecular chain and the destruction of polyester molecular structure, thereby reducing the density of polyester. At the same time, the increase of slurry temperature will also reduce the mutual attraction between polyester molecular chains, which will also have a certain impact on the structure of polymer. Slurry density has a direct impact on the reaction rate of polyester. Generally, high slurry density can increase the reaction rate. This is because under high slurry density, the collision probability between reactants is higher, and the generation of active centers and the increase of reaction rate will accelerate the reaction. However, too high slurry density will make the reaction system too dense, affecting the migration of reaction substances and the interaction between reaction substances and catalyst. This will have a negative impact on the reaction rate.

[0004] Therefore, the stable control of slurry temperature in polyester production is very important, and the temperature of PTA is relatively stable, so the stable control of the temperature of slurry EG is very important. UTILITY MODEL CONTENT

[0005] The utility model aims at solving one of the technical problems in the prior art, and adopts the following technical scheme:

[0006] A kind of high-temperature EG cooling system in process column bottom in polyester production, including slurry tank, esterification reactor one, esterification reactor two, process column and slurry glycol tank, slurry tank is connected with screw conveyor by pipeline, screw conveyor is used to stir material evenly, screw conveyor is connected with esterification reactor one by pipeline, esterification reactor one is connected with esterification reactor two by pipeline, esterification reactor two is connected with process column by pipeline, the bottom of process column is connected with circulating pump a by glycol pipeline one, circulating pump a is connected with esterification reactor one by pipeline, slurry glycol tank is connected with circulating pump b by pipeline, circulating pump b is connected with slurry tank by glycol pipeline three, the working principle of above-mentioned structure belongs to the routine means of the person skilled in the art, the application will not be described one by one.

[0007] The core improvement of the utility model is as follows: still be equipped with heat exchanger, heat exchanger one end is connected with glycol pipeline two, glycol pipeline two is connected with slurry glycol tank after heat exchange of heat exchanger, pipeline between heat exchanger and slurry glycol tank is equipped with temperature sensor and electromagnetic regulating valve, the pipeline of process column to slurry glycol tank is provided with jacket pipe for cooling.

[0008] Compared with the prior art, the utility model has the advantages that the jacket pipe is arranged on the pipeline from the process column to the slurry tank, which can play a role in cooling.

[0009] The automatic control of the cooling water flow and the glycol temperature of the slurry tank can maintain the stability of the slurry temperature. BRIEF DESCRIPTION OF DRAWINGS

[0010] The utility model will be further described below in combination with the drawings and examples.

[0011] Figure 1 The utility model is a working principle diagram.

[0012] In the drawing: 1-slurry tank, 2-esterification reactor one, 3-esterification reactor two, 4-process column, 5-slurry glycol tank, 6-glycol pipeline one, 7-glycol pipeline two, 8-glycol pipeline three, 9-screw conveyor, 10-electromagnetic regulating valve, 11-temperature sensor, 12-glycol vapor, 13-water vapor, 14-cooling water, 15-heat exchanger. DETAILED DESCRIPTION

[0013] This part will describe the specific embodiments of the utility model in detail, and the preferred embodiments of the utility model are shown in the drawings, and the drawings are used to supplement the description of the text part in the form of graphics, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the utility model, but it cannot be understood as the limitation of the protection scope of the utility model.

[0014] AsFigure 1 as shown:

[0015] A high-temperature EG cooling system at the bottom of a process column in polyester production, comprising a slurry tank 1, an esterification reactor 2, an esterification reactor 3, a process column 4 and a slurry glycol tank 5, the slurry tank 1 is connected with the esterification reactor 2 through a pipeline, the esterification reactor 2 is connected with the esterification reactor 3 through a pipeline, the esterification reactor 3 is connected with the process column 4 through a pipeline, the bottom of the process column 4 is connected with a circulating pump a through a glycol pipeline 1 6, the circulating pump a is connected with the esterification reactor 2 through a pipeline, the slurry glycol tank 5 is connected with a circulating pump b through a pipeline, the circulating pump b is connected with the slurry tank 1 through a glycol pipeline 3 8,

[0016] A heat exchanger 15 is further arranged, one end of the heat exchanger 15 is connected with the glycol pipeline 2 7, the glycol pipeline 2 7 is connected with the slurry glycol tank 5 after heat exchange through the heat exchanger 15, and a pipeline between the heat exchanger 15 and the slurry glycol tank 5 is provided with a temperature sensor 1 1 and an electromagnetic regulating valve 1 0;

[0017] A jacketed pipe is arranged on the pipeline from the process column 4 to the slurry glycol tank 5 for cooling;

[0018] The slurry tank 1 is connected with a screw conveyor 9 through a pipeline, and the screw conveyor 9 is connected with the esterification reactor 2 through a pipeline;

[0019] The working principle of the utility model is as follows:

[0020] The glycol temperature at the bottom of the process column 4 is about 180-190 DEG C, the glycol temperature of the slurry glycol tank 5 is about 50-70 DEG C, because of the glycol balance of the system, the glycol at the bottom of the process column 4 will continuously enter the slurry glycol tank 5 according to the liquid level of the process column, and the fluctuation of flow and temperature will cause the glycol temperature fluctuation of the slurry glycol tank, the pipeline from the process column 4 to the slurry glycol tank 5 is changed into a jacketed pipe, high-temperature glycol flows in the inner layer, and cooling water flows in the outer layer, an electromagnetic regulating valve 1 0 is installed at the outlet of the cooling water, and the control point of the electromagnetic regulating valve 1 0 is the glycol temperature of the slurry glycol tank, so that the temperature of the slurry glycol tank 5 can be stabilized, thereby ensuring the stability of the slurry density and the stability of the subsequent reaction.

[0021] The utility model is described in detail above in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge range possessed by ordinary skilled persons in the technical field without departing from the purpose of the utility model.

Claims

1. A system for cooling high-temperature EG at the bottom of a process tower in polyester production, comprising a slurry tank (1), an esterification reactor one (2), an esterification reactor two (3), a process tower (4), and a slurry preparation glycol tank (5), wherein the slurry tank (1) is connected to the esterification reactor one (2) via a pipeline, the esterification reactor one (2) is connected to the esterification reactor two (3) via a pipeline, the esterification reactor two (3) is connected to the process tower (4) via a pipeline, the bottom of the process tower (4) is connected to a circulating pump a via an ethylene glycol pipeline one (6), the circulating pump a is connected to the esterification reactor one (2) via a pipeline, the slurry preparation glycol tank (5) is connected to a circulating pump b via a pipeline, and the circulating pump b is connected to the slurry tank (1) via an ethylene glycol pipeline three (8), characterized in that, A heat exchanger (15) is also provided. One end of the heat exchanger (15) is connected to the second ethylene glycol pipeline (7). After the second ethylene glycol pipeline (7) exchanges heat through the heat exchanger (15), it is connected to the slurry ethylene glycol tank (5). The pipeline between the heat exchanger (15) and the slurry ethylene glycol tank (5) is equipped with a temperature sensor (11) and an electromagnetic regulating valve (10).

2. The system for cooling high-temperature EG at the bottom of a process tower in polyester production as described in claim 1, characterized in that, A jacketed pipe is installed on the pipeline from the process tower (4) to the slurry preparation glycol tank (5) for cooling.

3. The system for cooling high-temperature EG at the bottom of a process tower in polyester production as described in claim 1, characterized in that, The slurry tank (1) is connected to the screw conveyor (9) via a pipeline, and the screw conveyor (9) is connected to the esterification reactor (2) via a pipeline.

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