Anti-blocking continuous rectification purification device for glacial acetic acid

Abstract

The utility model discloses a kind of anti-clogging continuous glacial acetic acid rectification purification device, including sequentially connected raw material tank, preheater, rectifying tower, the outside of the raw material tank is equipped with first heat-preservation jacket, the outside of the rectifying tower is equipped with second heat-preservation jacket, the pipeline between the rectifying tower and the preheater is equipped with polymerization inhibitor injection port;The gas phase outlet of the top of the rectifying tower is connected with main condenser, the main condenser connects reflux tank, the reflux tank is connected product cooler by reflux pump, and the product cooler is connected with product storage tank;The liquid phase outlet of the bottom of the rectifying tower is connected with reboiler, and the reboiler is also connected with the rectifying tower, and the pipeline between the liquid phase outlet and the reboiler is also equipped with recovery tank.The utility model can present glacial acetic acid's high-purity continuous stable production, solve or greatly alleviate crystallization plugging problem in rectification process.

Description

Technical Field

[0001] This utility model relates to the field of glacial acetic acid production technology, and in particular to a continuous glacial acetic acid distillation and purification device with anti-clogging properties. Background Technology

[0002] Anhydrous acetic acid, commonly known as glacial acetic acid, has a high freezing point. When the ambient temperature is low or operating conditions fluctuate, it freezes into ice-like crystals, thus requiring distillation in the production process. The biggest challenge in traditional distillation columns processing glacial acetic acid is clogging of the top system (condenser, reflux tank, pipelines). This typically requires frequent shutdowns for hot water or steam purging, severely impacting continuous operation time and production efficiency. Some units even employ batch distillation, which is inefficient, energy-intensive, and results in significant product quality fluctuations. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a continuous glacial acetic acid distillation and purification device with anti-clogging, which aims to solve the technical problems of prominent clogging, low efficiency of intermittent operation, and impact on production continuity and efficiency in the existing technology.

[0004] The technical solution of this utility model is: a continuous anti-clogging glacial acetic acid distillation and purification device, comprising a raw material tank, a preheater, and a distillation column connected in sequence. The raw material tank is provided with a first insulation jacket, and the distillation column is provided with a second insulation jacket. An inhibitor injection port is provided on the pipeline between the distillation column and the preheater. The vapor phase outlet at the top of the distillation column is connected to a main condenser, which is connected to a reflux tank. The reflux tank is connected to a product cooler via a reflux pump, and the product cooler is connected to a product storage tank. The liquid phase outlet at the bottom of the distillation column is connected to a reboiler, which is also connected to the distillation column. A recovery tank is also provided on the pipeline between the liquid phase outlet and the reboiler.

[0005] Furthermore, in this utility model, the first insulation jacket is provided with an electric heating tube, which is inserted into the first insulation jacket; the second insulation jacket is provided with a heating coil, which is arranged along the height direction of the second insulation jacket.

[0006] Furthermore, the preheater described in this utility model is a shell-and-tube heat exchanger.

[0007] Furthermore, the distillation column described in this utility model is a structured packed column.

[0008] Furthermore, both the main condenser and the product cooler described in this utility model are falling film condensers, and the falling film condenser is provided with a warm water inlet and a warm water outlet.

[0009] Furthermore, the bottom of the reflux tank in this invention is conical, the outside of the reflux tank is entirely wrapped with a heat insulation layer, and a low-speed stirrer is provided at the bottom inside the reflux tank.

[0010] Furthermore, the reflux pump described in this utility model is a magnetically driven pump.

[0011] Furthermore, the storage tank described in this utility model is an insulated tank.

[0012] Furthermore, the reboiler described in this invention is a forced circulation reboiler or a thermosiphon reboiler.

[0013] Furthermore, the various devices in the device described in this utility model are connected by pipes, and each pipe is wrapped with a mineral wool insulation layer, and the mineral wool insulation layer is also provided with a stainless steel protective shell.

[0014] Compared with the prior art, this invention has the following advantages: It can preheat the raw material to a certain temperature to prevent solidification before it enters the column, and also helps remove some low-boiling-point impurities. The polymerization inhibitor injection port allows for the continuous injection of trace amounts of polymerization inhibitor into the raw material to suppress the polymerization reaction. The distillation column uses a structured packed column, which has a low pressure drop, low liquid holdup, and high separation efficiency, reducing the residence time of materials in the column and lowering the risk of polymerization. The forced circulation reboiler at the bottom of the column prevents scaling and blockage in the column bottom. The falling film condenser utilizes the liquid film flow characteristics to reduce material retention and crystallization opportunities. The condenser uses constant-temperature warm water as the cooling medium, making temperature control more precise than using cooling water. High-quality insulation throughout the pipeline minimizes heat loss, thereby achieving high-purity, continuous, and stable production of glacial acetic acid and solving or greatly alleviating the crystallization blockage problem during the distillation process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] The components are as follows: 1. Raw material tank; 1a. First insulation jacket; 1b. Electric heating tube; 2. Preheater; 3. Distillation column; 3a. Second insulation jacket; 3b. Heating coil; 4. Inhibitor injection port; 5. Main condenser; 6. Reflux tank; 6a. Insulation layer; 6b. Low-speed stirrer; 7. Reflux pump; 8. Product cooler; 9. Product storage tank; 10. Reboiler; 11. Recovery tank; 12. Warm water inlet; 13. Warm water outlet. Detailed Implementation

[0017] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0018] Example:

[0019] The accompanying drawings illustrate a specific embodiment of the anti-clogging continuous glacial acetic acid distillation and purification device of this utility model. Figure 1 It mainly includes a raw material tank 1, which is made of 316L stainless steel. The raw material tank 1 is provided with a first heat insulation jacket 1a on the outside. An electric heating tube 1b is provided inside the first heat insulation jacket 1a. The electric heating tube 1b is inserted into the first heat insulation jacket 1a for preliminary heating of the raw material.

[0020] The output end of raw material tank 1 is connected to preheater 2. After the raw material is initially heated in raw material tank 1, it can prevent cold material from entering preheater 2 and increasing the load. Preheater 2 is a shell and tube heat exchanger, which is used to further preheat the raw material acetic acid, making its temperature much higher than the freezing point, ensuring that the feed is liquid and there is no risk of crystallization.

[0021] Under the action of raw material tank 1 and preheater 2, the raw materials are heated to a certain temperature, which can prevent solidification before entering the tower and at the same time help to remove some low-boiling-point impurities.

[0022] The output end of preheater 2 is connected to distillation column 3, which is a structured packed column. Structured packed columns have low pressure drop, low liquid holdup, and high separation efficiency, which can reduce the residence time of materials in the column and reduce the risk of polymerization. A polymerization inhibitor injection port 4 is provided on the pipeline between distillation column 3 and preheater 2. Through the polymerization inhibitor injection port 4, a small amount of polymerization inhibitor can be continuously injected into the feed to inhibit the polymerization reaction.

[0023] The distillation column 3 is externally equipped with a second insulation jacket 3a, and a heating coil 3b is installed inside the second insulation jacket 3a, with the heating coil 3b arranged along the height direction of the second insulation jacket 3a. The high-quality insulation layer throughout the column ensures that the column wall temperature is maintained uniformly at the specified temperature, guaranteeing efficient distillation.

[0024] The vapor outlet at the top of distillation column 3 is connected to the main condenser 5, and the distilled gas is discharged into the main condenser 5 for condensation. The main condenser 5 is a falling film condenser, where acetic acid forms a thin film on the inner wall of the vertical tube and flows downwards, exchanging heat with the shell-side cooling medium. Utilizing the liquid film flow characteristics, it can reduce material retention and crystallization opportunities. The falling film condenser is equipped with a warm water inlet 12 and a warm water outlet 13. Using constant-temperature warm water as the cooling medium makes it easier to precisely control the temperature compared to using cooling water, ensuring that the temperature of the acetic acid condensate is always well above its freezing point.

[0025] The main condenser 5 is connected to the reflux tank 6. The condensate in the main condenser 5 collects at the bottom and flows into the reflux tank 6 under gravity. The reflux tank 6 has a vertical conical bottom design, ensuring that the condensate can drain completely by gravity without any dead corners. The reflux tank 6 is completely covered by an insulation layer 6a, which includes the conical bottom, ensuring that the temperature is uniform throughout the tank. A low-speed stirrer 6b is installed at the bottom inside the reflux tank 6. Through intermittent or continuous low-speed stirring, it can prevent localized overcooling or crystal nucleus aggregation.

[0026] The bottom of the reflux tank 6 is connected to the product cooler 8 via the reflux pump 7. The reflux pump 7 is a magnetically driven pump with no risk of leakage. The product cooler 8 is also a falling film condenser, which also uses warm water cooling to cool qualified products to a safe storage temperature.

[0027] The product cooler 8 is connected to the product storage tank 9, which is an insulated tank used for storing products in an insulated manner.

[0028] A reboiler 10 is connected to the liquid outlet at the bottom of the distillation column 3. The reboiler 10 is also connected to the distillation column 3. The reboiler 10 is a forced circulation reboiler or a thermosiphon reboiler. Preferably, the reboiler 10 is a forced circulation reboiler. The liquid flow rate in the forced circulation reboiler is relatively fast. The faster liquid flow rate helps to reduce the scaling rate in the pipeline. At the same time, the high-velocity liquid can also flush the inner wall of the pipeline, thereby significantly reducing the risk of scaling and clogging caused by high-boiling-point substances or polymers.

[0029] A recovery tank 11 is also provided on the pipeline between the liquid phase outlet and the reboiler 10 for periodically discharging waste liquid and preventing the accumulation of high-boiling substances and polymers.

[0030] The various devices in the system are connected by pipes, each of which is wrapped with a mineral wool insulation layer, and then further protected by a stainless steel casing. The pipes are insulated with high quality throughout, minimizing heat loss.

[0031] Of course, the above embodiments are only for illustrating the technical concept and features of this utility model, and their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be covered within the protection scope of this utility model.

Claims

1. A continuous anti-clogging distillation and purification apparatus for glacial acetic acid, characterized in that: The system includes a raw material tank (1), a preheater (2), and a distillation column (3) connected in sequence. The raw material tank (1) is provided with a first insulation jacket (1a) and the distillation column (3) is provided with a second insulation jacket (3a). An inhibitor injection port (4) is provided on the pipeline between the distillation column (3) and the preheater (2). The vapor phase outlet at the top of the distillation column (3) is connected to a main condenser (5). The main condenser (5) is connected to a reflux tank (6). The reflux tank (6) is connected to a product cooler (8) via a reflux pump (7). The product cooler (8) is connected to a product storage tank (9). The liquid phase outlet at the bottom of the distillation column (3) is connected to a reboiler (10). The reboiler (10) is also connected to the distillation column (3). A recovery tank (11) is provided on the pipeline between the liquid phase outlet and the reboiler (10).

2. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The first insulation jacket (1a) is provided with an electric heating tube (1b), which is inserted into the first insulation jacket (1a); the second insulation jacket (3a) is provided with a heating coil (3b), which is arranged along the height direction of the second insulation jacket (3a).

3. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The preheater (2) is a shell-and-tube heat exchanger.

4. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The distillation column (3) is a structured packed column.

5. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: Both the main condenser (5) and the product cooler (8) are falling film condensers, and the falling film condenser is provided with a warm water inlet (12) and a warm water outlet (13).

6. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The bottom of the reflux tank (6) is conical, and the outside of the reflux tank (6) is completely covered with a heat insulation layer (6a). A low-speed stirrer (6b) is provided at the bottom inside the reflux tank (6).

7. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The reflux pump (7) is a magnetically driven pump.

8. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The product storage tank (9) is an insulated tank.

9. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The reboiler (10) is a forced circulation reboiler or a thermosiphon reboiler.

10. The anti-clogging continuous glacial acetic acid distillation and purification apparatus according to claim 1, characterized in that: The various devices in the apparatus are connected by pipes, and each pipe is wrapped with a mineral wool insulation layer, which is further protected by a stainless steel shell.

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