A flash separation device for acetic acid production

Abstract

The utility model relates to chemical separation equipment technical field especially relates to a flash separation equipment for acetic acid production, including support frame, be provided with flash tank body on the support frame, be provided with evaporation chamber in the flash tank body inside, the annular interlayer structure is formed between the flash tank body with evaporation chamber, the upper middle position of flash tank body side wall is provided with feed pipe. Through the thread connection structure between the flow guide cover and the flash tank body, and the positioning block on the silk screen separator and the positioning groove on the top of the tank body are combined with the positioning groove clamping cooperation design, the silk screen separator can be taken out as a whole after the flow guide cover is rotated and opened, tool-free quick disassembly is realized, the modular structure greatly simplifies the overhaul process, and the maintenance difficulty and downtime are reduced.

Description

Technical Field

[0001] This utility model relates to the field of chemical separation equipment technology, and in particular to a flash separation device for acetic acid production. Background Technology

[0002] Acetic acid is an important organic chemical raw material, widely used in synthetic fibers, pharmaceuticals, pesticides, fragrances, dyes, and the food industry. In the industrial production of acetic acid, especially in the subsequent refining process after the methanol carbonylation method, multi-stage separation and purification of the reaction products are often required. Flash evaporation is one of the key steps to achieve efficient separation of gas and liquid phases. Flash evaporation refers to the rapid vaporization of a portion of a high-temperature, high-pressure liquid into steam when it enters a low-pressure space due to a sudden drop in system pressure, thereby achieving rapid separation between light and heavy components or between the gas and liquid phases. In acetic acid production, flash evaporation can effectively remove dissolved gases, low-boiling-point impurities, and recover steam, providing qualified feedstock for subsequent condensation, distillation, and other processes.

[0003] Currently, most commonly used flash evaporation equipment is vertical flash tank. Its basic structure includes a tank body, feeding device, gas outlet, liquid outlet, and necessary pressure control and safety accessories. However, in actual applications, in order to improve separation efficiency, gas-liquid separation components such as wire mesh separators, baffle plate separators, or cyclone plates are added inside. However, the tank body of flash evaporation equipment is usually welded or integrally press-fitted, while the gas-liquid separation components are fixed with bolts. The overall disassembly is inconvenient and cumbersome. Once the gas-liquid separation components are blocked or corroded, it is difficult to clean or replace them quickly, affecting continuous production.

[0004] Therefore, there is an urgent need to provide a flash separation device for acetic acid production that facilitates the disassembly and cleaning of the gas-liquid separation components. Utility Model Content

[0005] In order to overcome the shortcomings of existing flash evaporation equipment, which mostly adopts welded or integral press-fit structure for tank body and uses bolt fixed installation for gas-liquid separation components, making it difficult to disassemble, clean or replace the whole unit quickly, this utility model provides a flash evaporation separation equipment for acetic acid production that facilitates the disassembly and cleaning of gas-liquid separation components.

[0006] To address the aforementioned problems, this utility model adopts the following technical solution: a flash evaporation separation device for acetic acid production, comprising a support frame, a flash tank body mounted on the support frame, an evaporation chamber disposed inside the flash tank body, and an annular sandwich structure formed between the flash tank body and the evaporation chamber. A feed pipe is disposed at the upper middle part of the side wall of the flash tank body, one end of the feed pipe extending into and communicating with the evaporation chamber, and the other end protruding outside the flash tank body. A first stop valve is installed at the outer end of the feed pipe. A discharge pipe is connected to the bottom of the flash tank body and is connected to the annular sandwich structure. The flash tank is equipped with a second water stop valve on the discharge pipe, and a flow guide shroud is detachably installed on the top of the flash tank. The inner wall of the flow guide shroud is designed with internal threads, while the outer wall of the flash tank is designed with external threads. The flow guide shroud is detachably assembled with the flash tank through the threaded structure. A gas stop valve is installed on the flow guide shroud, and a wire mesh separator is installed inside the flow guide shroud. The wire mesh separator is provided with multiple positioning blocks evenly spaced along the circumference, and the top of the flash tank is provided with multiple positioning grooves evenly spaced along the circumference that match the positioning blocks. A cross-shaped pull rod is provided on the wire mesh separator.

[0007] Optionally, the bottom surface inside the flash tank is provided with a guide slope that is inclined toward the discharge pipe.

[0008] Optionally, a filter box is provided on the outside of the flash tank. The filter box is connected to the steam outlet of the guide shroud through a gas guide pipe. A filter frame is slidably installed inside the filter box. An air outlet is opened at the bottom of the filter frame. A handle is provided on one side of the filter frame.

[0009] Optionally, the grip is covered with a silicone sleeve.

[0010] Optionally, a support plate is fixed to the bottom of the flash tank, a servo motor is mounted on the support plate, and a stirring paddle is rotatably mounted inside the evaporation chamber, with the bottom end of the stirring paddle connected to the output shaft of the servo motor.

[0011] Optionally, a metal corrugated pipe is connected to the bottom end of the discharge pipe.

[0012] Optionally, the cross-shaped tie rod is fitted with a rubber sleeve.

[0013] Compared with the prior art, the present invention has the following technical effects: 1. By adopting a threaded connection structure between the flow guide and the flash tank, and combining the positioning block on the wire mesh separator with the positioning groove on the top of the tank, the wire mesh separator can be removed as a whole after the flow guide is rotated open, realizing tool-free quick disassembly. This modular structure greatly simplifies the maintenance process and reduces maintenance difficulty and downtime.

[0014] 2. An external filter box is connected to the steam outlet at the top of the hood via a gas guide pipe. The internal sliding filter frame, filled with filter material, can further adsorb residual organic matter, catalyst particles, and acid mist, significantly reducing the pollutant content in the steam and meeting emission or subsequent recovery standards.

[0015] 3. By installing a stirring paddle driven by a servo motor in the evaporation chamber, the liquid can be moderately stirred during flash evaporation, increasing the vaporization interface and helping the steam to escape quickly. At the same time, it prevents high-concentration acetic acid from polymerizing or coking due to local overheating at the bottom or on the wall, thus extending the service life of the equipment and improving operational stability. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This is a three-dimensional sectional view of the flash tank body, feed pipe, and discharge pipe of this utility model.

[0018] Figure 3 This is a three-dimensional sectional view of the flash tank, wire mesh separator, and positioning block components of this utility model.

[0019] Figure 4 This is a three-dimensional sectional view of the filter box, air guide pipe, and filter frame of this utility model.

[0020] Figure 5 This is a three-dimensional sectional view of the support plate, servo motor, and stirring paddle components of this utility model.

[0021] Explanation of reference numerals in the attached drawings: 1: Support frame, 2: Flash tank body, 201: Evaporation chamber, 3: Feed pipe, 4: First stop valve, 5: Discharge pipe, 6: Second stop valve, 7: Flow guide hood, 8: Gas stop valve, 9: Wire mesh separator, 10: Positioning block, 11: Cross-shaped pull rod, 12: Filter box, 13: Gas guide pipe, 14: Filter frame, 15: Handle, 16: Silicone sleeve, 17: Support plate, 18: Servo motor, 19: Stirring paddle, 20: Metal corrugated pipe, 21: Rubber sleeve. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Example 1: Please refer to Figures 1-3A flash evaporation separation device for acetic acid production includes a support frame 1, on which a flash tank 2 is mounted. An evaporation chamber 201 is located inside the flash tank 2 to contain the acetic acid raw material liquid to be processed and to perform the flash evaporation process. An annular sandwich structure is formed between the flash tank 2 and the evaporation chamber 201, serving as a collection and temporary storage space for the separated liquid phase product. A feed pipe 3 is located in the upper middle part of the side wall of the flash tank 2. One end of the feed pipe 3 extends into and communicates with the evaporation chamber 201, while the other end protrudes outside the flash tank 2 for connection to a liquid supply system. A first stop valve 4 is installed at the outer end of the feed pipe 3 for... The system precisely controls the feeding timing and flow rate, and achieves system sealing when not in operation. The bottom of the flash tank 2 is connected to a discharge pipe 5, which communicates with the annular jacket. This discharge pipe 5 discharges the liquid acetic acid that has settled at the bottom of the jacket after gas-liquid separation. Furthermore, the bottom surface inside the flash tank 2 has a guide slope inclined towards the discharge pipe 5. This guide slope allows the separated liquid acetic acid to flow naturally towards the inlet of the discharge pipe 5 under gravity, preventing liquid stagnation at the bottom of the tank. The bottom end of the discharge pipe 5 is connected to a metal bellows 20 for flexible connection to a collection device or pipeline system. The metal bellows 20 has axial and radial compensation capabilities and can absorb the acetic acid from the flash tank. To prevent pipe cracking or interface leakage caused by rigid connections, the displacement stress of body 2 due to thermal expansion and contraction, vibration, or installation deviation is mitigated. A second stop valve 6 is installed on the discharge pipe 5 to control the opening and closing of the discharge process and maintain pressure. A flow guide shroud 7 is detachably installed on the top of the flash tank 2. The inner wall of the flow guide shroud 7 is designed with internal threads, while the outer wall of the flash tank 2 is designed with external threads. The flow guide shroud 7 is detachably assembled with the flash tank 2 through its threaded structure. A gas-stop valve 8 is installed on the flow guide shroud 7. A wire mesh separator 9 is installed inside the flow guide shroud 7. The wire mesh separator 9 is made of multiple layers of metal wire mesh, possessing a large specific surface area and... With excellent interception efficiency, gas-liquid separation can be achieved through inertial collision, interception, and condensation. The wire mesh separator 9 is provided with four positioning blocks 10 evenly spaced around its circumference, while the top of the flash tank 2 is provided with four positioning grooves that match the positioning blocks 10 evenly spaced around its circumference. The positioning blocks 10 are engaged with the positioning grooves to achieve a snap-fit ​​fit, which facilitates the assembly and disassembly of the wire mesh separator 9. The wire mesh separator 9 is provided with a cross-shaped pull rod 11, which is convenient for operators to manually grasp during maintenance, so as to achieve the overall lifting and disassembly of the wire mesh separator 9. The cross-shaped pull rod 11 is covered with a rubber sleeve 21 to improve the comfort and anti-slip performance of the operator's grip.

[0024] When using this device, first open the first stop valve 4 to introduce preheated high-temperature acetic acid liquid into the evaporation chamber 201 through the feed pipe 3. Because the evaporation chamber 201 maintains a low pressure, and the feed liquid temperature is higher than its saturation boiling point at the current pressure, flash evaporation occurs rapidly upon entry, resulting in a large amount of vaporization and the formation of a gas-liquid two-phase mixture. The generated vapor carries some mist-like droplets upwards into the guide hood 7 area. The airflow first passes through the wire mesh separator 9, where droplets continuously collide and coalesce on the wire mesh surface, forming a larger liquid film. Under gravity, the film falls back to the wall of the evaporation chamber 201 and flows along the wall into the annular jacket. Subsequently, the acetic acid vapor passes through the wire mesh layer and exits through the top of the guide hood 7, entering the subsequent condensation or recovery system. The separated liquid product accumulates at the bottom of the annular jacket. After accumulating to a certain amount, the second stop valve 6 is opened to discharge high-purity liquid acetic acid from the discharge pipe 5. When the equipment is shut down for maintenance or the wire mesh separator 9 is clogged and needs cleaning, first close all valves and release the system pressure. Then, rotate counterclockwise to remove the guide cover 7 to expose the wire mesh separator 9. The operator holds the cross-shaped pull rod 11 and pulls it vertically upward to disengage the positioning block 10 on the wire mesh separator 9 from the positioning groove at the top of the flash tank 2. The entire wire mesh separator 9 can then be removed. After cleaning or replacement, it is reinstalled in reverse order. The positioning block 10 is aligned with the positioning groove and inserted. The wire mesh separator 9 is lowered, and the guide cover 7 is reinstalled and tightened to ensure a reliable seal.

[0025] Example 2: Based on Example 1, please refer to... Figure 4 The flash tank 2 is equipped with a filter box 12 on its exterior. The filter box 12 is connected to the steam outlet of the guide hood 7 through a gas guide pipe 13. A filter frame 14 is slidably installed inside the filter box 12. The filter frame 14 can be filled with filter material, which can be a composite layer of activated carbon particles and glass fiber filter cotton. An air outlet is opened at the bottom of the filter frame 14. A handle 15 is provided on the left side of the filter frame 14. A silicone sleeve 16 is fitted on the outside of the handle 15 to improve the stability of the operator when pulling the filter frame 14 and prevent the hand from slipping.

[0026] When the acetic acid vapor generated during the flash separation process is discharged from the top of the guide hood 7, it is introduced into the filter box 12 through the gas guide pipe 13. The gas enters the filter frame 14 and passes through the filter material filled inside the filter frame 14. The filter material intercepts droplets and adsorbs residual organic impurities, low molecular weight aldehydes and odor components, further improving the purity of the vapor. The purified gas is discharged from the outlet of the filter box 12 and enters the subsequent condensation system or emission treatment unit. Since the filter material will become saturated or clogged after long-term operation, the operator can hold the handle 15 on the filter frame 14 and pull the filter frame 14 horizontally to replace or clean the internal filter material, achieving quick maintenance.

[0027] Please see Figure 5 The bottom of the flash tank 2 is fixedly connected to a support plate 17, and a servo motor 18 is installed on the support plate 17. A stirring paddle 19 is rotatably installed inside the evaporation chamber 201. The bottom end of the stirring paddle 19 is connected to the output shaft of the servo motor 18. The servo motor 18 can drive the stirring paddle 19 to rotate and stir the acetic acid liquid.

[0028] During the acetic acid flash evaporation process, the high-temperature liquid enters the evaporation chamber 201 and rapidly vaporizes due to a sudden drop in pressure. To prevent the high-concentration acetic acid solution from overheating, coking, or generating a concentration gradient on the inner wall or bottom of the evaporation chamber 201, the servo motor 18 is activated, and the power is transmitted to the stirring paddle 19 through the output shaft. The rotational motion of the stirring paddle 19 causes the liquid to form a uniform flow field in the evaporation chamber 201. By disturbing the liquid surface, the vaporization interface is increased, which helps the vapor to escape quickly, while avoiding side reactions or polymer formation caused by local overheating.

[0029] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model 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 utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A flash separation device for acetic acid production, comprising a support frame (1), a flash tank (2) mounted on the support frame (1), an evaporation chamber (201) inside the flash tank (2), an annular sandwich structure formed between the flash tank (2) and the evaporation chamber (201), a feed pipe (3) located at the upper middle part of the side wall of the flash tank (2), one end of the feed pipe (3) extending into and communicating with the evaporation chamber (201), and the other end exposed outside the flash tank (2), a first stop valve (4) installed at the outer end of the feed pipe (3), a discharge pipe (5) connected to the bottom of the flash tank (2), the discharge pipe (5) communicating with the annular sandwich structure, a second stop valve (6) installed on the discharge pipe (5), and a detachable flow guide (7) installed on the top of the flash tank (2), characterized in that, The inner wall of the flow guide (7) is designed with internal threads, while the outer wall of the flash tank (2) is designed with external threads. The flow guide (7) is disassembled and assembled with the flash tank (2) through the threaded structure. A gas stop valve (8) is installed on the flow guide (7). A wire mesh separator (9) is installed inside the flow guide (7). The wire mesh separator (9) is evenly spaced with multiple positioning blocks (10) along the circumference. The top of the flash tank (2) is evenly spaced with multiple positioning grooves that match the positioning blocks (10). A cross-shaped pull rod (11) is provided on the wire mesh separator (9).

2. The flash evaporation separation equipment for acetic acid production as described in claim 1, characterized in that, The bottom surface of the flash tank (2) is provided with a guide slope that is inclined toward the discharge pipe (5).

3. The flash evaporation separation equipment for acetic acid production as described in claim 2, characterized in that, The flash tank (2) is equipped with a filter box (12) on the outside. The filter box (12) is connected to the steam outlet of the guide shroud (7) through the air guide pipe (13). A filter frame (14) is slidably installed inside the filter box (12). An air outlet is opened at the bottom of the filter frame (14). A handle (15) is provided on one side of the filter frame (14).

4. The flash evaporation separation equipment for acetic acid production as described in claim 3, characterized in that, The grip (15) is covered with a silicone sleeve (16).

5. The flash evaporation separation equipment for acetic acid production as described in claim 4, characterized in that, The flash tank (2) is fixed to the bottom of a support plate (17), and a servo motor (18) is installed on the support plate (17). An agitator (19) is rotatably installed inside the evaporation chamber (201), and the bottom end of the agitator (19) is connected to the output shaft of the servo motor (18).

6. The flash evaporation separation equipment for acetic acid production as described in claim 5, characterized in that, The bottom end of the discharge pipe (5) is connected to a metal corrugated pipe (20).

7. The flash evaporation separation equipment for acetic acid production as described in claim 6, characterized in that, The cross-shaped tie rod (11) is fitted with a rubber sleeve (21).

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