Equipment convenient for preparing acetyl tri-n-butyl citrate

Abstract

The invention discloses equipment convenient for preparing acetyl tri-n-butyl citrate, and relates to the technical field of chemical equipment. The reaction kettle comprises a kettle body and a kettle cover assembled at the top opening end of the kettle body in a matched mode, a jacket A is arranged on the peripheral side wall of the kettle body, and a jacket B is arranged on the peripheral side wall, located outside the jacket A, of the kettle body; a first constant-temperature heating cavity is formed between the jacket A and the peripheral side wall of the kettle body, and a second constant-temperature heating cavity is formed between the jacket B and the peripheral side wall of the kettle body. The jacket A and the jacket B are arranged on the outer side of the kettle body, and the jacket A is wrapped in the jacket B, so that a heating liquid with the heating temperature of 130 DEG C is injected into the jacket A during use, water is injected into the jacket B, and the reaction is carried out at different temperatures in different stages accompanying the reaction; then, citric acid, n-butyl alcohol and acetic anhydride which serve as raw materials react through one device to prepare a crude product of acetyl tri-n-butyl citrate.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical equipment, and particularly relates to a device for facilitating the preparation of tributyl acetylcitrate. Background Art

[0002] Tributyl acetylcitrate is a colorless and odorless oily liquid, insoluble in water and soluble in most organic solvents. It can be used as a non-toxic plasticizer for packaging materials such as dairy products, beverages, and foods. In the prior art, tributyl acetylcitrate is mostly prepared by mixing multiple materials; for example, in some preparation processes, citric acid and n-butanol as raw materials are subjected to an esterification reaction under the action of a catalyst to obtain tributyl citrate; then tributyl citrate is reacted with acetic anhydride, and after preparation, it is subjected to deacidification, neutralization, water washing, vacuum distillation, decolorization and filtration to obtain the finished product of tributyl acetylcitrate.

[0003] However, in the existing related technical solutions, it is necessary to first carry out an esterification reaction of citric acid and n-butanol under the action of a catalyst in a reaction device to obtain tributyl citrate; then tributyl citrate and acetic anhydride are put into another reaction device for reaction; this requires frequent replacement of reaction equipment during the preparation stage, and thus it is not convenient for actual production during actual use. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for facilitating the preparation of tributyl acetylcitrate. By providing a jacket A and a jacket B on the outer side of the kettle body, and the jacket A is wrapped inside the jacket B, when in use, a heating liquid with a heating temperature reaching 130°C is injected into the jacket A, and water is injected into the jacket B, so as to realize different temperatures during different stages of the reaction, and thus complete the reaction of citric acid, n-butanol and acetic anhydride as raw materials to obtain the crude product of tributyl acetylcitrate through one device, solving the problems raised in the existing background art.

[0005] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0006] The present invention is a device for facilitating the preparation of tributyl acetylcitrate, including a reaction kettle and a stirring mechanism for stirring the inside of the reaction kettle; the reaction kettle includes a kettle body and a kettle cover fitted to the open end at the top of the kettle body, and a feeding structure is communicated with the kettle cover; a jacket A is arranged on the outer peripheral side wall of the kettle body, and a jacket B is arranged on the outer peripheral side wall of the kettle body outside the jacket A; a first constant temperature heating chamber is formed between the jacket A and the outer peripheral side wall of the kettle body, and a second constant temperature heating chamber is formed between the jacket B and the outer peripheral side wall of the kettle body; the top and bottom positions of the outer side wall of the jacket A are respectively communicated with the water outlet pipe and the water inlet pipe of the first constant temperature heating chamber; an inlet and outlet water pipe communicated with the second constant temperature heating chamber is installed on the outer side wall of the jacket A.

[0007] It further includes a liquid supply tank, a water storage tank A and a water storage tank B; the top of the liquid supply tank is connected to a water outlet pipe through pipeline A, the water inlet pipe is connected to a circulating pump arranged in the liquid supply tank through pipeline B, and a valve A is arranged on pipeline A. The liquid supply tank is filled with a heating solution; the water inlet and outlet pipe is connected to a water pump through pipeline B; the water inlet end of the water pump is connected to the water storage tank A and the water storage tank B through pipeline C and pipeline D respectively. A heating module B is arranged in the water storage tank A, and a cooling module is arranged on pipeline D; valves C and D are respectively arranged on pipeline C and pipeline D; a pipeline E is connected between the bottom of the water storage tank A and the bottom of the water storage tank B, and a valve E is arranged on the pipeline E.

[0008] Further, the specific steps of the tributyl acetylcitrate include the following:

[0009] Step 1: Put citric acid, n-butanol and a catalyst into the kettle body, start the stirring mechanism, and reflux and react at 120 - 150 °C until the esterification is completed to produce a crude product of tributyl citrate.

[0010] Step 2: After the esterification reaction is completed, directly use the waste heat to reduce the pressure and remove alcohol to obtain a crude product of tributyl citrate.

[0011] Step 3: Put acetic anhydride and a catalyst into the kettle body for acetylation reaction, control the temperature of the kettle to slowly rise to 80 °C, and react under the condition that the temperature of the kettle is 80 - 85 °C to obtain a crude product of tributyl acetylcitrate.

[0012] Step 4: Take out the crude product of tributyl acetylcitrate from the kettle body, and subject the obtained crude product of tributyl acetylcitrate to deacidification, neutralization, water washing, vacuum distillation, decolorization and filtration to obtain a finished product of tributyl acetylcitrate.

[0013] Further, in Step 1, the heating solution filled in the liquid supply tank is heated to 120 - 150 °C by the heating module A arranged in the liquid supply tank, and the circulating pump is started to control the heating solution at 120 - 150 °C to circulate between the liquid supply tank and the first constant temperature heating chamber.

[0014] Further, in Step 3, it includes:

[0015] Stp31: First, pump the water at room temperature stored in the water storage tank B to the second constant temperature heating chamber through a water pump until the temperature sensor A arranged in the first constant temperature heating chamber detects that the temperature reaches 80 °C;

[0016] Stp32: Then heat the water stored in the water storage tank A to 80 - 85 °C through the heating module B arranged in the water storage tank.

[0017] Stp33. Pump the water stored in water storage tank A and heated to 80 - 85°C into the second constant temperature heating cavity until the internal liquid level reaches the preset value.

[0018] Further, after the Stp33, the following steps are also included:

[0019] Stp34. Wait until the temperature sensor B set in the second constant temperature heating cavity detects that the internal water temperature drops to 75°C, then open valve B and valve D. At this time, control a part of the water stored in the second constant temperature heating cavity to flow back into water storage tank B.

[0020] Stp35. Then close valve B and valve D, and open valve C. Pump the 80 - 85°C water stored in water storage tank A into the second constant temperature heating cavity.

[0021] Stp36. Open valve E, and pump the water stored in water storage tank B into water storage tank A through pipeline E.

[0022] Further, in step 3, after the reaction ends under the condition that the kettle temperature is 80 - 85°C, close valve C and valve E, and at the same time open valve D and valve B, and start the cooling module. Then cool down the water located in the second constant temperature heating cavity and flow it back to be stored in water storage tank B. The cooling module includes a pipe body and a condenser pipe. The pipe body is vertically arranged. The two ends of the pipe body are respectively provided with a water inlet hole and a water return hole communicating with the two ends of the condenser pipe. Limiting ring A and a limiting plate are respectively arranged on the inner wall of the pipe body on the upper and lower sides of the water inlet hole. An activity column that seals and slides up and down along the inner wall of the pipe body is arranged in the pipe body between the limiting ring A and the limiting plate. A ceramic column is arranged on the upper surface of the limiting plate of the activity column. A through hole that seals and cooperates with the ceramic column is arranged along the length direction of the activity column. A number of opening A are arranged on the limiting plate on the peripheral side of the ceramic column. An opening B is opened on one side wall of the pipe body above the limiting ring A. A cylinder body is communicated with the outer wall of the pipe body at the opening B. A piston is arranged in the cylinder body along its axial direction. A threaded through hole is arranged on the bottom side surface of the cylinder body, and an adjusting bolt is threadedly connected at the threaded through hole. The end of the adjusting bolt is connected to one end of the piston. The other end of the piston is connected to the top end of the activity column through a traction rope.

[0023] Further, flange A and flange B are respectively arranged at the opposite ends of the kettle body and the kettle cover, and flange A and flange B are connected by bolts. The stirring mechanism is installed on the top of the kettle cover, and the stirring blade part of the stirring mechanism extends into the kettle body.

[0024] Further, a pressure gauge A extending into the second constant-temperature heating chamber is fixed to the outside of the jacket B, and a pressure gauge B extending into the kettle body is fixed to the top of the kettle lid; a discharge port is provided at the bottom of the kettle body, and a valve structure is installed at the discharge port.

[0025] Further, a plurality of mounting seats are provided on the outer side wall of the jacket B; a heat preservation sleeve is fixedly installed outside the kettle lid.

[0026] Further, a citric acid feeding joint, a n-butanol feeding joint, an acetic anhydride feeding joint, and a catalyst feeding joint communicating with the inside of the kettle body are provided at the top of the kettle lid; in step 1, after the reaction raw material citric acid is added to the kettle body through the citric acid feeding joint, the citric acid feeding joint is connected to a condenser; in step 2, after the esterification reaction is completed, the citric acid feeding joint is connected to a n-butanol recovery device.

[0027] The present invention has the following beneficial effects:

[0028] In the present invention, by providing a jacket A and a jacket B outside the kettle body, and the jacket A is wrapped inside the jacket B, when in use, a heating liquid with a heating temperature reaching 130 °C is injected into the jacket A, and water is injected into the jacket B, so as to realize different temperature control in different stages of the reaction, and then a device is used to complete the reaction of citric acid, n-butanol and acetic anhydride as raw materials to prepare a crude product of tributyl acetylcitrate.

[0029] Of course, it is not necessary for any product implementing the present invention to achieve all the above advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic structural diagram of the reaction kettle of the present invention;

[0032] Figure 2 is Figure 1 front view;

[0033] Figure 3 is Figure 2 sectional view taken along line B-B in

[0034] Figure 4 It is a schematic structural diagram of the liquid supply tank and the first constant-temperature heating chamber of the present invention;

[0035] Figure 5 Schematic diagram of the cooperative structure of water storage tank A, water storage tank B and the second constant temperature heating chamber of the present invention;

[0036] Figure 6 Schematic diagram of the cooling module structure of the present invention. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery", etc. indicating the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0039] Please refer to Figures 1-3 As shown, the present invention is a device for facilitating the preparation of tributyl acetylcitrate, including a reaction kettle and a stirring mechanism 3 for stirring the inside of the reaction kettle.

[0040] Specifically, the reaction kettle provided by the present invention includes a kettle body 1 and a kettle cover 2 cooperatively assembled at the open end of the top of the kettle body 1. A feeding structure is communicated on the kettle cover 2, and flange A 10 and flange B 20 connected by bolts are respectively arranged at the opposite ends of the kettle body 1 and the kettle cover 2. The stirring mechanism 3 is installed on the top of the kettle cover 2, and the stirring blade part of the stirring mechanism 3 extends into the kettle body 1.

[0041] Similarly, in this technical solution, the preparation of tributyl acetylcitrate provided by the present invention uses citric acid, n-butanol and acetic anhydride as reaction raw materials and prepares tributyl acetylcitrate under the action of a catalyst.

[0042] That is, during use, in order to facilitate the addition of reaction raw materials and control the discharge of products during use, a pressure gauge B 26 extending into the kettle body 1 is fixed on the top of the kettle cover 2; a discharge port 13 is arranged at the bottom of the kettle body 1, and a valve structure 131 is installed at the discharge port 13; the feeding structure includes a citric acid feeding joint 22, an n-butanol feeding joint 23, an acetic anhydride feeding joint 24, and a catalyst feeding joint 25 arranged on the top of the kettle cover 2 and communicated with the inside of the kettle body 1.

[0043] Meanwhile, on the above basis, in order to facilitate the reaction during each stage of actual operation control, a jacket A11 is provided on the outer peripheral side wall of the kettle body 1, and a jacket B12 is provided on the outer peripheral side wall of the kettle body 1 outside the jacket A11; a first constant temperature heating cavity is formed between the jacket A11 and the outer peripheral side wall of the kettle body 1, and a second constant temperature heating cavity is formed between the jacket B12 and the outer peripheral side wall of the kettle body 1; the top and bottom positions of the outer side wall of the jacket A11 are respectively connected to the water outlet pipe 14 and the water inlet pipe 16 of the first constant temperature heating cavity; a water inlet and outlet pipe 15 communicating with the second constant temperature heating cavity is installed on the outer side wall of the jacket A11; and a pressure gauge A17 extending into the second constant temperature heating cavity is fixed outside the jacket B12; a plurality of mounting seats 18 are provided on the outer side wall of the jacket B12; a heat preservation sleeve 21 is fixedly installed outside the kettle cover 2.

[0044] Specifically, as Figures 4-5 , during use, in order to control the temperature of each reaction stage, it further includes a liquid supply tank 5, a water storage tank A6a and a water storage tank B6b; the top of the liquid supply tank 5 is connected to the water outlet pipe 14 through a pipeline A51, the water inlet pipe 16 is connected to a circulating pump 50 arranged in the liquid supply tank 5 through a pipeline B52, and a valve A50 is arranged on the pipeline A51, and a heating solution is filled in the liquid supply tank 5; the water inlet and outlet pipe 15 is connected to a water pump 62 through a pipeline B61; the water inlet end of the water pump 62 is connected to the water storage tank A6a and the water storage tank B6b through a pipeline C63 and a pipeline D65 respectively, a heating module B67 is arranged in the water storage tank A6a, and a cooling module 68 is arranged on the pipeline D65; valves C64 and D66 are respectively arranged on the pipeline C63 and the pipeline D65; a pipeline E69 is connected between the bottom of the water storage tank A6a and the bottom of the water storage tank B6b, and a valve E610 is arranged on the pipeline E69.

[0045] It can be known that on the basis of using citric acid, n-butanol and acetic anhydride as reaction raw materials, the following provides a specific preparation method of tributyl acetylcitrate:

[0046] Step 1: Put a citric acid feeding joint 22, an n-butanol feeding joint 23 and a catalyst feeding joint 25 into the kettle body 1 to feed citric acid, n-butanol and a catalyst, start the stirring mechanism 3, and react under reflux at 135 °C until the esterification is completed to obtain a crude product of tributyl citrate.

[0047] Step 2: After the esterification reaction is completed, directly use the waste heat to reduce the pressure and remove alcohol to obtain a crude product of tributyl citrate.

[0048] Step 3: Put acetic anhydride and a catalyst into the kettle body 1 for acetylation reaction, control the temperature of the kettle to slowly rise to 80 °C, and react under the condition that the temperature of the kettle is 80 - 85 °C to obtain a crude product of tributyl acetylcitrate.

[0049] Step 4: Take out the crude product of tributyl acetylcitrate from the kettle body 1 through the discharge port 13 provided at the bottom of the kettle body 1, and obtain the finished product of tributyl citrate by subjecting the obtained crude product of tributyl acetylcitrate to deacidification, neutralization, water washing, vacuum distillation, and decolorization filtration.

[0050] Specifically, in the above Step 1, the heating module A54 provided in the liquid supply tank 5 heats the heating solution filled in the liquid supply tank 5 to 135°C, and the circulation pump 50 is started to control the heating solution at 135°C to circulate between the liquid supply tank 5 and the first constant temperature heating chamber.

[0051] In Step 1, after the reaction raw material citric acid is added to the kettle body 1 by using the citric acid feeding joint 22, the citric acid feeding joint 22 is connected to a condenser; in Step 2, after the esterification reaction is completed, the citric acid feeding joint 22 is connected to a n-butanol recovery device.

[0052] Specifically, the provided Step 3 is subdivided into:

[0053] Stp31: First, the water at room temperature stored in the water storage tank B6b is pumped to the second constant temperature heating chamber by the water pump 62 until the temperature sensor A provided in the first constant temperature heating chamber detects that the temperature reaches 80°C.

[0054] Stp32: Then, the water stored in the water storage tank A6a is heated to 85°C by the heating module B67 provided in the water storage tank 6.

[0055] Stp33: The water stored in the water storage tank A6a and heated to 85°C is pumped to the second constant temperature heating chamber by the water pump 62 until the internal liquid level reaches the preset value.

[0056] Stp34: When the temperature sensor B provided in the second constant temperature heating chamber detects that the internal water temperature drops to 75°C, open the valve B60 and the valve D66. At this time, control a part of the water stored in the second constant temperature heating chamber to flow back to the water storage tank B6b.

[0057] Stp35: Then close the valve B60 and the valve D66, and open the valve C64 to pump the water at 80 - 85°C stored in the water storage tank A6a to the second constant temperature heating chamber.

[0058] Stp36: Open the valve E610, and pump the water stored in the water storage tank B6b to the water storage tank A6a through the pipeline E69.

[0059] It can be known that in the above-mentioned step 2, the residual heat of the heating solution at 135°C filled in the first constant-temperature heating chamber is used for vacuum de-alcoholization. At this stage, the heating module B67 arranged in the water storage tank 6 is turned off, and the circulation pump 50 is kept started to control the heating solution to circulate between the liquid supply tank 5 and the first constant-temperature heating chamber.

[0060] Specifically, after step 3, when the reaction ends under the condition that the kettle temperature is 80 - 85°C, the valve C64 and the valve E610 are closed, and at the same time, the valve D66 and the valve B60 are opened, and the cooling module 68 is started. Then, the water in the second constant-temperature heating chamber is cooled and then refluxed and transported to the water storage tank B6b for storage.

[0061] In the above technical solution, the heating liquid can be selected from organic solutions or oil solutions such as ethylene glycol solution, glycerol solution, silicone oil solution, and mineral oil solution.

[0062] In the above function, in order to conveniently control the heating solution in the first constant-temperature heating chamber to quickly cool down to about 80 - 85°C in step 3, at this time, water at room temperature or lower temperature is needed to control the heating solution inside the first constant-temperature heating chamber to cool down. Based on this, in actual use, the cooling module 68 is needed to cool the water in the second constant-temperature heating chamber and then reflux it to the water storage tank B6b for storage, so as to facilitate subsequent use in step Stp31.

[0063] Specifically, as Figure 6 shown, the cooling module 68 includes a pipe body 680 and a condenser tube. The pipe body 680 is vertically arranged. The two ends of the pipe body 680 are respectively provided with a water inlet hole 681 and a water return hole 682 communicating with both ends of the condenser tube. The inner walls of the pipe body 680 on the upper and lower sides of the water inlet hole 681 are respectively provided with a limiting ring A683 and a limiting plate 684. An activity column 685 that seals and slides up and down along the inner wall of the pipe body 680 is arranged inside the pipe body 680 between the limiting ring A683 and the limiting plate 684. A ceramic column 6841 is arranged on the upper surface of the limiting plate 684 of the activity column 685. The activity column 685 is provided with a through hole 6851 that is hermetically matched with the ceramic column 6841 along its length direction. A number of opening holes A6842 are arranged on the limiting plate 684 on the circumferential side of the ceramic column 6841. An opening hole B686 is opened on one side wall of the pipe body 680 above the limiting ring A683. A cylinder body 687 is communicated with the outer side wall of the pipe body 680 at the opening hole B686. A limiting ring B is arranged at the port of the cylinder body 687. A piston 688 is arranged inside the cylinder body 687 along its axial direction. A threaded through hole 6871 is arranged on the bottom side surface of the cylinder body 687, and an adjusting bolt 6872 is threadedly connected to the threaded through hole 6871. The end of the adjusting bolt 6872 is connected to one end of the piston 688. The other end of the piston 688 is connected to the top end of the activity column 685 through a traction rope 689.

[0064] Based on the above settings of the cooling module 68, during use, it is necessary to control the opening or closing of the cooling module 68 according to the actual situation; that is, during use, when the piston 688 is driven to move on the inner wall of the cylinder 687 by rotating the adjusting bolt 6872, and synchronously under the action of the traction rope 689, the control movable column 685 is moved up and down inside the pipe body 680, and then when the movable column 685 abuts against the limiting ring A683 during use, at this time, the water inlet hole 681 is blocked by the movable column 685, and thus the cooling module 68 is relatively closed; conversely, by controlling the rotation of the adjusting bolt 6872 to drive the piston 688 to move on the inner wall of the cylinder 687, and under the gravity of the movable column 685, the ceramic column 6841 is controlled to insert into the through hole 6851, and then at this time, the opening A6842 is blocked by the movable column 685, then the water entering the pipe body 680 from the end of the pipe body 680 enters the condensing pipe through the water inlet hole 681, and then the relatively long condensing pipe is used to cool the flowing water.

[0065] In a specific embodiment, the condensing pipe is a serpentine coiled pipe or a meander-shaped coiled pipe, and the condensing pipe is placed in the air, and a fan is used to blow air directly at the condensing pipe for cooling.

[0066] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0067] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, according to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A device for preparing tri-n-butyl acetyl citrate, characterized in that: It comprises a reaction kettle and a stirring mechanism (3) for stirring the interior of the reaction kettle; The reaction kettle comprises a kettle body (1), and a kettle cover (2) assembled on the top open end of the kettle body (1), wherein the kettle cover (2) is connected to a feed structure; The outer peripheral side wall of the kettle body (1) is provided with a jacket A (11), and the outer peripheral side wall of the kettle body (1) located outside the jacket A (11) is provided with a jacket B (12); A first constant temperature heating chamber is formed between the jacket A (11) and the outer peripheral side wall of the kettle body (1), and a second constant temperature heating chamber is formed between the jacket B (12) and the outer peripheral side wall of the kettle body (1); The top and bottom positions of the outer wall of the jacket A (11) are respectively connected to the water outlet pipe (14) and the water inlet pipe (16) of the first constant temperature heating chamber; the outer wall of the jacket A (11) is installed with the water inlet and outlet pipes (15) connected to the second constant temperature heating chamber.

2. The device for preparing tri-n-butyl acetyl citrate according to claim 1, characterized in that: The tri-n-butyl acetyl citrate specifically comprises the following steps: Step 1, adding citric acid, n-butanol and a catalyst into a kettle (1), starting a stirring mechanism (3), and reflux reacting at 120-150° C. until esterification is completed to generate a crude product of tributyl citrate; Step 2: After the esterification reaction is completed, the residual heat is directly used to reduce the pressure and dealcoholate to obtain a crude product of tributyl citrate; Step 3, adding acetic anhydride and a catalyst into the kettle (1) for acetylation reaction, controlling the kettle temperature to slowly rise to 80° C., and reacting at a kettle temperature of 80-85° C. to obtain a crude product of acetyl tri-n-butyl citrate; Step 4: taking out the crude product of tri-n-butyl acetyl citrate from the kettle (1), and subjecting the obtained crude product of tri-n-butyl acetyl citrate to deacidification, neutralization, water washing, vacuum distillation, decolorization and filtration to obtain the finished product of tri-n-butyl acetyl citrate.

3. The device for preparing tri-n-butyl acetyl citrate according to claim 2, characterized in that: It also includes a liquid supply tank (5), a water storage tank A (6a) and a water storage tank B (6b); The top of the liquid supply tank (5) is connected to the water outlet pipe (14) through the pipeline A (51), the water inlet pipe (16) is connected to the circulation pump (50) arranged in the liquid supply tank (5) through the pipeline B (52), and the pipeline A (51) is provided with a valve A (50), and the liquid supply tank (5) is filled with a heating solution; The water inlet and outlet pipes (15) are connected to a water pump (62) through a pipeline B (61); the water inlet end of the water pump (62) is connected to a water tank A (6a) and a water tank B (6b) through a pipeline C (63) and a pipeline D (65) respectively; a heating module B (67) is provided in the water tank A (6a), and a cooling module (68) is provided on the pipeline D (65); valves C (64) and valves D (66) are provided on the pipeline C (63) and the pipeline D (65) respectively; A pipeline E (69) is connected between the bottom of the water storage tank A (6a) and the bottom of the water storage tank B (6b), and a valve E (610) is provided on the pipeline E (69).

4. The device for preparing tri-n-butyl acetyl citrate according to claim 3, characterized in that: In step 1, a heating solution filled in the liquid supply tank (5) is heated to a temperature of 120-150° C. by a heating module A (54) disposed in the liquid supply tank (5), and a circulation pump (50) is started to control the heating solution at a temperature of 120-150° C. to circulate between the liquid supply tank (5) and the first constant temperature heating chamber; In step 3, include: Stp31, firstly transport the room temperature water stored in the water storage tank B (6b) to the second constant temperature heating chamber through the water pump (62), until the temperature sensor A arranged in the first constant temperature heating chamber detects that the temperature reaches 80°C; Stp32, then heat the water stored in the water storage tank A (6a) to 80-85°C through the heating module B (67) arranged in the water storage tank (6); Stp33, the water stored in the water storage tank A (6a) and heated to 80-85°C is transported to the second constant temperature heating chamber through the water pump (62) until the internal liquid level reaches a preset value.

5. The device for preparing tri-n-butyl acetyl citrate according to claim 4, characterized in that: After Stp33, it also includes: Stp34, the temperature sensor B to be set in the second constant temperature heating chamber detects that the internal water temperature has dropped to 75°C, and opens valve B (60) and valve D (66), at which time the water stored in the second constant temperature heating chamber is controlled to flow back to the water storage tank B (6b); Stp35, then close valve B (60) and valve D (66), and open valve C (64) to transport the 80-85°C water stored in the water storage tank A (6a) to the second constant temperature heating chamber; Stp36, open valve E (610) and transfer the water stored in water tank B (6b) to water tank A (6a) through pipeline E (69).

6. The device for preparing tri-n-butyl acetyl citrate according to claim 5, characterized in that: In step 3, after the reaction is completed at a kettle temperature of 80-85° C., valve C (64) and valve E (610) are closed, valve D (66) and valve B (60) are opened, and the cooling module (68) is started, so that the water in the second constant temperature heating chamber is cooled and then refluxed to the water storage tank B (6b) for storage; The cooling module (68) comprises a tube body (680) and a condenser tube, the tube body (680) being arranged vertically, and a water inlet hole (681) and a water return hole (682) connected to the two ends of the condenser tube being arranged at both ends of the tube body (680), and a limit ring A (683) and a limit plate (684) are arranged on the inner wall of the tube body (680) located at the upper and lower sides of the water inlet hole (681); A movable column (685) is provided in the tube body (680) between the limiting ring A (683) and the limiting plate (684) and is sealed and slidable up and down along the inner wall of the tube body (680); a ceramic column (6841) is provided on the upper surface of the movable column (685) of the limiting plate (684); a through hole (6851) is provided along the length direction of the movable column (685) and is sealed and matched with the ceramic column (6841); and a plurality of openings A (6842) are provided on the limiting plate (684) located on the peripheral side of the ceramic column (6841); An opening B (686) is provided on one side wall of the tube body (680) located above the limiting ring A (683); the outer side wall of the tube body (680) located at the opening B (686) is connected to a cylinder body (687); a piston (688) is provided in the cylinder body (687) along its axial direction; a threaded through hole (6871) is provided on the bottom side surface of the cylinder body (687); and an adjusting bolt (6872) is threadedly connected to the threaded through hole (6871); an end of the adjusting bolt (6872) is connected to one end of the piston (688), and the other end of the piston (688) is connected to the top end of the movable column (685) via a traction rope (689).

7. The device for preparing tri-n-butyl acetyl citrate according to claim 3, characterized in that: The kettle body (1) and the kettle cover (2) are respectively provided with flanges A (10) and flanges B (20) at opposite ends, and the flanges A (10) and flanges B (20) are connected by bolts; The stirring mechanism (3) is installed on the top of the kettle cover (2), and the stirring blade part of the stirring mechanism (3) extends into the interior of the kettle body (1).

8. The device for preparing tri-n-butyl acetyl citrate according to claim 7, characterized in that: A pressure gauge A (17) extending into the second constant temperature heating chamber is fixed to the outside of the jacket B (12), and a pressure gauge B (26) extending into the kettle body (1) is fixed to the top of the kettle cover (2); a discharge port (13) is provided at the bottom of the kettle body (1), and a valve structure (131) is installed at the discharge port (13).

9. The device for preparing tri-n-butyl acetyl citrate according to claim 8, characterized in that: The outer wall of the jacket B (12) is provided with a plurality of mounting seats (18); and a heat-insulating sleeve (21) is fixedly mounted on the outside of the kettle cover (2).

10. The device for preparing tri-n-butyl acetyl citrate according to claim 9, characterized in that: The top of the kettle cover (2) is provided with a citric acid feeding joint (22), a n-butanol feeding joint (23), an acetic anhydride feeding joint (24), and a catalyst feeding joint (25) which are connected to the kettle body (1); In step 1, after the reaction raw material citric acid is added to the kettle body (1) by using the citric acid feeding joint (22), the citric acid feeding joint (22) is connected to a condenser; In step 2, after the esterification reaction is completed, the citric acid feeding connector (22) is connected to a n-butanol recovery device.

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