A continuous anhydride-forming device for pyromellitic acid

Abstract

The present invention relates to the field of chemical production equipment, specifically a continuous anhydride-forming device for isophthalic acid, which comprises: a rotating cylinder, which is horizontally and penetratingly arranged on an outer shell, the rotating cylinder is rotatably connected to the outer shell, a spiral propulsion blade is arranged on the outer peripheral wall of the rotating cylinder, the spiral propulsion blade is hollow inside and communicated with the inner cavity of the rotating cylinder, and the inner cavities of the rotating cylinder and the spiral propulsion blade are respectively a feed heating section, an anhydride-forming heating section and a discharge heating section from left to right; and a heating mechanism, which provides a circulating high-temperature liquid for the feed heating section, the anhydride-forming heating section and the discharge heating section. In the present invention, the forward speed, reaction time and reaction environment of all materials can maintain a high degree of consistency, which helps to ensure the anhydride-forming effect. And directly providing temperature for the isophthalic acid raw material through the rotating cylinder and the spiral propulsion blade helps to achieve uniform temperature transfer, further ensuring the anhydride-forming effect.

Description

Technical Field

[0001] The invention relates to the field of chemical production equipment, in particular to a device for continuously generating anhydride from pyromellitic acid. Background Art

[0002] Pyromellitic anhydride (PMDA), referred to as anhydride, is an important organic synthetic industrial raw material and a major component for the development of new chemical materials and high value-added fine chemical products. At present, the industry generally adopts the gas phase oxidation method. After heating the fixed bed, a mixture of tetramethylbenzene and air is introduced, and the molten salt circulation heat exchange is used to cool the reaction, capture, hydrolyze, crystallize and sublime to obtain pyromellitic anhydride.

[0003] The Chinese patent with the announcement number CN217747100U discloses a device for continuously generating anhydride from pyromellitic acid. The shell includes an outer shell and an inner shell of a double-layer structure, a heating medium cavity is arranged between the outer shell and the inner shell, two parallel main shafts are arranged in the shell, and highly consistent outer spiral propulsion blades are arranged on the two main shafts, and a semicircular gas phase cavity is left above the outer spiral propulsion blade. The device has low working energy consumption and less material residue, providing technical support for the large-scale industrial production of pyromellitic acid anhydride.

[0004] However, the above-mentioned disclosed scheme has the following shortcomings: the interaction between the outer spiral propulsion blades and the inner spiral propulsion blades may cause part of the raw materials to be in the anhydride formation area for a long time, resulting in different reaction times of the raw materials, affecting the anhydride formation effect, and it is difficult to achieve uniform temperature transfer. Summary of the invention

[0005] The invention aims to provide a device for continuously generating anhydride of pyromellitic acid, aiming at the problem that the reaction conditions of raw materials are difficult to maintain consistency and the temperature is difficult to be uniformly transmitted in the background technology.

[0006] The technical solution of the present invention is: a device for continuously generating anhydride from pyromellitic acid, comprising a base and a shell arranged on the base through a support seat, the shell is cylindrical in shape and closed at both ends, a feed inlet is arranged at the top of one side of the shell, a discharge outlet is arranged at the bottom of the other side, and a gas phase outlet is arranged at the middle top of the shell; and further comprising:

[0007] The rotating cylinder is horizontally and penetrated on the outer shell, the rotating cylinder is rotatably connected to the outer shell, a spiral propulsion blade is arranged on the outer peripheral wall of the rotating cylinder, the spiral propulsion blade is hollow inside and communicated with the inner cavity of the rotating cylinder, and the inner cavities of the rotating cylinder and the spiral propulsion blade are respectively a feed heating section, anhydride heating section and a discharge heating section from left to right;

[0008] And a heating mechanism, the heating mechanism provides circulating high-temperature liquid for the feed heating section, the anhydride heating section and the discharge heating section.

[0009] Preferably, two partitions are arranged on the spiral propulsion blade, and the spiral propulsion blade forms a feed heating section, anhydride heating section and a discharge heating section from left to right with the two partitions as nodes; baffle a, baffle b, baffle c and baffle d are arranged in the rotating cylinder from left to right, so that a feed heating section is formed between baffle a and baffle b, anhydride heating section is formed between baffle b and baffle c, and a discharge heating section is formed between baffle c and baffle d.

[0010] Preferably, a motor mounting seat is arranged on the base, a motor is arranged on the motor mounting seat, a gear b is arranged on the output shaft of the motor, a gear a is arranged on the outer peripheral wall of the rotating cylinder, and the gear a is meshed with the gear b.

[0011] Preferably, the heating mechanism includes a heating component a for providing circulating high-temperature liquid for the feed heating section and the anhydride heating section, and a heating component b for providing circulating high-temperature liquid for the discharge heating section.

[0012] Preferably, the heating assembly a includes two end plates a, and cylinders a, b, c and d which are arranged in sequence from the inside to the outside between the two end plates a; a liquid outlet pipe a is arranged on cylinder a, which passes through cylinders b, c and d and extends into the feed heating section, a reflux pipe a is arranged on cylinder b, which passes through cylinders c and d and extends into the feed heating section; a liquid outlet pipe b is arranged on cylinder c, which passes through cylinder d and extends into the anhydride heating section, a reflux pipe b is arranged on cylinder d, which extends into the anhydride heating section; two liquid supply pipes and two reflux main pipes are arranged on the left end plate a, the two liquid supply pipes are respectively connected to the inner cavities of cylinders a and c, and the two reflux main pipes are respectively connected to the inner cavities of cylinders b and d; two high-temperature liquid conveying devices are arranged on the base, the high-temperature liquid conveying devices convey liquid through the liquid supply pipes, and realize liquid circulation through the reflux main pipes.

[0013] Preferably, the liquid outlet pipe a and the reflux pipe a are respectively located at the left and right sides of the feed heating section; the liquid outlet pipe b and the reflux pipe b are respectively located at the left and right sides of the anhydride forming heating section.

[0014] Preferably, the heating assembly b includes two end plates b, and a cylinder e and a cylinder f arranged between the two end plates b from the inside to the outside; a liquid outlet pipe c is arranged on the cylinder e, and the liquid outlet pipe c passes through the cylinder f and extends into the discharge heating section; a reflux pipe c is arranged on the cylinder f, and the reflux pipe c extends into the discharge heating section; a liquid supply pipe and a reflux main pipe are arranged on the right end plate b, the liquid supply pipe is connected with the inner cavity of the cylinder e, and the reflux main pipe is connected with the inner cavity of the cylinder f; a high-temperature liquid conveying device is arranged on the base, and the high-temperature liquid conveying device conveys liquid through the liquid supply pipe, and realizes liquid circulation through the reflux main pipe.

[0015] Preferably, the high-temperature liquid delivery device contains liquid and is provided with a heating device, and a delivery pump is provided in the high-temperature liquid delivery device, and the delivery pump is connected to the liquid supply pipe.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: the forward speed of all materials, the reaction time and the reaction environment can maintain a high degree of consistency, which helps to ensure the anhydride formation effect. Moreover, the temperature is directly provided to the pyromellitic acid raw material by the rotating cylinder and the spiral propulsion blades, which helps to achieve uniform temperature transfer, further ensuring the anhydride formation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0018] Figure 2 for Figure 1 Schematic diagram of the structure after removing the outer shell;

[0019] Figure 3 for Figure 2 A schematic diagram of a partial structure cutaway;

[0020] Figure 4 for Figure 3 A is an enlarged schematic diagram;

[0021] Figure 5 for Figure 3 The enlarged schematic diagram of point B in FIG.

[0022] 1. outer shell; 2. feed port; 3. discharge port; 4. gas phase outlet; 5. gas phase chamber; 6. rotating cylinder; 7. spiral propulsion blade; 8. partition plate; 9. rotary seal; 10. support seat; 11. gear a; 12. gear b; 13. motor; 14. motor mounting seat; 15. baffle a; 16. baffle b; 17. baffle c; 18. baffle d; 19. end plate a; 20. cylinder a; 21. cylinder b; 22. cylinder c; 23. cylinder d; 24. liquid outlet pipe a; 25. reflux pipe a; 26. liquid outlet pipe b; 27. reflux pipe b; 28. liquid supply pipe; 29. ​​reflux main pipe; 30. end plate b; 31. cylinder e; 32. cylinder f; 33. liquid outlet pipe c; 34. reflux pipe c; 35. high-temperature liquid conveying device; 36. base. DETAILED DESCRIPTION

[0023] Embodiment 1

[0024] like Figure 1-Figure 3As shown, a continuous anhydride-forming device for pyromellitic acid proposed by the present invention comprises a base 36 and a shell 1 arranged on the base 36 through a support seat 10, the shell 1 is cylindrical and closed at both ends, a feed port 2 is arranged at the top of one side of the shell 1, a one-way valve is arranged on the feed port 2, a discharge port 3 is arranged at the bottom of the other side, a one-way valve is arranged on the discharge port 3, a gas phase outlet 4 is arranged at the middle top of the shell 1, in an optional embodiment, a gas phase chamber 5 is arranged at the middle top of the shell 1, the gas phase outlet 4 is arranged on the gas phase chamber 5, the gas phase outlet 4 is connected to a vacuum pump via a vacuum condenser, and the vacuum pressure in the shell 1 is 0.01-0.09Mpa; and further comprises:

[0025] The rotating cylinder 6 is horizontally and penetratedly arranged on the outer shell 1, and the rotating cylinder 6 is rotatably connected to the outer shell 1. Specifically, a rotating seal 9 is arranged between the rotating cylinder 6 and the end of the outer shell 1, and a spiral propulsion blade 7 is arranged on the outer peripheral wall of the rotating cylinder 6. The spiral propulsion blade 7 is located in the outer shell 1. The spiral propulsion blade 7 is hollow inside and communicates with the inner cavity of the rotating cylinder 6. The inner cavities of the rotating cylinder 6 and the spiral propulsion blade 7 are respectively a feeding heating section, anhydride heating section and a discharging heating section from left to right; a motor mounting seat 14 is arranged on the motor mounting seat 14, a motor 13 is arranged on the output shaft of the motor 13, and a gear a11 is arranged on the outer peripheral wall of the rotating cylinder 6. The gear a11 and the gear b12 is meshed, in an optional embodiment, the speed of gear a11 is lower than that of gear b12, which can be achieved by changing the size of gear a11 and gear b12; two partitions 8 are arranged on the spiral propulsion blade 7, and the spiral propulsion blade 7 forms a feed heating section, anhydride heating section and a discharge heating section from left to right with the two partitions 8 as nodes; baffles a15, baffles b16, baffles c17 and baffles d18 are arranged in the rotating cylinder 6 from left to right, so that a feed heating section is formed between baffle a15 and baffle b16, anhydride heating section is formed between baffle b16 and baffle c17, and a discharge heating section is formed between baffle c17 and baffle d18;

[0026] And a heating mechanism, which provides circulating high-temperature liquid for the feed heating section, the anhydride heating section and the discharge heating section. Specifically, the liquid temperature provided by the feed heating section is 240°C, the liquid temperature provided by the anhydride heating section is 295°C, and the liquid temperature provided by the discharge heating section is 283°C.

[0027] Embodiment 2

[0028] like Figure 3-Figure 5 As shown, a continuous anhydride-forming device for isophthalic acid proposed in the present invention, compared with the first embodiment, this embodiment introduces the structure of the heating mechanism in detail.

[0029] The heating mechanism comprises a heating component a for providing circulating high-temperature liquid for the feed heating section and the anhydride heating section, and a heating component b for providing circulating high-temperature liquid for the discharge heating section.

[0030] Further, the heating assembly a includes two end plates a19, and cylinders a20, b21, c22 and d23 arranged in sequence between the two end plates a19 from the inside to the outside; a liquid outlet pipe a24 is arranged on the cylinder a20, and the liquid outlet pipe a24 passes through the cylinders b21, c22 and d23 and extends into the feed heating section; a reflux pipe a25 is arranged on the cylinder b21, and the reflux pipe a25 passes through the cylinders c22 and d23 and extends into the feed heating section; a liquid outlet pipe b26 is arranged on the cylinder c22, and the liquid outlet pipe b26 passes through the cylinder d23 extends into the anhydride heating section, and a reflux pipe b27 is arranged on the cylinder d23, and the reflux pipe b27 extends into the anhydride heating section; two liquid supply pipes 28 and two reflux main pipes 29 are arranged on the left end plate a19, and the two liquid supply pipes 28 are respectively connected to the inner cavities of the cylinder a20 and the cylinder c22, and the two reflux main pipes 29 are respectively connected to the inner cavities of the cylinder b21 and the cylinder d23; two high-temperature liquid conveying devices 35 are arranged on the base 36, and the high-temperature liquid conveying devices 35 convey liquid through the liquid supply pipe 28, and realize liquid circulation through the reflux main pipe 29. The liquid outlet pipe a24 and the reflux pipe a25 are respectively located at the left and right sides of the feed heating section; the liquid outlet pipe b26 and the reflux pipe b27 are respectively located at the left and right sides of the anhydride heating section.

[0031] Furthermore, the heating component b includes two end plates b30, and a cylinder e31 and a cylinder f32 arranged between the two end plates b30 from the inside to the outside; a liquid outlet pipe c33 is arranged on the cylinder e31, and the liquid outlet pipe c33 passes through the cylinder f32 and extends into the discharge heating section; a reflux pipe c34 is arranged on the cylinder f32, and the reflux pipe c34 extends into the discharge heating section; a liquid supply pipe 28 and a reflux main pipe 29 are arranged on the right end plate b30, the liquid supply pipe 28 is connected to the inner cavity of the cylinder e31, and the reflux main pipe 29 is connected to the inner cavity of the cylinder f32; a high-temperature liquid conveying device 35 is arranged on the base 36, and the high-temperature liquid conveying device 35 conveys liquid through the liquid supply pipe 28, and realizes liquid circulation through the reflux main pipe 29.

[0032] Embodiment 3

[0033] The present invention proposes a continuous anhydride-forming device for isomellitic acid. Compared with the first or second embodiment, this embodiment introduces the structure of the high-temperature liquid conveying device 35 in detail.

[0034] The high-temperature liquid conveying device 35 contains liquid and is provided with a heating device to heat the liquid to different temperatures according to different needs. A conveying pump is provided in the high-temperature liquid conveying device 35. The conveying pump is a high-temperature resistant pump, such as a spiral rotor pump, a high-pressure magnetic pump, a peristaltic pump, etc. The conveying pump is connected to the liquid supply pipe 28.

[0035] In summary, the present invention provides circulating liquids of different temperatures for the feed heating section, the anhydride heating section and the discharging heating section respectively through the heating mechanism when in use, thereby providing different temperature intervals. The pyromellitic acid raw material enters the shell 1 through the feed port 2, and the pyromellitic acid raw material is gradually heated to melting in the feed heating section, and mainly plays the role of anhydride in the anhydride heating section. The water deviated is continuously pumped away by the vacuum pump. In the material advancement process, the material in the anhydride section is advanced to the discharging direction under the action of the spiral propulsion blade 7, and continuous anhydride is achieved. All material forward speeds, reaction times and reaction environments can maintain a high degree of consistency, which helps to ensure the anhydride effect. And the temperature is directly provided for the pyromellitic acid raw material by rotating the cylinder 6 and the spiral propulsion blade 7, which helps to achieve the uniform transmission of temperature, and further ensures the anhydride effect.

[0036] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto, and various changes can be made within the knowledge scope of technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A device for continuously converting pyromellitic acid into anhydride, comprising a base (36) and a shell (1) arranged on the base (36) via a support base (10), the shell (1) being cylindrical in shape and closed at both ends, a feed inlet (2) being arranged at the top of one side of the shell (1), a discharge outlet (3) being arranged at the bottom of the other side, and a gas phase outlet (4) being arranged at the middle top of the shell (1); characterized in that: Also includes: A rotating cylinder (6) is horizontally and penetrated on the outer shell (1), the rotating cylinder (6) is rotatably connected to the outer shell (1), a spiral propulsion blade (7) is arranged on the outer peripheral wall of the rotating cylinder (6), the spiral propulsion blade (7) is hollow inside and communicates with the inner cavity of the rotating cylinder (6), and the inner cavities of the rotating cylinder (6) and the spiral propulsion blade (7) are, from left to right, a feed heating section, an anhydride heating section, and a discharge heating section; and a heating mechanism, which provides circulating high-temperature liquid for the feed heating section, the anhydride forming heating section and the discharge heating section; Two partitions (8) are arranged on the spiral propulsion blade (7), and the spiral propulsion blade (7) forms a feed heating section, an anhydride heating section and a discharge heating section in sequence from left to right with the two partitions (8) as nodes; baffles a (15), baffles b (16), baffles c (17) and baffles d (18) are arranged in sequence from left to right in the rotating cylinder (6), so that the feed heating section is formed between baffles a (15) and baffles b (16), the anhydride heating section is formed between baffles b (16) and baffles c (17), and the discharge heating section is formed between baffles c (17) and baffles d (18); The heating mechanism comprises a heating component a for providing circulating high-temperature liquid for the feed heating section and the anhydride heating section, and a heating component b for providing circulating high-temperature liquid for the discharge heating section; The heating assembly a comprises two end plates a (19), and a cylinder a (20), a cylinder b (21), a cylinder c (22) and a cylinder d (23) which are arranged in sequence from the inside to the outside between the two end plates a (19); a liquid outlet pipe a (24) is arranged on the cylinder a (20), and the liquid outlet pipe a (24) passes through the cylinder b (21), the cylinder c (22) and the cylinder d (23) and extends into the feed heating section; a reflux pipe a (25) is arranged on the cylinder b (21), and the reflux pipe a (25) passes through the cylinder c (22) and the cylinder d (23) and extends into the feed heating section; a liquid outlet pipe b (26) is arranged on the cylinder c (22), and the liquid outlet pipe b (26) passes through the cylinder d (23) extends into the anhydride heating section, a reflux pipe b (27) is arranged on the cylinder d (23), and the reflux pipe b (27) extends into the anhydride heating section; two liquid supply pipes (28) and two reflux main pipes (29) are arranged on the left end plate a (19), the two liquid supply pipes (28) are respectively connected to the inner cavities of the cylinder a (20) and the cylinder c (22), and the two reflux main pipes (29) are respectively connected to the inner cavities of the cylinder b (21) and the cylinder d (23); two high-temperature liquid conveying devices (35) are arranged on the base (36), and the high-temperature liquid conveying devices (35) convey liquid through the liquid supply pipe (28) and realize liquid circulation through the reflux main pipe (29); The heating assembly b comprises two end plates b (30), and a cylinder e (31) and a cylinder f (32) which are arranged between the two end plates b (30) from the inside to the outside; a liquid outlet pipe c (33) is arranged on the cylinder e (31), and the liquid outlet pipe c (33) passes through the cylinder f (32) and extends into the discharge heating section; a return pipe c (34) is arranged on the cylinder f (32), and the return pipe c (34) extends into the discharge heating section; a liquid supply pipe (28) and a return main pipe (29) are arranged on the right end plate b (30), the liquid supply pipe (28) is connected to the inner cavity of the cylinder e (31), and the return main pipe (29) is connected to the inner cavity of the cylinder f (32); a high-temperature liquid conveying device (35) is arranged on the base (36), and the high-temperature liquid conveying device (35) conveys liquid through the liquid supply pipe (28) and realizes liquid circulation through the return main pipe (29).

2. The continuous anhydride-forming device for pyromellitic acid according to claim 1, characterized in that: A motor mounting seat (14) is arranged on the base (36), a motor (13) is arranged on the motor mounting seat (14), a gear b (12) is arranged on the output shaft of the motor (13), a gear a (11) is arranged on the outer peripheral wall of the rotating cylinder (6), and the gear a (11) and the gear b (12) are meshed.

3. The continuous anhydride-forming device for pyromellitic acid according to claim 1, characterized in that: The liquid outlet pipe a (24) and the reflux pipe a (25) are respectively located at the left and right sides of the feed heating section; the liquid outlet pipe b (26) and the reflux pipe b (27) are respectively located at the left and right sides of the anhydride heating section.

4. The continuous anhydride-forming device for pyromellitic acid according to claim 1, characterized in that: The high-temperature liquid delivery device (35) contains liquid and is provided with a heating device. A delivery pump is provided in the high-temperature liquid delivery device (35), and the delivery pump is connected to the liquid supply pipe (28).

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